U.S. patent application number 09/879563 was filed with the patent office on 2001-11-01 for circuit interrupting device with reverse wiring protection.
Invention is credited to DiSalvo, Nicholas L., Ziegler, William R..
Application Number | 20010036049 09/879563 |
Document ID | / |
Family ID | 27385266 |
Filed Date | 2001-11-01 |
United States Patent
Application |
20010036049 |
Kind Code |
A1 |
DiSalvo, Nicholas L. ; et
al. |
November 1, 2001 |
Circuit interrupting device with reverse wiring protection
Abstract
Resettable circuit interrupting devices, such as GFCI devices,
that include reverse wiring protection, and optionally an
independent trip portions and/or a reset lockout portion are
provided. The reverse wiring protection operates at both the line
and load sides of the device so that in the event line side wiring
to the device is improperly connected to the load side, fault
protection for the device remains. The trip portion operates
independently of a circuit interrupting portion used to break the
electrical continuity in one or more conductive paths in the
device. The reset lockout portion prevents the reestablishing of
electrical continuity in open conductive paths if the circuit
interrupting portion is non-operational or if an open neutral
condition exists.
Inventors: |
DiSalvo, Nicholas L.;
(Levittown, NY) ; Ziegler, William R.; (East
Northport, NY) |
Correspondence
Address: |
GREENBERG TRAURIG, LLP
885 Third Avenue -- 21st Floor
New York
NY
10022
US
|
Family ID: |
27385266 |
Appl. No.: |
09/879563 |
Filed: |
June 11, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09879563 |
Jun 11, 2001 |
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09379138 |
Aug 20, 1999 |
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6246558 |
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09379138 |
Aug 20, 1999 |
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09369759 |
Aug 6, 1999 |
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6282070 |
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09369759 |
Aug 6, 1999 |
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09138955 |
Aug 24, 1998 |
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6040967 |
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Current U.S.
Class: |
361/42 |
Current CPC
Class: |
H01H 83/04 20130101;
H02H 1/0015 20130101; H02H 5/083 20130101; H01H 2083/045 20130101;
H01H 2083/201 20130101; H01H 71/62 20130101; H02H 3/338 20130101;
H02H 3/335 20130101; H01H 71/524 20130101 |
Class at
Publication: |
361/42 |
International
Class: |
H02H 003/00 |
Claims
What is claimed:
1. A reset lockout device comprising: a reset connection to a
switch for enabling a reset of the switch from a tripped position
to a normal position, wherein the switch includes a switch trip
condition sensor and a switch trip actuator for tripping the switch
from the normal position to the tripped position in response to an
indication from the switch trip condition sensor; a test connection
to the switch for enabling a test of the switch trip condition
sensor and the switch trip actuator; a reset actuator connected to
the test connection and reset connection having a rest position, a
test position for initiating the test and a reset position for
initiating the switch reset to place the switch in a normal
position; and a reset actuator lockout connected to the reset
actuator for blocking the enabling of the switch reset unless the
test succeeds.
2. The device of claim 1 further comprising: a trip connection to
the switch for tripping the switch from the normal position to the
tripped position using a second switch trip actuator; wherein the
reset actuator further comprises an initial trip position; and
wherein the reset actuator actuation sequence from a reset position
must first engage the initial trip position, then the test position
and then the reset position, wherein the reset actuator lockout
blocks the reset actuator from reaching the reset position unless
the test succeeds.
3. The device of claim 2 wherein, the switch is capable of making
and breaking an electrical circuit.
4. The device of claim 3 wherein, the switch trip condition sensor
is capable of sensing a ground fault or open neutral condition in
the electrical circuit.
