Information
-
Patent Grant
-
6259340
-
Patent Number
6,259,340
-
Date Filed
Monday, May 10, 199925 years ago
-
Date Issued
Tuesday, July 10, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Cantor Colburn LLP
- Horton; Carl B.
-
CPC
-
US Classifications
Field of Search
-
International Classifications
-
Abstract
In an exemplary embodiment of the invention, a dual test mechanism is presented for use in a circuit breaker. More specifically, the dual test mechanism includes a dual test button which comprises a single switch for testing both the AFCI and GFCI circuits of the breaker. The test mechanism includes a circuit board, which forms a part of the circuit breaker, and a test button assembly which includes a test button and signaling components which are electrically connected to the circuit board.
Description
BACKGROUND OF THE INVENTION
The present invention relates generally to a circuit breaker. More specifically the present invention relates to a dual test button and test mechanism to check both an arc fault circuit interruption (AFCI) and a ground fault circuit interruption (GFCI) in a circuit breaker.
Conventional residential and light industrial and commercial circuit breakers typically have a thermal trip mechanism which responds to persistent overcurrents of moderate magnitude to provide a delayed trip in the breaker. Also included in the circuit breaker is a magnetic trip mechanism which responds instantaneously to overcurrent conditions of greater magnitudes. It is becoming more common for these circuit breakers to further include a ground fault trip mechanism as one of the active mechanisms. The ground fault trip mechanism includes a trip unit which detects faults between the line conductor and ground and the neutral conductor and ground. Line to ground faults are commonly detected by the use of a differential transformer. The line and neutral conductors are passed through the coil so that in the absence of a line to ground fault, the currents are equal and opposite and no signal is generated. However, when a line to ground fault exists, it creates a sizeable imbalance between the two currents in the two conductors which can be level detected As is known, a neutral to ground fault may be detected by injecting a signal onto the neutral conductor which will produce an oscillation if feedback is provided.
In addition, conventional circuit breakers include mechanisms designed to protect against arc faults. For example, an arc fault may occur in the device when bare or stripped conductors come into contact with one another and the current caused by such a fault produces magnetic repulsion forces which push the conductors apart, thereby striking an arc. The arc that is caused by these faults can damage the conductors by melting the copper therein and this is especially true for stranded wire conductors such as extension cords, which can ignite surrounding materials.
Typically, the circuit breaker includes contacts that open upon sensing arcing from line to ground and/or from line to neutral. Arc fault circuit breakers typically use a differential transformer to measure arcing from line to ground. Detecting arcing from line to neutral is accomplished by detecting rapid changes in load current by measuring voltage drop across is a relatively constant resistance, usually a bi-metal resistor.
Unfortunately, many conventional circuit breakers, including residential circuit breakers, do not permit the user to test both the AFCI and GFCI circuits in the device. Furthermore, the ability to test both of these circuits is very important for customer safety and because a vast amount of individuals do not understand the implications of a circuit failure, it is important to best educate these individuals about these implications and what systems are available to minimize the likelihood that such a circuit failure occurs.
BRIEF SUMMARY OF THE INVENTION
In an exemplary embodiment of the invention, a dual test mechanism is presented for use in a circuit breaker. More specifically, the dual test mechanism includes a dual test button which comprises a single switch for testing both the AFCI and GFCI circuits of the breaker. The test mechanism includes a circuit board, which forms a part of the circuit breaker, and a test button assembly which includes a test button and signaling components which are electrically connected to the circuit board.
The test button has a first position and a second position, wherein positioning the test button in the first position produces a first signal and positioning the test button in the second position produces a second signal. A trip mechanism is included in the circuit breaker and includes a pair of separable contacts, wherein the trip mechanism is electrically connected to the circuit board so that in response to receiving one of the first and second signals, the circuit board generates a trip signal which directs the trip mechanism to separate the pair of separable contacts. In the preferred embodiment, the first position comprises a test position for the AFCI circuit and the second position comprises a test position for the GFCI circuit. Thus, the present invention permits the customer to test both the AFCI and GFCI circuits by positioning a single test button accordingly in either the first or second test button positions.
