Note: Descriptions are shown in the official language in which they were submitted.
CA 02425810 2005-12-28
CIRCUIT INTERRUPTING DEVICE
BACKGROUND
Field
The present invention is directed to resettable circuit interrupting devices
including
without limitation ground fault circuit interrupters (GFCI's), arc fault
circuit interrupters
(AFCI's), immersion detection circuit interrupters (IDCI's), appliance leakage
circuit
interrupters (ALCI's), equipment leakage circuit interrupters (ELCI's),
circuit breakers,
contactors, latching relays and solenoid mechanisms.
Certain embodiments of the present invention are directed to circuit
interrupting
devices including a reset lock out portion capable of preventing the device
from resetting in
certain circumstances.
Certain embodiments of the present invention are directed to circuit
interrupting
devices that include a circuit interrupting portion that can break
electrically conductive
paths between a line side and a load side of the device and between a line
side and a user
load. Certain embodiments of the present application are directed to circuit
interrupting
devices including a reset lock out portion capable of preventing the device
from resetting if
the circuit interrupting portion is not functioning, if an open neutral
condition exists or if
the device is mis-wired. Certain embodiments of the present application are
directed to
methods of manufacturing circuit interrupting devices to be initially in a
tripped condition.
Certain embodiments of the present application are directed to methods of
manufacturing
circuit interrupting devices to be initially in a reset lock out condition.
Certain embodiments of the present invention are also directed to circuit
interrupting devices that include a circuit interrupting portion that can
isolate a power
source connector from a load connector.
\\ny2-srv01\637045v01
CA 02425810 2005-12-28
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Certain embodiments of the present invention is directed to resettable circuit
interrupting devices including without limitation GFCIs. Certain embodiments
of the
present invention are directed to circuit interrupting devices using a neutral
fault
simulation. Certain embodiments of the present application are directed to
circuit
S interrupting devices including a neutral to neutral test switch.
Certain embodiments of the present invention relate to surge suppression, and
in
particular to circuit interrupters and GFCIs and related products with
enhanced transient
suppression and protection characteristics.
Certain embodiments of the present invention are directed to GFCIs that
include a
reset lock out portion that does not fire the solenoid for test
Certain embodiments of the present invention are directed to IDCIs that
include a
reset lock portion capable of preventing the device from resetting under
certain
circumstances and an independent trip mechanism.
Certain embodiments of the present invention are directed to ALCIs and IDCIs
that
include a reset lock out portion capable of preventing the device from
resetting under
certain circumstances.
Certain embodiments of the present application are also directed to resettable
residual current devices (RCDs). More particularly, the present application is
directed to a
RCE that can lockout the reset function if a predetermined condition exists.
Other embodiments of the present invention pertain to ground fault circuit
interrupters and more particularly to a GFCI which employs a combination of
colored
lights and an audible alarm signal to shown various states of the GFCI and
designate time
periods for taking certain actions.
2. Description of the Related Art
I. Inoperative Trip Mechanism
Many electrical wiring devices have a line side, which is connectable to an
electrical
power supply, and a load side, which is connectable to one or more loads and
at least one
conductive path between the line and load sides. Electrical connections to
wires supplying
electrical power or wires conducting electricity to the one or more loads are
at line side and
\lny2-srv01\637045v01
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load side connections. The electrical wiring device industry has witnessed an
increasing
call for circuit breaking devices or systems which are designed to interrupt
power to
various loads, such as household appliances, consumer electrical products and
branch
circuits. Many electrical appliances have an electrical cord having a line
side, which is
connectable to an electrical power supply, and a load side that is connected
to the
appliance, which is an electrical load. Certain appliances may be susceptible
to immersion
in a conductive fluid, which may present a shock hazard. Other fault scenarios
may be
addressed by other circuit interrupters alone or in combination. Accordingly,
the electrical
wiring device industry has witnessed an increasing call for circuit breaking
devices or
systems which are designed to interrupt power to various loads, such as
household
appliances, consumer electrical products and branch circuits. In particular,
appliances
utilized in areas that may be wet, such as hair dryers, may be equipped with
an IDCI to
protect against immersion hazards. Such products have been marketed by
companies under
brand names including Conair, Windmere and Wellong. In particular, electrical
codes
require electrical circuits in home bathrooms and kitchens to be equipped with
ground fault
circuit interrupters (GFCI), for example. Presently available GFCI devices,
such as the
device described in commonly owned U.S. Patent 4,595,894, use an electrically
activated
trip mechanism to mechanically break an electrical connection between the line
side and the
load side of a GFCI. Such devices are resettable after they are tripped by,
for example, the
detection of a ground fault. In the device discussed in the '894 patent, the
trip mechanism
used to cause the mechanical breaking of the circuit (i.e., the conductive
path between the
line and load sides) includes a solenoid (or trip coil). A test button is used
to test the trip
mechanism and circuitry used to sense faults, and a reset button is used to
reset the
electrical connection between line and load sides.
However, instances may arise where an abnormal condition, caused by for
example
a lightning strike, occurs which may result not only in a surge of electricity
at the device
and a tripping of the device but also a disabling of the trip mechanism used
to cause the
mechanical breaking of the circuit. This may occur without the knowledge of
the user.
Under such circumstances an unknowing user, faced with a GFCI which has
tripped, may
press the reset button which, in turn, will cause the device with an
inoperative trip
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mechanism to be reset without the ground fault protection available. The GFCI
will be in a
dangerous condition because it will then provide power to a load without
ground fault
protection.
Further, an open neutral condition, which is defined in Underwriters
Laboratories
(UL) Standard PAG 943A, may exist with the electrical wires supplying
electrical power to
such GFCI devices. If an open neutral condition exists with the neutral wire
on the line
(versus load) side of the GFCI device, an instance may arise where a current
path is
created from the phase (or hot) wire supplying power to the GFCI device
through the load
side of the device and a person to ground. In the event that an open neutral
condition
exists, current GFCI devices, which have tripped, may be reset even though the
open
neutral condition may remain.
Commonly owned application Serial No. 09/138,955, filed August 24, 1998, now
U.S. Patent No. 6,040,967
describes a family of resettable circuit interrupting devices capable of
locking out the reset
portion of the device if certain conditions exist including the circuit
interrupting portion
being non-operational or if an open neutral condition exists. Such a device
may use a
simulated ground fault to initiate a device test. Accordingly, it may be
advantageous to
lockout the reset function under certain circumstances.
II. The Problem of Mis-wiring
Some of the circuit interrupting devices described above also have a user
accessible
load connection. The user accessible load side connection includes one or more
connection
points where a user can externally connect to electrical power supplied from
the line side.
The load side connection and user accessible load connection are typically
electrically
connected together. An example of such a circuit interrupting device is a
typical GFCI
receptacle, where the line and load side connections are binding screws and
the user
accessible load side connection is the plug connection to an internal
receptacle. As noted,
such devices are connected to external wiring so that line wires are connected
to the line
side connection and load side wires are connected to the load side connection.
However,
instances may occur where the circuit interrupting device is improperly
connected to the
CA 02425810 2005-12-28
external wires so that the load wires are connected to the line side
connection and the line
wires are connected to the load connection. This is known as reverse wiring.
In the event
the circuit interrupting device is reverse wired, fault protection to the user
accessible load
connection may be eliminated, even if fault protection to the load side
connection remains.
5 Furthermore, studies related to GFCI devices indicate that perhaps 10-20% or
more
of all GFCI devices installed were found to be inoperable by the user.
However, after
those devices were returned to the manufacturer, most were found to be
operational.
Accordingly, it has been suggested that the devices were reverse wired by the
user (line -
load side reversal). Furthermore, regulatory codes and industry standards
codes such as
those by Underwriters Laboratories (UL) may require that GFCI devices be
manufactured
with a warning label advising the user to correctly wire the line and load
terminals of the
device. However, even such warnings may not be adequate as suggested by the
studies
above. Furthermore, a reasonably foolproof mis-wiring prevention scheme may
obviate
the need for such a warning label.
Conventional GFCI devices may utilize a user load such as a face receptacle.
Typically GFCIs are four terminal devices, two phase or AC leads for
connection to AC
electrical power and two LOAD leads for connection to downstream devices. If a
conventional GFCI is properly wired, the GFCI provides ground fault protection
for
devices downstream and the incorporated receptacle. However, if a conventional
GFCI is
reverse wired, unprotected power is provided to the receptacle face at all
times. For
example, when a conventional GFCI is reverse wired, the face receptacle is
"upstream"
from the current imbalance sensor coil. Accordingly, if the conventional GFCI
is in either
the tripped or normal state, the face receptacle is provided unprotected
power.
In spite of detailed instructions that come packaged with most GFCIs and
identification of AC and LOAD terminals, GFCIs are sometimes mis-wired. One
reason
that this problem exists is that in new construction, both the input line and
downstream
cables appear identical when the installer is connecting a new ground fault
circuit
interrupter. This is especially a problem in new construction where there is
no power
available in order to test which cable is leading current into the device.
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The problem may be compounded when it is considered that many typical duplex
receptacle GFCIs have a test button that will trip and shut off the power when
pushed to
verify operations of internal functions in the GFCI. However, use of the test
button does
not indicate whether the built in duplex receptacle is protected. Typical
users may not be
aware of this. Users simply test the device after installation and verify that
the unit trips
upon pressing the test button by way of an audible click, for example. This
gives the user
a false sense that all is well. What is actually happening when the GFCI is
reverse wired
is that the GFCI disconnects power from and protects everything downstream,
but does not
protect the receptacle contacts of the GFCI itself. The device will trip
depending on the
condition of internal components and irrespective of how the GFCI was wired.
It does not
matter that the GFCI was reverse wired when it was tested.
Certain references described devices that attempt to warn the user of a
reverse
wiring condition. For example, one approach utilizes a GFCI with reverse line
polarity
lamp indicator to indicate proper installation of the GFCI. See, for example,
U.S. Patent
No. 4;412,193 issued to Bienwald et al. on October 25, 1983 and assigned to
the owner of
the present invention. However, a push button needs to be manually pressed in
accordance
with instructions in order to detect whether the GFCI is mis-wired.
In another example, U.S. Parent No. 5,477,412 issued to Neiger et al, on
December
19, 1995 and owned by the assignee of the present invention, is directed to a
ground fault
circuit interrupter incorporating mis-wiring prevention circuitry. Mis-wiring
sense
circuitry automatically triggers the generation of visual and audible alarms
in the event of
mis-wiring conditions. The circuit employs an alarm inhibiting technique that
incorporates
sense circuitry connected to the AC terminals on one side of the internal GFCI
switches or
relays and alarm generation circuitry connected to the load terminal on the
opposite side.
Commonly owned application Serial No. application Serial No. 09/204,861, filed
December 3, 1998" now issued as US 6,252,407 ~ describes a
device to test for reverse wiring and provide an indication of reverse wiring.
The applications referenced above as related applications are commonly ownec~~
The applications generally relate to locking out a rest
CA 02425810 2005-12-28
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function or otherwise disabling a circuit interrupting device on the
occurrence of a
condition.
United States Patent No. 5,933,063 to Keung, et al., purports to describe a
GFCI
device and apparently utilizes a single center latch. U. S. Patent No.
5,933,063 is hereby
in its entirety be reference. United States Patent No. 5,594,398 to Marcou, et
al., purports
to describe a GFCI device and apparently utilizes a center latch.
United States Patent No. 5,510,760 to
Marcou, et al., purports to describe a GFCI device and apparently utilizes a
center latch.
A typical GFCI design
that may benefit from a modification according to the present invention has
been marketed
under the designation Pass & Seymour Catalog No. 1591.
Another GFCI design that may benefit from a modification according to the
present
invention has been marketed under the designation Bryant Catalog Number
GFR52FTW.
Commonly owned application Serial No. No. 09/379,138 filed August 20, 1999,
now issued as US 6,246,558 describes a family of resettable
circuit interrupting devices capable of independently tripping and protecting
against reverse
wiring.
III. Inadeguate Sure Protection
Known GFCI products typically include a metal oxide varistor (MOV) positioned
across the power lines of the GFCI product, with the MOV providing some surge
protection to the GFCI product circuitry by clamping transient voltages to
acceptable
levels. The degree of clamping is determined by the size of the disc and
voltage rating
associated with the MOV. Heretofore, GFCI products have been limited to
handling
transient voltages of 6 kV at 1.00 A. A need exists for GFCI products capable
of sustaining
greater transient conditions.
In addition, due to deregulation of local power authorities, overvoltage
conditions
may be more prevalent, requiring circuits to survive, for example, 240 V
overvoltage
conditions for a 120 V rated product. When such conditions occur, GFCI
components such
as the MOV in the prior art have not survived; for example, a MOV in the prior
art
CA 02425810 2005-12-28
operating beyond its rating at overvoltage may disintegrate, and thus such
conditions may
also destroy the rest of the electronics in the GFCI product.
A need exists for a surge protection circuit which allows components such as a
MOV to survive power conditions exceed voltage and current ratings, and thus
enabling a
GFCI product to survive overvoltage conditions.
IV. Lack of Status Indication
As discussed above, there are various circumstances which may cause a circuit
interrupting device to malfunction. Present GFCI's generally provide no
information to the
user as to the status of the GFCI. One GFCI currently on sale provides a
single LED to
show that the device is operating, that is the main switch contacts are
closed. Therefore,
there is a need for a user to be able to determine whether a circuit
interrupting device is
malfunctioning by obtaining the status of such a device.
SUMMARY
The present application relates to a resettable circuit interrupting devices
that
provide a reset lockout under certain conditions. Certain embodiments of the
present
application are directed to circuit interrupting devices including a reset
lock out portion
capable of preventing the device from resetting if the circuit interrupting
portion is not
functioning, if an open neutral condition exists or if the device is mis-wired
by testing
portions of a device before allowing a reset. Certain embodiments maintain
fault
protection for the circuit interrupting device even if the device is reverse
wired by utilizing
a bridge circuit to separately break the line inputs from each respective load
side connector
and user load connector.
The circuit interrupting device may also include reset lockout portion that
prevents
the reestablishing of electrical continuity in either the phase or neutral
conductive path or
both conductive paths, unless the circuit interrupting portion is operating
properly and/or
connected properly. In certain embodiments, the reset portion may be
configured so that at
least one reset contact is electrically connected to the sensing portion of
the circuit
interrupting portion, and that depression of a reset button causes at least a
portion of the
phase conductive path to contact at least one reset contact. When contact is
made between
CA 02425810 2005-12-28
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the phase conductive path and the at least one reset contact, the circuit
interrupting portion
is activated so that the reset lockout portion is disabled and electrical
continuity in the
phase and neutral conductive paths can be reestablished.
The circuit interrupting device may also include a trip portion that operates
independently of the circuit interrupting portion. In one embodiment, the trip
portion
includes a trip actuator accessible from an exterior of the housing and a trip
arm preferably
within the housing and extending from the trip actuator. The trip arm is
preferably
configured to facilitate mechanical breaking of electrical continuity in the
phase and/or
neutral conductive paths, if the trip actuator is actuated.
In certain embodiments, the circuit interrupter is manufactured having a
bridge
circuit separately disconnecting a load side and a user load when the circuit
interrupter
trips. In another embodiment, two single-pole, single throw switching devices
are used to
switch each power line from the load and the user load respectively. In
another
embodiment, the circuit interrupter is manufactured in a reset lock out state.
In another
embodiment, a removable or fixedly connected trip force device is utilized to
force a trip
upon installation. In another embodiment, an indicator provides an indication
of reverse
wiring. In another embodiment, a separate trip force device is connected to
the circuit
interrupter before it is delivered into the stream of commerce. In a method
embodiment,
the circuit interrupter is set to a reset lock out state before being
delivered into the stream
of commerce.
The present invention also relates to a resettable circuit interrupting
devices that
maintain fault protection for the circuit interrupting device even if the
device is reverse
wired.
In one embodiment, the circuit interrupting device includes a housing and
phase and
neutral conductive paths disposed at least partially within the housing
between line and load
sides. Preferably, the phase conductive path terminates at a first connection
capable of
being electrically connected to a source of electricity, a second connection
capable of
conducting electricity to at least one load and a third connection capable of
conducting
electricity to at least one user accessible load. Similarly, the neutral
conductive path,
preferably, terminates at a first connection capable of being electrically
connected to a
CA 02425810 2005-12-28
source of electricity, a second connection capable of providing a neutral
connection to the
at least one load and a third connection capable of providing a neutral
connection to the at
least one user accessible load;
The circuit interrupting device also includes a circuit interrupting portion
that is
S disposed within the housing and configured to cause electrical discontinuity
in one or both
of the phase and neutral conductive paths, between said line side and said
load side upon
the occurrence of a predetermined condition. A reset portion is disposed at
least partially
within the housing and is configured to reestablish electrical continuity in
the open
conductive paths.
10 Preferably, the phase conductive path includes a plurality of contacts that
are
capable of opening to cause electrical discontinuity in the phase conductive
path and closing
to reestablish electrical continuity in the phase conductive path, between
said line and load
sides. The neutral conductive path also includes a plurality of contacts that
are capable of
opening to cause electrical discontinuity in the neutral conductive path and
closing to
reestablish electrical continuity in the neutral conductive path, between said
line and load
sides. In this configuration, the circuit interrupting portion causes the
plurality of contacts
of the phase and neutral conductive paths to open, and the reset portion
causes the plurality
of contacts of the phase and neutral conductive paths to close.
One embodiment for the circuit interrupting portion uses an electro-mechanical
circuit interrupter to cause electrical discontinuity in the phase and neutral
conductive
paths, and sensing circuitry to sense the occurrence of the predetermined
condition. For
example, the electro-mechanical circuit interrupter include a coil assembly, a
movable
plunger attached to the coil assembly and a banger attached to the plunger.
The movable
plunger is responsive to energizing of the coil assembly, and movement of the
plunger is
translated to movement of said banger. Movement of the banger causes the
electrical
discontinuity in the phase and/or neutral conductive paths.
The circuit interrupting device may also include reset lockout portion that
prevents
the reestablishing of electrical continuity in either the phase or neutral
conductive path or
both conductive paths, unless the circuit interrupting portion is operating
properly. That
is, the reset lockout prevents resetting of the device unless the circuit
interrupting portion is
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operating properly. In embodiments where the circuit interrupting device
includes a reset
lockout portion, the reset portion may be configured so that at least one
reset contact is
electrically connected to the sensing circuitry of the circuit interrupting
portion, and that
depression of a reset button causes at least a portion of the phase conductive
path to contact
at least one reset contact. When contact is made between the phase conductive
path and the
at least one reset contact, the circuit interrupting portion is activated so
that the reset
lockout portion is disabled and electrical continuity in the phase and neutral
conductive
paths can be reestablished.
The circuit interrupting device may also include a trip portion that operates
independently of the circuit interrupting portion. The trip portion is
disposed at least
partially within the housing and is configured to cause electrical
discontinuity in the phase
and/or neutral conductive paths independent of the operation of the circuit
interrupting
portion. In one embodiment, the trip portion includes a trip actuator
accessible from an
exterior of the housing and a trip arm preferably within the housing and
extending from the
trip actuator. The trip arm is preferably configured to facilitate mechanical
breaking of
electrical continuity in the phase and/or neutral conductive paths, if the
trip actuator is
actuated. Preferably, the trip actuator is a button. However, other known
actuators are
also contemplated.
In an embodiment, the circuit interrupter is manufactured having a bridge
circuit separately
disconnecting a load side and a user load when the circuit interrupter trips.
In another
embodiment, two single-pole, single throw switching devices are used to switch
each
power line from the load and the user toad respectively. In another
embodiment, the
circuit interrupter is manufactured in a reset lock out state. In another
embodiment, a
removable or fixedly connected trip force device is utilized to force a trip
upon installation.
In another embodiment, an indicator provides an indication of reverse wiring.
In another
embodiment, a separate trip force device is connected to the circuit
interrupter before it is
delivered into the stream of commerce. In a method embodiment, the circuit
interrupter is
set to a reset lock out state before being delivered into the stream of
commerce.
The present invention also relates to a resettable circuit interrupting
devices having
a reset lockout that does not rely on a test of the solenoid.
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The present invention also relates to resettable circuit interrupting devices
that
include a user interface. Before the device is used, it is tripped. The user
must then use
the user interface to enable a test actuator to initiate a test the device. If
the test passes, the
device will reset. Otherwise, the device will be locked out. In another
embodiment, the
device may be tripped by a user interface to a mechanical trip mechanism.
One embodiment for the circuit interrupting portion uses an e(ectro-mechanical
circuit interrupter to cause electrical discontinuity in at least one of the
phase and neutral
conductive paths of the device, and sensing circuitry to sense the occurrence
of a
predetermined condition. The mechanical trip arm may be configured to
facilitate
mechanical breaking of electrical continuity in the phase and/or neutral
conductive paths, if
the trip actuator is actuated. Furthermore, the mechanical trip arm or level
may be
configured so that it will not be operable to reset the device.
The present invention also: relates to a resettable RCD that may be locked out
from
reset. A user actuated reset lever moves from an off state to an on state
through a test
state. The test state will test the device and only allow progression to the
on state if the
test passes.
The present invention also relates to a resettable circuit interrupting
devices that
simulate a fault condition by simulating a neutral fault condition. The
neutral fault may be
simulated by connecting a load neutral line to a line neutral line using a
switch to create a
feedback path in the sensor that will trigger the circuit interrupter.