5. A circuit interrupting device comprising: a housing; a phase
conductive path and a neutral conductive path each disposed at
least partially within said housing between a line side and a load
side, said phase conductive path terminating 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, and said neutral conductive
path terminating at a first connection capable of being
electrically connected to a source of electricity, a second
connection capable of providing a neutral connection to said at
least one load and a third connection capable of providing a
neutral connection to said at least one user accessible load; a
circuit interrupting portion disposed within said housing and
configured to cause electrical discontinuity in said phase and
neutral conductive paths between said line side and said load side
upon the occurrence of a predetermined condition; and a reset
portion disposed at least partially within said housing and
configured to reestablish electrical continuity in said phase and
neutral conductive paths; said circuit interrupting device further
comprising a reset lockout portion that prevents reestablishing
electrical continuity in said phase and neutral conductive paths if
said circuit interrupting portion is non-operational, if an open
neutral condition exists or if a reverse wiring condition exists,
wherein said reset portion comprises: a reset button; and at least
one reset contact which when depressed is capable of contacting at
least a portion of said phase conductive path to cause said
predetermined condition, wherein if said circuit interrupting
portion is operational, the circuit interrupting portion is
activated to disable said reset lockout portion and facilitate
reestablishing electrical continuity in said phase and neutral
conductive paths, and wherein if said circuit interrupting portion
is non-operational, said reset lockout portion remains enabled so
that reestablishing electrical continuity in said phase and neutral
conductive paths is prevented; and wherein said phase conductive
path comprises a plurality of contacts that are capable of opening
to cause said electrical discontinuity in said phase conductive
path and closing to reestablish electrical continuity in said phase
conductive path at both said line and load sides, and wherein said
neutral conductive path comprises a plurality of contacts that are
capable of opening to cause said electrical discontinuity in said
neutral conductive path and closing to reestablish electrical
continuity in said neutral conductive path, between said line and
load sides.
6. The circuit interrupting device according to claim 5, wherein
said circuit interrupting portion causes said plurality of contacts
of said phase and neutral conductive paths to open.
7. The circuit interrupting device according to claim 6, wherein
said reset portion causes said plurality of contacts of said phase
and neutral conductive paths to close.
8. The circuit interrupting device according to claim 5, wherein
said circuit interrupting portion includes an electromechanical
circuit interrupter used to cause electrical discontinuity in said
phase and neutral conductive paths, and sensing circuitry used to
sense the occurrence of said predetermined condition.
9. The circuit interrupting device according to claim 8, wherein
said electro-mechanical circuit interrupter comprises a coil
assembly, a movable plunger responsive to energizing of said coil
assembly and a banger attached to said plunger, wherein movement of
said plunger is translated to movement of said banger, and wherein
movement of said banger causes electrical discontinuity in said
phase and neutral conductive paths.
10. The circuit interrupting device according to claim 5 further
comprising a trip portion disposed at least partially within said
housing and configured to cause electrical discontinuity in said
phase and neutral conductive paths independently of said circuit
interrupting portion operation.
11. The circuit interrupting device according to claim 10, wherein
said trip portion comprises a trip actuator accessible from an
exterior of said housing and a trip arm extending from said trip
actuator, said trip arm being configured to mechanical cause
electrical discontinuity in said phase and neutral conductive
paths, if said trip actuator is actuated.
12. The circuit interrupting device according to claim 11, wherein
said trip actuator comprises a button.
13. The circuit interrupting device according to claim 5, wherein
said predetermined condition comprises a ground fault, an arc
fault, an appliance leakage fault or an immersion fault.
14. A circuit interrupting device for use with an electrical wiring
system having at least one conductor comprising: a line side
connection capable of being electrically connected to a source of
electricity for connecting to the electrical wiring system; a load
side connection capable of being electrically connected to a load
side conductor for providing electricity to load side; a user load
connection capable of conducting electricity to at least one load
for providing an electrical connection to the electrical wiring
system; a first conductive path capable of providing an electrical
connection between the line side connection and the user load
connection; a second conductive path capable of providing an
electrical connection between the line side connection and the load
side connection; a circuit interrupter configured to cause
electrical discontinuity in said first conductive path and said
second conductive path upon the occurrence of at least one
predetermined condition; a reset portion configured to reestablish
electrical continuity in said first conductive path and said second
conductive path; a reset lockout portion that prevents
reestablishing electrical continuity in said first conductive path
and said second conductive path if said circuit interrupter is
non-operational or if an open neutral condition exists; wherein
activation of said reset portion first simulates at least one of
the predetermined conditions, wherein if said circuit interrupter
is operational, the circuit interrupter causes said reset lockout
portion to be disabled to facilitate reestablishing electrical
continuity in said first and second conductive paths.
15. The device of claim 14 wherein, the reset lockout portion
prevents reestablishing electrical continuity in said first
conductive path and said second conductive path if said circuit
interrupter is non-operational, if an open neutral condition exists
or if a reverse wiring condition exists; and wherein activation of
said reset portion first simulates at least one of the
predetermined conditions, wherein if said circuit interrupter is
operational and if said circuit interrupting device is not reverse
wired to the electrical wiring system, the circuit interrupter
causes said reset lockout portion to be disabled to facilitate
reestablishing electrical continuity in said first and second
conductive paths.
