Claims:1. An apparatus (100) for acknowledging fault conditions of circuit breakers, the apparatus comprising:
a contact element (120) configured in an electrical circuit of circuit breaker (126);
an operating unit (104) coupled to the contact element (120), the contact element is movable by the operating unit to open and close the electrical circuit of circuit breaker during normal operations;
a first latch element (114) configured in the electrical circuit of circuit breaker, and a second latch element (112) pivotally coupled to the operating unit, the second latch element (112), is operated by the operating unit, to engage the second latch element with the first latch element (114);
an indicator (102) coupled to the operating unit(104), the indicator (102) adapted to indicate the fault conditions of the circuit breaker;
a slider (108) configured in the electrical circuit, the slider is adapted to latch and de-latch the indicator from the slider; and
an actuation device (118) configured in the electrical circuit, the actuation device, upon detection of the fault condition, adapted to disengage the second latch element with the first latch element,
wherein, in response to fault condition, the actuation device (118) contacts the slider (108) to de-latch the indicator (102) from the slider (108), the de-latched indicator is rotated to reach a trip state to restrict the flow of current, when the operating unit (104) is activated from the trip state, to acknowledge the fault condition, and
wherein, upon acknowledging the fault condition, the indicator (102) is latched with the slider (108) at a reset state, to be activated by the operating unit, to perform normal operation of the electrical circuit.
2. The apparatus as claimed in claim 1, wherein the operating unit (104) is rotated with a pre-defined angle to operate the contact element (120) to open or close the electrical circuit.
3. The apparatus as claimed in claim 1, wherein the operating unit (104) is adapted to operate the contact element through U-pin (116).
4. The apparatus as claimed in claim 1, wherein a C-link (122) is configured between the first latch element and second latch element.
5. The apparatus as claimed in claim 1, wherein, at the trip state, when the operating unit (104) is activated, the indicator (102) is configured to exert force on the first latch element to disengage the first latch element from second latch element to restrict the flow of current.
6. The apparatus as claimed in claim 1, wherein, upon disengagement, the first latch element, the C-link, and the contact element are deactivated.
7. The apparatus as claimed in claim 6, wherein, upon disengagement of the first latch element and the second latch element, the operating unit is deactivated.
8. The apparatus as claimed in claim 1, wherein at the reset state, the indicator (102) is latched with the slider (108).
9. The apparatus as claimed in claim 1, wherein, when the operating unit (102) is activated from the reset state, the first latch element is adapted to be engaged with the second latch element to allow the passage of current.
10. The apparatus as claimed in claim 1, wherein the fault conditions comprise any or a combination of overcurrent, short circuit and residual current fault.

Description:TECHNICAL FIELD
[0001] The present disclosure relates, in general, to circuit breakers, and more specifically, relates to an apparatus to acknowledge fault state of electrical circuit.

BACKGROUND
[0002] Currently, due to the increase of industry size and automation, the requirement of protection devices has also increased and become mandatory. Along with the competitive criterions such as compactness, cost-effectiveness and reliability, advance safety features continue to be of utmost attraction in protection. Therefore, any enhancement in safety will always be welcome in electrical industry. Existing circuit breakers which are having two stable state (on and off) does not indicate fault condition. If the product is in off state, it is not possible to understand whether the product was tripped due to any fault or it was switched off.
[0003] Recently, some of the circuit breakers has introduced a flag to differentiate off state and inform whether it was tripped or switched off. In these circuit breakers, products do not require any kind of reset or acknowledgement operation for subsequent switching operation. Even after introducing this fault indication feature, an operator can switch on the circuit breaker on fault without noticing the indication. These products do not require resetting operation or any kind of acknowledgment for subsequent operation.
[0004] There are two types circuit breakers based on number of stable states, type-1 has three stable state – on, trip and off and type-2 has two stable state – on and off. In second type of circuit breakers, it is not possible to identify the reason for being the product in off state. Whether it is tripped due to fault or it is switched off. In most of the circuit breakers known in the art, the differentiation of off and trip condition was done by some kind of indication, where product will have two stable state, on and off. However, in these type of circuit breakers, circuit breaker can be switched on after tripping without acknowledging the fault condition as there is no interlock.
[0005] In circuit breakers with three stable state (on, trip and off), circuit breakers need to be reset before turning on. This trip state provides indication as well as interlock between off and on state. Similar feature is required for the circuit breakers with two stable state to avoid circuit closing on fault without acknowledging it. However, any attempt to operate the circuit breaker without acknowledging the unhealthy condition of the circuit can be very dangerous from electrical safety point of view.
[0006] Therefore, there is a need in the art to provide a means that can acknowledge the fault of the circuit to eliminate any unintentional hazards.