Furthermore, the neutral fault may be simulated using a third wire through the
transformer or by connecting a load phase line to a line phase line.
The fault switch is preferably configured to facilitate mechanical connection
between the
line and load neutral paths. However, other known actuators are also
contemplated.
The present invention also relates to a resettable circuit interrupting
devices that
lockout the reset function under certain conditions. In one embodiment, a test
mechanism
is utilized to test the circuit interrupter before allowing a reset. In an
embodiment, a reset
plunger is modified to exert force on a trip latch in order to close a test
circuit that will
allow the reset plunger to continue to a reset position only if the circuit
interrupter is
functioning.
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13
The present invention also relates to a suppression and protection circuit
used in
conjunction with a metal oxide varistor (MOV) in a ground fault circuit
interrupter (GFCI)
product for handling transient surges and overvoltage conditions. The
suppression and
protection circuit includes a spark gap to prevent overvoltages, and an LC low
pass filter
for suppressing transient surges.
The present invention also provides a GFCI that gives the user a great deal of
information on the status of the GFCI and the circuit it is to protect. The
GFCI includes a
dual color Iamp which can produce three distinct colors. Further, the lamp is
intended to
be blinked at a first slow rate or a second higher rate. An audible alarm can
be operated or
maintained silent. The information given the user will depend upon the color
of the lamp,
the speed at which it is blinked and the presence or absence of an audible
alarm signal. It
is an object of the instant invention to provide a novel GFCI.
It is another object of the instant invention to provide a novel GFCI with
signaling
means to show the status of the GFCI and associated circuits.
It is another object of the instant invention to provide a novel GFCI with
signaling
means comprising blinking colored lights and an audible alarm to show the
status of the
GFCI and associated circuits.
Other objects and features of the invention will be pointed out in the
following
description and claims and illustrated in the accompanying drawings, which
disclose, by
~,y,ay of example, the principles of the invention, and the best mode which is
presently
contemplated for carrying them out.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the present application are described herein with
reference to the drawings in which similar elements are given similar
reference characters,
wherein:
FIGS. 1-41 show a sliding latch GFCI with reset lockout and in particular:
F1G. 1 is a perspective view of a GFCI constructed in accordance with the
concepts
of the invention;
FIG. 2 is a bottom perspective view of the GFCI of FIG. 1;
CA 02425810 2005-12-28
14
FIG. 3 is similar to FIG. 1 but with the top and bottom covers of the GFCI
removed;
FIG. 4 is a perspective view of the mounting strap of the device of FIG. 1;
FIG. 5 is a bottom perspective view of the load neutral and load phase
terminals of
the device of FIG. 1;
FIG. 6 is a perspective view of the printed circuit board and reset assemblies
of the
device of FIG. 1;
FIG. 7 is a perspective view of the devices of FIG. 6 with the reset lever and
PC
board removed;
FIG. 8 is a perspective view of the bobbin assembly of the device of FIG. 1;
FIG. 9 is a perspective view of the main movable contacts of the device of
FIG. 1;
FIG. 10 is a bottom perspective view of the plunger, latch plate and auxiliary
contacts of the device of FIG. 1;
FIG. 11 is a perspective view showing the transformers mounted on the printed
circuit board of the device of FIG. 1;
FIG. 12 is a side elevational view partly in section of the transformer
bracket
assembly of FIG. 11;
FIG. 13 is a perspective view of the test lever and button of the device of
FIG. l;
FIG. 14 is front elevational view of the test lever, test button, test arm and
test pin
in the open position;
FIG. 15 is a front elevational view of the components shown in FIG. 14 in the
closed, test position;
FIG. 16 is a perspective view of the reset lever and reset button of the
device of
FIG. 1;
FIG. 17 is a front elevational view of the reset lever reset button, main
contacts and
auxiliary contacts in the closed or reset condition;
FIG 18 is a side elevational view of the device according to FIG. 17;
FIG. 19 is a front elevational view of the components of FIG. 17 in the
tripped
condition;
FIG. 20 is a side elevational view of the device of FIG. 19;
w _
CA 02425810 2005-12-28
FIG. 21 is a table to show the relationships between the status of the GFCI
and
associated circuits and the color, speed of blinking and the presence or
absence of an
audible signal;
FIG. 22 is a schematic diagrams of a GFCI according to an embodiment of the
present invention;
FIG. 23 is a schematic diagrams of a GFCI according to an embodiment of the
present invention having a bridge circuit;
FIG. 24 is a schematic diagrams of a GFCI according to an embodiment of the
present invention having a bridge circuit an independent trip mechanism;
10 FIGS. 25-28b are partial cutaway diagrams of the reset lockout mechanism of
a
GFCI according to an embodiment of the present invention;
FIGS. 29a-c are partial cutaway diagrams of the reset lockout mechanism of a
GFCI
according to another embodiment of the present invention;
FIG. 30 is a partial cutaway diagram of the reset lockout mechanism of a GFCI
15 according to the embodiment of FIG. 29a-c showing a manual trip mechanism;
FIGS. 31a-f are partial cutaway diagrams of the reset lockout mechanism of a
GFCI
according to the embodiment of FIG. 29a-c showing a manual trip mechanism;
FIGS. 32a-b are partial cutaway diagrams of the reset lockout mechanism of a
GFCI
according to another embodiment of the present invention;
FIGS. 33a-f are partial cutaway diagrams of the reset lockout mechanism of a
GFCI
according to another embodiment of the present invention;
FIGS. 34a-f are partial cutaway diagrams of the reset lockout button of a GFCI
according to two embodiments of the present invention;
FIG. 35 is a perspective view of one embodiment of a ground fault circuit
interrupting device according to the present application having a user load
activated switch;
FIGS. 36a-b are perspective views of one embodiment of a ground fault circuit
interrupting device according to the present application having a user load
activated switch
device;
FIG. 37 is a perspective view of one embodiment of a ground fault circuit
interrupting device according to the present application having a user load
activated switch;
CA 02425810 2005-12-28
16
FIGS. ~38a-c are perspective views of one embodiment of a ground fault circuit
interrupting device according to the present application having a user load
activated switch
device;
FIG. 39 is a perspective views of one embodiment of a ground fault circuit
interrupting device according to the present application having a user load
activated switch
devices for trip and reset activation without user buttons; and
FIG. 40 is a perspective view of one embodiment of a ground fault circuit
interrupting device according to the present application having a user load
activated switch
device and no buttons;
FIG. 41 is a perspective views of one embodiment of a ground fault circuit
interrupting device according to the present application having a movable face
plate and
face plate movement activated switch devices for trip and reset activation
without user
buttons.
FIGS. 42-70 show a circuit interrupting device with reset lockout and reverse
wiring protection and method of manufacture such a device wherein:
FIG. 42 is a perspective view of one embodiment of a ground fault circuit
interrupting device according to the present application;
FIG. 43 is side elevational view, partly in section, of a portion of the GFCI
device
shown in FIG. 42, illustrating the GFCI device in a set or circuit making
position;
FIG. 44 is an exploded view of internal components of the circuit interrupting
device of FIG. 42;
FIG. 45 is a plan view of portions of electrical conductive paths located
within the
GFCI device of FIG. 42;
FIG. 46 is a partial sectional view of a portion of a conductive path shown in
FIG. 4;
FIG. 47 is a partial sectional view of a portion of a conductive path shown in
FIG. 4;
FIG. 48 is a side elevational view similar to FIG. 2, illustrating the GFCI
device in
a circuit breaking or interrupting position;
FIG. 49 is a side elevational view similar to FIG. 2, illustrating the
components of
the GFCI device during a reset operation;
w
CA 02425810 2005-12-28
17
FIGS. 50-52 are schematic representations of the operation of one embodiment
of
the reset portion of the present application, illustrating a latching member
used to make an
electrical connection between line and load connections and to relate the
reset portion of the
electrical connection with the operation of the circuit interrupting portion;
FIG. 53 is a schematic diagram of a circuit for detecting ground faults and
resetting
the GFCI device of FIG. 1;
FIG. 54 is a perspective view of an alternative embodiment of a ground fault
circuit
interrupting device according to the present application;
FIG. 55 is side elevational view, partly in section, of a portion of the GFCI
device
shown in FIG. 54, illustrating the GFCI device in a set or circuit making
position;
FIG. 56 is a side elevational view similar to FIG. 55, illustrating the GFCI
device
in a circuit breaking position;
FIG. 57 is a side elevational view similar to FIG. 14, illustrating the
components of
the GFCI device during a reset operation;
FIG. 58 is an exploded view of internal components of the GFCI device of FIG.
13;
FIG. 59 is a schematic diagram of a circuit for detecting ground faults and
resetting
the GFCI device of FIG. 54;
FIG. 60 is side elevational view, partly in section, of components of a
portion of the
alternative embodiment of the GFCI device shown in FIG. 54, illustrating the
device in a
set or circuit making position;
FIG. 61 is a side elevational view similar to FIG. 60, illustrating of the
device in a
circuit breaking position;
FIG. 62 is a block diagram of a circuit interrupting system according to the
present
application;
FIGS. 63a-b are partial schematic diagrams of a conventional GFCI properly
wired
in FIG. 63a and reverse wired in FIG. 63b;
FIGS. 64a-b are partial schematic diagrams of a GFCI according to an
embodiment
of the present invention properly wired in FIG. 64a and reverse wired in FIG.
64b;
CA 02425810 2005-12-28
18
FIGS. 65a-b are partial schematic diagrams of a GFCI according to an another
embodiment of the present invention having a reset lock out shown properly
wired in FIG.
65a and reverse wired in FIG. 65b;
FIG. 66a is a partial schematic diagram of a GFCI according to an another
embodiment of the present invention utilizing two single pole single throw
switch devices
per line;
FIG. 66b is a partial schematic diagram of a GFCI according to an another
embodiment of the present invention utilizing a dual pole single throw switch
device with
one end shorted per line;
FIG. 67 is a partial schematic diagram of a GFCI according to an another
embodiment of the present invention utilizing an indicator;
FIG. 68 is a partial schematic diagram of a test connection used to configure
a
GFCI according to an embodiment of the present invention;
FIGS. 69a-c are flow charts of methods to prepare a circuit interrupting
device
according to embodiments of the present invention; and
FIG. 70 is a perspective view of a trip force device according to an
embodiment of
the present invention.
FIGS. 71-76 show a pivot point reset lockout mechanism for a GFCI wherein:
FIG. 71 is a partial side cutaway view of a GFCI similar to the device of FIG.
42
according to another embodiment of the present application;
FIG. 72a is a partial side cutaway view of a GFCI similar to the device of
FIG. 42
according to another embodiment of the present application;
FIG. 72b is a partial side cutaway view of a GFCI similar to the device of
FIG. 1
according to another embodiment of the present application;
FIG. 73 is a side elevational view similar to FIG. 56, illustrating another
embodiment of the GFCI;
FIGS. 74a-b are perspective sectional view of a reset lockout groove and reset
lockout arm in different positions;
FIG. 75a is a sectional view of the banger from the device of FIG. 15;
CA 02425810 2005-12-28
19
FIG. 75b is a sectional view of the banger in accordance with the embodiment
of
the present invention shown in FIG. 73; and
FIGS. 76a-b are perspective sectional view of a reset button and banger in
accordance with the embodiment of the present invention shown in FIG. 73.
FIGS. 77-91 show an IDCI with reset lockout and independent trip wherein:
FIGS. 77-80 show a first embodiment of the IDCI of the present invention;
FIGS. 81-82 show a second embodiment of the IDCI of the present invention;
FIG. 83 shows a third embodiment of the present invention.
FIG. 84 is a perspective view of one embodiment of as immersion detection
circuit
interrupting device IDCI according to the present invention;
FIG. 85 is a schematic diagram representation of one embodiment of an IDCI
according to the present invention;
FIG. 85a is an exploded perspective view of components of the IDCI;
FIG. 85b is a perspective view of a reset button and trip arm of the IDCI;
FIG. 85c is a perspective view of a catch of the IDCI;
FIG. 85d is a perspective view of a latch and latch spring of the IDCI;
FIG. 86 is a top view of an IDCI according to the present application;
FIG. 87 is a partial cutaway perspective view of the IDCI along line 4 shown
in a
tripped state;
FIG. 87a is a partial cutaway perspective view of the IDCI along line 4a shown
in a
tripped state;
FICI. 87b is a partial cutaway perspective view of the IDCI along line 4b
shown in a
tripped state;
FIG. 87c is a partial cutaway perspective view of the IDCI along line 4c shown
in a
tripped state;
FIG. 87d is a detail view of section 4d from FIG. 4c;
FIG. 88 is a partial cutaway front view of the IDCI in a reset lockout state;
FIG. 88a is a detail partial section perspective view of the IDCI along line
Sa in a
reset lockout state;
CA 02425810 2005-12-28
FIG. 88b is a partial cutaway perspective view of the IDCI along line Sb shown
in a
reset lockout state;
FIG. 88c is a partial cutaway perspective view of the IDCI along line Sc shown
in a
reset lockout state;
5 FIG. 89 is a partial cutaway perspective view of the IDCI shown in an
intermediate
state with plunger moving latch;
FIG. 89a is a detail view of the IDCI shown in an intermediate state with
plunger
moving latch;
FIG. 90 is a partial cutaway front view of the IDCI in an on state;
10 FIG. 90a is a detail partial section perspective view of the IDCI along
line Sa in an
on state;
FIG. 90b is a partial cutaway perspective view of the IDCI along line 7b shown
in
an on state;
FIG. 90c is a partial cutaway perspective view of the IDCI along line 7c shown
in
15 an on state;
FIG. 91 is a partial cutaway perspective view of the IDCI shown in an
intermediate
state with manual trip actuator moving latch;
FIGS. 92-95 show an ALCI with reset lockout and independent trip wherein:
FIGS. 92a and FIG. 92c are perspective views of an ALCI according to an
20 embodiment of the present invention;
FIGS. 92b and FIG. 92d are perspective views of an ALCI such as a
Windmere/TRC ALCI;
FIGS. 93a-93e are perspective views of an IDCI such as Konhan Industries IDCI
Catalog No. 303-0118;
FIGS. 93f-93g are perspective views of an IDCI according to an embodiment of
the
present invention;
FIGS. 94a-94f are perspective views of an IDCI such as Electric shock
Protection
Catalog Nos. ESP-12 and ESP-31;
FIGS. 94g-94h are perspective views of an IDCI according to an embodiment of
the
present invention;
CA 02425810 2005-12-28
21
FIGS. 95a-95b are perspective views of an IDCI such as a Wellong Catalog No.
PBS;
FIG. 95c is a perspective view of an IDCI according to an embodiment of the
present invention;
FIGS. 96-97 show a lockout mechanism for an RCD wherein:
FIG. 96 is a schematic representation of the operation of an RCD in a failed
condition according to the present application;
FIG. 97 is a schematic representation of the operation of an RCD in a passed
condition according to the present application;
FIGS. 98-101 show a neutral switch test mechanism for a circuit interrupter
wherein:
FIG. 98 is a schematic diagram of a GFCI having an electrical test and bridge
circuit according to the present invention;
FIG. 99 is a schematic diagram of a GFCI having an independent trip such as a
mechanical trip for a test button and an electrical ground fault simulation
test for reset
lockout according to the present application;
FIG. 100 is a schematic diagram of a GFCI having an independent trip such as a
mechanical trip for a test button and a mechanical switch (electrical test)
for a neutral fault
simulation test for reset lockout according to the present application;
FIGS. lOla and lOlb is a mechanical switch to effectuate a neutral fault
simulation
for a GFCI such as that as shown in Application Serial No. TBD, attorney
docket 0267-
1415CIP9(41912.015600);
FIGS. 102-117 show a reset lockout mechanism and independent trip mechanism
for
a center latch circuit interrupting device wherein:
FIGS. 102a-b is an exploded view of a prior art GFCI;
FIGS. 103a-b is a sectional side view of the mechanism of the prior art GFCI
of
FIGS. 102a-b;
FIG. 104 is a detailed side view of the mechanism of the prior art GFCI shown
in
FIGS 103a-b showing the movable contact;
CA 02425810 2005-12-28
22
FIG. 105 is a side view of a mechanism of a GFCI according to the present
invention;
FIG. 106 is a side view of a GFCI plunger according to the present invention;
FIGS. 107a-c is a side view of the GFCI mechanism during stages of reset
according
to the present invention;
FIGS. 108a-b is a sectional side view of the mechanism of a prior art GFCI ;
FIG. 109 is a perspective view of one embodiment of a ground fault circuit
interrupting device according to the present invention;
FIG. 110 is an exploded view of a portion of a GFCI according to the present
invention;
FIGS. l l la-f is a sectional side view of the mechanism of a portion of the
GFCI of
FIG. 109;
FIG. 112 is an exploded view of a prior art GFCI as shown in FIGS. 108a-b;
FIG. 113 is a perspective view of one embodiment of a ground fault circuit
interrupting device according to the present invention;
FIG. 114a is a perspective view of a solenoid plunger of a GFCI according to
another
embodiment of the present invention according to FIG. 113 as modified from
plunger 166 of
FIG. 112;
FIG. 114b is a perspective view of a reset button/lift plunger/test contact of
a GFCI
according to the embodiment of the present invention according to FIG. 113 as
modified from
128 of FIG. 112;
FIG. 114c is a perspective view of a trip button of a GFCI according to the
embodiment of the present invention according to FIG. 113 as modified from 126
of FIG.
112;
FIG. 114d is a perspective view of a release lever wire of a GFCI according to
the
embodiment of the present invention according to FIG. 114;
FIG. 114e is a perspective view of a contact carrier with switch attached of a
GFCI
according to the embodiment of the present invention according to FIG. 113 as
modified from
180-182 of FIG. 112;
CA 02425810 2005-12-28
23
FIG. 114f is a perspective view of a shuttle/test contact of a GFCI according
to the
embodiment of the present invention according to FIG. 113 as modified from 178
of FIG.
112;
FIG. 114g is a side and partial top view of the latch of a GFCI according to
another
S embodiment of the present invention that is similar to FIG. 113 as modified
from 178 of FIG.
112;
FIGS. 115a-c is a cutaway representation of part of a prior art GFCI.
FIG. 116 is a cutaway representation of part of a GFCI according to an
embodiment of
the present invention and relates to FIGS. 14a-c; and
FIGS. 117a-b is a cutaway representation of part of a GFCI according to an
embodiment of the present invention and relates to FIGS. 115a-c.
FIGS. 118-124 show a circuit interrupter with improved surge suppression
wherein:
FIG. 118 illustrates a block diagram of the disclosed suppression and
protection
circuit connected between power inputs and the GFCI circuit;
FIG. 119 illustrates the circuits and components in FIG. 118 in an example
embodiment with greater detail.
FIG. 120 illustrates a schematic diagram of a GFCI circuit having a
suppression and
protection circuit and a grounded neutral reset lockout test according to an
embodiment of
the present invention;
FIG. 121 illustrates a schematic diagram of an alternative embodiment of the
GFCI
circuit of FIG. 3, utilizing a gas tube crowbar device;
FIG. 122a illustrates a spark gap device having a spark gap with a 0.1 inch
width;
FIG. 122b illustrates a spark gap device having a spark gap with a 0.04 inch
width;
FIG. 122c illustrates a spark gap device haing a spark gap with a .OS inch
width;
FIG. 122d illustrates a spark gap device with a vertical header pin and an
angularly
oriented header pin;
FIG. 122e illustrates a spark gap device with two angularly oriented header
pins;
FIG. 123a illustrates a gas tube device having a spark gap formed by two
vertical
header pins;
CA 02425810 2005-12-28
24
FIG. 123b illustrates a gas tube device having a spark gap formed by a
vertical
header pin and an angularly oriented header gin;
FIG. 124a illustrates a hybrid protection circuit for an MOV, having a low
pass
filter using a Zener diode and a resistor; and
FIG. 124b illustrates a hybrid protection circuit for an MOV, having a low
pass
filter using a Zener diode and an inductor.
FIGS. 125-145 show a GFCI with status indication wherein:
FIG. 125 is a perspective view of a GFCI constructed with status indication
capability;
FIG.126 is a bottom perspective view of the GFCI of FIG. 125;
FIG. 127 is similar to FIG. 125 but with the top and bottom covers of the GFCI
removed;
FIG. 128 is a perspective view of the mounting strap of the device of FIG.
125;
FIG. 129 is a bottom perspective view of the load neutral and load phase
terminals
of the device of FIG. 125;
FIG. 130 is a perspective view of the printed circuit board and reset
assemblies of
the device of FIG. 125;
FIG. 131 is a perspective view of the devices of FIG. 130 with the reset lever
and
PC board removed.
FIG. 132 is a perspective view of the bobbin assembly of the device of FIG.
125;
FIG. 133 is a perspective view of the main movable contacts of the device of
FIG.
125;
FIG. 134 is a bottom perspective view of the plunger, latch plate and
auxiliary
contacts of the device of FIG. 125.
FIG. 135 is a perspective view showing the transformers mounted on the printed
circuit board of the device of FIG. 125;
FIG. 136 is a side elevational view partly in section of the transformer
bracket
assembly of FIG. 135;
FIG. 137 is a perspective view of the test lever and button of the device of
FIG.
125.