16. The circuit interrupting device according to claim 14 further
comprising an independent trip portion configured to cause
electrical discontinuity in said first and second conductive paths
independently of a predetermined condition sensor of the circuit
interrupter.
17. The circuit interrupting device according to claim 14, wherein
said predetermined condition comprises a ground fault.
18. The circuit interrupting device according to claim 14, wherein
said predetermined condition comprises a ground fault or an arc
fault.
19. The circuit interrupting device according to claim 14, wherein
said predetermined condition comprises an appliance leakage
fault.
20. The circuit interrupting device according to claim 14, wherein
said predetermined condition comprises an immersion fault.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No.
09/379,138 filed Aug. 20, 1999, which is a continuation-in-part of
application Ser. No. 09/369,759 filed Aug. 6, 1999, which is a
continuation-in-part of application Ser. No. 09/138,955, filed Aug.
24, 1998, all of which are incorporated herein in their entirety by
reference.
BACKGROUND
[0002] 1. Field
[0003] The present application is directed to reset lockout devices
including resettable circuit interrupting devices and systems such
as 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.
[0004] 2. Description of the Related Art
[0005] 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 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. 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. Pat. No. 4,595,894, use an
electrically activated trip mechanism to mechanically break an
electrical connection between the line side and the load side. 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.
[0006] 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
mechanism to be reset without the ground fault protection
available.
[0007] 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.
[0008] Commonly owned application Ser. No. 09/138,955, filed Aug.
24, 1998, which is incorporated herein in its entirety by
reference, describes a family of resettable circuit interrupting
devices capable of locking out the reset portion of the device if
the circuit interrupting portion is non-operational or if an open
neutral condition exists. Commonly owned application Ser. No.
09/175,228, filed Sep. 20, 1998, which is incorporated herein in
its entirety by reference, describes a family of resettable circuit
interrupting devices capable of locking out the reset portion of
the device if the circuit interrupting portion is non-operational
or if an open neutral condition exists and capable of breaking
electrical conductive paths independent of the operation of the
circuit interrupting portion.
[0009] Some of the circuit interrupting devices described above
have a user accessible load side connection in addition to the line
and load side connections. 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 side connection are
typically electrically connected together. An example of such a
circuit interrupting device is a GFCI receptacle, where the line
and load side connections are binding screws and the user
accessible load side connection is the plug connection. 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 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.
SUMMARY
[0010] The present application relates to a family of resettable
circuit interrupting devices that maintains fault protection for
the circuit interrupting device even if the device is reverse
wired.
[0011] 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 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;
[0012] The circuit interrupting device also includes a circuit
interrupting portion that is 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.
[0013] 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.
[0014] One embodiment for the circuit interrupting portion uses an
electromechanical 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 electromechanical 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.
[0015] 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 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.
[0016] 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.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Preferred embodiments of the present application are
described herein with reference to the drawings in which similar
elements are given similar reference characters, wherein:
[0018] FIG. 1 is a perspective view of one embodiment of a ground
fault circuit interrupting device according to the present
application;
[0019] FIG. 2 is side elevational view, partly in section, of a
portion of the GFCI device shown in FIG. 1, illustrating the GFCI
device in a set or circuit making position;
[0020] FIG. 3 is an exploded view of internal components of the
circuit interrupting device of FIG. 1;
[0021] FIG. 4 is a plan view of portions of electrical conductive
paths located within the GFCI device of FIG. 1;
[0022] FIG. 5 is a partial sectional view of a portion of a
conductive path shown in FIG. 4;
[0023] FIG. 6 is a partial sectional view of a portion of a
conductive path shown in FIG. 4;
[0024] FIG. 7 is a side elevational view similar to FIG. 2,
illustrating the GFCI device in a circuit breaking or interrupting
position;
[0025] FIG. 8 is a side elevational view similar to FIG. 2,
illustrating the components of the GFCI device during a reset
operation;
[0026] FIGS. 9-11 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;
[0027] FIG. 12 is a schematic diagram of a circuit for detecting
ground faults and resetting the GFCI device of FIG. 1;
[0028] FIG. 13 is a perspective view of an alternative embodiment
of a ground fault circuit interrupting device according to the
present application;
[0029] FIG. 14 is side elevational view, partly in section, of a
portion of the GFCI device shown in FIG. 13, illustrating the GFCI
device in a set or circuit making position;
[0030] FIG. 15 is a side elevational view similar to FIG. 14,
illustrating the GFCI device in a circuit breaking position;
[0031] FIG. 16 is a side elevational view similar to FIG. 14,
illustrating the components of the GFCI device during a reset
operation;
[0032] FIG. 17 is an exploded view of internal components of the
GFCI device of FIG. 13;
[0033] FIG. 18 is a schematic diagram of a circuit for detecting
ground faults and resetting the GFCI device of FIG. 13;
[0034] FIG. 19 is side elevational view, partly in section, of
components of a portion of the alternative embodiment of the GFCI
device shown in FIG. 13, illustrating the device in a set or
circuit making position;
[0035] FIG. 20 is a side elevational view similar to FIG. 19,
illustrating of the device in a circuit breaking position; and
[0036] FIG. 21 is a block diagram of a circuit interrupting system
according to the present application.