The above-discussed and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
FIG. 1
is a perspective view of a dual test button for use in a dual test mechanism in accordance with the present invention;
FIG. 2
is a side elevation view of an exemplary printed circuit board layout in accordance with the present invention;
FIG. 3
is a bottom plan view of the printed circuit board of
FIG. 2
taken along the line
3
—
3
,
FIG. 4
is a perspective view of a single pole circuit breaker in accordance with present invention;
FIG. 5
is an exploded view of the mechanical compartment of the single pole circuit breaker of
FIG. 4
;
FIG. 6
is an exploded view of the electronics compartment of the single pole circuit breaker of
FIG. 4
;
FIG. 7
is a side elevation view of a dual test mechanism including the dual test button of
FIG. 1
for use in a circuit breaker in accordance with the present invention; and
FIG. 8
is a schematic of an exemplary circuit for the dual test button of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to
FIG. 1
, an exemplary dual test button for use to check both AFCI and GFCI circuits in a circuit breaker
100
(
FIG. 4
) is generally shown at
10
. Test button
10
includes a first cantilevered surface
12
and a second cantilevered surface
14
which are designed as surfaces for the user to depress depending upon which circuit is to be tested in circuit breaker
100
. More specifically, first cantilevered surface
12
is depressed if testing of the AFCI circuit is desired and second cantilevered surface
14
is depressed if testing of the GFCI circuit is desired. First and second cantilevered surfaces
12
and
14
are integral with one another and converge along a central line. A perimetric lip
16
extends around first and second cantilevered surfaces
12
and
14
so that surfaces
12
and
14
extend above perimetric lip
16
. A bottom portion of test button
10
comprises a clamp member
18
which receives a pivotable leaf spring
20
which forms a part of a test button assembly
32
(shown in FIG.
2
). Clamp member
18
has a pair of biasing arms
22
which securely hold pivotable leaf spring
20
therebetween. Pivotable leaf spring
20
pivots when either first or second cantilevered surfaces
12
and
14
are depressed. Preferably, test button
10
is formed of a plastic material as is known in the art.
Turning now to
FIGS. 1-3
which illustrate exemplary current sensing components
30
for use in circuit breaker
100
(
FIG. 4
) along with test button assembly
32
. Current sensing components
30
comprise a circuit board
34
which is electrically connected to a solenoid
36
and a current sensing transformer
38
. Furthermore, test button assembly
32
includes signaling components comprising a pivotable leaf spring
20
which is disposed intermediate a first flat conductor (flat)
40
and a second flat conductor (flat)
42
, all of which are electrically connected to circuit board
34
. Pivotable leaf spring
20
is preferably a planar member, while first and second flats
40
and
42
each have a lower planar segment and an angled upper segment which is inclined toward pivotable leaf spring
20
. It being understood that test button
10
is secured to pivotable leaf spring
20
by simply inserting a top end of pivotable leaf spring
20
within clamp member
18
. The biasing forces of the pair of arms
22
pinch and hold pivotable leaf spring
20
in place.
Test button assembly
32
comprises a two position switch assembly (AFCI and GFCI), wherein depressing first cantilevered surface
12
causes pivotable leaf spring
20
to contact second flat
42
resulting in a first signal being injected into circuit board
34
, wherein the first signal comprises a test signal for the AFCI circuit. In contrast, depressing second cantilevered surface
14
causes pivotable leaf spring
20
to contact first flat
40
resulting in a second signal being injected into circuit board
34
, wherein the second signal comprises a test signal for the GFCI circuit. Upon receiving either the first or the second signal, circuit board
34
generates a trip signal to solenoid
36
resulting in the actuation of solenoid
36
which causes a pair of separable contacts to separate and interrupt the current flow in circuit breaker
100
(FIG.
