Note: Descriptions are shown in the official language in which they were submitted.
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BASE POWER FEED INTEGRAL
SURGE AND SPIKE PROTECTOR
Background of the Invention
This invention relates generally to apparatus for protecting
equipment from surges and spikes in the electrical power supply. More
particularly, the present invention relates to apparatus for protecting
equipment from surges and spikes in the electrical base power supply.
Surge protector and noise filtration devices, variously known as
voltage spike protectors or voltage surge and noise suppressors, are
well known and in widespread use. These devices include electronic
circuitry to protect sensitive electronic equipment from high energy
transient disturbances that may occur on an alternating current (AC)
power line. Conventional surge protectors and noise filters are typically
found in two types of installations.
The first type of installation is an electrical panel mount model.
An electrical panel mount surge protector is typically installed in the
main service panel connecting the panel to the external power supply.
This "whole building" surge protector isolates the entire building from
extremely large external voltage surges, such as those produced by
lightening, that are introduced over the power supply line. A whole
building surge protector does not protect the equipment within the
building from internally generated power surges and transients. In
addition, a whole building surge protector does not protect the
equipment within the building from power surges having a magnitude
which is not extremely large. Electrical panel mount surge protectors
may also be mounted in the electrical sub-panels located between the
main service panel and the electrical loads. These surge protectors are
intended to suppress power surges having a magnitude which is
somewhat less than that of the whole building surge protector.
The second type of installation is a point-of-use surge protector
which is an integral part of a local power supply. Such local power
supplies protect the devices which are plugged into the female
receptacles of the local power supply from external power surges and
transients generated outside of the building in which the device is
located and from internal power surges and transients generated inside
of the building. However, local power supplies of this type do not
provide surge protection to any device which does not receive its
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electrical power via the local power supply. The. number of devices
which may be supplied via a single local power supply is limited by the
capacity of the power supply, the number of female receptacles, and the
lengths of the power cords of the various devices. Consequently, a
typical office building generally requires a separate surge protected local
power supply for each of the work stations contained therein.
The best known surge protected local power supply is a power
supply strip which includes an electrical power cord which acts as an
extension cord, a male plug mounted on one end of the power cord, and
a receptacle box mounted on the other end of the power cord. The
receptacle box has one or more female receptacles and houses the surge
suppression circuitry. Indicating lights and a reset switch may also be
located on the receptacle box. The male electrical power plug of the
device to be protected is plugged into one of the female receptacles of
the receptacle box to provide power to the device.
Another type of surge protected local power supply may be found
in some office buildings where some of the individual circuits within the
building may have integral surge protective apparatus. In buildings
having such surge protected circuits, it is often difficult to differentiate
between the outlets which are served by the surge protected circuits
and which outlets are not served by the surge protected circuits.
Consequently, devices requiring surge protection may be accidently
plugged into non-surge protected circuits.
The surge protection capabilities of conventional local power
supplies vary greatly from brand-to-brand and from model-to-model
within the product line of any given manufacturer. For example, the
average conventional local power supply is rated at 13,000 amps, has
clamping voltages of 500 to 600 volts, and protects only one or two of
the three power lines. Lower cost "bargain" local power supplies may
have lower amperage ratings and clamping voltages and higher cost
"professional" local power supplies may have higher amperage ratings
and clamping voltages, although sometimes the "professional" local
power supplies simply have higher costs with no additional protection.
Consequently, users of such surge protected local power supplies may
not be receiving the protection that they require.
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Summary of the Invention
Briefly stated, the invention in a preferred form is a base power
feed integral surge and spike protector for use in a building having
modular office cubicles disposed therein. The surge protector comprises
a protective module including a circuit board having a plurality of
protective circuits, with each of the protective circuits having at least
one electrical terminal. Each wire of the power distribution network of
the modular office cubicles is connected electrically to one of the
terminals of the circuit board.
The circuit board of the surge protector includes a plurality of line
protective circuits, with each of the line protective circuits having a hot
terminal and a neutral terminal. The circuit board also includes a first
ground protective circuit having a system ground terminal and a second
ground protective circuit having an isolated ground terminal.
The protective module of the surge protector also includes means
for providing an alarm when any one of the protective circuits ceases to
function. The alarm may be provided by a plurality of indicating lights,
with each of the lights being associated with one of the protective
circuits, or by an audible alarm associated with all of the protective
circuits.