DETAILED DESCRIPTION
[0037] The present application 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 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).
[0038] 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 according to the present application can be
included in any of the various devices in the family of resettable
circuit interrupting devices.
[0039] 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.
[0040] In one embodiment, the GFCI receptacle has a circuit
interrupting portion, a reset portion and a reset lockout. This
embodiment is shown in FIGS. 1-12. In another embodiment, the GFCI
receptacle is similar to the embodiment of FIGS. 1-12, except the
reset lockout is omitted. Thus, in this embodiment, the GFCI
receptacle has a circuit interrupting portion and a reset portion,
which is similar to those described in FIGS. 1-12. In another
embodiment, the GFCI receptacle has a circuit interrupting portion,
a reset portion, a reset lockout and an independent trip portion.
This embodiment is shown in FIGS. 13-20.
[0041] The circuit interrupting and reset portions described herein
preferably use electromechanical 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.
[0042] 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.
[0043] 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 nonoperational, if an open
neutral condition exists and/or if the device is reverse wired.
[0044] In the embodiments including 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.
[0045] The above-described features can be incorporated in any
resettable circuit interrupting device, but for simplicity the
descriptions herein are directed to GFCI receptacles.
[0046] Turning now to FIG. 1, the GFCI receptacle 10 has a housing
12 consisting of a relatively central body 14 to which a face or
cover portion 16 and a rear portion 18 are removably secured. The
face portion 16 has entry ports 20 and 21 for receiving normal 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 22 to accommodate a three-wire
plug. The receptacle also includes a mounting strap 24 used to
fasten the receptacle to a junction box.
[0047] A test button 26 extends through opening 28 in the face
portion 16 of the housing 12. 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
reset button 30 forming a part of the reset portion extends through
opening 32 in the face portion 16 of the housing 12. The reset
button is used to activate a reset operation, which reestablishes
electrical continuity in the open conductive paths.
[0048] Electrical connections to existing household electrical
wiring are made via binding screws 34 and 36, where screw 34 is an
input (or line) phase connection, and screw 36 is an output (or
load) phase connection. It should be noted that two additional
binding screws 38 and 40 (seen in FIG. 3) are located on the
opposite side of the receptacle 10. These additional binding screws
provide line and load neutral connections, respectively. A more
detailed description of a GFCI receptacle is provided in U.S. Pat.
No. 4,595,894, which is incorporated herein in its entirety by
reference. It should also be noted that binding screws 34, 36, 38
and 40 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.
[0049] Referring to FIGS. 2-6, the conductive path between the line
phase connection 34 and the load phase connection 36 includes
contact arm 50 which is movable between stressed and unstressed
positions, movable contact 52 mounted to the contact arm 50,
contact arm 54 secured to or monolithically formed into the load
phase connection 36 and fixed contact 56 mounted to the contact arm
54. The user accessible load phase connection for this embodiment
includes terminal assembly 58 having two binding terminals 60 which
are capable of engaging a prong of a male plug inserted
therebetween. The conductive path between the line phase connection
34 and the user accessible load phase connection includes, contact
arm 50, movable contact 62 mounted to contact arm 50, contact arm
64 secured to or monolithically formed into terminal assembly 58,
and fixed contact 66 mounted to contact arm 64. These conductive
paths are collectively called the phase conductive path.