4
). The precise testing mechanisms and signaling will be described in great detail hereinafter.
Solenoid
36
includes a plunger assembly
44
at one end, wherein plunger assembly
44
includes a rod having an end extension
46
which attaches at a right angle to the plunger rod. End extension
46
comprises the component of plunger assembly
44
which moves within a recess
48
formed in circuit board
34
. Referring to
FIG. 2
, the actuation of solenoid
36
causes plunger assembly
44
to move in a left-to-right direction and end extension
46
moves within recess
48
in a direction away from circuit board
34
. End extension
46
is intended to engage a test mechanism
200
(shown in
FIG. 7
) which causes the pair of contacts to separate and interrupt current flow within circuit breaker
100
, as will be described hereinafter.
Circuit board
34
, test button assembly
32
and solenoid
36
and test mechanism
200
(
FIG. 7
) may be used as a component of any number of suitable circuit breakers in which the selected movement of dual test button
10
permits one of two test signals to be injected into circuit board
34
resulting in the testing of both AFCI and GFCI circuits within circuit breaker
100
. For the purpose of illustration only and not limitation, an exemplary single pole arc circuit board
100
is illustrated in
FIGS. 4-6
and is further described in commonly assigned U.S. patent application Ser. No. 09/246,322 filed on Feb. 9, 1999, which is hereby incorporated by reference in its entirety.
Referring to
FIG. 4
, circuit breaker
100
comprises a first housing
102
, a second housing
104
, and a cover
106
that are assembled securely together with a plurality of bolts (not shown). First housing
102
defines a mechanical compartment
108
, having load current carrying and switching components
110
disposed therein (see FIG.
5
). Second housing
104
defines an electronics compartment
112
, having current sensing components
114
and neutral current carrying components
116
disposed therein (see FIG.
6
). A load current from a source (not shown) connects to a line connection
118
(see FIG.
5
), and conducts along the current carrying and switching components
110
to a load lug
120
for customer connection to a load (not shown). A neutral current from the load connects to a neutral lug
122
, (see
FIG. 4
) and conducts along the neutral current carrying components
116
to a neutral return wire
124
for customer connection to the source. Arc faults are sensed and processed by sensing components
114
. As more particularly described hereinafter, arc fault circuit breaker
100
is preferably assembled such that electrical interconnections, i.e., electrical connections between the mechanical and electronics compartments
108
and
112
, are made without disassembling any previously assembled compartment.
Referring to
FIG. 5
, the mechanical compartment
108
is shown in detail. First housing
102
is generally rectangular in shape, and formed of electrical insulative material, i.e., plastic. First housing
102
comprises a first insulative tab
126
, a first rim
128
, and a first side wall
130
. First tab
126
protrudes forwardly from the front of first housing
102
adjacent load lug
120
to provide an insulative barrier. First rim
128
extends around the periphery of first side wall
130
. A first rectangular slot
132
is located in first rim
128
at the top and back of first housing
102
and is sized to receive a pole handle
134
. First side wall
130
and first rim
128
define mechanical compartment
108
which includes the load current carrying and switching components
110
. The load current carrying and switching components
110
within the mechanical compartment
108
are electrically connected, e.g., welded, bolted, or crimped, to form a load current path. The load current path begins at line connection
118
where the load current enters the mechanical compartment
108
. Line connection
118
includes a lower tab
138
to connect to a source line (not shown), and a fixed contact
140
which extends downwardly from the upper end of line connection
118
. A blade
142
is pivotally engaged to first housing
102
and is pivotally attached to insulated pole handle
134
. A lower end of blade
142
includes a flat contact
144
which is forcibly biased against contact
140
to provide electrical continuity for the load current. Pole handle
134
is pivotally attached to first housing
102
and extends outwardly from mechanical compartment
108
into electronics compartment
112
.