CA 02425810 2005-12-28
FIG. 138 is front elevational view of the test lever, test button, test arm
and test pin
in the open position;
FIG. 139 is a front elevational view of the components shown in FIG. 138 in
the
closed, test position;
5 FIG. 140 is a perspective view of the reset lever and reset button of the
device of
FIG. 125;
FIG. 141 is a front elevational view of the reset lever reset button, main
contacts
and auxiliary contacts in the closed or reset condition;
FIG 142 is a side elevational view of the device according to FIG. 141;
10 FIG. 143 is a front elevational view of the components of FIG. 141 in the
tripped
condition;
FIG. 144 is a side elevational view of the device of FIG. 143;
FIG. 145 is a table to show the relationships between the status of the GFCI
and
associated circuits and the color, speed of blinking and the presence or
absence of an
15 audible signal.
DETAILED DESCRIPTION OF EMBODIMENTS
The present invention contemplates various types of circuit interrupting
devices that
are capable of breaking at least one conductive path at both a line side and a
load side of
the device. The conductive path is typically divided between a line side that
connects to
20 supplied electrical power and a load side that connects to one or more
loads. As noted, the
various devices in the family of resettable circuit interrupting devices
include: ground fault
circuit interrupters (GFCI's), arc fault circuit interrupters (AFCI's),
immersion detection
circuit interrupters (IDCI's), appliance leakage circuit interrupters (ALCI's)
and equipment
leakage circuit interrupters (ELCI's).
25 For the purpose of the present application, the structure or mechanisms
used in the
circuit interrupting devices, shown in the drawings and described hereinbelow,
are
incorporated into a GFCI receptacle suitable for installation in a single-gang
junction box
used in, for example, a residential electrical wiring system. However, the
mechanisms
CA 02425810 2005-12-28
26
according to the present application can be included in any of the various
devices in the
family of resettable circuit interrupting devices.
The GFCI receptacles described herein have line and load phase (or power)
connections, line and load neutral connections and user accessible load phase
and neutral
connections. The connections permit external conductors or appliances to be
connected to
the device. These connections may be, for example, electrical fastening
devices that secure
or connect external conductors to the circuit interrupting device, as well as
conduct
electricity. Examples of such connections include binding screws, lugs,
terminals and
external plug connections.
The circuit interrupting and reset portions described herein preferably use
electro-
mechanical components to break (open) and make (close) one or more conductive
paths
between the line and load sides of the device. However, electrical components,
such as
solid state switches and supporting circuitry, may be used to open and close
the conductive
paths.
Generally, the circuit interrupting portion is used to automatically break
electrical
continuity in one or more conductive paths (i.e., open the conductive path)
between the line
and load sides upon the detection of a fault, which in the embodiments
described is a
ground fault. The reset portion is used to close the open conductive paths. In
the
embodiments including a reset lockout, the reset portion is used to disable
the reset
lockout, in addition to closing the open conductive paths. In this
configuration, the
operation of the reset and reset lockout portions is in conjunction with the
operation of the
circuit interrupting portion, so that electrical continuity in open conductive
paths cannot be
reset if the circuit interrupting portion is non-operational, if an open
neutral condition
exists and/or if the device is reverse wired.
In an alternative embodiment, the circuit interrupting devices may also
include a
trip portion that operates independently of the circuit interrupting portion
so that in the
event the circuit interrupting portion becomes non-operational the device can
still be
tripped. Preferably, the trip portion is manually activated and uses
mechanical components
to break one or more conductive paths. However, the trip portion may use
electrical
CA 02425810 2005-12-28
27
circuitry and/or electro-mechanical components to break either the phase or
neutral
conductive path or both paths.
The above-described features can be incorporated in any resettable circuit
interrupting device, but for simplicity the descriptions herein are directed
to GFCI
receptacles. A more detailed description of a GFCI receptacle is provided in
U.S. Patent
4,595,894, which is incorporated herein in its entirety by reference and in
commonly
owned application number 09/688,481 now issued as US 6,437,700 i
. It should also be noted that binding screws are exemplary of the types of
wiring
terminals that can be used to provide the electrical connections. Examples of
other types of
wiring terminals include set screws, pressure clamps, pressure plates, push-in
type
connections, pigtails and quick-connect tabs.
Several illustrative embodiments of a center latch GFCI are now provided.
Turning now to FIGS. 1 and 2, a GFCI 30 according to the present invention is
shown. GFCI 30 is made up of a top cover 32, middle housing 34 and a bottom
housing
36 held in assembly by the deflectable tabs (not shown) on bottom housing 36
engaging the
U-shaped members 38 on top cover 32. A mounting strap 40 is mounted between
top cover
32 and middle housing 34 and has two apertures 42 to mount the GFCI 30 to the
mounting
ears of a standard gang box (not shown). Top cover 32 has a face 44 which
contains two
sets of slots each to receive a three-bladed grounded plug (not shown). Each
set of slots is
made up of a slot 46, 48 of a first length and a slot 50, 52 of a longer
length and a U-
shaped slot 54, 56 to receive the grounding prong of the plug. Because the
slots 50, 52 are
longer than the slots 46, 48 the plug is naturally polarized and conforms to
NEMA
standard 5-15R. In the depression 58 in top cover 32 is placed a reset button
60, a test
button 62 and an indicator lamp means 64. Indicator lamp means 64 is a dual
color lamp
which produces a first color when a first filament is activated, a second
color when a
second filament is activated and a third color when both filaments are
activated. Bottom
housing 36 has a series of four terminal screws (only two of which are shown
in the
figures). Terminal screw 66 is connected to the load neutral terminal as will
be described
below. A similar terminal screw 68 is connected to the load phase terminal.
Terminal
screw 70 is connected to the line neutral terminal and a similar terminal
screw 72 is
CA 02425810 2005-12-28
28
connected to the line phase terminal as will be described below. Adjacent each
terminal
screw 66, 68, 70 and 72 are two apertures 74 to receive the bared ends of
electrical
conductors (not shown). As will be described below, the conductor ends extend
between a
terminal contact and a wire nut which engages the conductor and pushes it
against the
terminal contact as the terminal screw is advanced. At the rear wall of middle
housing 34 is
a grounding screw 76 to which may fastened a ground conductor (not shown
inserted into
slot 78.)
Turning now to FIG. 3 which shows GFCI 30 with the top cover 32 and the bottom
housing 36 removed and FIGS 4 and 5 which show details of the mounting strap
40 and the
load phase and neutral terminals. Mounting strap 40 has two apertures 42 as
above
described and a generally centrally located circular opening 80 to receive the
reset lever
and a square opening 82 to receive the test lever. Two clips 84, 86 are
arranged to engage
the grounding prong of inserted plugs and are connected to mounting strap 40
by rivets 88.
A bent down tab 90 has a threaded aperture to receive the ground screw 76. A
ground nut
92 is pulled against tab 90 as ground screw 76 is advanced to hold the bared
end of a
conductor inserted in slot 78 and between tab 90 and ground nut 92.
FIG. 5 shows the load neutral terminal 94 and the load phase terminal 96. Each
terminal 94, 96 has a central body portion 98, 100, respectively, with male
blade grip
fingers 102, 104 at each end. The male blades of the plug with fit between
each pair of grip
fingers 102, 104 to make mechanical and electrical contact with the male
blades of the
inserted plug. An interned tab 106 on load neutral terminal 94 receives the
main fixed
neutral contact 106 while interned tab 110 receives the main fixed phase
contact 112. A
depending three sided tab 114 has a slot 116 to receive therethough the
threaded portion of
terminal screw 66. A similar depending three sided tab 118 has a slot 120 to
receive
therethrough the threaded portion of terminal screw 68.
In FIG. 3 the mounting strap 40 of FIG. 4 and the terminals 94, 96 of FIG. 5
are
shown assembled to middle housing 34. Also mounted to middle housing 34 is the
printed
circuit board (hereafter PCB) 122 which contains the various circuits which
determine the
indicator lamp means color, its blinking rate and control the beeper. The PCB
122 also
contains the various components of the fault detectors, transformers and
solenoid as will be
CA 02425810 2005-12-28
29
described below. Terminal screw 70 is connected to a tab 124 having a slot 126
therein to
receive the threaded portion of terminal screw 70. A similar structure is
present for
terminal screw 72 not visible in the figure.
Referring now to FIG. 6 the PCB 122 assembly and the reset assembly are shown
with the middle housing 34 removed. The reset assembly comprises a reset
button 60, a
reset lever 128 and a reset spring 130 and a latch pin to be described below
with respect to
FIGS 16 to 20. A plunger 132 is positioned in the passageway of a solenoid
coil 134. The
plunger 132 is shown in its reset position extending partially out of the
passageway of
solenoid coil 134. When the solenoid coil 134 is operated by the circuits on
the PCB 122
the plunger 132 is drawn further into solenoid coil 134. The plunger 132
controls the
position of the latch plate to be described with reference to FIG. 10. The
latch plate in
cooperation the latch pin and reset spring 130 move the lifter 136 upwardly
against the
movable contact arms 138 to close the main movable contacts 140 to the main
fixed
contacts 108; 112 on the underside of interned tabs 106, 110, respectively.
The movable
contact arms 138 are biased away from their associated interned tabs 106, 110
and when
the latch pin has been released push the lifter 136 and latch plate downwardly
to move the
movable contacts 140 away from their associated fixed contacts 108, 112. Also
mounted on
the PCB 122 is a neutral transformer 142 and a differential transformer 144.
Only the
neutral transformer 142 is shown in FIG. 6. Both transformers and the
transformer bracket
assembly 146 are shown in FIG. 12. Neutral transformer 142 is stacked upon
differential
transformer 144 with a fiber washer 148 therebetween. The bracket assembly 146
substantially surrounds the transformers 142, 144 except for a slot 150 as
shown in FIG.
11 and slots into which conductors are placed. The leads for the windings of
the
transformers are brought out to four transformer pins 152 to which may be
coupled the line
and load conductors. One of the transformers will sense the current going to
the load from
the source and the other will sense the current from the load back to the
source. Any
difference in current through these transformers is an indication that there
is a fault in the
circuit wiring. A device which can measure small differences in current and
supply a fault
signal is an integrated circuit available from many sources, for example, type
number
LM1851 from National Semiconductor or type number MC3426 from Motorola. This
IC is
CA 02425810 2005-12-28
located on PCB 122. The line neutral terminal 154 and the line phase terminal
156 have
arms 158, 160 (see FIG. 9) which extend through the slots in the top of
transformer
bracket assembly 146. As shown in FIG. 7, terminal screw 70 extends through
slot 126 of
tab 124 that is part of line neutral terminal 154 and into a threaded aperture
in nut 162 to
5 thus connect the line neutral conductor (not shown) to the two transformers.
The arms
158,160 act as one turn windings for the transformers 142 and 144. The line
phase
conductor (not shown) is connected via terminal screw 72 to tab 164 which
extends through
a slot 166 in tab 164 into the threaded aperture of a nut 168. Tab 162 is part
of the line
phase terminal 156. An insulator 168 extends between the arms 158, 160 to
prevent
10 shorting between them. The solenoid coil 134 is connected to two bobbin
pins 170 to
permit connection to PCB 122. FIG. 7 is similar to FIG. 6 but omits the PCB
122, the
reset button 60, the reset lever 128 and the reset spring 130.
FIG. 8 shows the bobbin assembly 172 having solenoid coil 134 connected to
bobbin pins 170 and containing plunger 132 in its passageway. A chamber 174
receives the
15 lifter 136 and supports the lifter 136 when in its low position. A cross
member 176
supports the auxiliary switch made up of auxiliary fixed contact arm 178 and
auxiliary
movable contact arm 180. The auxiliary switch when auxiliary fixed contact 186
and
auxiliary movable contact 188 are engaged provides power to various components
on the
PCB 122. The auxiliary switch, when auxiliary fixed contact 186 and auxiliary
movable
20 contact 188 are not engaged cut-off the power to the components on PCB 122
and prevent
possible damage to the PCB 122 components. For example, if the signal to the
solenoid
coil 134 were repeatedly applied while the main contacts are open there is a
chance to burn
out the solenoid coil 134. The auxiliary movable contact arm 180 is biased
towards
auxiliary fixed contact arm 178 and will engage it unless forced to open the
contacts.
25 FIG. 9 shows the lifter 136 in contact with the movable contact arms 138
and
positioned by the latch plate 182 which in turn is controlled by the plunger
132 and the
plunger reset spring 184. The lifter 136 and latch plate 182 positions are
dependent upon
the reset lever 128 position as will be described below. The lifter 136 also
controls the
auxiliary movable contact arm 180. When the lifter 136 in its low position,
the auxiliary
30 movable contact 188 is moved away from contact with the auxiliary fixed
contact 188 (not
CA 02425810 2005-12-28
31
shown). A latch plate return spring (not shown) resets the latch plate once
the plunger 132
is reset as will be set out with respect to FIG. 10.
In FIG. 10 there is shown the latch plate 182, the plunger 132 and the
auxiliary
fixed arm 178 with auxiliary fixed contact 186 and the auxiliary movable arm
180 with
auxiliary movable contact 188. Plunger reset spring 184 is anchored on the
back edge 200
of latch plate 182 and the tab 198 extending into the rectangular opening 196.
When the
plunger 132 is moved to the right in FIG. 10 as a result of the activation of
solenoid coil
134 the plunger reset spring 184 is compressed and expands to return the
plunger 132 to its
initial position partially out of the solenoid coil 134 as shown in FIG. 6
when the solenoid
coil 134 is deactivated. Latch plate return spring 190 is connected between
lifter 136 and
tab 198 and is compressed by the movement of latch plate 182 to the right in
FIG. 10 due
to movement of plunger 132 to the right as well. When the plunger 132 is
withdrawn, the
latch plate return spring 190 expands to return the latch plate 182 to the
left in FIG. 10.
The arms 192 support arms of lifter 136. A central aperture 194 is oval in
shape with its
longer axis extending along a central longitudinal axis of latch plate 182. At
the center of
aperture 194, the aperture 194 is large enough for a latch pin (not shown) to
pass through
aperture 194 and move without engaging the lifter 136. At one of the smaller
ends the latch
pin is held by the latch plate 182 and causes the lifter 136 to move with the
latch pin as will
be described below. The auxiliary movable arm 180 is biased upwardly so that
it brings
auxiliary movable contact 188 into contact with auxiliary fixed contact 186 on
auxiliary
fixed arm 178. As will be described below an arm of the lifter 136 will engage
the
auxiliary movable arm 180 to push it downwardly in FIG. 10 to separate the
auxiliary
movable contact 188 from the auxiliary fixed contact 186 and open the
auxiliary circuit.
Turning now to FIGS 13, I4 and 15 the test button 62 is shown and its
operation
described. Test button 62 has a top member 204 from which extend side members
206.
Also extending from top member 204 is a central lever 208 which contains a cam
210. The
lever 208 extends through square opening 82 in mounting strap 40. The cam 210,
when the
test button 62 is depressed, engages a test arm 212 and moves its free end 214
into contact
with test pin 216. The position of the test pin 216 is shown in FIG. 6. The
test pin 216 is
coupled to a small resistor and a lead which extends through one of the
transformers 142,
CA 02425810 2005-12-28
32
144 to produce an unbalance in the power lines and cause the integrated
circuit LM 1851 to
produce a signal to operate the solenoid 134 and thus simulate a fault. The
test button
return spring (not shown) returns the test button 62 to its initial position.
FIG. 14 shows
the reset position of test button 64 with cam 210 not depressing test arm 212
and the free
end 214 separated from test pin 216. When the test button 62 is depressed as
shown in
FIG. 15, the cam 210 forces the free end 214 of test arm 212 downwardly into
contact with
test pin 216 to cause a simulated fault and operate the GFCI 30 to determine
that the GFCI
30 is working properly. When released test button 62 returns to its reset
position as shown
in FIG. 14.
The reset button 60 is shown in FIG. 16. Reset button 60 has a top member 218
from which depend side members 220. Also extending from top member 218 is a
latch
lever 222 which ends in a latch pin 224. Latch pin 224 is generally pointed at
its free end
228. The diameter of latch pin 224 is greater than the diameter of the latch
lever 222
resulting in a latch shoulder 226. A reset spring 230 surrounds latch lever
222 as shown in
FIG. 17. FIGS 17 and 18 show the GFCI 30 in its reset position. FIG. 17 is a
rear view
while FIG. 18 is a side elevational review. The surrounding structure is shown
in light line
to permit the switching components of GFCI 30 to stand out. In FIG. 18 the
plunger 132
extends out of the solenoid coil 134 and the latch plate 182 is drawn to the
left of the figure
so that a smaller end of the oval aperture 194 engages the latch lever 222.
The latch pin
224 cannot be drawn through oval aperture 194. The leading end 232 of latch
plate 182
rests upon the latch shoulder 226 and also is positioned under lifter 136. The
reset spring
230 urges the latch lever 222 upwardly causing the lifter 136 to also move
upwardly. This
upward movement causes the movable contact arms 138 to also move upwardly
bringing
movable contacts 140 into contact with fixed contacts 108, 112 (see FIG. 17).
The
extension 234 of lifter 136 moves away from its contact with auxiliary movable
arm 180
and the upwardly braised auxiliary movable arm 180 causes its auxiliary
movable contact
188 to engage auxiliary fixed contact 186 on auxiliary fixed arm 178 and thus
supply
power to the PCB.
In response to an internal or external fault or in response to a test
employing test
button 62, the GFCI 30, if working properly will go to a trip state shown in
FIGS 19 and
CA 02425810 2005-12-28
33
20 wherein both the main circuits and the auxiliary circuit will be opened.
The presence of
the trip condition is signaled by the circuits of the PCB. A signal will be
supplied to the
solenoid coil 134 which draws the plunger 132 further into solenoid coil 134.
Plunger 132
causes the latch plate 182 to move to the right in FIG. 20 and place the
central portion of
oval aperture 194 over latch pin 224. In this position leading end 232 of the
latch plate 182
not longer engages the latch shoulder 226 and the latch lever 222 is free to
move through
the oval aperture 194. As a result there is nothing to hold the movable
contacts 140 on
movable contact arms 138 in contact with fixed contacts 108, 112 on the fixed
arms 106,
110, respectively. The movable contact arms 138, biased downwardly bear upon
the lifter
136 moving it downwardly separating contacts 108, 112 and 140. The extension
234 bears
against auxiliary movable arm 180 and causes its downward movement separating
the
auxiliary movable contact 188 from the auxiliary fixed contact 186 and opening
the
auxiliary circuit to supply power to the circuits on the PCB. The reset button
60 pops up as
a result of the action of reset spring 230 to indicate that the GFCI 30 needs
to be reset.
In addition to the pop-up of the reset button 60, the GFCI has a dual color
indicator
lamp means 64 and a piezo resonator 236 driven by an oscillator on the PCB
(not shown)
to produce an audible output. By selecting the oscillator frequency of 3.OKHZ
+/- 20%
and controlling the time of operation of the oscillator, the audible signal
shall be active for
0.10 second and inactive for 2 seconds. FIG. 21 shows the various combinations
of light
color, light flashing speed and beeper sound which can be produced to show
various states
of the GFCI 30. A supervisory signal that indicates that the GFCI 30 is
working is
provided for the first 25 days of the GFCI 30 cycle. It is recommended that
the GFCI 30 be
tested and reset every 30 days to ensure that the GFCI 30, is working
properly.
However, for the most part this instruction is disregarded by users. To
encourage
the testing of the GFCI 30 the various lights and beeper approach is employed.
At the end
of 25 days the slow flashing green light which signaled the device as workings
changes to a
faster blink. The supervisory or slow blink is 0.10 seconds "on" and 15
seconds "off'. The
faster blink is 0.10 seconds on and 0.9 seconds off. This fast blink extends
for five days at
which time both filaments of the indicator lamp means 64 are energized to
produce an
amber light which is blinked at the fast blink rate. If the power comes on
reset the amber
CA 02425810 2005-12-28
34
light will also blink at the fast rate until the supervisory condition is
reached. The time
periods are established by a counter and a clock generator on the PCB. If an
external fault
is detected the amber light is lit and the audible signal is generated. The
GFCI 30 will need
to be reset. If the fault is in the GFCI 30 itself, for example the solenoid
coil 134 is burned
out, then the red filament of the indicator lamp means 64 is activated and the
audible signal
is generated. The GFCI 30 will have to be replaced if the fault is in the GFCI
30.
A circuit interrupting device having a reset lockout device and a separate
user load
break point may be desirable.
Referring to FIG. 22, a schematic diagrams of a GFCI according to an
embodiment
of the present invention is shown having a reset lockout mechanism using an
electrical test
through R4'.
Referring to FIG. 23, a schematic diagrams of a GFCI according to an
embodiment
of the present invention is shown incorporating a bridge circuit with reset
lockout. As can
be appreciated, the bridge circuit can be implemented in the device of FIGS. 1-
21 by
separately isolating the load side and user load from the line side for each
of the phase and
neutral lines. For example, bars 98 and 100 need to be modified to isolate
tabs 114 and
118 respectfully from tab 102 and its opposing counterpart. An extra contact
at 106, 108
would be utilized.
Referring to FIG. 24, a schematic diagrams of a-GFCI according to an
embodiment
of the present invention having a bridge circuit with reset lockout and an
independent trip
mechanism is shown.
Referring to FIGS. 25-28b, a reset lockout mechanism and independent manual
trip
are provided for the device of FIGS: 1-21.
The device of FIGS. 1-21 has a reset mechanism that operates as follows. When
the reset button is pressed down, the end of the reset pin centers the holes
on the latch and
the lifter, allowing the reset pin to go through the holes. Once the pin is
through the holes,
the latch spring moves the latch to its normal position. The device is then in
a "reset
position" (contact made between line & load). When the solenoid fires (due to
a fault or
by pressing the test button) the plunger opens the latch and releases the
reset pin.