[0050] Similarly, the conductive path between the line neutral
connection 38 and the load neutral connection 40 includes, contact
arm 70 which is movable between stressed and unstressed positions,
movable contact 72 mounted to contact arm 70, contact arm 74
secured to or monolithically formed into load neutral connection
40, and fixed contact 76 mounted to the contact arm 74. The user
accessible load neutral connection for this embodiment includes
terminal assembly 78 having two binding terminals 80 which are
capable of engaging a prong of a male plug inserted therebetween.
The conductive path between the line neutral connection 38 and the
user accessible load neutral connection includes, contact arm 70,
movable contact 82 mounted to the contact arm 70, contact arm 84
secured to or monolithically formed into terminal assembly 78, and
fixed contact 86 mounted to contact arm 84. These conductive paths
are collectively called the neutral conductive path.
[0051] Referring to FIG. 2, 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 90, a plunger 92
responsive to the energizing and de-energizing of the coil assembly
and a banger 94 connected to the plunger 92. The banger 94 has a
pair of banger dogs 96 and 98 which interact with a movable
latching members 100 used to set and reset electrical continuity in
one or more conductive paths. The coil assembly 90 is activated in
response to the sensing of a ground fault by, for example, the
sense circuitry shown in FIG. 12. FIG. 12 shows conventional
circuitry for detecting ground faults that includes a differential
transformer that senses current imbalances.
[0052] The reset portion includes reset button 30, the movable
latching members 100 connected to the reset button 30, latching
fingers 102 and reset contacts 104 and 106 that temporarily
activate the circuit interrupting portion when the reset button is
depressed, when in the tripped position. Preferably, the reset
contacts 104 and 106 are normally open momentary contacts. The
latching fingers 102 are used to engage side R of each contact arm
50,70 and move the arms 50,70 back to the stressed position where
contacts 52,62 touch contacts 56,66, respectively, and where
contacts 72,82 touch contacts 76,86, respectively.
[0053] The movable latching members 102 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.
[0054] In the embodiment shown in FIG. 2 and 3, the reset lockout
portion includes latching fingers 102 which after the device is
tripped, engages side L of the movable arms 50,70 so as to block
the movable arms 50,70 from moving. By blocking movement of the
movable arms 50,70, contacts 52 and 56, contacts 62 and 66,
contacts 72 and 76 and contacts 82 and 86 are prevented from
touching. Alternatively, only one of the movable arms 50 or 70 may
be blocked so that their respective contacts are prevented from
touching. Further, in this embodiment, latching fingers 102 act as
an active inhibitor that prevents the contacts from touching.
Alternatively, the natural bias of movable arms 50 and 70 can be
used as a passive inhibitor that prevents the contacts from
touching.
[0055] Referring now to FIGS. 2 and 7-11, 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. 2, the
GFCI receptacle is shown in a set position where movable contact
arm 50 is in a stressed condition so that movable contact 52 is in
electrical engagement with fixed contact 56 of contact arm 54. If
the sensing circuitry of the GFCI receptacle senses a ground fault,
the coil assembly 90 is energized to draw plunger 92 into the coil
assembly 90 so that banger 94 moves upwardly. As the banger moves
upwardly, the banger front dog 98 strikes the latch member 100
causing it to pivot in a counterclockwise direction C (seen in FIG.
7) about the joint created by the top edge 112 and inner surface
114 of finger 110. The movement of the latch member 100 removes the
latching finger 102 from engagement with side R of the remote end
116 of the movable contact arm 50, and permits the contact arm 50
to return to its pre-stressed condition opening contacts 52 and 56,
seen in FIG. 7.
[0056] After tripping, the coil assembly 90 is de-energized so that
spring 93 returns plunger 92 to its original extended position and
banger 94 moves to its original position releasing latch member
100. At this time, the latch member 100 is in a lockout position
where latch finger 102 inhibits movable contact 52 from engaging
fixed contact 56, as seen in FIG. 10. As noted, one or both
latching fingers 102 can act as an active inhibitor that prevents
the contacts from touching. Alternatively, the natural bias of
movable arms 50 and 70 can be used as a passive inhibitor that
prevents the contacts from touching.