Blade
142
is electrically connected to a bottom distal end of a bimetal resistor
146
via a braid
148
. A top distal end of bimetal resistor
146
is in turn electrically connected to an L-shaped strap
150
. L-shaped strap
150
comprises a vertical strap body
152
and a horizontal strap extension
154
. Horizontal strap extension
154
forms a substantially right angle with vertical strap body
152
, and extends outwardly from mechanical compartment
108
into electronics compartment
112
. A load terminal
156
also extends outwardly from the mechanical compartment
108
into electronics compartment
112
. Load terminal
156
is in turn electrically connected to load lug
120
. The load current path conducts the load current from the line connection
118
, through contacts
140
and
144
, through blade
142
, braid
148
, bimetal resistor
146
, and L-shaped strap
150
. At this point, the load current path passes out of the mechanical compartment
108
through horizontal strap extension
154
. The load current path returns to the mechanical compartment
108
through load terminal
156
and out through the load lug
120
to the load. When an arc fault is detected the pole handle
134
pivots clockwise, which in turn pivots blade
142
to separate contacts
140
and
144
and thereby open the load current path.
A twisted pair conductor
158
is electrically connected to the bottom distal end of bimetal resistor
146
and horizontal strap extension
154
of the L-shaped strap
150
to sense arcing from the line to neutral as is well known. This is accomplished by measuring the voltage drop across the bimetal resistor
146
that results from rapid changes in load current caused by arcing from line to neutral.
Referring to
FIG. 6
, the electronics compartment
112
is shown in detail. Second housing
104
is generally rectangular in shape and formed of electrical insulative material, i.e., plastic. Second housing
104
comprises a second insulative tab
160
, a second rim
162
, and a second side wall
164
. Second tab
160
protrudes forwardly from the front of second housing
104
adjacent neutral lug
122
to provide an insulative barrier. Second rim
162
extends around the periphery of second side wall
164
. A second rectangular slot
166
is located in rim
162
and cooperates with slot
132
to receive and secure pole handle
134
when housings
102
and
104
are assembled together. Second side wall
164
and second rim
162
define the electronics compartment
112
which includes the current sensing components
114
and the neutral current carrying components
116
. The second housing
104
is assembled securely against first housing
102
with a plurality of bolts (not shown) to enclose mechanical compartment
108
and to capture the components wiin, as well as to insulate and secure load lug
120
between tabs
126
and
160
.
Second side wall
164
of second housing
104
includes rectangular through holes
168
and
170
and circular through hole
172
to provide openings in the second housing
104
to permit the load terminal
156
, horizontal strap extension
154
and twisted pair conductor
158
to extend through to the electronics compartment
112
. This enables all electrical interconnections between compartments
108
and
112
to be completed in electronics compartment
112
. During production, this allows compartments
108
and
112
to be assembled sequentially without the need to disassemble mechanical compartment
108
. That is, mechanical compartment
108
is assembled first with the interconnecting components
154
,
156
and
158
extending outwardly from the compartment
108
. Second housing
104
is then assembled to first housing
102
enclosing the mechanical compartment
108
, but allowing the interconnecting components
154
,
156
, and
158
to extend therethrough. The electronics compartment
112
may then be assembled and the associated components be interconnected to the components of the mechanical compartment
108
without any disassembly of mechanical compartment
112
. This provides for a large work space for tooling and assembly when interconnecting the components of the compartments
108
and
112
. Therefore, high quality interconnections are more consistently, and cost effectively made then in prior art circuit breakers.
Second side wall
164
further includes a window
190
, preferably in the shape of a rectangle. Window
190
is intended to receive end extension
46
of plunger
44
of solenoid
36
. More specifically, end extension
46
freely moves within window
190
upon actuation of solenoid
36
after circuit board
34
generates a trip signal which is received by solenoid
36
. End extension
46
engages test mechanism
200
(shown in
FIG. 7
) to cause handle
134
to pivot resulting in contacts
140
and
144
separating.
Current sensing components
114
comprise circuit board
34
which is electrically connected to solenoid
36
, current sensing transformer
38
and optional to current sensing transformer
38
′. Upon receiving signals indicative of an arc fault, circuit board
34
provides a trip signal to trip the arc fault circuit breaker
100
.