CA 02425810 2005-12-28
Referring to FIGS. 25-28b; an embodiment of a reset mechanism has a disc 510
toward the end reset shaft 502 attached to reset button 500. When the reset
button 500 is
pressed down, the reset pin disc 510 interferes with latch 530 because of
misalignment
between the hole 534 in the latch 530 and the reset pin disc 510 as shown in
FIG. 26.
5 When this occurs, the device is in a locked out state. Continuing the
downward movement
of the reset shaft 502 causes the test switch 550 to close. The test, if
successful, will cause
the solenoid (not shown) to fire, thereby aligning the hole 534 in the latch
530 with the
reset pin disc 510. When the reset pin disc 510 passes fully through the latch
530, the
latch returns to its normal position shown in FIG. 28 a and a return spring
(not shown)
10 pulls the reset disc 510 upward into a reset position, thereby closing the
contacts (not
shown). A manual trip is provided, whereby a test button shaft is angled at a
distal end
such that it will force latch 532 through a cam action such that the reset pin
disc 510 will
clear hole 534 and the device will reset.
Referring to FIGS. 29a-30, another embodiment of a reset mechanism has a reset
15 button 600 and a reset end 620. When the reset button 600 is pressed down
the latch 640
moves to an opened position as in the embodiment above. In this embodiment, a
spacer
650 keeps the latch 640 in its opened position, preventing engagement of the
reset pin end
620. The spacer 650 is forced into place, between the lifter 630, latch 640
and bobbin 644
by a spring 652.
20 While the reset button 600 is pushed down, the test switch pin 610
activates a test
switch 616. If the device is able to fire the solenoid (not shown), it will
fire and cause the
plunger extension ramp 642 to push the spacer 650 away from the latch 640,
allowing it to
close. The device is now in a "reset position".
As can be appreciated, the test switch pin 610 cannot activate the test switch
616
25 while the device is in the "reset position" as shown in FIG. 29c.
As can be appreciated, If the solenoid (not shown) fails to fire for any
reason, the
reset button 600 can be released by pressing the manual trip button 670 (may
be marked
test button). When the test button 670 (biased upward by spring 672) is
depressed, the
profile at the end of the shaft 674 acts as a cam against an arm 676 on the
latch 640,
30 causing it to open up and release the reset pin end 620 which is biased
upward.
CA 02425810 2005-12-28
36
As can be appreciated, the reset button 600 can be fully depressed, without
obstruction and returned to its upper position without engagement, if the
solenoid does not
1 rre for any reason.
Referring to FIGS. 31a-f, various views of the components of the reset lockout
mechanism of this embodiment as described above in various stages of operation
are
shown.
Referring to FIGS. 32a-b, another embodiment of the present invention is shown
using a single button activation method for reset lockout. In this embodiment,
the device
resets as shown in the device of FIG. 25. The lockout method is also the same.
When the
device is in the reset position, as shown in FIG. 32a, the latch plate 706
moves up in
direction C and holds a tilt plate 704 into a "ready" position. At this point,
pushing down
on the reset button (not shown) causes the latch plate 706 to release the tilt
plate 704 when
shoulder 712 hits 706. The tilt plate 704 then pushes against the reset pin
702, causing it
to tilt forward and remain in that position as shown in FIG. 32b. As the reset
button (not
shown) is released, the spring (not shown) that biases the reset pin 702 pulls
the reset pin
upward in direction C, the bottom of the reset pin 710 passes thru the hole in
the latch
plate 707 because the reset pin 702 is still being tilted as shown in FIG.
32b. When the
reset button (not shown) is fully up (not shown), the reset pin 702 acts as a
cam, and
pushes the tilt plate 704 back into a locked position (not shown). The device
has now been
tripped manually.
The mechanism of this embodiment allows the device to be placed in a reset
position, and then a trip position, with the use of only one button. The
operation of the
device of this embodiment is similar to that of a latching push button switch.
Referring to FIGS. 33a-f, another embodiment of the present invention is shown
using a single button activation method for reset lockout. In this embodiment,
the device
of FIG. 25 may be used with this single button activation method of the reset
lockout
mechanism. In this embodiment, a two piece reset button 720 resets and trips
the GFCI.
The operation of this embodiment is similar to that of a latching push button
switch. The
device is tripped (contacts open) when the button ?20 is up as shown in FIG.
33a. When
CA 02425810 2005-12-28
37
the button 720 is pushed down, the device will reset only if the test
succeeds. If the test,
such as a simulated ground fault, fails, the button 720 will be locked out and
will not reset.
Starting with the GFCI in the reset position (power contacts closed). Pushing
the
button 720 trips the device, and the button 720 comes up. A trip arm 722,
connected to the
upper part of the reset button 720, uses a cam action to push a trip block 724
against a
latch plate 726. The action causes the latch plate 726 to move and release.
The device
then acts according to the device of FIG. 25. It has a test switch 728. The
two piece reset
button 720 has two springs 730 and 732 to produce two different actions, when
the reset
button is pressed. A first portion of travel through a reset button depression
may force a
mechanical trip, while a second portion may use reset lockout to require a
successful test
before resetting the device. FIG. 33 a shows the device in a tripped, contact
open state.
FIG. 33b shows the device locked out. FIG. 33e shows the device in a reset,
contacts
closed state.
Referring to FIGS. 34a-c and 34d-f, two additional embodiments of the present
invention are shown using a single button activation method for reset lockout.
In this
embodiment, the device of FIG. 25 may be used with this single button
activation method
of the reset lockout mechanism. When the plunger 752, 753 of a reset lock out
mechanism
is engaged, normally to trip the GFCI mechanically, a separate test or trip
button is used.
That button may move a sliding plate to a position by which the shaft 752, 753
(plunger)
will be free to release (tripped) just as if the solenoid (not shown) fired.
As shown in this
embodiment, this disengagement can done with the same reset button 750, 751
where the
shaft (plunger) 752, 753 is acting as a lever. With the shaft 752, 753 engaged
as shown in
FIGS. 34b and e, one can use the button 750, 751 as toggle type switch as
shown in FIGS.
34c and f to trip the mechanism.
The use of a GFCI as a representative circuit interrupter is illustrative only
and not
to be considered limiting. With reference to FIGS. 35-41, a GFCI 810 with a
user load
activated switching device is shown.
Referring to GFCI 810 of FIG. 35, as shown in FIG. 36a, each time a user
inserts a
plug having plug blades 811 into the device, a mechanical trip is initiated.
User plug blade
811 engages trigger arm 820, that is biased by spring 825. As the trigger arm
820 travels
CA 02425810 2005-12-28
38
in direction A, a cam action forces sliding plate 831 that first moves in
direction D. The
device 810 is mechanically tripped and the reset lockout mechanism must allow
a reset
before the device 810 will supply power to the user load. As can be
appreciated, the user
receptacle may exert enough force to hold plug 811 in place despite the force
exerted by
bias.spring 825.
Referring to FIG. 36b, each time a user removes a plug having plug blades 811
from the device, a mechanical trip is initiated. User plug blade 811 engages
trigger arm
820, that is biased by spring 825. As the blade 811 travels in direction B,
the spring 825
forces trigger arm 820 to travel in direction B and sliding plate 830 first
moves in direction
C. The device 810 is again mechanically tripped and the reset lockout
mechanism must
allow a reset before the device 810 will supply power to the user load.
As can be appreciated, a GFCI receptacle with more than one user receptacle
may
utilize two such switches that may also utilize common components to initiate
the trip
mechanism. Similarly, the device may be configured to trip only when the first
plug is
inserted or only when the last plug is removed.
Accordingly, in this embodiment, a user is forced to manually reset the device
for
each use - a test-to-use arrangement when used with a reset lockout GFCI. In
the device
of this embodiment employing a reset lock out mechanism, the device will only
be reset is
the GFCI is operational, not in an open neutral condition and not reverse
wired.
In this embodiment an independent mechanical trip is initiated. However, a
momentary switch may be utilized to provide for an electrical test based trip
of the device
as described above. The electrical test circuits described above may be
utilized to initiate a
device trip. Of course, the device may be manufactured or initiated into a
reset Lock out
state as described above. Additionally, the trigger arm bias can be provided
with other
known means including a trigger arm mounted to provide a spring bias.
With reference to FIGS. 37 and 38a-b, a device with only a reset button is
shown.
Because the plug will initiate a mechanical trip each time it is inserted or
removed, there
may be no need for a test or trip button. The device of FIGS. 38a-b is the
same as the one
of FIGS. 36a-b except there is no test button mechanism.
CA 02425810 2005-12-28
39
With reference to FIG. 39, another embodiment of the present invention is
shown.
An automatic test GFCI device 910 is shown that is configured to automatically
test itself
when a user load is accessed. A user load activated spring and switch such as
shown in
FIG. 36a will execute a trip and reset that will be locked out if the device
is non-
operational, in an open neutral state or reverse wired. When the user plug 811
is removed,
the device may again be tripped. As can be appreciated, for a duplex user
receptacle such
as that of device 810, the first plug inserted may execute the test and reset,
while the last
plug removed may trip the device into a standby tripped state. Accordingly,
because a trip
and reset lockout test is accomplished for each plug insertion, there may be
no need for
user buttons.
As shown in FIG. 40, the mechanism for a buttonless device 910 is shown. Plug
prong 911 will engage trigger arm 920, that is biased by spring 925. As the
blade 911
travels in direction B, the trigger arm 920 first mechanically trips the
device with a low
cam forcing sliding plate 931 to release the reset shaft 930 to a tripped
position. The
trigger arm continues down until it contacts reset shaft 930 and engages a
test to reset lock
out mechanism as described above. Accordingly, a device may not require any
buttons and
is preferably delivered in a tripped state.
With reference to FIG. 41, another embodiment of the present invention is
shown.
An automatic test GFCI device 912 is shown that is similar to device 910,
except that the
user load switch activation mechanism is activated by pressure on a face plate
916 that is
biased to an outward position and forced in when a user plug is inserted.
As noted, although the components used during circuit interrupting and device
reset
operations are electro-mechanical in nature, the present application also
contemplates using
electrical components, such as solid state switches and supporting circuitry,
as well as
other types of components capable or making and breaking electrical continuity
in the
conductive path.
Turning now to FIG. 42, the GFCI receptacle 310 has a housing 312 consisting
of a
relatively central body 314 to which a face or cover portion 316 and a rear
portion 318 are
removably secured. The face portion 316 has entry ports 320 and 321 for
receiving normal
CA 02425810 2005-12-28
or polarized prongs of a male plug of the type normally found at the end of a
lamp or
appliance cord set (not shown), as well as ground-prong-receiving openings 322
to
accommodate a three-wire plug. The receptacle also includes a mounting strap
24 used to
fasten the receptacle to a junction box.
5 A test button 326 extends through opening 328 in the face portion 16 of the
housing
312. The test button is used to activate a test operation, that tests the
operation of the
circuit interrupting portion (or circuit interrupter) disposed in the device.
The circuit
interrupting portion, to be described in more detail below, is used to break
electrical
continuity in one or more conductive paths between the line and load side of
the device. A
10 reset button 330 forming a part of the reset portion extends through
opening 332 in the face
portion 316 of the housing 312. The reset button is used to activate a reset
operation,
which reestablishes electrical continuity in the open conductive paths.
Electrical connections to existing household electrical wiring are made via
binding
screws 334 and 336, where screw 334 is an input (or Line) phase connection,
and screw
15 336 is an output (or load) phase connection. It should be noted that two
additional binding
screws 338 and 340 (seen in FIG. 44) are located on the opposite side of the
receptacle
310. These additional binding screws provide line and load neutral
connections,
respectively. A more detailed description of a GFCI receptacle is provided in
U.S. Patent
4,595,894, which is incorporated herein in its entirety by reference. It
should also be
20 noted that binding screws 334, 336, 338 and 340 are exemplary of the types
of wiring
terminals that can be used to provide the electrical connections. Examples of
other types of
wiring terminals include set screws, pressure clamps, pressure plates, push-in
type
connections, pigtails and quick-connect tabs.
Referring to FIGS. 43-47, the conductive path between the line phase
connection
25 334 and the load phase connection 336 includes contact arm 350 which is
movable between
stressed and unstressed positions, movable contact 352 mounted to the contact
arm 350,
contact arm 354 secured to or monolithically formed into the load phase
connection 336
and fixed contact 356 mounted to the contact arm 354. The user accessible load
phase
connection for this embodiment includes terminal assembly 358 having two
binding
30 terminals 360 which are capable of engaging a prong of a male plug inserted
therebetween.
CA 02425810 2005-12-28
41
The conductive path between the line phase connection 334 and the user
accessible load
phase connection includes, contact arm 350, movable contact 362 mounted to
contact arm
350, contact arm 364 secured to or monolithically formed into terminal
assembly 358, and
fixed contact 366 mounted to contact arm 364. These conductive paths are
collectively
called the phase conductive path:
Similarly, the conductive path between the line neutral connection 338 and the
load
neutral connection 340 includes, contact arm 370 which is movable between
stressed and
unstressed positions, movable contact 372 mounted to contact arm 370, contact
arm 374
secured to or monolithically formed into load neutral connection 340, and
fixed contact 376
mounted to the contact arm 374. The user accessible load neutral connection
for this
embodiment includes terminal assembly 378 having two binding terminals 380
which are
capable of engaging a prong of a male plug inserted therebetween. The
conductive path
between the line neutral connection 338 and the user accessible load neutral
connection
includes, contact arm 370, movable contact 382 mounted to the contact arm 370,
contact
arm 384 secured to or monolithically formed into terminal assembly 378, and
fixed contact
386 mounted to contact arm 384. These conductive paths are collectively called
the neutral
conductive path.
Referring to FIG. 43, the circuit interrupting portion has a circuit
interrupter and
electronic circuitry capable of sensing faults, e.g., current imbalances, on
the hot and/or
neutral conductors. In a preferred embodiment for the GFCI receptacle, the
circuit
interrupter includes a coil assembly 390, a plunger 392 responsive to the
energizing and
de-energizing of the coil assembly and a banger 394 connected to the plunger
392. The
banger 394 has a pair of banger dogs 396 and 398 which interact with a movable
latching
members 1100 used to set and reset electrical continuity in one or more
conductive paths.
The coil assembly 390 is activated in response to the sensing of a ground
fault by, for
example, the sense circuitry shown in FIG. 53. FIG. 53 shows
conventional circuitry for detecting ground faults that includes a
differential transformer
that senses current imbalances.
The reset portion includes reset button 330, the movable latching members 1100
connected to the reset button 330, latching fingers 1102 and reset contacts
1104 and 1106
CA 02425810 2005-12-28
42
that temporarily activate the circuit interrupting portion when the reset
button is depressed,
when in the tripped position. Preferably, the reset contacts 1104 and 1106 are
normally
open momentary contacts. The latching fingers 1102 are used to engage side R
of each
contact arm 350,370 and move the arms 350,370 back to the stressed position
where
contacts 352,362 touch contacts 356,366, respectively, and where contacts
372,382 touch
contacts 376,386, respectively.
The movable latching members 1102 are, in this embodiment, common to each
portion (i.e., the circuit interrupting, reset and reset lockout portions) and
used to facilitate
making, breaking or locking out of electrical continuity of one or more of the
conductive
paths. However, the circuit interrupting devices according to the present
application also
contemplate embodiments where there is no common mechanism or member between
each
portion or between certain portions. Further, the present application also
contemplates
using circuit interrupting devices that have circuit interrupting, reset and
reset lockout
portions to facilitate making, breaking or locking out of the electrical
continuity of one or
both of the phase or neutral conductive paths.
In the embodiment shown in FIG. 43 and 44, the reset lockout portion includes
latching fingers 1102 which after the device is tripped, engages side L of the
movable arms
330,370 so as to block the movable arms 350,370 from moving. By blocking
movement of
the movable arms 350,370, contacts 352 and 356, contacts 362 and 366, contacts
372 and
376 and contacts 382 and 386 are prevented from touching. Alternatively, only
one of the
movable arms 350 or 370 may be blocked so that their respective contacts are
prevented
from touching. Further, in this embodiment, latching fingers 1102 act as an
active
inhibitor that prevents the contacts from touching. Alternatively, the natural
bias of
movable arms 350 and 370 can be used as a passive inhibitor that prevents the
contacts
from touching.
Referring now to FIGS. 43 and 48-52, the mechanical components of the circuit
interrupting and reset portions in various stages of operation are shown. For
this part of
the description, the operation will be described only for the phase conductive
path, but the
operation is similar for the neutral conductive path, if it is desired to open
and close both
conductive paths. In FIG. 43, the GFCI receptacle is shown in a set position
where
CA 02425810 2005-12-28
43
movable contact arm 350 is in a stressed condition so that movable contact 52
is in
electrical engagement with fixed contact 356 of contact arm 354. If the
sensing circuitry of
the GFCI receptacle senses a ground fault, the coil assembly 390 is energized
to draw
plunger 392 into the coil assembly 390 so that banger 394 moves upwardly. As
the banger
moves upwardly, the banger front dog 398 strikes the latch member 1100 causing
it to
pivot in a counterclockwise direction C (seen in FIG. 48) about the joint
created by the top
edge 1112 and inner surface 1114 of finger 1110. The movement of the latch
member
1100 removes the latching finger 1102 from engagement with side R of the
remote end
1116 of the movable contact arm 350, and permits the contact arm 350 to return
to its pre-
stressed condition opening contacts 352 and 356, seen in FIG. 48.
After tripping, the coil assembly 390 is de-energized so that spring 393
returns
plunger 392 to its original extended position and banger 394 moves to its
original position
releasing latch member 1100. At this time, the latch member 1100 is in a
lockout position
where latch finger 1102 inhibits movable contact 352 from engaging fixed
contact 356, as
seen in FIG. 51. As noted, one or both latching fingers 1102 can act as an
active inhibitor
that prevents the contacts from touching. Alternatively, the natural bias of
movable arms
350 and 370 can be used as a passive inhibitor that prevents the contacts from
touching.
To reset the GFCI receptacle so that contacts 352 and 356 are closed and
continuity
in the phase conductive path is reestablished, the reset button 330 is
depressed sufficiently
to overcome the bias force of return spring 1120 and move the latch member
1100 in the
direction of arrow A, seen in FIG. 49. While the reset button 330 is being
depressed, latch
forger 1102 contacts side L of the movable contact arm 350 and continued
depression of the
reset button 330 forces the latch member to overcome the stress force exerted
by the arm
350 causing the reset contact 1104 on the arm 350 to close on reset contact
1106. Closing
the reset contacts activates the operation of the circuit interrupter by, for
example
simulating a fault, so that plunger 392 moves the banger 394 upwardly striking
the hatch
member 1100 which pivots the latch finger 1102, while the latch member 1100
continues to
move in the direction of arrow A. As a result, the latch finger 1102 is lifted
over side L of
the remote end 1116 of the movable contact arm 350 onto side R of the remote
end of the
movable contact arm, as seen in FIGS. 48 and 52. Contact arm 350 returns to
its
CA 02425810 2005-12-28
44
unstressed position, opening contacts 352 and 356 and contacts 362 and 366, so
as to
terminate the activation of the circuit interrupting portion, thereby de-
energizing the coil
assembly 390.
After the circuit interrupter operation is activated, the coil assembly 390 is
de-
S energized so that so that plunger 392 returns to its original extended
position, and banger
394 releases the latch member 1100 so that the latch finger 1102 is in a reset
position, seen
din FIG. 50. Release of the reset button causes the latching member 1100 and
movable
contact arm 350 to move in the direction of arrow B (seen in FIG. SO) until
contact 352
electrically engages contact 356, as seen in FIG. 43.
As noted above, if opening and closing of electrical continuity in the neutral
conductive path is desired, the above description for the phase conductive
path is also
applicable to the neutral conductive path.
In an alternative embodiment, the circuit interrupting devices may also
include a
trip portion that operates independently of the circuit interrupting portion
so that in the
event the circuit interrupting portion becomes non-operational the device can
still be
tripped. Preferably, the trip portion is manually activated and uses
mechanical components
to break one or more conductive paths. However, the trip portion may use
electrical
circuitry and/or electro-mechanical components to break either the phase or
neutral
conductive path or both paths.
For the purposes of the present application, the structure or mechanisms for
this
embodiment are also incorporated into a GFCI receptacle, seen in FIGS. 54-61,
suitable for
installation in a single-gang junction box in a home. However, the mechanisms
according
to the present application can be included in any of the various devices in
the family of
resettable circuit interrupting devices.
Turning now to FIG. 54, the GFCI receptacle 1200 according to this embodiment
is
similar to the GFCI receptacle described in FIGS. 42-53. Similar to FIG. 42,
the GFCI
receptacle 200 has a housing 12 consisting of a relatively central body 314 to
which a face
or cover portion 316 and a rear portion 318 are, preferably, removably
secured.
A trip actuator 1202, preferably a button, which is part of the trip portion
to be
described in more detail below, extends through opening 328 in the face
portion 316 of the
CA 02425810 2005-12-28
housing 312. The trip actuator is used, in this exemplary embodiment, to
mechanically trip
the GFCI receptacle, i.e., break electrical continuity in one or more of the
conductive
paths, independent of the operation of the circuit interrupting portion.