[0057] To reset the GFCI receptacle so that contacts 52 and 56 are
closed and continuity in the phase conductive path is
reestablished, the reset button 30 is depressed sufficiently to
overcome the bias force of return spring 120 and move the latch
member 100 in the direction of arrow A, seen in FIG. 8. While the
reset button 30 is being depressed, latch finger 102 contacts side
L of the movable contact arm 50 and continued depression of the
reset button 30 forces the latch member to overcome the stress
force exerted by the arm 50 causing the reset contact 104 on the
arm 50 to close on reset contact 106. Closing the reset contacts
activates the operation of the circuit interrupter by, for example
simulating a fault, so that plunger 92 moves the banger 94 upwardly
striking the latch member 100 which pivots the latch finger 102,
while the latch member 100 continues to move in the direction of
arrow A. As a result, the latch finger 102 is lifted over side L of
the remote end 116 of the movable contact arm 50 onto side R of the
remote end of the movable contact arm, as seen in FIGS. 7 and 11.
Contact arm 50 returns to its unstressed position, opening contacts
52 and 56 and contacts 62 and 66, so as to terminate the activation
of the circuit interrupting portion, thereby de-energizing the coil
assembly 90.
[0058] After the circuit interrupter operation is activated, the
coil assembly 90 is de-energized so that so that plunger 92 returns
to its original extended position, and banger 94 releases the latch
member 100 so that the latch finger 102 is in a reset position,
seen din FIG. 9. Release of the reset button causes the latching
member 100 and movable contact arm 50 to move in the direction of
arrow B (seen in FIG. 9) until contact 52 electrically engages
contact 56, as seen in FIG. 2.
[0059] 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.
[0060] 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 electromechanical components to break either the
phase or neutral conductive path or both paths.
[0061] For the purposes of the present application, the structure
or mechanisms for this embodiment are also incorporated into a GFCI
receptacle, seen in FIGS. 13-20, 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.
[0062] Turning now to FIG. 13, the GFCI receptacle 200 according to
this embodiment is similar to the GFCI receptacle described in
FIGS. 1-12. Similar to FIG. 1, the GFCI receptacle 200 has a
housing 12 consisting of a relatively central body 14 to which a
face or cover portion 16 and a rear portion 18 are, preferably,
removably secured.
[0063] A trip actuator 202, preferably a button, which is part of
the trip portion to be described in more detail below, extends
through opening 28 in the face portion 16 of the housing 12. 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.
[0064] A reset actuator 30, preferably a button, which is part of
the reset portion, extends through opening 32 in the face portion
16 of the housing 12. 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.
[0065] As in the above embodiment, electrical connections to
existing household electrical wiring are made via binding screws 34
and 36, where screw 34 is an input (or line) phase connection, and
screw 36 is an output (or load) phase connection. It should be
noted that two additional binding screws 38 and 40 (seen in FIG. 3)
are located on the opposite side of the receptacle 200. These
additional binding screws provide line and load neutral
connections, respectively. A more detailed description of a GFCI
receptacle is provided in U.S. Pat. No. 4,595,894, which is
incorporated herein in its entirety by reference.
[0066] Referring to FIGS. 4-6, 14 and 17, the conductive paths in
this embodiment are substantially the same as those described
above. The conductive path between the line phase connection 34 and
the load phase connection 36 includes, contact arm 50 which is
movable between stressed and unstressed positions, movable contact
52 mounted to the contact arm 50, contact arm 54 secured to or
monolithically formed into the load phase connection 36 and fixed
contact 56 mounted to the contact arm 54 (seen in FIGS. 4, 5 and
17). The user accessible load phase connection for this embodiment
includes terminal assembly 58 having two binding terminals 60 which
are capable of engaging a prong of a male plug inserted
therebetween. The conductive path between the line phase connection
34 and the user accessible load phase connection includes, contact
arm 50, movable contact 62 mounted to contact arm 50, contact arm
64 secured to or monolithically formed into terminal assembly 58,
and fixed contact 66 mounted to contact arm 64. These conductive
paths are collectively called the phase conductive path.
[0067] Similarly, the conductive path between the line neutral
connection 38 and the load neutral connection 40 includes, contact
arm 70 which is movable between stressed and unstressed positions,
movable contact 72 mounted to contact arm 70, contact arm 74
secured to or monolithically formed into load neutral connection
40, and fixed contact 76 mounted to the contact arm 74 (seen in
FIGS. 4, 6 and 17). The user accessible load neutral connection for
this embodiment includes terminal assembly 78 having two binding
terminals 80 which are capable of engaging a prong of a male plug
inserted therebetween. The conductive path between the line neutral
connection 38 and the user accessible load neutral connection
includes, contact arm 70, movable contact 82 mounted to the contact
arm 70, contact arm 84 secured to or monolithically formed into
terminal assembly 78, and fixed contact 86 mounted to contact arm
84. These conductive paths are collectively called the neutral
conductive path.