The surge protector may also include a conventional base power
in connector which has been adapted to provide electrical
communication between the electrical conductors of the circuit board
and the wires of the power distribution network. An inlet connector
portion of the base power in connector is hard-wired to the wires of the
building power supply system and a base power in connector portion is
inserted into the receptacle of the power distribution network to
connect the circuit board to the power distribution network.
It is an object of the invention to provide a single modular device
that will provide surge and spike protection to the power distribution
network of modular office cubicles.
It is also an object of the invention to provide a base power feed
integral surge and spike protector which has a single circuit board
design which is adaptable to all configurations of the power distribution
networks found in modular office cubicles.
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It is further an object of the invention to provide a base power
feed integral surge and spike protector which provides a visible or
audible indication when the surge suppression circuitry has ceased to
function.
Other objects and advantages of the invention will become
apparent from the drawings and specification.
Brief Description of the Drawings
The present invention may be better understood and its numerous
objects and advantages will become apparent to those skilled in the art
by reference to the accompanying drawings in which:
Figure 1 is perspective view of a first embodiment of a base
power feed integral surge and spike protector in accordance with the
invention installed on a modular office cubicle wall panel;
Figure 2 is an enlarged perspective view of the base power feed
integral surge and spike protector of Figure 1;
Figure 3 is side view of the base power feed integral surge and
spike protector of Figure 2;
Figure 4 is a schematic view of the circuit board of the base
power feed integral surge and spike protector of Figure 1, illustrating the
wiring arrangement for a SteelcaseT"" "3 + D" 8-wire modular office
cubicle wall panel;
Figure 5 is a schematic view of the circuit board of the base
power feed integral surge and spike protector of Figure 1, illustrating the
wiring arrangement for a SteelcaseTM "P-3" 5-wire modular office cubicle
wall panel;
Figure 6 is a perspective view of a second embodiment of a base
power feed integral surge and spike protector in accordance with the
invention; and
Figure 7 is a perspective view of a third embodiment of a base
power feed integral surge and spike protector in accordance with the
invention.
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Detailed Description of the Preferred Embodiment
With reference to the drawings wherein like numerals represent
like parts throughout the several figures, a base power feed integral
surge and spike protector in accordance with the present invention is
5 generally designated by the numeral 10. In many conventional office
buildings, modular office cubicles 12 formed of substantially identical
wall panels 14 are utilized to form clusters of cubicles. Typically, the
wall panels 14 of the modular office cubicles 12 include 120 volt AC
pre-wired raceways 16 which may be easily connected during the setup
of the cubicles 12 to form the distribution system 18. The raceways 16
carry three to six electrical circuits for providing power to the cubicle
cluster The base power feed integral surge and spike protector 10
includes at least one connector 20 carrying a plurality of electrical
service wires and a protector module 22 to provide power surge and
power transient protection to each of the electrical circuits of the power
distribution system 18 served by the base power feed integral surge and
spike protector 10.
With reference to Figures 1 and 2, a first embodiment of a base
power feed integral surge and spike protector 10 is an "in-line" device
that in part provides an interface between the building electrical supply
system 24 and the modular office cubicle power distribution system 18.
The in-line base power feed integral surge and spike protector 10 is
commonly used in new construction for cubicle clusters that have a
portion adjacent to a wall 26 through which the building power supply
system 24 may be routed.
The power distribution system 18 of many types of modular
office cubicles 12 utilize modular "base power in" connectors 28.
Generally, one end of such a connector 28 is hard-wired to five to
twelve electrical service wires of the building electrical supply system
24 and the other end plugs into an appropriate receptacle in a modular
office cubical 12 to connect the service wires to the panel power
distribution system 18. The in-line base power feed integral surge and
spike protector 10 includes what is essentially an elongated base power
in connector 28 comprising an inlet connector portion 30 which is hard-
wired into the electrical supply system 24 running through the building
wall 26, a "base power in" connector portion 32 which is plugged into
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a receptacle of the power distribution system 18 of the modular office
cubicles 12, and a bridge portion 34 defined by the portion of the wires
36 which extend between the inlet connector portion 30 and the base
power in connector portion 32. The wires 36 of the bridge portion 34
are disposed within the housing 38 of a protector module 22 which
provides power surge and power transient protection to each of the
electrical circuits of the power distribution system 18 served by the in
line base power feed integral surge and spike protector 10.