A reset actuator 330, preferably a button, which is part of the reset portion,
extends
5 through opening 332 in the face portion 316 of the housing 312. The reset
button is used
to activate the reset operation, which re-establishes electrical continuity in
the open
conductive paths, i.e., resets the device, if the circuit interrupting portion
is operational.
As in the above embodiment, electrical connections to existing household
electrical
wiring are made via binding screws 334 and 336, where screw 334 is an input
(or line)
10 phase connection, and screw 336 is an output (or load) phase connection. It
should be
noted that two additional binding screws 338 and 340 (seen in FIG. 44) are
located on the
opposite side of the receptacle 1200. These additional binding screws provide
line and load
neutral connections, respectively. A more detailed description of a GFCI
receptacle is
provided in U.S. Patent 4,595,894, which is incorporated herein in its
entirety by
15 reference.
Referring to FIGS. 45-47, 55 and 58, the conductive paths in this embodiment
are
substantially the same as those described above. The conductive path between
the line
phase connection 334 and the load phase connection 336 includes, contact arm
350 which is
movable between stressed and unstressed positions, movable contact 352 mounted
to the
20 contact arm 350, contact arm 354 secured to or monolithically formed into
the load phase
connection 336 and fixed contact 356 mounted to the contact arm 354 (seen in
FIGS. 45,
46 and 58). The user accessible load phase connection for this embodiment
includes
terminal assembly 358 having two binding terminals 360 which are capable of
engaging a
prong of a male plug inserted therebetween. The conductive path between the
line phase
25 connection 334 and the user accessible load phase connection includes,
contact arm 350,
movable contact 362 mounted to contact arm 350, contact arm 364 secured to or
monolithically formed into terminal assembly 358, and fixed contact 366
mounted to
contact arm 364. These conductive paths are collectively called the phase
conductive path.
Similarly, the conductive path between the line neutral connection 338 and the
load
30 neutral connection 340 includes, contact arm 370 which is movable between
stressed and
CA 02425810 2005-12-28
46
unstressed positions, movable contact 372 mounted to contact arm 370, contact
arm 374
secured to or monolithically formed into load neutral connection 340, and
fixed contact 376
mounted to the contact arm 374 (seen in FIGS. 45, 47 and 58). The user
accessible load
neutral connection for this embodiment includes terminal assembly 378 having
two binding
terminals 380 which are capable of engaging a prong of a male plug inserted
therebetween.
The conductive path between the line neutral connection 338 and the user
accessible load
neutral connection includes, contact arm 370, movable contact 382 mounted to
the contact
arm 370, contact arm 384 secured to or monolithically formed into terminal
assembly 378,
and fixed contact 386 mounted to contact arm 384. These conductive paths are
collectively
called the neutral conductive path.
There is also shown in FIG. 55, mechanical components used during circuit
interrupting and reset operations according to this embodiment of the present
application.
Although these components shown in the drawings are electro-mechanical in
nature, the
present application also contemplates using semiconductor type circuit
interrupting and
reset components, as well as other mechanisms capable of making and breaking
electrical
continuity.
The circuit interrupting device according to this embodiment incorporates an
independent trip portion into the circuit interrupting device of FIGS. 42-53.
Therefore, a
description of the circuit interrupting, reset and reset lockout portions are
omitted.
Referring to FIGS. 55-57 an exemplary embodiment of the trip portion according
to
the present application includes a trip actuator 1202, preferably a button,
that is movable
between a set position, where contacts 352 and 356 are permitted to close or
make contact,
as seen in FIG. 55, and a trip position where contacts 352 and 356 are caused
to open, as
seen in FIG. 56. Spring 1204 normally biases trip actuator 1202 toward the set
position.
2S The trip portion also includes a trip arm 1206 that extends from the trip
actuator 1202 so
that a surface 1208 of the trip arm 1206 moves into contact with the movable
latching
member 1100, when the trip button is moved toward the trip position. When the
trip
actuator 1202 is in the set position, surface 1208 of trip arm 1202 can be in
contact with or
close proximity to the movable latching member 1100, as seen in FIG. 55. Of
course the
trip button may be labeled as a standard test button.
CA 02425810 2005-12-28
47
In operation, upon depression of the trip actuator 1202, the trip actuator
pivots
about point T of pivot arm 1210 (seen in FIG. 56) extending from strap 324 so
that the
surface 1208 of the trip arm 1206 can contact the movable latching member
1100. As the
trip actuator 1202 is moved toward the trip position, trip arm 120b also
enters the path of
movement of the finger 1110 associated with reset button 330 thus blocking the
finger 1102
from further movement in the direction of arrow A (seen in FIG. 56). By
blocking the
movement of the finger 1110, the trip arm 1206 inhibits the activation of the
reset
operation and, thus, inhibits simultaneous activation of the trip and reset
operations.
Further depression of the trip actuator 1202 causes the movable latching
member 1100 to
pivot about point T in the direction of arrow C (seen in FIG. 56). Pivotal
movement of the
latching member 1100 causes latching finger 1102 of latching arm 1100 to move
out of
contact with the movable contact arm 350 so that the arm 350 returns to its
unstressed
condition, and the conductive path is broken. Resetting of the device is
achieved as
described above. An exemplary embodiment of the circuitry used to sense faults
and reset
the conductive paths, is shown in FIG. 59.
As noted above, if opening and closing of electrical continuity in the neutral
conductive path is desired, the above description for the phase conductive
path is also
applicable to the neutral conductive path.
An alternative embodiment of the trip portion will be described with reference
to
FIGS. 60 and 61, In this embodiment, the trip portion includes a trip actuator
1202 that at
is movable between a set position, where contacts 352 and 356 are permitted to
close or
make contact, as seen in FIG. 60, and a trip position where contacts 352 and
356 are
caused to open, as seen in FIG. 61. Spring 1220 normally biases trip actuator
1202 toward
the set position. The trip portion also includes a trip arm 1224 that extends
from the trip
actuator 1202 so that a distal end 1226 of the trip arm is in movable contact
with the
movable latching member 1100. As noted above, the movable latching member 1100
is, in
this embodiment, common to the trip, circuit interrupting, reset and reset
lockout portions
and is used to make, break or lockout the electrical connections in the phase
and/or neutral
conductive paths.
CA 02425810 2005-12-28
48
In this embodiment, the movable latching member 1100 includes a ramped portion
1100a which facilitates opening and closing of electrical contacts 352 and 356
when the trip
actuator 1202 is moved between the set and trip positions, respectively. To
illustrate,
when the trip actuator 1202 is in the set position, distal end 1226 of trip
arm 1224 contacts
the upper side of the ramped portion 1100a, seen in FIG. 60. When the trip
actuator 1202
is depressed, the distal end 1226 of the trip arm 1224 moves along the ramp
and pivots the
latching member 360 about point P in the direction of arrow C causing latching
finger 1102
of the latching member 1100 to move out of contact with the movable contact
arm 350 so
that the arm 350 returns to its unstressed condition, and the conductive path
is broken.
Resetting of the device is achieved as described above.
The circuit interrupting device according to the present application can be
used in
electrical systems, shown in the exemplary block diagram of FIG. 62. The
system 1240
includes a source of power 1242, such as ac power in a home, at least one
circuit
interrupting device, e.g., circuit interrupting device 310 or 1200,
electrically connected to
the power source, and one or more loads 1244 connected to the circuit
interrupting device.
As an example of one such system, ac power supplied to single gang junction
box in a
home may be connected to a GFCI receptacle having one of the above described
reverse
wiring fault protection, independent trip or reset lockout features, or any
combination of
these features may be combined into the circuit interrupting device. Household
appliances
that~are then plugged into the receptacle become the load or loads of the
system.
A circuit interrupting device having a reset lockout device and a separate
user load
break point may be desirable.
Referring to FIGS. 63a-b, a prior art circuit interrupting device, GFCI 1300
is
shown. Predetermined condition sensor 310 will open switch devices 1312, 1314
in order
to isolate the line Phase 1302 and Neutral 1306 from the Load, 1304 and 1308
respectively. As can be appreciated, when the device is reverse wired as shown
in FIG.
63b, the user load, receptacle 1320 is not protected by the sensor 1310.
Referring to FIGS. 64a-b, portions of a circuit interrupting device according
to
another embodiment of the present invention is shown (GFCI 1400). The device
is
properly wired in FIG. 64a and reverse wired in FIG. 64b. Predetermined
condition
CA 02425810 2005-12-28
49
sensor 1410 will open switch devices 1412,1414 in order to isolate the line
Phase 1402 and
Neutral 1406 from the Load, 1404 and 1408 respectively. As can be appreciated,
when the
device is reverse wired as shown in FIG. 64b, the user load, receptacle 1420
is protected
by the sensor 1410 when the switch devices are tripped. As can be appreciated,
if the
device does not include a reset lock out, it may be reset, even though it is
reverse wired.
As shown in FIG. 46 also, a two contact switch 1414 may be utilized to
separately break
the line connection 1402, 1406 from the load side 1404, 1408 and a user load
1420. Such
a configuration can be considered to be a bridge circuit, as shown in FIG.
65a, the
configuration may include conductors crossing over in a bridge configuration.
As shown in FIGS. 42-53 and the corresponding detailed description above, a
mechanical reset lock out device is provided.
As can be appreciated, multiple failure modes are anticipated for circuit
interrupters
and they may also be designed to protect against various faults. For instance,
GFCIs
generally protect against ground current imbalances. They generally protect
against
grounded neutrals by using two sensing transformers in order to trip the
device when a
grounded neutral fault occurs. As can be appreciated, a GFCI may protect
against open
neutrals. Such protection may be provided in corded GFCIs because the wires
are flexed,
whereas the receptacle GFCI is a fixed installation. Accordingly, as can be
appreciated, an
open neutral can be protected against by utilizing a constant duty relay
solenoid switch
powered across the phase and neutral of the line, for example; across 338 and
334 of FIG.
59. In such an instance, if power went out by the neutral opening, the
constant duty coil
would fire and open the phase and neutral line conductors.
The GFCI of an embodiment of the present invention also protects against
reverse
wiring.
Referring to FIGS. 65a-b, portions of a circuit interrupting device according
to
another embodiment of the present invention is shown (GFCI 1401). The device
is
properly wired in FIG. 65a and reverse wired in FIG. 65b. Predetermined
condition
sensor 1410 will open switch devices 1412, 1414 in order to isolate the line
Phase 1402
and Neutral 1406 from the Load, 1404 and 1408 respectively. As can be
appreciated,'
when the device is reverse wired as shown in FIG. 65b, the user load,
receptacle 1420 is
CA 02425810 2005-12-28
protected by the sensor 1410 when the switch devices are tripped. As can be
appreciated,
if the device does include a reset lock out, it may not be reset, even though
it is reverse
wired. The reset lock out will test the device be moving contact 1414 to 1422
along A-B
such that a circuit through current limiting resistor 1424 is established and
picked up be
5 sensor 1410, preferably a toroid coil. Because a two contact switch 1414 is
utilized to
separately break the line connection 1402, 1406 from the load side 1404, 1408
and a user
load 1420, when reverse wired as in FIG. 65b, the reset lockout test across
resistor 1424
will not work because the power from the line is isolated by switch 1414.
Referring to FIGS. 65a-b, circuit interrupting devices 1403, 1405 according to
other
10 embodiments of the invention may utilize a bridge circuit in varying
configurations. For
example, device 1403 preferably utilized two single pole, single throw
mechanical switches
1430, 1432 to isolate a line. Other switch devices including semiconductor
switches may
be used. Furthermore, device 1405 utilizes a ganged double pole, single throw
switch with
one end tied together 1444.
15 Referring to FIG. 67, a circuit interrupting device 1407 according to
another
embodiment of the present invention preferably includes an indicator for
providing an
indication of a reverse wiring condition. As can be appreciated, the device
1407 with a
circuit bridge and reset lock out may have a user load 1420 protected and open
from the
source of power. The user load may be a receptacle 1420. However, it may be
desirable
20 to provide an indication of a reverse wiring condition even if the device
is tripped and
"safe." Such an indication may relieve user frustration in ascertaining a
problem.
Accordingly, this embodiment utilizes switches 1452 and 1454 that operate to
connect
indicator 1450 to the side of the circuit interrupter that normally has the
load (1404 and
1408). Switches 1452 and 1454 are preferably mechanical switches ganged with
switches
25 1412 and 1414 respectively. However, other switch devices such as
semiconductor
switches may be used. If device 1407 is reverse wired as shown and the device
is tripped,
switches 1452 and 1454 will signal indicator 1450 to activate. The switches
preferably
switch power to the indicator that is preferably includes a neon lamp.
However, other
indicators such as audio, visual or communication indicators may be used.
Similarly, the .
30 indicator 1450 may be powered from a source other than the source of power
to the circuit
\. __._ _.
CA 02425810 2005-12-28
51
interrupting device and may be battery powered and may receive only an
activate signal
from switches 1452 and 1454.
In embodiments of the present invention utilizing a mechanical lock out
mechanism,
the device may be manufactured such that the circuit interrupter is provided
to a user in a
reset lock out state.
Referring to FIG. 69a, a method of preparing a circuit interrupting device is
provided 1500. As shown, a circuit interrupting device may be manufactured
1510 such
that the circuit interrupting device is manufactured in a reset lock out state
1520. The
device manufacture is completed 1522. Optionally, the reset button is tested
when the
device is not powered to ensure that reset is not possible 1524. Thereafter
the device 1400
may be placed in the stream of commerce 1526.
Referring to FIG. 69b, a method of preparing a circuit interrupting device is
provided 500. As shown, a circuit interrupting device may be manufactured 510
such that
the circuit interrupting device is manufactured in a reset lock out state 520.
The device
manufacture is completed 522. Optionally, the reset button is tested when the
device is not
powered to ensure that reset is not possible 524. Thereafter the device 400
may be placed
in the stream of commerce 526.
Referring to FIGS. 68 and 69c, a method of preparing a circuit interrupting
device
is provided. A lock out set apparatus such as a test mock up in order to
achieve a lock out
state may be used before the circuit interrupting device is delivered into the
stream of
commerce. For example, a GFCI circuit interrupter that has a test mechanism, a
reset lock
out mechanism and a bridge reverse wiring user load protection mechanism as
described
above may be manufactured and connected to a power source. The test mechanism
may be
initiated in order to set the reset lock out mechanism to the lock out state.
The GFCI
circuit interrupter is then delivered into the stream of commerce in the reset
lock out state.
As can be appreciated, quality assurance steps may be performed and the
manufacture in a
tripped state may be part of a quality assurance task. As shown, a circuit
interrupting
device such as GFCI 1400 may be connected to a test power supply 1490 in order
to preset
the device into a reset lock out state before shipping it to users. A method
of ensuring the
device is shipped in the reset lock out state is described 1540. During
manufacture 1541 of
CA 02425810 2005-12-28
52
the device 1400, a test button is provided 1542. After manufacture, a power
source 1490
is connected to the device 1544. The trip test is activated to trip the
device, thereby setting
a reset lock out state 1546. Thereafter the device 1400 may be placed in the
stream of
commerce 1548. For example, a quality assurance task may be done with or about
1544.
S Referring to FIGS. 42 and 70, a trip force device 1610 is provided. As
shown, the
device has a body 1638 capable of exerting force on a trip force protrusion
1640 when the
trip force device is inserted into a receptacle of a circuit interrupting
device 310. As can
be appreciated, prongs 1631, 1632, 1633 and, 1634 may be inserted into a
circuit
interrupting device 310 such that protrusion 1640 will depress test button
326.
Accordingly, the device 310 will be set to trip when installed. The device 310
may be
fitted with such a trip force device 1610 before it is placed into the stream
of commerce.
An embodiment that may be described with reference to FIG. 42, is a circuit
interrupting device having a face or cover portion 316 and a test button 326.
A removable
test force tab (not shown) may be attached or molded into cover 316. When a
user
1S installed the circuit interrupting device 310, the device would be tripped
and a reset lock
out state thereby necessarily set. Thereafter, the removable test force tab
may be removed
and the device will only reset if the circuit interrupter is operational, an
open neutral
condition does not exist and the device is not reverse wired.
As can be appreciated, if a reset lock out device utilizes electronic means
such as
nonvolatile memory to store a state condition variable, such device may be
manufactured in
the reset lock out state or initialized to such a state before delivery.
As noted, although the components used during circuit interrupting and device
reset
operations are electro-mechanical in nature, the present application also
contemplates using
electrical components, such as solid state switches and supporting circuitry,
as well as
2S other types of components capable or making and breaking electrical
continuity in the
conductive path.
With reference to FIGS. 71, 72a and 72b, another embodiment of the present
invention is described. The GFCI 2300 of this embodiment is similar to the
device of
FIGS. 42-S3 and only the differences are explained. With reference to FIG. 71,
GFCI
2300 has a reset button 2330, reset latch 2300 and a lockout arm 2305. A test
switch 2306
CA 02425810 2005-12-28
53
that is not in the same location as the previously described device will
connect R4 in to the
test circuit when banger 2396 pivots about pivot point 2302.
With reference to FIGS. 72a and 72b, operation of the reset lockout is
described.
When the GFCI 2301 is in the tripped state (off), the reset button 2330 is in
its uppermost
S position. When a user begins to depress the reset button 2330, the reset
latch 2300 will
begin downward and lockout arm will force the banger 2396 down until it closes
switch
2306. If the test passes and the solenoid fires, the banger will pass lockout
arm 2305 and
allow the device to reset. Otherwise, the lockout arm 2305 will prevent the
reset of the
device 2301.
Referring to FIGS. 73, 74a, 74b, 75a, 75b, 76a and 76b another embodiment of a
GFCI according to the present application is described. Referring to FIG. 73,
the GFCI
400 has a reset button 2430 with rest button legs 2405. The banger 2496 has
ribs 2497 and
a reset lockout wire 2430 having an end 2431 attached to the banger 2496.
Referring to
FIGS 74a and b, a reset lockout groove is created in the bottom of the housing
2440. The
banger ribs 2497 perform a lockout function because wire 2430 prevents the
banger 2496
from retracting all the way when the wire is in position B, the lockout
position. Thus the
ribs prevent the reset button from being depressed.
The operation is as follows. When going to the trip state, the banger 2496
moves,
and wire 2430 causes wire tip 2431 to travel in the groove 2442 in a path from
point A to
B and eventually to C where it comes to a lockout state. In this position,
banger 2496 is
initially up and ribs 2497 block reset button 2430 from resetting the device
2400. To
unlock the device, an electrical test is performed, preferably by the user
pressing the test
button (not shown). The solenoid (not shown) fires and housing portion 2445
causes the
wire tip 2431 to travel from position C through the groove 2422 to position D
and
eventually E, where the device can be reset because banger ribs 2497 are no
longer
interfering with reset button legs 2405. Accordingly, the device 2400 is reset
and may
supply power. Accordingly, the wire 2430 is added to the banger 2496. The
housing
mould may be configured with portions 2440, 2460, 2445, 2443 and 2450. As can
be
appreciated from FIG. 74a, housing portion 2450 assures that the wire tip 2431
first takes
the path to the left. A ramp 2443 may provide a one-way lock in the groove
2442 such
CA 02425810 2005-12-28
54
that the wire tip passes over ramp 2443 near position B and will not retrace
its path but go
to position C. A notch on housing portion 2445 may ensure that when the
solenoid (not
shown) fires, the wire tip 2431 will travel from position C to D and
eventually E.
Accordingly, a "detent" or "catch and latch" action, similar to that of a push
button pen is
employed. Once the solenoid (not shown) fires, the banger 2496 would be locked
into a
forward position. Two ribs 2497 added to the end of the banger 2496 act as
stops,
preventing the reset button from being able to move to a downward position,
thus locking
out the reset button as shown in FIGS. 75a-b. In order to reset the device
2400, the
solenoid would have to fire, unlocking the banger 2496 from its forward
position. When
the banger 2496 returns to its backward position, the reset button is free to
move down.
As can be appreciated, to reset the device 2400 of the present embodiment, the
test button
must be pressed first. If the device test succeeds (solenoid fires), the
device will be able to
reset.
As noted, although the components used during circuit interrupting and device
reset
operations are electro-mechanical in nature, the present application also
contemplates using
electrical components, such as solid state switches and supporting circuitry,
as well as
other types of components capable or making and breaking electrical continuity
in the
conductive path.
Another embodiment of the present invention shown in FIGS. 77-91 are described
with reference to the devices of commonly owned application Serial No.
09/379,138 filed
August 20, 1999, now issued as US 6,246,558 ~ l Only the
changes from the devices incorporated above will be described.
With reference to Figures 77-80, a first embodiment is described. When the
coil is
energized, the banger is moved to unlatch the contacts. When this occurs, the
latch rises
and catches in the latch hole preventing the spring assisted return of the
plungerlbanger
from occurring. Pressing the reset button lowers the latch, releasing the
latch hook from
the latch hole, allowing reset to occur under normal conditions. If however
the SCR has
shorted, causing overheating and ultimately coil burnout and plunger seizure,
reset is not
possible because the banger is holding the latch away from the contacts.
CA 02425810 2005-12-28
For further assurance that reset is not possible if the coil seizes while
latched, the
guide posts of the reset button, if lengthened, would be blocked from being
pressed, by the
banger as explained below.
To ensure that the coil seizes upon over-heating, the plunger can of the coil
where
5 the plunger slides can be made of or fitted with a heat-shrinkable material.