[0068] There is also shown in FIG. 14, 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 electromechanical 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.
[0069] The circuit interrupting device according to this embodiment
incorporates an independent trip portion into the circuit
interrupting device of FIGS. 1-12. Therefore, a description of the
circuit interrupting, reset and reset lockout portions are
omitted.
[0070] Referring to FIGS. 14-16 an exemplary embodiment of the trip
portion according to the present application includes a trip
actuator 202, preferably a button, that is movable between a set
position, where contacts 52 and 56 are permitted to close or make
contact, as seen in FIG. 14, and a trip position where contacts 52
and 56 are caused to open, as seen in FIG. 15. Spring 204 normally
biases trip actuator 202 toward the set position. The trip portion
also includes a trip arm 206 that extends from the trip actuator
202 so that a surface 208 of the trip arm 206 moves into contact
with the movable latching member 100, when the trip button is moved
toward the trip position. When the trip actuator 202 is in the set
position, surface 208 of trip arm 202 can be in contact with or
close proximity to the movable latching member 100, as seen in FIG.
14.
[0071] In operation, upon depression of the trip actuator 202, the
trip actuator pivots about point T of pivot arm 210 (seen in FIG.
15) extending from strap 24 so that the surface 208 of the trip arm
206 can contact the movable latching member 100. As the trip
actuator 202 is moved toward the trip position, trip arm 206 also
enters the path of movement of the finger 110 associated with reset
button 30 thus blocking the finger 102 from further movement in the
direction of arrow A (seen in FIG. 15). By blocking the movement of
the finger 110, the trip arm 206 inhibits the activation of the
reset operation and, thus, inhibits simultaneous activation of the
trip and reset operations. Further depression of the trip actuator
202 causes the movable latching member 100 to pivot about point T
in the direction of arrow C (seen in FIG. 15). Pivotal movement of
the latching member 100 causes latching finger 102 of latching arm
100 to move out of contact with the movable contact arm 50 so that
the arm 50 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. 18.
[0072] 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.
[0073] An alternative embodiment of the trip portion will be
described with reference to FIGS. 19 and 20. In this embodiment,
the trip portion includes a trip actuator 202 that at is movable
between a set position, where contacts 52 and 56 are permitted to
close or make contact, as seen in FIG. 19, and a trip position
where contacts 52 and 56 are caused to open, as seen in FIG. 20.
Spring 220 normally biases trip actuator 202 toward the set
position. The trip portion also includes a trip arm 224 that
extends from the trip actuator 202 so that a distal end 226 of the
trip arm is in movable contact with the movable latching member
100. As noted above, the movable latching member 100 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.
[0074] In this embodiment, the movable latching member 100 includes
a ramped portion 100a which facilitates opening and closing of
electrical contacts 52 and 56 when the trip actuator 202 is moved
between the set and trip positions, respectively. To illustrate,
when the trip actuator 202 is in the set position, distal end 226
of trip arm 224 contacts the upper side of the ramped portion 100a,
seen in FIG. 19. When the trip actuator 202 is depressed, the
distal end 226 of the trip arm 224 moves along the ramp and pivots
the latching member 60 about point P in the direction of arrow C
causing latching finger 102 of the latching member 100 to move out
of contact with the movable contact arm 50 so that the arm 50
returns to its unstressed condition, and the conductive path is
broken. Resetting of the device is achieved as described above.
[0075] The circuit interrupting device according to the present
application can be used in electrical systems, shown in the
exemplary block diagram of FIG. 21. The system 240 includes a
source of power 242, such as ac power in a home, at least one
circuit interrupting device, e.g., circuit interrupting device 10
or 200, electrically connected to the power source, and one or more
loads 244 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.
[0076] As noted, although the components used during circuit
interrupting and device reset operations are electromechanical 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.
[0077] While there have been shown and described and pointed out
the fundamental features of the invention, it will be understood
that various omissions and substitutions and changes of the form
and details of the device described and illustrated and in its
operation may be made by those skilled in the art, without
departing from the spirit of the invention.
* * * * *