Twisted pair conductor
158
is electrically interconnected to circuit board
34
. Circuit board
34
senses the voltage across the bi-metal resistor
146
and generates a trip signal to actuate solenoid
36
in response to a rapid voltage drop indicative of arcing across the line and neutral leads.
The load current path is completed by electrically interconnecting strap extension
154
and load terminal
156
to a respective distal ends of a wire connector
180
. Wire connector
180
can be formed from various suitable conductive materials, e.g., insulated wire, rectangular formed magnetic wire, square formed magnetic wire, or insulated sleeve covered braided copper. Wire connector
180
is routed through a center of sensing transformer
38
such that the flow of the load current through the center of transformer
38
is in a known direction.
The neutral current carrying components
116
within the electronics compartment
112
are electrically connected, e.g., welded, bolted, or crimped, to form a neutral current path for the neutral current. The neutral current path begins at neutral lug
122
where the neutral current enters the electronics compartment
112
. Neutral lug
122
secures the neutral lead connected to the load against a neutral terminal
182
to provide electrical continuity thereto. Neutral terminal
182
is electrically connected to neutral return wire
124
via a copper braid
184
. An insulated sleeve
186
surrounds a portion of copper braid
184
and provides electrical insulation between copper braid
184
and circuit board
34
. Copper braid
184
is routed through the center of sensing transformer
38
such that the flow of the neutral current through the center of transformer
38
is in the opposite direction of the flow of the load current through wire connector
180
.
Both the copper braid
184
of the neutral current path, and wire connector
180
of the load current path are routed through the current sensing transformer
38
to sense arcing from line to ground as is well known. This is accomplished by routing the flow of the neutral current through the sensing transformer
38
in the opposite direction to the flow of the load current. The total current flow through sensing transformer
38
thus cancels unless an external ground fault current is caused by arcing from line to ground. The resulting differential signal, sensed by sensing transformer
38
, is indicative of the ground fault current and is processed by circuit board
34
.
Optional current sensing transformer
38
′ is used for ground fault applications where a separate sensor is needed to detect improper wiring by the customer, e.g., the neutral current path is wired backwards. That is, copper braid
184
of the neutral current path is routed through the optional current sensing transformer
38
′. The resulting signal, sensed by optional current sensing transformer
38
′, is indicative of the neutral current direction and magnitude, and is processed by circuit board
34
.
Turning now to
FIGS. 1-8
.
FIG. 7
illustrates test mechanism
200
in greater detail. It being understood that test mechanism
200
of
FIG. 7
is merely exemplary in nature and it is within the scope of the present invention that other known test mechanism
200
may be employed with test button assembly
32
including dual test button
10
and circuit board
34
to cause handle
134
to pivot resulting in contacts
140
and
144
opening to interrupt current during either AFCI or GFCI tnp conditions. Test mechanism
200
includes a latch assembly
202
having a pivotable armature latch (not shown). The pivotable armature latch comprises the main component of test mechanism
200
which interacts with end extension
46
in that upon actuation of solenoid
36
, the solenoid rod is driven causing end extension
46
to ride within window
190
(FIG.
6
). As end extension
46
is driven itself, it contacts the annature latch causing the armature latch to rotate counterclockwise.
The pivotable armature latch selectively engages and positions a cradle
204
so that when the armature latch is rotated counter clockwise, cradle
204
is released from the armature latch resulting in cradle
204
being free to rotate. Cradle
204
rotates downward in a clockwise manner and falls out of window
190
. A spring
206
interconnected between blade
142
and cradle
204
creates a biasing force therebetween so that when cradle
204
rotates clockwise, after being released from the annature latch, the spring biasing forces causes blade
142
and handle
134
to rotate to a trip position, wherein contacts
140
and
144
are opened.