With reference to FIGS. 81-82, a second embodiment is described. It is similar
in
theory to the first embodiment. However, instead of latch/hook set-up, a
spring on the
underside of the GFCI housing can be placed in the banger guide slot in such a
way as to
catch the banger guide pin when the coil has been energized.
10 Pressing the reset button pushes the catch spring to allow the plunger-
banger to
return under normal conditions. Coil seizure will prevent reset as explained
in the first
embodiment.
Referring to Figure 83, a third embodiment is described. If the coil plunger
seizes
in the 'ready for reset' position, as it often does, pressing of the reset
button can be
15 blocked by modifying the latches as shown in Figure 83. If the banger was
seized,
pressing reset would try and move the banger to the left but could not,
causing reset
blockage:
As noted, although the components used during circuit interrupting and device
reset
operations are electro-mechanical in nature, the present application also
contemplates using
20 electrical components, such as solid state switches and supporting
circuitry, as well as
other types of components capable or making and breaking electrical continuity
in the
conductive path.
For the purpose of the next embodiment of the present invention, the structure
or
mechanisms used in the circuit interrupting devices, shown in the drawings
(FIGS. 84-91)
25 and described hereinbelow, are incorporated into a IDCI device suitable for
installation in
an appliance or an appliance power cord. However, the mechanisms according to
the
present application can be included in any of the various devices in the
family of resettable
circuit interrupting devices.
A common IDCI utilizes a single switch configured as a dual pole single throw
30 (DPST) switch. In this embodiment of the present invention, S1 comprises a
dual pole dual
CA 02425810 2005-12-28
56
throw (DPDT) center off switch. A typical IDCI may not have a test circuit. In
this
embodiment, R4 is used to create a test circuit. A typical IDCI may have a
solenoid
plunger that is not isolated from the latch. In this embodiment, latch 2070 is
isolated from
plunger 2086 by insulator 2074 and the plunger 2086 may be shortened to make
room for
S the insulator. A typical IDCI may not have a test feature, as described
below, this
embodiment uses additional contacts and arms to provide a line powered test of
the device
without power being applied to the load.
Turning now to FIG. 84, a representative IDCI 1 is shown configured with an
IDCI
attached at the end of an appliance power cord 2002. A source of power may be
connected
to line side prongs 2030, 2035. The IDCI of this embodiment has two user
interfaces, a
reset button 2020 and independent trip lever 2040.
FIG. 85 is a schematic diagram representation of one embodiment of an IDCI
according to the present application. As can be appreciated many physical
configurations
may be utilized in accordance with the teachings of the present invention. S1
is a dual pole
dual throw center off switch used for a reset with reset lockout protection
using an
electrical test of the device. Switch S2 and R4 comprise a test circuit that
will exercise the
sense circuit and coil. Coil L1 is a solenoid coil that will trigger a trip of
the device. A
sense wire is positioned to detect immersion and connected to a sense circuit
R1, R2, C1,
D1 that will trigger SCR to fire coil L1 when a fault is detected.
With reference to FIG. 85a, an exploded view of the IDCI of the present
embodiment is shown. A top cover 2005 and bottom cover 2006 are provided with
fasteners 2008. A power cord 2002 having phase and neutral wires 2004,2003 are
provided. A strain relief 2007 is provided. A printed circuit board (PCB) 2050
is
connected to the bottom cover. A solenoid 2080 having coil 2082, plunger 2086
and
plunger bias spring 2084 is connected to the PCB 2050. A trip latch 2070 is
biased by
latch spring 2072 and mates with catch 2060. Reset button 2020 has a test
contact 2022
and is biased by spring 2068.. Test contact 2022 is connected to test wire
2024 that
attaches to test resistor R4 (not shown). Plugs 2035, 2030 have contacts 2036,
2031
respectively attached. Movable arms 2066,2062 are connected to the power cord.
Arm
_ _.
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57
2064 is attached to movable arm 2066 using fastener 2054, 2055, 2056. Clamp
2052 is
connected to catch 2060. A trip arm 2040 is pivotally connected in reset
button 2020.
With reference to FIG. 85b, reset button 2020 is shown with trip arm 2040 and
test
contact 2022.
With reference to FIG. 85c, a catch 2060 is shown. The latch 2070 is slidably
connected to the catch 2060 and the reset button 2020 may interact with the
latch 2070
inside the catch 2060.
With reference to FIG. 85d, latch 2070 is shown with latch spring 2072 and an
insulator 2074 added to insulate the plunger 2086 from the latch 2070.
Referring to FIG. 86, a top view of the IDCI is shown.
With reference to FIGS. 87, 87a, 87b, 87c, and 87d, the IDCI is shown in a
tripped
state. As shown in FIG. 87, the movable arm 2066 and the connected arm 2064
are not in
contact with contact 2037 of prong 2035 such that the line circuit is broken.
As shown in
FIG. 87b, the other movable arm 2062 is also open and not connected to contact
2063 of
prong 2030. As can be seen in FIG. 87a, the reset button 2040 is in a raised
state as
biased by spring 2068. As shown in FIGS. 87c and 87d, the latch 2070 has moved
right,
releasing reset button 2020 when it is moved from reset button catch 2026.
With reference to FIG. 88, 88a, 88b, and 88c the device is shown in a reset
locked
out state. As shown in FIG. 88, the reset button is depressed. As shown in
FIG. 89a, test
contact 2022 comes in contact with latch 2070. A test circuit is closed
through wire 2024
and resistor R4 (not shown). As can be appreciated, if the solenoid coil 2082
does not fire,
the reset button will not continue as it is blocked by the latch 2070.
As shown in FIG. 88c, depressing the reset button will move switch S1B to
connect
the line neutral to the load neutral conductors using connector 2031 and arm
2062. As
shown in FIG. 88b, the arm 2064 and its extension 2064' connect to the phase
prong 2036
without energizing movable arm 2066 that is isolated from the appliance plug
phase wire
2003. In this way, the IDCI circuit may be powered without powering the
appliance.
As can be appreciated; the line phase is connected to the test circuit, but
not
connected to the load phase during the test, as shown in FIG. 85.
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58
As shown in FIGS. 89 and 89a, if the test circuit successfully fires the
solenoid
2080, plunger 2086 will strike latch 2070 (at insulator 2074) and will move to
the right and
reset button 2020 can continue downward such that the IDCI will enter the on
state and the
reset button will be latched in the catch 2060 by the latch 2070 when it
returns to the left
under bias of spring 2072.
As shown in FIGS. 90, 90a, 90b, and 90c, the IDCI is in an on state. As shown
in
FIG. 90a, the reset button 2020 is down in the on state and is latched by
latch 2070 in
button groove 2026. As shown in FIGS. 90 and 90b, movable arm 2066 is
connected to
arm 2064 that is connected to prong 2035. As can be appreciated, the circuit
is now
complete from the line phase prong 2035 to the load phase wire 2003. This
differs from
the situation above when only the IDCI circuit was connected to the phase of
the line side.
As shown in FIG. 90c, the neutral side is also closed to complete the neutral
circuit from
the line side to the load wire 2004 using contact 2063 of prong 2030 and
movable arm
2062.
As shown with reference to FIG. 91 an independent trip is described. In this
embodiment, the independent trip is a mechanical trip. Trip arm 2040 may be
activated by
a user pressing it in the X direction. The trip arm 2040 is pivotally
connected to pivot
2029 of the reset button 2020. As shown, the trip lever bottom 49 will move in
the Y
direction, and will force latch 2070 in the Y direction such that the reset
button 2040 will
be released under bias of spring 2068 and the device will be independently
tripped without
the solenoid 2080 firing.
As noted, although the components used during circuit interrupting and device
reset
operations are electro-mechanical in nature, the present application also
contemplates using
electrical components, such as solid state switches and supporting circuitry,
as well as
other types of components capable or making and breaking electrical continuity
in the
conductive path.
An ALCI and IDCI with reset lockout and independent trip are now discussed.
Referring now to FIGS. 92b and 92d, a conventional ALCI is shown. Referring to
FIGS.
92a and 92c, an ALCI according to an embodiment of the present invention. is
shown.
Reset Lockout prevents a the ALCI from being reset if the device is not
functional (or if
CA 02425810 2005-12-28
59
the device has no power). It utilizes the same electro-mechanical system to
allow reset as
was designed to accomplish a trip if a fault were detected. The Mechanical
Trip allows a
defective or unpowered device to be tripped. A tripped device is a positive
indicator to a
lay person that the device is defective when the device can't be reset,
whereas if the device
were to remain operational, it could be mistaken to be safe.
The embodiment differs from the conventional unit as follows. The latch no
longer
has a "lead-in" taper, causing a tab that is similar to the holding latch
edge. (This causes
the latch to operate in a similar manner in the reset mode as in the trip
mode.) The "test"
switch is moved from the external location to an internal point that will
operate when a
reset is attempted by detecting the extending of the moveable are of the
switched contacts.
This arm moves as a result of the force applied to the moveable contact
assembly by the tab
created on the latch. A mechanical trip lever is added in place of the former
test switch.
The embodiment operates as follows. The mechanical Trip is operated to insure
that the test is exercised and that the device is put into a tripped state so
that if the device is
IS not functional it will not operate. With the unit powered, the reset button
is depressed.
This pushes the moveable contacts further apart causing the test contact to
close, invoking
the test cycle. If the test functioned properly, firing the solenoid released
the latch from
the lockout position, in the same manner as it would have released the latch
from the reset
position. If the test had failed the latch would not have been released from
the lockout
position and the device would be remain in the safe state. The latch, under
manual
pressure, travels to the armed side of the moveable contacts, also because the
moveable
contacts are no longer being forced apart the test switch opens ending the
test cycle. The
cycle is completed when the reset button is released closing the moveable
contacts and
powering the device.
Figures 93a-93f show a conventional IDCI and figures 93g-93h show an IDCI
according to an embodiment of the present invention incorporating a Reset
Lockout and a
Mechanical Test method.
Figure 93a is a view of a complete conventional IDCI for a hairdryer.
Figure 93b is an exploded view of latching mechanism. The plunger neck is
installed between the two arms of the moving latch when the device is fully
assembled.
CA 02425810 2005-12-28
The moving latch slides into the Contact Carriage (it is fully in the left
direction when in
the on state and momentarily pulled to the rights in the tripping operation).
The moving
latch secures the contact carriage to the reset button on the on state. The
Penny is shown
as a size reference.
5 Figure 93c is a side view of figure 93b. Red arrows show configuration when
unit
is in the On state (the Moving Latch is installed through the Contact Carriage
and the
protruding end latches onto the Reset button just below the step on the Reset
Button in this
view. The penny is shown as a size reference.
Figure 93d is a close up exploded view of the Reset button (left) and the
Contact
10 Carriage (right). The blue arrows show how the two are attached together in
the On state
by the Moving Latch.
Figure 93e is a close up picture and drawing of the Contact Carriage. The red
lines
in the photo highlight the geometry of the Contact Carriage.
Figure 93f is a conventional design of the IDCI Reset button and Figure 93g is
an
15 embodiment of the present invention (Mechanical Test Method not shown). In
the
embodiment, the step of the Reset Button will now catch the Moving Latch on
its under
side in addition to catching on its upper side. If the device is in the
Tripped state, pushing
the Reset button downward by hand would close the Test Circuit contacts and
the plunger
would pull to the right. If the solenoid is operational, the plunger would
cause the Test
20 contacts to open (preventing repeated bring of the solenoid). The Reset
button can then be
further pressed downward by hand until the stop would catch the Moving Latch
on the
underside of the Moving Latch and pull it upwards with the Contact Carriage
and put the
device online. The moving latch is pushed towards the left in this view by the
action of a
spring which allows it to be propelled to the left once it has cleared the
step of the Reset
25 button on either the top or bottom of this step. The Contact Carriage may
be slightly
modified to accommodate the new Test contacts. The Mechanical Test Method,
illustrated
in Figure 93h, calls for the addition of a vertical tab on the Moving Latch.
This additional
tab is not shown here in the interest of simplicity.
CA 02425810 2005-12-28
61
Figure 93h is an IDCI of an embodiment of the present invention. Pressing Test
button down hit moving latch which has been modified by the addition of the
vertical tab
and moves the latch to the right in the same manner as the plunger.
Figures 94a-94f illustrate the current design of the conventional IDCI and
figures
94g-94h illustrate the IDCI according to the embodiment of the present
invention
incorporating the reset lockout feature and a mechanical test method.
Figure 94a is a view of complete IDCI. Please note that the solenoid plunger
is
pushed outward during tripping operation.
Figure 94b is a front view of a conventional IDCI. Note Reset button and
contact
carriage.
Figure 94c is a close up view of reset button (shown upside-down).
Figure 94d iS the front view of the IDCI with the Reset button removed (shown
upside-down).
Figure 94e is a side view of the IDCI with the reset button removed.
Figure 94f is a three dimensional drawing of contact carriage.
Figure 94g - proposed modification to contact carriage and reset button (this
view
is a skewed isometric view).
FIG. 94h is a Drawing of the Reset Button and mechanical Test Method. Method
of Operation: If the device is in the tripped state and the Reset button is
depressed, the Test
contact on the underside of the step on the modified Reset button will make
electrical
contact with the Test contact that was added to the upper horizontal surface
on the Contact
Carriage shown in FIG. 94g. When the two Test contacts close, the Solenoid
will fire,
pushing the tower part of the Reset button to the left in this view causing
the step of the
Reset button to disengage from the Contact Carriage and the Test contacts to
open
preventing repeated firing of the solenoid. This will allow the Reset button
to be further
depressed by hand until the upper surface of the Reset button step engages
underneath the
lower horizontal surface of the Contact Carriage. When the Reset button is
released by the
end user, the Contact Carriage is pulled upward (in this view) by the action
of the Reset
Spring and the device contacts are closed, and the device is pulled on-line.
If the Solenoid
does not fire, pushing the Reset button will only push the moving contacts
further away
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62
from the fixed contacts. When Mechanical Test button is depressed, the ramp on
the
button causes the Mechanical Test Arm to rotate counterclockwise in this view
and hit the
bottom portion of the Reset button and deflect the reset button in the same
manner as the
plunger which then disengages the Reset button from the Contact Carriage and
opens the
device contacts.
Referring to figures 95a-95b, a conventional IDCI is shown and in Figure 95c,
an
IDCI according to an embodiment of the present invention is shown. Another
embodiment
(not shown) eliminates the "Auxiliary contact" and simplifies any modification
of a
conventional device as this contact will not require modification.
The embodiment consists of a means to prevent a defective IDCI (GFCI) from
being
reset causing power to be applied to a device in which the protection has
failed.
This device may accomplish the above goal by altering the Auxiliary contact
(The
contact removes power from the protection circuitry.) such that the end travel
of the reset
button when the device is in the tripped state opens this contact. This design
may allow
power to be applied to the protection circuitry when an attempt to reset the
device is
initiated (The present design open this contact with an arm on the main
contact carrier.).
The embodiment may connect the spring latch (The part that is moved by the
solenoid.) to the Line Neutral terminal. (This will be used to activate the
Test circuitry.)
The embodiment may have a Reset button that differs from the conventional unit
as
follows: a) Remove the taper on the bottom end. b) Add a contact on the bottom
and up
the edge that is opposite the notch. (When depressed, this contact is to
connect to the
spring latch.) c) Modify the resistor side of the test contact so that it the
spring of the reset
button makes contact with the reset button and this .contact.
The embodiment may modify the function of the test button from an electrical
device to a mechanical TRIP function. This may be accomplished by extending a
probe
from the button through the circuit card to the lever that is operated by the
solenoid. The
embodiment operates as folllows:
The Trip Button is depressed. Due to it being a mechanical function, the
device is tripped even if the Protection Circuitry is not functional.
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63
2 Depressing the Reset Button establishes power (if connected) to the
protection circuit and is blocked by but makes contact with the spring latch.
3 If the protection circuit is functional, the solenoid activates, admitting
the
probe of the reset button to pass through the latch, breaking the previously
established test
contact.
4 The test circuit is deactivated (by the loss of contact) and the solenoid
and
latch spring return. The Reset button is locked in the Reset position.
5 Releasing the Reset button causes the power contacts to engage, completing
the sequence.
The embodiment reset button may be changed as shown in FIG. 95b to as shown in
FIG. 95c. The main change is to remove the lead-in taper to a 90° step
so that the notch
will not engage the latch without relay/solenoid activation.
As noted, although the components used during circuit interrupting and device
reset
operations are electro-mechanical in nature, the present application also
contemplates using
electrical components, such as solid state switches and supporting circuitry,
as well as
other types of components capable or making and breaking electrical continuity
in the
conductive path.
The next embodiment of the present invention contemplates various types of
circuit
interrupting devices that are capable of breaking at least one conductive path
at both a line
side and a load side of the device. In particular, a shim that will allow
operation of an
RCD is only allowed to move into operating position if a test passes.
Turning now to FIG. 96, the relevant portions of the RCD are depicted, showing
the motion of the mechanism as from an off state to an on state through an
intermediate test
state. The invention provides a non engagement (lock-out) mechanism for
residual current
devices (RCD Breakers).
The RCD unit 3100 starts in a tripped state with the user handle 3110 in the
off
position 1. The user operated reset handle or rocker 3110 can be moved in
direction A
from an off state 1 to a test state 2. The handle 3110 will move compression
arm 3120
such that switch 3130 is closed by contact 3132 connecting with contact 3134.
Then a test
of the device. will occur using the test circuit (not shown). If the test
fails, the solenoid
CA 02425810 2005-12-28
64
3150 will not move magnet 3160 that is biased by spring 3152 and the shim 3140
will stay
in place. Accordingly, the switch 3175 will not close contacts 3170 and 3180
and the
device will not pass current and will remain in the off state. When shim 3140
stays in
place, the magnet 3160 will not allow the relay 3100 to operate. Relay 3195 is
normally
biased closed, but the magnet will hold it open.
Referring now to FIG. 97, the device is shown in the state if the test passes.
As can
be appreciated, if the test switch 3130 causes the solenoid 3150 to fire, the
magnet 3160
will be pulled against spring 3152 and the shim 3140 will move down in
direction B such
that the shim will come down between the solenoid magnet 3160 and magnet 3190
so that
the relay will work normally and the handle can progress to the on state. The
normally
closed relay 3195 will then close.
As noted, although the components used during circuit interrupting and device
reset
operations are electro-mechanical in nature, the present application also
contemplates using
electrical components, such as solid state switches and supporting circuitry,
as well as
other types of components capable or making and breaking electrical continuity
in the
conductive path.
The features of the next embodiment of the present invention can be
incorporated in
any resettable circuit interrupting device having neutral fault protection,
but for simplicity
the descriptions herein are directed to GFCI receptacles.
In one embodiment, the GFCI receptacle has a circuit interrupting portion, a
reset
portion and a reset lockout as shown in commonly owned application serial no.
TBD,
attorney docket 0267-1415CIP9(41912.015600).
In an embodiment using a mechanical independent trip test button, the present
invention utilizes a neutral fault simulation switch that allows resistor R4'
to be removed.
A new switch such as that shown in FIGS. lOla and lOlb will replace a neutral
tab such
that upon depressing the reset button, when the test is required, it will be
accomplished
using a neutral fault.
Referring to FIG. 98, a GFCI is described having an electrical test and bridge
circuit according to the present application. As can be appreciated a test
trip is
CA 02425810 2005-12-28
accomplished by pushing button 4026 that closes the test circuit through
current limiting
resistor R4 to create a simulated ground fault to trip the device.
Referring to FIG. 99 a schematic diagram of a GFCI having an independent trip
such as a mechanical trip for a test button and an electrical ground fault
simulation test for
5 reset lockout according to the present application is shown. As can be
appreciated, the
reset lockout test is accomplished by using a ground fault simulation through
current
limiting resistor R4'.
Referring to FIG. 100 a schematic diagram of a GFCI having an independent trip
such as a mechanical trip for a test button and a mechanical switch
(electrical test) for a
10 neutral fault simulation test for reset lockout according to the present
application is shown.
As can be appreciated, the schematic shown has an independent mechanical trip
for a test,
but could have an electrical ground fault simulation test. Similarly, the test
button may
also fire a neutral fault test simulation. As shown the rest lockout test is
accomplished by
switch S1 closing and completing a circuit from the line neutral 4038 to the
load neutral
15 4040. This circuit creates a feedback path that will trigger the device if
it is working
properly and the reset will be allowed. As can be appreciated, an open neutral
fault can be
protected against using a continuous duty solenoid K2 which wilt open the line
side if
power drops out such as an open neutral.
The neutral fault condition simulated is generally providing a low impedance
path
20 through the two transformers of the GFCI. As can be appreciated, a switch
similar to S1
may accomplish. a fault simulation by switching a circuit from the line phase
4034 to the
load phase 4.036.
Certain circuit interrupters do not allow convenient access to the line side.
In such
situations and others such as high current devices, a third sense line may be
used. A third
25 wire through the sense transformers to simulate a fault.
Referring to FIG. 101, an particular neutral fault simulation switch is shown
that
may be used with the GFCI devices shown above.
As noted, although the components used during circuit interrupting and device
reset
operations are electro-mechanical in nature, the present application also
contemplates using
30 electrical components, such as solid state switches and supporting
circuitry, as well as
CA 02425810 2005-12-28
66
other types of components capable or making and breaking electrical continuity
in the
conductive path.
In the next embodiment of the present invention which includes an independent
trip
portion, electrical continuity in one or more conductive paths can be broken
independently
of the operation of the circuit interrupting portion. Thus, in the event the
circuit
interrupting portion is not operating properly, the device can still be
tripped.