The housing 38 has a first opening 40 for receiving and mounting
a proximal end portion 42 of the base power connector portion 32 and
a second opening 44 for receiving and mounting a proximal end portion
46 of the inlet connector portion 30. As illustrated in Figure 2, the first
and second openings 40, 44 may be located in oppositely disposed first
and second end panels 48, 48' of the housing. Alternatively, one of the
openings may be located in an end panel of the housing and the other
of the openings may be located in a side panel of the housing, or one of
the openings may be located in an end panel of the housing and the
other of the openings may be located in a rear panel of the housing, or
both of the openings may be located in one of the end panels of the
housing, depending on the particular installation requirements.
With reference to Figures 2 and 3, the housing 38 may also have
openings 50 for receiving and mounting multiple pairs of connectors 52
for inserting a surge suppression device located within the housing 38
into the circuit of low voltage electrical signal circuits associated with
the work stations in the cubicle cluster. For example, three to six pairs
of RJ 1 1 connectors 52 may be mounted in openings 50 on a first side
54 of the housing 38 to act as input and output connectors for the
telephone circuits servicing the work stations. In addition three to six
pairs of RJ11 connectors 52 may be mounted in openings 50 in the
second side 56 of the housing 38 to act as input and output connectors
for the data circuit of a local area network servicing the work stations.
Alternatively, three to six pairs of coaxial cable connectors (not shown)
may be provided for connecting a video system servicing the work
stations. It should be appreciated that surge suppression devices
appropriate for any electrical circuit, and associated connectors for
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inserting the device into the electrical circuit, may be included in the
protector module.
If the in line base power feed integral surge and spike protector
is to be mounted within eyesight, the housing 38 will preferably
5 include one opening 58 for receiving and mounting an indicating light 60
for each of the electrical circuits which is powered through the in line
base power feed integral surge and spike protector 10. Preferably, the
openings 58 for the indicating lights 60 are located in the front panel 62
of the housing 38, as shown in Figure 2. If the in line base power feed
10 integral surge and spike protector 10 is to be mounted out of eyesight,
the housing 38 will preferably include a single opening 64 for receiving
and mounting an audible alarm 66 associated with all of the electrical
circuits which are powered through the in line base power feed integral
surge and spike protector 10. The indicating lights 60 are lit when the
line protective circuit 70 serving the associated electrical circuit is
operating properly. The indicating lights 60 go out and the audible
alarm 66 sounds if the line protective circuit 70 serving the associated
electrical circuit ceases to function.
It should be appreciated that there are many manufacturers of
modular office cubicles 12 and that there is no industry standard that
dictates the requirements for the power distribution system 18 serving
the cubicle clusters, other than the applicable safety standards.
Consequently, the requirements of the power distribution systems 18
(for example the use of system grounds versus isolated grounds or
common neutrals versus dedicated neutrals) can and do vary from
manufacturer to manufacturer. In addition, several of the larger
manufacturers of modular office cubicles 12 offer several product lines
where the requirements of the power distribution systems 18 are
different between the various product lines.
With reference to Figures 4 and 5, elements mounted to a circuit
board 68 disposed within the housing 38 provide surge protection for
each of the electrical circuits serviced by the base power feed integral
surge and spike protector 10. To accommodate the circuit
combinations which are most commonly utilized in modular office
cubicles 12, base power feed integral surge and spike protectors 10
having circuit boards 68 with three, four, five, or six line protective
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circuits 70 are provided, where there is a separate line protective circuit
70 for each of the electrical circuits of the power distribution system
18. In addition to the line protective circuits 70, each circuit board 68
includes two ground protective circuits 69, 71, as explained further
below. Each of the protective circuits 69, 70, 71 includes conventional
transient voltage, surge suppression, spike suppression, noise, and
harmonic filtration protection circuit elements. The circuit board 68
shown if Figures 4 and 5 has four line protective circuits 72, 74, 76,
78.
To minimize manufacturing costs, the base power feed integral
surge and spike protector 10 is designed such that a single circuit board
design accommodates the requirements of every electrical distribution
system found within the modular office cubicle industry. The wiring
interface 80 between the protective circuits 70 and the power
distribution system 18 provides the flexibility that is required to adapt
a single circuit board design to any specific application.