As best shown in
FIGS. 2 and 6
, a test wire
195
is routed through sensing transformer
38
, such that the flow of current in test wire
195
through the center of sensing transformer
38
is in a known direction. During non-test and non-trip conditions, the total current flowing in opposite directions through transformer
38
cancels one another and thus sensing transfonner
38
does not detect a differential signal, which is indicative of a trip or test condition. Test wire
195
is electrically connected to circuit board
34
and test button assembly
32
so that when the second signal (GFCI test signal) is generated when pivotable leaf spring
20
and first flat
40
make contact, a current is passed through test wire
195
causing a current differential through sensing transformer
38
. More specifically, one end of test wire
195
is electrically connected to first flat
40
and an opposite end of test wire
195
is electrically connected to horizontal strap extension
154
after test wire
195
has passed through sensing transformer
38
.
Referring to
FIGS. 1-7
, in exemplary circuit breaker
100
, the testing of the AFCI circuit proceeds in the following manner. First cantilevered surface
12
of test button
10
is depressed causing pivotable leaf spring
20
to contact second flat
42
resulting in the first signal being injected into circuit board
34
. The first signal comprises a test signal for the AFCI circuit of circuit breaker
100
and in response to the first signal, circuit board
34
generates a trip signal which is communicated with solenoid
36
. Upon receipt of the trip signal, solenoid
36
is actuated and plunger
44
is driven so that end extension
46
of plunger
44
contacts and causes the armature latch to rotate counter clockwise, thereby releasing cradle
204
. This results in handle
134
being rotated causing contacts
140
and
144
to open. Test button
10
is designed so that once first cantilevered portion
12
is no longer depressed, test button
10
moves back to its original off position, wherein pivotable leaf spring
20
is centered and not in contact with either first or second flats
40
and
42
. Consequently, after the trip mechanism of circuit breaker
100
, including handle
134
, blade
142
and contacts
140
and
144
are reset to a non-trip position, test button
10
is in an off position and thus no test signals are being delivered to circuit board
34
.
In order to test the GFCI circuit of circuit breaker
100
, second cantilevered surface
14
is depressed causing pivotable leaf spring
20
to contact first flat
40
resulting in the second signal being injected into circuit board
34
in the following manner. Upon contact between pivotable leaf spring
20
and first flat
40
, test wire
195
, which is routed through sensing transformer
38
, carries current through sensing transformer
38
thereby canceling the indifference in total current flowing through sensing transformer
38
because the opposing flow of current through sensing transformer
38
no longer cancels one another. The resulting differential signal, sensed by sensing transformer
38
, is indicative of the ground fault current and is processed by circuit board
34
. As previously described, in response to the second signal, circuit board
34
generates a trip signal which is communicated with solenoid
36
. Upon receipt of the trip signal, solenoid
36
is actuated and engages test mechanism
200
to cause rotation of handle
134
and opening of contacts
140
and
144
in the manner described hereinbefore.
FIG. 8
is a schematic of exemplary circuitry for dual test button
10
and is therefore self-explanatory in nature. Thus, the present invention provides a means for providing a first test signal and a second test signal, wherein the first test signal is generated to test the AFCI circuit and the second signal is generated to test the GFCI circuit. Test button assembly
32
is merely one exemplary means for providing these two signals and it is within the scope of the present invention that other means may be used such as a switching device, e.g., toggle switch having two positions which generate first and second test signals.
Of course one of sill in the art would appreciate that the test mechanism
200
and dual test button
10
may be employed in a two pole arc fault circuit breaker. In this embodiment, the AFCI and GFCI of the two pole arc fault circuit breaker are easily and conveniently tested
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 understood that the present invention has been described by way of illustrations and not limitation.