The features of the next embodiment can be incorporated in any resettable
circuit .
interrupting device, but for simplicity the descriptions herein are directed
to GFCI
receptacles. A circuit interrupting device having any one or more of a reset
lockout
mechanism, an independent trip mechanism or a separate user load break point
may be
desirable.
A portion of the mechanism of a prior art GFCI is shown in FIGS. 102a, 102b,
103a, 103b and 104.
The relevant portion of the operation of the prior art GFCI is summarized as
follows. When the reset button 5080 is pressed down the plunger cone forces
the latch
5060 to be pressed to the right in FIG. 103a. The latch 5060 will come into a
position
where the hole in the latch 5060 is aligned with the plunger 5078 such that
the conical tip
5078b of the plunger 5078a will pass through the hole. When the plunger goes
all the way
through the hole, the sliding latch is biased to go back to the left in FIG.
103b, such that
the shoulder of the plunger conical tip comes into contact with the latch
5060. When the
reset button is released, the plunger 5078 is biased upward and the latch 5060
is pressed
upward causing the device to reset and cause contact 5030 to connect to
contact 5070 in
FIG. 104. If the device trips and the solenoid 5050 causes the plunger 5054 to
move latch
5060 to the right, the plunger 5078 will pass upward through latch 5060 and
allow the
latch, which is biased down to break the contacts.
With reference to FIGS. 105-107, an embodiment of the present invention
includes
a reset plunger 5078' that includes a notched conical tip 5078b' that forces
latch 5060' to
act to close switch S1 when the reset plunger 5078' is depressed. When switch
S1 is
depressed, a circuit is closed from the load phase to the line neutral through
a current
limiting resistor R.
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With reference to FIG. 106, the embodiment of the present invention includes a
reset plunger 5078' that includes a notched conical tip 5078b'.
With reference to FIGS. 107a-107c, the reset lockout mechanism of the this
embodiment is described. When the reset plunger 5078' starts down in direction
A, the
latch 5060' is in its leftmost position. The notched plunger tip 5078b' will
hit the top of
latch 5060' and force it down such that switch S1 is closed to engage a test.
As shown in
FIG. 107b, in this embodiment, the test is accomplished by completing the
circuit from the
load phase to the line neutral through a current limiting resistor R. If the
circuit
interrupting device is operational and properly wired as shown by the test,
the solenoid
forces plunger 5054 to slide latch 5060' in direction B out from under the
notch in 5078b'
allowing the reset plunger 5078' to complete its journey in direction A such
that latch
5060' will move left and rest atop plunger shoulder 5078c' as shown in FIG.
107c
Thereafter, the reset plunger, when released will pull up latch 5060' under
its bias to
complete the reset of the device.
As can be appreciated, if the test fails, the latch 5060' will not move in
direction B
and the notched conical tip 5078b' of the reset plunger 5078' will keep the
plunger from
going through the hole in the latch 5060' and the device will be locked out
from the reset
function.
As can be appreciated, a bridge circuit may be implemented to provide reverse
wiring protection as described in the pending commonly owned application
referenced
above. For example, with reference to FIG. 102a of the prior art, a single
contact
5068,5070 is utilized to close a circuit to a load phase terminal 5064c and
two user load
phase terminals 5064a and 5064b through connector 5064. As can be appreciated,
terminal
5064c could be isolated from connector 5064 and arm 5024 may utilize a second
contact to
independently provide a circuit to 5064c. Similarly, the modification would be
made to
both conductive paths of the device. Furthermore an indicator such as a neon
bulb may be
utilized to indicate a reverse wiring condition.
As can also be appreciated, the device may be manufactured or initialized into
a
tripped state and distributed in the tripped state such that a user would be
required to reset
the device before using it.
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68
A portion of the mechanism of another prior art GFCI is shown in FIGS. 108a,
and
108b and is somewhat similar to the previously described prior art unit in
some details.
The relevant portion of the operation of the prior art GFCI is summarized as
follows. When the reset button 5128 is pressed down the lower cone shaped end
of the
S plunger forces a sliding spring latch to the side until the plunger can go
through and the
latch will spring back to rest on the shoulder of the sliding spring latch and
then pull the
device into a reset position.
With reference to FIGS. 109-l l 1f, another embodiment of the present
invention
includes a GFCI 201 having a rest button 5210 and trip button 5212.
With reference to FIG. 1 I0, the reset button 5210 has a bias spring S210a, a
shaft
S210b, a conical tip with step S210d and the conical tip has a shoulder S210c.
The trip
button 5212 has a bias spring S212a, and a formed wire shaft 5212b. A sliding
plate 5214
and sliding spring 5216 fit into grooves of housing 5220 that is mated to
solenoid 5218 and
solenoid plunger 5218a. Switch 5222 is mounted in the housing under the
sliding spring
1S 5216.
With reference to FIGS. l l la-f, the operation of the relevant portion of the
device
is described. FIG. l l la shows the device as in normal operation with current
allowed to
passthrough.
FIG 11 1b shows the operation when tripped. Solenoid 5218 pulls plunger S218a
and pushes sliding spring 5216 and sliding plate 5214 to the right such that
sliding spring
5216 no longer holds down reset plunger shoulder S210c and the spring bias of
spring
5210a forces plunger 5210b upward and the circuit is broken (not shown).
FIG. l l lc shows the reset lockout mechanism in use. After the tripped state,
when
the reset button 5210 is depressed, the step in conical tip 5210d presses down
on sliding
2S spring 5216 and forces switch 5222 to close. This view is prior to the
solenoid actuation.
FIG, llld shows the test being completed successfully. The switch 5222 closes
the
test circuit that causes solenoid 5218 to fire and the plunger forces sliding
spring 5216 and
sliding plate 5214 to the right, allowing the plunger to continue to travel
downward once
the plunger tip step S218d clears the hole in the sliding spring S216b.
CA 02425810 2005-12-28
69
FIG. l l 1e shows the device after the test is completed. The plunger tip
S210d
clears the hole S216b and the sliding spring releases upward and test switch
5222 opens .
ending the test cycle. The solenoid 5218 releases plunger 5218' and sliding
spring 5216
and sliding plate 5214 return to the left. The sliding spring 216 then rests
on top of the
S plunger tip shoulder 210d and the spring S210a pulls the spring up to reset
the device.
FIG. 111 f shows the independent trip mechanism of the device 5201. The
independent trip will trip the device without using the sense mechanism or the
solenoid. It
is preferably a mechanical device, but can be implemented with electronic or
electro-
mechanical components. As trip button 5212 is pressed downward, formed wire
S212b
moves downward and the sloped shape interacts with hole 5214a of sliding plate
5214 to
force the sliding plate and sliding spring to the right such that hole S216b
moves enough to
allow reset plunger 5210b to release upward and trip the device. Accordingly,
the sliding
plate 5214 is utilized to move the sliding spring 5216 into alignment. The
sliding plate
5214 may be held in place by the middle and bobbin housings. The formed wire
S212b
1S causes a cam action and moves the sliding plate 5214, causing the device to
trip.
As can be appreciated, the mechanical trip described will function to trip the
device
even if the solenoid or other parts are not functioning.
As can be appreciated from the discussion above, a bridge circuit may be
implemented to provide reverse wiring protection as described in the pending
commonly
owned application referenced above. Furthermore an indicator such as a neon
bulb may be
utilized to indicate a reverse wiring condition. As can also be appreciated,
the device may
be manufactured or initialized into a tripped state and distributed in the
tripped state such
that a user would be required to reset the device before using it.
FIG. 112 shows a representative prior art GFCI without a reset lockout
mechanism
2S or independent trip.
FIGS. 113 and 114a-114f show modifications to parts of the representative GFCI
to
facilitate a reset lockout and independent mechanical trip according to
another embodiment
of the invention.
The primary purpose of the Reset Lockout and Mechanical Trip is to lockout the
resetting of a GFCI Type device unless the device is functional, as
demonstrated by the
CA 02425810 2005-12-28
built in test, .at the time of reset. The Mechanical Trip is a part of this
test cycle by
insuring that the device is in the tripped state even if the device is
unpowered or non-
operational. The means and electronics by which this device trips upon ground
fault
conditions are not modified. These same means and electronics are now employed
as a
condition of reset. The test function is incorporated in the reset function,
therefore no
separate test is required and the test button is employed for a mechanical
reset.
As shown in FIGS. 114a-f, the reset plunger 5328 was changed from a semi cone
(to, lead into the shuttle), to a reverse taper. The diameter of the top edge
(the area that
latches the contacts closed) remains unchanged so that the holding power and
release effort
remains unchanged from the original design. The lower end has the taper
removed and the
diameter increased so that it will not pass through the shuttle unless the
shuttle is positioned
in the release position by the activation of the solenoid. The shaft notch
5328a is insulated
and the bottom 5328b is conductive.
Additionally, the contact carrier 5380 has a contact added 5382 so that when
the
plunger is in the tripped position, the plunger is connected to the phase
line, after the point
at which it passes through the sense transformer, Additionally, the shuttle
5378 is wired to
the circuit board at the point of the original test contact.
In a further embodiment, another test switch may be used. Pushing the Test
button
5326 mechanically trips the plunger by moving the shuttle in the same
direction as would
the solenoid. This is independent of power or functionality of the unit.
While the large end of the plunger is within the contact carrier, it is
connected to
the phase line. When the reset button is pressed, the plunger pushes against
the shuttle, but
does not pass through. The shuttle is the other terminal of the test contact
and contacting it
with the live plunger initiates the test cycle. If the test is successful, the
firing of the
solenoid (exactly the same as on the trip cycle) opens the port for the
plunger to pass
through to the armed position. This causes the large end of the plunger to
pass completely
through the contact carrier, removing the phase line contact from the plunger,
ending the
test cycle. Upon release of the reset button, the return spring lifts the
shuttle, raising the
contact carrier to establish output exactly as before the modification.
CA 02425810 2005-12-28
71
In order for the above design to function a momentary operation of the latch
solenoid must operate. If this operation is activated via the test circuit
their reset of the'
device also tests the device eliminating the need for the test button to
perform an electrical
trip. This leaves the test button available to be converted to a mechanical
trip mechanism.
The reset mechanism could have electrical contacts added such that the base of
the
plunger (latch) makes contact in the side wall of the guide hole located on
the contact
carrier of the device. This side wall contact would be connected using a small
gauge very
flexible conductor to the existing test contact (molded in the solenoid
housing or on the PC
board). A second connection would be required from the phase load conductor
after the
point at which it passes through the sense coils to the latch mechanism (the
part that is
acted on by the solenoid.)
The reset button is depressed. The plunger on the lower end of the reset
button is in
electrical contact with its guide hole which in run is wired to the electrical
test circuit.
When the bottom end of the plunger contacts the Latch (which is in electrical
contact with
phase line) if the device is powered and if the test circuit is functional,
the solenoid moves
the latch to the open position and the plunger passes through to the opposite
side. As the
plunger is no longer in electrical contact with the side wall of the guide,
the solenoid
releases the latch to return to its test position. Releasing the reset button
pulls the latch up
as in the original design.
A mechanical test mechanism may be fashioned by removing and discarding the
test
electrical contact clip (switch) of FIG. 112.
As shown in FIG. 114g, a tab with a hole may be added to the part of the latch
that
is operated by the solenoid in the area of the spring end 5378a. Corresponding
holes and
mechanism may be added to the test button such that depressing the test button
pushes a
lever into the hole in the latch that would cause it to move in a manner
similar to activation
of the solenoid, causing the latch plunger to release on in a normal trip
mode.
The latch (shuttle) is modified to have the "plunger operating hole" size
reduced to
prevent the plunger from being forced through when the latch is not in the
release position.
Another embodiment is described with reference to FIGS. IIS-117. FIGS. 115a-c
show a prior art GFCI 5400 in various stages of operation as described.
CA 02425810 2005-12-28
72
Referring to FIG. 115a, when the reset button 5430 is pressed down in
direction B,
a raised edge 5440 on the reset arm 5438 slides down to an angled portion 5451
of a lifter
5450 as shown in FIG. 115c (but shown during a trip). As shown in FIG. 115b
and c, the
spring 5434 on the reset arm 5438 allows it to move in direction D as it
slides past the
notch 5451 in the lifter 5450. When the raised edge 5440 of the reset arm 438
clears the
lifter 5450, the reset arm moves back in direction C to a vertical position
under the bias of
spring 5434. The shoulder of the raised edge 5440 then becomes engaged with
the bottom
of lifter 5450 because the reset arm is under bias upward of reset spring
5436. The device
is now reset as shown in FIG. 115b with contact 5458 engaging 5470 and contact
5456
engaging contact 5472. The lifter 5450 is biased down on spring 5452 on the
right side of
pivot 5454 and the reset mechanism is biased upward by spring 5436.
Accordingly, as
shown in FIG. 115c, when the solenoid 5462 fires because of a trip or test,
the reset bar
5438 is moved in the D direction by plunger 5460 until the raised edge 5440
clears the
lifter notch 5451 and the bias spring 5452 forces the circuits open by pushing
the lifter
5450 down on the right side of pivot 5454:
Another embodiment of a GFCI 5500 of the present invention is shown with
reference to FIGS. 116-117b, and in relation to FIGS. 115a-c. As shown in the
prior art
FIG. 117a, there is an angled portion of the lifter 451 that is removed as
shown in FIG.
117b to create lifter edge 5551. Accordingly, as shown in FIG. 116, the
solenoid 5562
must fire and move the reset arm 5538 past the lifter 5550 and edge 5551. If
the solenoid
does not fire, the reset arm will not be able to pass the lifter as in the
prior art device
because the angled lifter notch 5451 is removed.
Another arm 5582 is attached to the reset button which makes contact with
contact
5584 when reset button 5530 is pressed down in the B direction. The test
circuit (not
shown) is then completed using current limiting resistor R. this will fire the
solenoid 5562
and move the reset arm 5538 past the lifter 5550 allowing the device to reset.
If the
solenoid 5562 fails to fire for some reason, the device will be locked out and
a reset not
possible.
In another embodiment, an independent trip mechanism is provided as a
mechanical
trip feature based upon the test button 5510. When test button 5510 is
depressed in the B
CA 02425810 2005-12-28
73
direction, angled test bar 5516 cams angled trip bar 5580 in the D direction.
This will
push the reset bar 5538 and release the reset button to trip the device (not
shown). As can
be appreciated, FIG. 116 shows the device already tripped. Because allowing
the manual
trip would not be useful, ribs (not shown) are placed to ensure that the test
button may only
be depressed when the reset button is down and the device is powered.
Accordingly, the device 5500 may be tripped even if the solenoid 5562 is not
able
to fire.
As noted, although the components used during circuit interrupting and device
reset
operations are electro-mechanical in nature, the present application also
contemplates using
electrical components, such as solid state switches and supporting circuitry,
as well as
other types of components capable or making and breaking electrical continuity
in the
conductive path.
The next embodiment is a circuit interrupting device with improved surge
suppression. Referring to FIG. 118, the suppression and protection circuit
6010 is shown
to interface between power inputs 6012 and a ground fault circuit interrupter
(GFCI) circuit
6014 and/or related products connected to a load 6016, with the suppression
and protection
circuit 10 providing enhanced suppression of transient surges as well as
protection from
overvoltage conditions. The circuit 6010 includes a filter circuit 6018 and a
overvoltage
prevention component 6020, which are described in greater detail with
reference to FIG.
119.
FIG. I19 illustrates one example embodiment of the circuit 6010 and the GFCI
6014. The GFCI 6014 includes a metal oxide varistor (MOV) 6022 positioned
between
input power lines as the power inputs 6012, for example, an alternating
current (AC) line
connection having a phase line 6024 and a neutral line 6026. The lines 6024,
6026 are
connected through the overvoltage prevention circuit 20, which. in an example
embodiment
is a spark gap device known in the art, and through a ground neutral
transformer 6028 and
a differential or sensing transformer 6030 to the load 6016, which may include
a phase load
connection 6032 and the neutral load connection 6034, as in FIG. 119. A test
line 6036
may also be provided in a manner known in the art including, for example, a
test switch
6038 an~ resistor R4 having a 15 KSZ resistance. Optionally, a relay 6040
and/or circuit
~37045v01
CA 02425810 2005-12-28
74
breaker known in the art may be provided, as further described herein,
connecting the
differential transformer 6030 to the load lines 6032-6034.
A processor 6042 of the GFCI 6014 is connected via a plurality of pins or
connectors to the transformers 6028, 6030 in a manner known in the art, for
example,
using capacitors C3 and C6-C9, a resistor R4, and a diode D2. In the example
embodiment shown in FIG. 119, the resistor R3 has a 100 S2 resistance, and the
capacitors
C3 and C6-C9 have capacitances of .O1 ~F, 100 pF, .0033 pF, 10 pF, and 100 pF,
respectively, each having a voltage rating of 50 V, except for the capacitor
C8 having a
voltage rating of 6.3 V.
The processor 6042 may be, for example, a model LM1851 ground fault
interrupter
controller commercially available from "NATIONAL SEMICONDUCTOR"; capable of
providing ground fault protection for AC power outlets in consumer and
industrial
environments. The processor 6042 is also connected via its pins/connectors to
the MOV
6022 in a manner known in the art, for example, using capacitors CZ and C4-CS
having
capacitances of .O1 p.F, 1 pF, and .018 p,F, respectively, at 50 V; a
capacitor C10 having a
680 pF capacitance at 500 V; resistors R1 and R2 having 15 kS2 and 2 MS2
resistances,
respectively; a diode D1; a rectifier Q1 such as a silicon controlled
rectifier (SCR); and a
set of diodes D3-D6 forming a bridge circuit or configuration, as shown in
FIG. 119.
The MOV 6022 as well as the filter circuit 6018 are connected to the set of
diodes
D3-D6. In an example embodiment, the filter circuit 6018 includes an inductor
6044 and a
capacitor 46, labeled C1 in FIG. 120 and having a capacitance of, for example,
.O1 p,F at
400 V. In this example, the filter circuit 6018 functions as an LC low pass
filter for input
power applied to the MOV 6022.
The inductor 6044 may be a solenoid bobbin acting as a trip coil, such that
the
inductor 6044 also functions as an actuator to disengage the relay mechanism
6040 on the
load side. The capacitor C1 6046 maybe normally present in the GFCI product
6014 as a
by-pass capacitor. In the disclosed circuit 6010, the capacitor C1 6046 serves
as a by-pass
capacitor as well as the capacitance in the LC filter of the filter circuit
6018.
In the embodiment shown in FIG. 119, the MOV b022 clamps the voltage exposed
to the capacitor C1 6046 to be within the voltage rating of the capacitor
6046, for example,
CA 02425810 2005-12-28
400 V. In one example, transient voltage surges of 3 kV or higher are thus
clamped down
to 400 V or less. As in the prior art, the MOV 6022 itself in a GFCI product
6014 is
capable of handling transient surges and overvoltage conditions of, for
example, less than 3
kV at 3 kA such as a 100 A surge. Using the LC low pass filter 6018 in the
disclosed
5 suppression and protection circuit 6010, transient voltages exceeding, for
example, 3 kV at
3 kA and even 6 kV at 3 kA, are suppressed. Accordingly, the MOV 6022 in the
GFCI
product 6014 is capable of handing voltages exceeding a root-mean-square (RMS)
voltage
rating of the MOV 6022, permitting the MOV 6022 to survive and provide
protection from
other transient, surge, and overvoltage conditions, as described herein. Test
transients are
10 often configured with standard pulse ramp up and duration time waveforms.
In another embodiment for providing overvoltage protection, the overvoltage
prevention circuit 6020 includes the spark gap 6048 which generates arcs
across its
terminals to perform a breakover at transients exceeding a predetermined
voltage, such as 3
kV, and further provides mufti-mode surge protection and transient
suppression. When
15 breakover occurs, the resulting voltage to the transformer 6028 is
approximately 200 V. In
addition, the filter 6018 also functions to limit the current to which the MOV
22 is exposed
during an overvoltage surge condition. Accordingly, when the current in the
MOV 6022 is
thus limited, the exposure of the MOV 6022 to RMS voltages beyond the RMS
voltage
rating of the MOV 6022 does not damage the MOV 6022, and further, does not
damage
20 the rest of the GFCI circuit 6014.
In this manner, existing components are combined with other known components
to
be used as a low pass filter 6018 and to cooperate and function with a spark
gap device
6048 to significantly improve surge suppression and overvoltage protection.
Referring to FIGS. 120 and 121, embodiments of the present invention are
25 described. In FIG. 120, as in the above embodiment, an LC low pass filter
is utilized 44'.
The MOV 6022' is a variable resistance that may have an effect as voltage
changes.
Similarly a crowbar device 6048' is utilized.
In FIG. 121, as in the above embodiment, an LC low pass filter is utilized
44".
The MOV 6022" is a variable resistance that may have an effect as voltage
changes.
30 Similarly a gas tube crowbar device 6048" is utilized.
CA 02425810 2005-12-28
76
As can be appreciated, a high frequency transient can be attenuated by a
series low
pass filter. Additionally, a transient may be diverted by absorbing it in a
device capable of
absorbing energy or shunting it away from a sensate load.
Voltage clamping devices include without limitation selenium cells, Zener
diodes,
silicon carbide varistors and metal oxide varistors MOVs. An MOV has a
generally fast
response time and are commonly used for transient suppression. An MOV will
hold a line
voltage down while a disproportionately high current flows through it. Source
impedance
may be relied upon for clamping.