Each line protective circuit 72, 74, 76, 78 of the circuit board 68
has a "hot" terminal, H 1, H2, H3, H4 for the illustrated circuit board 68,
and a "neutral terminal", N 1, N2, N3, N4 for the illustrated circuit board
68. In addition, the circuit board 68 has two ground protective circuits
69, 71 with a single system ground terminal SG connected to the first
ground protective circuit 69 and a single isolated ground terminal IGI
connected to the second ground protective circuit 71. The system
ground terminal SG is connected via the circuit board 68 to only the first
protective circuit 72 white the isolated ground terminal IGI is connected
to all of the remaining protective circuits 74, 76, 78. Depending on
which terminals are utilized, the circuit board 68 can be adapted to
operate with any of the power distribution system 18 which may be
offered by a vendor. The appropriate terminals are connected via tap
wires 82 to the wires 36 of bridge portion 34 to connect the protective
circuits 72, 74, 76, 78 of the circuit board 68 to the power distribution
system 18.
For example, Figure 4 illustrates a circuit board 68 which is wired
to interface with a SteelcaseTM "3 + D" power distribution system 18.
The "3 + D" power distribution system 18 has eight wires 84 providing
four electrical circuits including three isolated circuits (three separate hot
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lines 86, 88, 90 color coded red, black and blue, a _shared, or common,
neutral line 92 color coded white, and a shared, or common, ground line
94 color coded green) and one dedicated circuit (separate hot line 96
color coded pink, separate neutral line 98 color coded grey, and
separate ground line 100 color coded green with a yellow stripe). To
interface the circuit board 68 with the "3 + D" power distribution system
18, the first, second, and third hot lines 86, 88, 90 (red, black and
blue) are connected via tap wires 82 to three of the "hot" terminals H 1,
H2, H3, the fourth hot line 96 (pink) for the dedicated circuit is
connected via a tap wire 82 to the fourth "hot" terminal H4, the
common neutral line 92 (white) is connected via a tap wire 82 to neutral
terminal N2, the dedicated neutral line 98 (grey) is connected via a tap
wire 82 to neutral terminal N4, the common ground line 94 (green) is
connected via a tap 82 wire to the system ground terminal SG, and the
dedicated ground line 100 (green with yellow stripe) is connected via a
tap wire 82 to the isolated ground terminal IGI.
When the circuit board 68 is connected to the power distribution
system 18 in this manner, the first line protective circuit 72 provides
surge protection to the first hot line 86, the second line protective
circuit 74 provides surge protection to the second hot line 88 and the
common neutral line 92, the third line protective circuit 76 provides
surge protection to the third hot line 90, the fourth line protective circuit
78 provides surge protection to the hot line 96 and the neutral line 98,
and the first ground protective circuits 69, 71 provide surge protection
to the common ground line 94 and the ground line 100 of the dedicated
circuit.
Figure 5 illustrates a circuit board 68 which is wired to interface
with a SteelcaseT"" "P-3" power distribution system 18'. The "P-3"
power distribution system 18' has five wires 102 providing three
isolated circuits (three separate hot lines 104, 106, 108 color coded
red, black and blue, a shared, or common, neutral line 1 10 color coded
white, and a shared, or common, ground line 1 12 color coded green).
To interface the circuit board 68 with the "P-3" electrical distribution
system, the first, second, and third hot lines 104, 106, 108 (red, black
and blue) are connected via tap wires 82 to three of the "hot" terminals
H 1, H2, H3, the common neutral line 1 10 (white) is connected via a tap
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wire 82 to neutral terminal N2, and the common ground line 1 12 (green)
is connected via a tap wire 82 to the system ground terminal SG.
When the circuit board 68 is connected to the power distribution
system 18' in this manner, the first line protective circuit 72 provides
5 surge protection to first hot line 104, the second line protective circuit
74 provides surge protection to the second hot line 106 and the
common neutral line 1 10, the third line protective circuit 76 provides
surge protection to the third hot line 108, and the ground protective
circuit 69 provides surge protection to the common ground line 1 12.
10 With reference to Figure 6, a parallel base power feed integral
surge and spike protector 10' is most commonly used to provide surge
protection to an existing cubicle cluster. The circuit board 68 of the
parallel base power feed integral surge and spike protector 10' is wired
to the base power in connector 1 14 in the manner described above with
the exception that the wires of the base power connector 1 14 are wired
directly to the terminals of the circuit board 68. The housing 1 16 has
an opening for receiving and mounting a proximal end portion 1 18 of
the base power connector 1 14. If the parallel base power feed integral
surge and spike protector 10' is to be mounted within eyesight, the
housing 116 will include one opening for receiving and mounting an
indicating light 120 for each of the electrical circuits which is served by
the base power feed integral surge and spike protector 10'. If the
parallel base power feed integral surge and spike protector 10' is to be
mounted out of eyesight, the housing 116 will preferably include a
single opening for receiving and mounting an audible alarm 122. The
housing 116 may also have openings for receiving and mounting
multiple pairs of connectors 124 for inserting a surge suppression
device located within the housing into the circuit of low voltage
electrical signal circuits associated with the work stations in the cubicle
cluster.