Claims
- 1. A test mechanism for a circuit breaker comprising:a circuit board; a test button assembly including a test button, the test button including a top portion having first and second cantilevered surfaces, and a bottom portion having a clamp member, the clamp member having a pair of biasing arms pinching a first end of a pivotable conductor to the test button, the pivotable conductor comprising a leaf spring and further comprising a second end, the test button assembly further including signaling components comprising first and second flat conductors which are electrically connected to the circuit board, wherein depressing the first cantilevered surface places the test button in a first position and moves the second end of the pivotable conductor into contact with the second flat conductor to direct a first test signal to the circuit board, and depressing the second cantilevered surface places the test button in a second position and moves the second end of the pivotable conductor into contact with the first flat conductor to direct a second test signal to the circuit board; and a trip mechanism including a pair of separable contacts, the trip mechanism being electrically connected to the circuit board so that in response to receiving one of the first and second test signals, the circuit board generates a trip signal causing the trip mechanism to separate the pair of separable contacts.
- 2. The test mechanism of claim 1 wherein the circuit breaker includes an arc fault circuit interruption circuit (AFCI) and a ground fault circuit interruption (GFCI) circuit.
- 3. The test mechanism of claim 2 wherein the first position comprises a test position for the AFCI circuit and the second position comprises a test position for the GFCI circuit.
- 4. The test mechanism of claim 1 wherein the circuit breaker further includes a current sensing transformer.
- 5. The test mechanism of claim 4 wherein the first flat conductor is electrically connected to one end of a test wire which passes through the current sensing transformer, an opposite end of the test wire being electrically connected to a bi-metal resistor.
- 6. The test mechanism of claim 5 wherein the second signal is provided by passing current through the test wire when the pivotable conductor and the first conductive flat are in contact.
- 7. The test mechanism of claim 1 wherein the trip mechanism includes a pivotable handle.
- 8. The test mechanism of claim 7 wherein the trip mechanism includes a solenoid which is electrically connected to the circuit board and actuation of the solenoid causes the handle to pivot and separate the contacts.
- 9. The test mechanism of claim 8 wherein the solenoid is actuated by receipt of the trip signal from the circuit board.
- 10. A circuit breaker comprising:a trip unit including a circuit board; a pair of separable contacts for interrupting the flow of current; and a test mechanism including a test button, the test button including a top portion having first and second cantilevered surfaces, and a bottom portion having a clamp member, the clamp member having a pair of biasing arms pinching a first end of a pivotable conductor to the test button, the pivotable conductor comprising a leaf spring and further comprising a second end, the test button assembly further including signaling components comprising first and second flat conductors, wherein depressing the first cantilevered surface places the test button in a first position and moves the second end of the pivotable conductor into contact with the second flat conductor to direct a first test signal to the circuit board, and depressing the second cantilevered surface places the test button in the second position and moves the second end of the pivotable conductor into contact with the first flat conductor to direct a second test signal to the circuit board, and wherein the circuit board generates a trip signal in response to receiving one of the first and second test signals, the trip signal being delivered to an actuator which causes separation of the contacts.
- 11. The circuit breaker of claim 10 wherein the first position is for testing an arc fault circuit interruption and the second position is for testing a ground fault circuit interruption.
- 12. The circuit breaker of claim 10 wherein the actuator comprises a solenoid.
- 13. The circuit breaker of claim 10, further including an arc fault circuit interruption circuit (AFCI) and a ground fault circuit interruption (GFCI) circuit.
- 14. The circuit breaker of claim 13 wherein the first position comprises a test position for the AFCI circuit and the second position comprises a test position for the GFCI circuit.
- 15. The circuit breaker of claim 10 wherein the first flat conductor is electrically connected to one end of a test wire which passes through the current sensing transformer, an opposite end of the test wire being electrically connected to a bi-metal resistor.
- 16. The circuit breaker of claim 15 wherein the second signal is provided by passing current through the test wire when the pivotable conductor and the first conductor flat are in contact.
US Referenced Citations (78)
Foreign Referenced Citations (3)
Number |
Date |
Country |
2036032 |
Aug 1991 |
CA |
WO 9113454 |
Sep 1991 |
WO |
WO 9520235 |
Jul 1995 |
WO |