There is uncertainty as to the long term effects on an MOV that is exposed to
IO repeated transient surges and whether there are "aging" effects. While an
MOV may or
may not continuously degrade as it is exposed to transient voltages, reducing
the energy
level to the MOV will increase the likelihood that a transient may be
suppressed and
downstream devices protected.
MOV devices may theoretically be utilized in parallel to absorb more energy.
However such devices may have to be closely matched so that they would each be
turned
on by a transient at nearly the same time. Of course, if one MOV turned on
first, it would
absorb the full transient. Further, the use of two devices would require
greater space and
spacing. Such a configuration would also be more costly.
Accordingly a GFCI according to an embodiment of the present invention will
reduce energy delivered to the MOV.
Crowbar devices may be utilized as a transient suppressor to divert transients
and
protect against overvoltage conditions. Such a device will typically short a
transient to the
return. Crowbar device can include, without limitation, spark gaps, gas tubes
and carbon-
block protectors. Generally the gas (air for a header spark gap) must
avalanche before the
crowbar effect is initiated. Accordingly, a 0.10" space header may have too
large a gap to
provide avalanche in air at an acceptable voltage level for use as a surge
suppressor on an
AC power line. Accordingly, a more narrow spark gap may be selected.
For example, an over 3000 volt transient may break down across a spark gap and
the rest of the circuit will be exposed to an approximately 200V resulting
voltage that an
MOV may safely suppress. Similarly in an overvoltage condition of 240V, a low
pass
CA 02425810 2005-12-28
77
filter will limit the current that the MOV is exposed to allowing the MOV to
survive
beyond its rating.
Referring to FIGs. 122a-122c, various spark gap configurations are shown
having
differing spark gap widths. As can be appreciated, varying suppression effects
may be had
with the differing gaps of devices 6110, 6111 and 6112. At header pins 6114
and 6116 at
sufficiently high voltages, the air or gas in between the header pins will
become ionized
and a plasma will develop that will dissipate energy and crowbar the transient
voltage to a
lower value. As can be appreciated, the base 6118 should withstand the spark
energy. The
and or forward drop during the discharge is low such that the device can carry
current to a
return path without a relatively large power dissipation in the device.
Referring to FIGS. 122d-122e, configurations of a spark gap utilizing a device
and
related phenomena referred to as a Jacob's ladder are described 6140, 6141. As
can be
appreciated, having one or two of the header pins 6144, 6146, 6147 at an angle
produce a
varying spark gap increasing in the vertical direction that will have a
varying suppression
effect as the spark "walks" up the gap. As can be appreciated, the base 148
should
withstand the spark energy.
As can be appreciated, humidity may effect the performance of a spark gap.
Accordingly, measures to avoid humid air such as encapsulating the spark gap
may be
utilized.
Referring to FIGs. 123a-123b, various gas tube configurations are shown having
differing spark gap widths and may be used as device 6048" . As can be
appreciated,
varying suppression effects may be had with the differing gaps of devices 6150
and 6151.
At header pins 6154 and 6156 at sufficiently high voltages, the air or gas in
between the
header pins will become ionized and a plasma will develop that will dissipate
energy and
crowbar the transient voltage to a lower value. As can be appreciated, the
base 6158
should withstand the spark energy.
As can be appreciated, the gas 6152 may be contained by tube 6153. Connectors
6155 and 6157 provide connections. Other suitable materials 6152 may be
utilized in the
spark gap.
CA 02425810 2005-12-28
7$
Referring to FIGS. 124a and 124b, a hybrid protection circuit may protect the
MOV. The voltage clamp device MOV 6180 may be in parallel with a low pass
filter or
another voltage clamping device such as a Zener diode 6182 and a resistor 6184
or
inductor 6186.
Additionally, it is known in the art to provide a visual indication that a
device
equipped with surge suppression is still operating with surge suppression
capability. In an
embodiment of the present invention, a visual indicator is provided to
indicate that the
device is operating with adequate surge suppression capability. Similarly, an
alarm such as
an audio indicator may be provided to indicate that the device is no longer
operating with
adequate surge suppression capabilities.
Turning now to FIGS. 125 and 126, a complete GFCI 7030 constructed with status
indication capability is shown.
GFCI 7030 is made up of a top cover 7032, middle housing 7034 and a bottom
housing 7036 held in assembly by the deflectable tabs (not shown) on bottom
housing 7036
engaging the U- shaped members 7038 on top cover 7032. A mounting strap 7040
is
mounted between top cover 7032 and middle housing 7034 and has two apertures
7042 to
mount the GFCI 7030 to the mounting ears of a standard gang box (not shown).
Top cover
7032 has a face 7044 which contains two sets of slots each to receive a three-
bladed
grounded plug (not shown). Each set of slots is made up of a slot 7046, 7048
of a first
length and a slot 7050, 7052 of a longer length and a U-shaped slot 7054, 7056
to receive
the grounding prong of the plug. Because the slots 7050, 7052 are longer than
the slots
7046, 7048 the plug is naturally polarized and conforms to NEMA standard 5-
15R. In the
depression 7058 in top cover 7032 is placed a reset button 7060, a test button
7062 and an
indicator lamp means 7064. Indicator lamp means 7064 is a dual color lamp
which
produces a first color when a first filament is activated, a second color when
a second
filament is activated and a third color when both filaments are activated.
Bottom housing
7036 has a series of four terminal screws (only two of which are shown in the
figures).
Terminal screw 7066 is connected to the load neutral terminal as will be
described below.
A similar terminal screw 7068 is connected to the load phase terminal.
Terminal screw
7070 is connected to the line neutral terminal and a similar terminal screw
7072 is
CA 02425810 2005-12-28
79
connected to the line phase terminal as will be described below. Adjacent each
terminal
screw 7066, 7068, 7070 and 7072 are two apertures 7074 to receive the bared
ends of
electrical conductors (not shown). As will be described below, the conductor
ends extend
between a terminal contact and a wire nut which engages the conductor and
pushes it
against the terminal contact as the terminal screw is advanced. At the rear
wall of middle
housing 7034 is a grounding screw 7076 to which may fastened a ground
conductor (not
shown inserted into slot 7078.)
Turning now to FIG. 127 which shows GFCI 7030 with the top cover 7032 and the
bottom housing 7036 removed and FIGS. 128 and 129 which show details of the
mounting
strap 7040 and the load phase and neutral terminals. Mounting strap 7040 has
two
apertures 7042 as above described and a generally centrally located circular
opening 7080
to receive the reset lever and a square opening 7082 to receive the test
lever. Two clips
7084, 7086 are arranged to engage the grounding prong of inserted plugs and
are connected
to mounting strap 7040 by rivets 7088. A bent down tab 7090 has a threaded
aperture to
receive the ground screw 7076. A ground nut 7092 is pulled against tab 7090 as
ground
screw 7076 is advanced to hold the bared end of a conductor inserted in slot
7078 and
between tab 7090 and ground nut 7092.
FIG. 129 shows the load neutral terminal 7094 and the load phase terminal 96.
Each terminal 7094, 7096 has a central body portion 7098, 7100, respectively,
with male
blade grip fingers 7102, 7104 at each end. The male blades of the plug with
fit between
each pair of grip fingers 7102, 7104 to make mechanical and electrical contact
with the
male blades of the inserted plug. An interned tab 7106 on load neutral
terminal 7094
receives the main fixed neutral contact 7106 while interned tab 7110 receives
the main
fixed phase contact 7112. A depending three sided tab 7114 has a slot 7116 to
receive
therethough the threaded portion of terminal screw 7066. A similar depending
three sided
tab 7118 has a slot 7120 to receive therethrough the threaded portion of
terminal screw
7068.
In FIG. 127 the mounting strap 7040 of FIG. 129 and the terminals 7094, 7096
of
FIG. 130 are shown assembled to middle housing 7034. Also mounted to middle
housing
7034 is the printed circuit board (hereafter PCB) 7122 which contains the
various circuits
\\ny2-srv01\637045v01
CA 02425810 2005-12-28
which determine the indicator lamp means color, its blinking rate and control
the beeper.
The PCB 7122 also contains the various components of the fault detectors,
transformers
and solenoid as will be described below. Terminal screw 7070 is connected to a
tab 7124
having a slot 7126 therein to receive the threaded portion of terminal screw
7070. A
5 similar structure is present for terminal screw 7072 not visible in the
figure.
Referring now to FIG. 130 the PCB 122 assembly and the reset assembly are
shown
with the middle housing 7034 removed. The reset assembly comprises a reset
button 7060,
a reset lever 7128 and a reset spring 7130 and a latch pin to be described
below with
respect to FIGS 140 to 144. A plunger 7132 is positioned in the passageway of
a solenoid
10 coil 7134. The plunger 7132 is shown in its reset position extending
partially out of the
passageway of solenoid coil 7134. When the solenoid coil. 7134 is operated by
the circuits
on the PCB 7122 the plunger 7132 is drawn further into solenoid coil 7134. The
plunger
7132 controls the position of the latch plate to be described with reference
to FIG. 135.
The latch plate in cooperation the latch pin and reset spring 7130 move the
lifter 7136
15 upwardly against the movable contact arms 7138 to close the main movable
contacts 7140
to the main fixed contacts 7108, 7112 on the underside of interned tabs 7106,
7110,
respectively. The movable contact arms 7138 are biased away from their
associated
interned tabs 7106, 7110 and when the latch pin has been released push the
lifter 7136 and
latch plate downwardly to move the movable contacts 7140 away from their
associated
20 fixed contacts 7108, 7112. Also mounted on the PCB 122 is a neutral
transformer 7142
and a differential transformer 7144. Only the neutral transformer 7142 is
shown in FIG.
130. Both transformers and the transformer bracket assembly 7146 are shown in
FIG.
137. Neutral transformer 7142 is stacked upon differential transformer 7144
with a fiber
washer 7148 therebetween. The bracket assembly 7146 substantially surrounds
the
25 transformers 7142, 7144 except for a slot 7150 as shown in FIG. 136 and
slots into which
conductors are placed. The leads for the windings of the transformers are
brought out to
four transformer pins 7152 to which may be coupled the line and load
conductors. One of
the transformers will sense the current going to the load from the source and
the other will
sense the current from the load back to the source. Any difference in current
through these
30 transformers is an indication that there is a fault in the circuit wiring.
A device which can
CA 02425810 2005-12-28
81
measure small differences in current and supply a fault signal is an
integrated circuit
available from many sources, for example, type number LM1851 from National
Semiconductor or type number MC3426 from Motorola. This IC is located on PCB
7122.
The Iine neutral terminal 7154 and the line phase terminal 7156 have arms
7158, 7160 (see
FIG. 133) which extend through the slots in the top of transformer bracket
assembly 7146.
As shown in FIG. 131, terminal screw 7070 extends through slot 7126 of tab
7124 that is
part of line neutral terminal 7154 and into a threaded aperture in nut 7162 to
thus connect
the line neutral conductor (not shown) to the two transformers. The arms
7158,7160 act as
one turn windings for the transformers 7142 and 7144. The line phase conductor
(not
shown) is connected via terminal screw 7072 to tab 7164 which extends through
a slot 7166
in tab 7164 into the threaded aperture of a nut 7168. Tab 7162 is part of the
line phase
terminal 7156. An insulator 7168 extends between the arms 7158, 7160 to
prevent
shorting between them. The solenoid coil 7134 is connected to two bobbin pins
7170 to
permit connection to PCB 7122. FIG. 131 is similar to FIG. 130 but omits the
PCB 7122,
the reset button 7060, the reset lever 7128 and the reset spring 7130.
FIG. 7132 shows the bobbin assembly 7172 having solenoid coil 7134 connected
to
bobbin pins 7170 and containing plunger 7132 in its passageway. A chamber 7174
receives the lifter 7136 and supports the lifter 7136 when in its low
position. A cross
member 176 supports the auxiliary switch made up of auxiliary fixed contact
arm 7178
and auxiliary movable contact arm 7180. The auxiliary switch when auxiliary
fixed contact
7186 and auxiliary movable contact 7188 are engaged provides power to various
components on the PCB 7122. The auxiliary switch, when auxiliary fixed contact
7186
and auxiliary movable contact 7188 are not engaged cut-off the power to the
components
on PCB 7122 and prevent possible damage to the PCB 7122 components. For
example, if
the signal to the solenoid coil 7134 were repeatedly applied while the main
contacts are
open there is a chance to burn out the solenoid coil 7134. The auxiliary
movable contact
arm 180 is biased towards auxiliary fixed contact arm 178 and. will engage it
unless forced
to open the contacts.
FIG. 133 shows the lifter 7136 in contact with the movable contact arms 7138
and
positioned by the latch plate 7182 which in turn is controlled by the plunger
7132 and the
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82
plunger reset spring 7184. The lifter 7136 and latch plate 7182 positions are
dependent
upon the reset lever 7128 position as will be described below. The lifter 7136
also controls
the auxiliary movable contact arm 7180. When the lifter 7136 in its low
position, the
auxiliary movable contact 7188 is moved away from contact with the auxiliary
fixed
contact 7188 (not shown). A latch plate return spring (not shown) resets the
latch plate
once the plunger 7132 is reset as will be set out with respect to FIG. 7134.
In FIG. 7134 there is shown the latch plate 7182, the plunger 7132 and the
auxiliary
fixed arm 7178 with auxiliary fixed contact 7186 and the auxiliary movable arm
180 with
auxiliary movable contact 7188. Plunger reset spring 7184 is anchored on the
back edge
7200 of latch plate 7182 and the tab 7198 extending into the rectangular
opening 7196.
When the plunger 7132 is moved to the right in FIG. 134 as a result of the
activation of
solenoid coil 7134 the plunger reset spring 7184 is compressed and expands to
return the
plunger 7132 to its initial position partially out of the solenoid coil 7134
as shown in FIG.
6 when the solenoid coil 7134 is deactivated. Latch plate return spring 7190
is connected
between lifter 7136 and tab 7198 and is compressed by the movement of latch
plate 7182 to
the right in FIG. 7134 due to movement of plunger 7132 to the right as well.
When the
plunger 7132 is withdrawn, the latch plate return spring 7190 expands to
return the latch
plate 7182 to the left in FIG. 134. The arms 7192 support arms of lifter 7136.
A central
aperture 7194 is oval in shape with its longer axis extending along a central
longitudinal
axis of latch plate 182. At the center of aperture 7194, the aperture 7194 is
large enough
for a latch pin (not shown) to pass through aperture 7194 and move without
engaging the
lifter 7136. At one of the smaller ends the latch pin is held by the latch
plate 7182 and
causes the lifter 7136 to move with the latch pin as will be described below.
The auxiliary
movable arm 7180 is biased upwardly so that it brings auxiliary movable
contact 7188 into
contact with auxiliary fixed contact 7186 on auxiliary fixed arm 7178. As will
be
described below an arm of the lifter 7136 will engage the auxiliary movable
arm 7180 to
push it downwardly in FIG. 134 to separate the auxiliary movable contact 7188
from the
auxiliary ftxed contact 7186 and open the auxiliary circuit.
Turning now to FIGS 137, 138 and 139 the test button 7062 is shown and its
operation described. Test button 7062 has a top member 7204 from which extend
side
CA 02425810 2005-12-28
83
members 7206. Also extending from top member 7204 is a central lever 7208
which
contains a cam 7210. The lever 7208 extends through square opening 7082 in
mounting
strap 7040. The cam 7210, when the test button 7062 is depressed, engages a
test arm
7212 and moves its free end 7214 into contact with test pin 7216. The position
of the test
pin 7216 is shown in FIG. 130. The test pin 7216 is coupled to a small
resistor and a lead
which extends through one of the transformers 7142, 7144 to produce an
unbalance in the
power lines and cause the integrated circuit LMI851 to produce a signal to
operate the
solenoid 7134 and thus simulate a fault. The test button return spring (not
shown) returns
the test button 7062 to its initial position. FIG. 138 shows the reset
position of test button
7064 with cam 7210 not depressing test arm 7212 and the free end 7214
separated from
test pin 7216. When the test button 7062 is depressed as shown in FIG. 139,
the cam 7210
forces the free end 7214 of test arm 7212 downwardly into contact with test
pin 216 to
cause a simulated fault and operate the GFCI 7030 to determine that the GFCI
7030 is
working properly. When released test button 7062 returns to its reset position
as shown in
FIG. 138.
The reset button 7060 is shown in FIG. 140. Reset button 7060 has a top member
7218 from which depend side members 7220. Also extending from top member 7218
is a
latch lever 7222 which ends in a latch pin 7224. Latch pin 7224 is generally
pointed at its
free end 7228. The diameter of latch pin 7224 is greater than the diameter of
the latch
lever 7222 resulting in a latch shoulder 7226. A reset spring 230 surrounds
latch lever
7222 as shown in FIG. 142. FIGS 141 and 142 show the GFCI 7030 in its reset
position.
FIG. 141 is a rear view while FIG. 142 is a side elevational review. The
surrounding
structure is shown in light line to permit the switching components of GFCI
7030 to stand
out. In FIG. 142 the plunger 132 extends out of the solenoid coil 7134 and the
latch plate
7182 is drawn to the left of the figure so that a smaller end of the oval
aperture 7194
engages the latch lever 7222. The latch pin 7224 cannot be drawn through oval
aperture
7194. The leading end 7232 of latch plate 7182 rests upon the latch shoulder
7226 and
also is positioned under Lifter 7136. The reset spring 7230 urges the latch
lever 7222
upwardly causing the lifter 7136 to also move upwardly. This upward movement
causes
the movable contact arms 7138 to also move upwardly bringing movable contacts
7140 into
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84
contact with fixed contacts 7108, 7112 (see FIG. 141). The extension 7234 of
lifter 7136
moves away from its contact with auxiliary movable arm 7180 and the upwardly
braised
auxiliary movable arm 7180 causes its auxiliary movable contact 7188 to engage
auxiliary
fixed contact 7186 on auxiliary fixed arm 7178 and thus supply power to the
PCB.
In response to an internal or external fault or in response to a test
employing test
button 7062, the GFCI 7030, if working properly will go to a trip state shown
in FIGS.
143 and 144 wherein both the.main circuits and the auxiliary circuit will be
opened. The
presence of the trip condition is signaled by the circuits of the PCB. A
signal will be
supplied to the solenoid coil 7134 which draws the plunger 7132 further into
solenoid coil
134. Plunger 132 causes the latch plate 182 to move to the right in FIG. 144
and place the
central portion of oval aperture 7194 over latch pin 7224. In this position
leading end 7232
of the latch plate 7182. not longer engages the latch shoulder 7226 and the
latch lever 7222
is free to move through the oval aperture 7194. As a result there is nothing
to hold the
movable contacts 7140 on movable contact arms 7138 in contact with fixed
contacts 7108,
7112 on the fixed arms 7106, 7110, respectively. The movable contact arms
7138, biased
downwardly bear upon the lifter 7136 moving it downwardly separating contacts
7108,
7112 and 7140. The extension 7234 bears against auxiliary movable arm 7180 and
causes
its downward movement separating the auxiliary movable contact 7188 from the
auxiliary
fixed contact 7186 and opening the auxiliary circuit to supply power to the
circuits on the
PCB. The reset button 7060 pops up as a result of the action of reset spring
7230 to
indicate that the GFCI 7030 needs to be reset.
In addition to the pop-up of the reset button 7060, the GFCI has a dual color
indicator lamp means 7064 and a piezo resonator 7236 driven by an oscillator
on the PCB
(not shown) to produce an audible output. By selecting the oscillator
frequency of
3.OKHZ~20% and controlling the time of operation of the oscillator, the
audible signal
shall be active for 0.10 second and inactive for 2 seconds. FIG. 145 shows the
various
combinations of light color, light flashing speed and beeper sound which can
be produced
to show various states of the GFCI 7030. A supervisory signal that indicates
that the GFCI
7030 is working is provided for the first 25 days of the GFCI 7030 cycle. It
is
CA 02425810 2005-12-28
recommended that the GFCI 7030 be tested and reset every 30 days to ensure
that the
GFCI 7030 , is working properly.
However, for the most part this instruction is disregarded. To encourage the
testing
of the GFCI 7030 the various lights and beeper approach is employed. At the
end of 25
5 days the slow flashing green light which signaled the device as workings
changes to a faster
blink. The supervisory or slow blink is 0.10 seconds "on" and 15 seconds
"off". The
faster blink is 0.10 seconds on and 0.9 seconds off. This fast blink extends
for five days at
which time both filaments of the indicator lamp means 7064 are energized to
produce an
amber light which is blinked at the fast blink rate. If the power comes on
reset the amber
10 light will also blink at the fast rate until the supervisory condition is
reached. The time
periods are established by a counter and a clock generator on the PCB. If an
external fault
is detected the amber light is lit and the audible signal is generated. The
GFCI 7030 will
need to be reset. If the fault is in the GFCI 7030 itself, for example the
solenoid coil 7134
is burned out, then the red filament of the indicator lamp means 7064 is
activated and the
15 audible signal is generated. The GFCI 7030 will have to be replaced if the
fault is in the
GFCI 7030.
While there has been shown and described and pointed out the fundamental novel
features of the invention as applied to the preferred embodiment, as presently
contemplated
for carrying them out, it will be understood that various omissions and
substitutions and
20 changes of the form and details of the device illustrated and in its
operation may be made
by those skilled in the art, without departing from the spirit of the
invention.