With reference to Figure 7, a power pole base power feed integral
surge and spike protector 10" is most commonly used to provide surge
protection in new construction for cubicle clusters receive power from
the building power supply system via a power pole. The circuit board
68 of the power pole base power feed integral surge and spike protector
10" is hard-wired to the wires of the electrical supply system 24 in the
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power pole in the manner described above. The housing 126 has an
opening for receiving and mounting an inlet 128 for receiving the wires
of the electrical supply system 24. If the power pole base power feed
integral surge and spike protector 10" is to be mounted within eyesight,
the housing will include one opening for receiving and mounting an
indicating light 130 for each of the electrical circuits which is powered
through the base power feed integral surge and spike protector. If the
power pole base power feed integral surge and spike protector 10" is
to be mounted out of eyesight, the housing 126 will preferably include
a single opening for receiving and mounting an audible alarm 132. The
housing 126 may also have openings for receiving and mounting
multiple pairs of connectors 134 for inserting a surge suppression
device located within the housing into the circuit of non-power electrical
circuits associated with the work stations in the cubicle cluster.
Although each of the circuit elements in the protective circuit 70
is of conventional design, the protective limits of the circuit elements
are significantly higher than those found in conventional protective
devices. For example, the surge current capacity for conventional
devices is generally about 13,000 amps while that of the subject
protective circuit is 33,000 amps. The higher the surge current
capacity the better the protection.
Similarly, each protective circuit 70 has a UL 1449 clamping
voltage of 330 volts while conventional devices have clamping voltages
of 500 to 600 volts. The clamping voltage establishes the point at
which the surge suppression circuit components will begin to suppress
a voltage surge. The higher the value of the clamping voltage, the
higher the level of the voltage surge which will be passed by the surge
suppression circuit. If the value of the clamping voltage is too high,
surges will be let through which may damage hardware and/or corrupt
data. The lower the value of the clamping voltage, the more often the
surge suppression circuit component will be actuated, resulting in
accelerated age-related deterioration. Surge suppression circuit
components having a low clamping voltage value must be composed of
superior grade components or be subject to premature failure, leaving
equipment vulnerable to future surges and spikes. A 330 volt clamping
provides the best protection for sensitive electronic equipment.
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Each base power feed integral surge and spike protector 10, 10',
10" protects all three lines (L-N, L-G, N-G), while conventional devices
allow surges along the ground and/or neutral line. Each base power
feed integral surge and spike protector 10, 10', 10" provides thermal
fusing for all three lines, while conventional devices generally provide
thermal fusing for only the L-G. If there is a catastrophic surge in a
circuit protected by a conventional device, the device goes into thermal
runaway and can melt or catch fire. The base power feed integral surge
and spike protector's thermal fusing and all metal housing prevent
thermal runaway and any potential damage from occurring.
It should be appreciated the use of a base power feed integral
surge and spike protector 10, 10', 10" provides many benefits beyond
simply providing superior surge and transient protection. With the base
power feed integral surge and spike protector 10, 10', 10", all
workstation outlets are protected. Consequently, users at the
workstations do not have to know which outlets are surge protected
and all possibility of plugging equipment into an unprotected outlet is
eliminated. The base power feed integral surge and spike protector's
prominent indication lights 60, 120, 130 and single location point allow
it to be easily monitored for correct operation. Using surge receptacles
and plug strips require multiple units to be monitored, many of which
may be in hard to reach places with no physical warning signs of failure.
The audible alarm 66, 122, 132 provides similar protection for power
pole and between panel skin applications. Because the base power feed
integral surge and spike protector 10, 10', 10" is integrated into the
base power of the workstations, it requires no additional labor to install
or replace. This limits downtime and lowers maintenance costs. One
base power feed integral surge and spike protector unit 10, 10', 10"
will protect up to eight workstations. To protect the same amount of
workstations would require 24-36 surge receptacles.
While preferred embodiments have been shown and described,
various modifications and substitutions may be made thereto without
departing from the spirit and scope of the invention. Accordingly, it is
to be understood that the present invention has been described by way
of illustration and not limitation.