OBJECTS OF THE PRESENT DISCLOSURE
[0007] An object of the present disclosure relates, in general, to circuit breakers, and more specifically, relates to an apparatus to acknowledge fault state of the electrical circuit.
[0008] Another object of the present disclosure is to provide an apparatus to ensure fault acknowledgement by an operator before subsequent switching operation.
[0009] Another object of the present disclosure is to provide an apparatus to operate the circuit breaker by acknowledging the unhealthy condition of the circuit to enhance safety.
[0010] Another object of the present disclosure is to provide an apparatus in which same fault acknowledgement mechanism is capable of indicating fault condition.
[0011] Another object of the present disclosure is to provide an apparatus that do not require additional components and hence additional hardware cost can be reduced.
[0012] Another object of the present disclosure is to provide an apparatus to be capable of differentiating between tripping due to any fault and tripping due to external signal given by any accessories as the fault acknowledgement mechanism is independent of main mechanism circuit breaker.
[0013] Yet another object of the present disclosure is to provide an apparatus to improve safety by eliminating unwanted reclosing of circuit on fault.

SUMMARY
[0014] The present disclosure relates, in general, to circuit breakers, and more specifically, relates to an apparatus to provide interlock mechanism to acknowledge fault state of the electrical circuit.
[0015] In an aspect, the present disclosure provides an apparatus for acknowledging fault conditions of circuit breakers, the apparatus including: a contact element configured in an electrical circuit of circuit breaker, an operating unit coupled to the contact element, the contact element is movable by the operating unit to open and close the electrical circuit of circuit breaker during normal operations, a first latch element configured in the electrical circuit of circuit breaker, and a second latch element pivotally coupled to the operating unit, the second latch element, is operated by the operating unit, to engage the second latch element with the first latch element, an indicator coupled to the operating unit, the indicator adapted to indicate the fault conditions of the circuit breaker, a slider configured in the electrical circuit, the slider is adapted to latch and de-latch the indicator from the slider, and an actuation device configured in the electrical circuit, the actuation device, upon detection of the fault condition, adapted to disengage the second latch element with the first latch element, wherein, in response to fault condition, the actuation device contacts the slider to de-latch the indicator from the slider, the de-latched indicator is rotated to reach a trip state to restrict the flow of current, when the operating unit is activated from the trip state, to acknowledge the fault condition, and wherein, upon acknowledging the fault condition, the indicator is latched with the slider at a reset state, to be activated by the operating unit, to perform normal operation of the electrical circuit.
[0016] In another embodiment, the operating unit can be rotated with a pre-defined angle to operate the contact element to open or close the electrical circuit.
[0017] In another embodiment, the operating unit can be adapted to operate the contact element through a U-pin.
[0018] In another embodiment, a C-link can be configured between the first latch element and second latch element.
[0019] In an embodiment, at the trip state, when the operating unit is activated, the indicator can be configured to exert force on the first latch element to disengage the first latch element from second latch element to restrict the flow of current.
[0020] In another embodiment, upon disengagement, the first latch element, the C-link, and the contact element can be deactivated.
[0021] In another embodiment, upon disengagement of the first latch element and the second latch element, the operating unit can be deactivated.
[0022] In another embodiment, at the reset state, the indicator can be latched with the slider.
[0023] In another embodiment, when the operating unit can be activated from the reset state, the first latch element can be adapted to be engaged with the second latch element to allow the passage of current.
[0024] In another embodiment, the fault conditions comprise any or a combination of overcurrent, short circuit and residual current fault.
[0025] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The following drawings form part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein.
[0027] FIG. 1 illustrate exemplary representation of an apparatus for acknowledging fault conditions of circuit breakers, in accordance with an embodiment of the present disclosure.
[0028] FIG. 2 is a schematic view illustrating the “off” condition of the apparatus, in accordance with an embodiment of the present disclosure.
[0029] FIG. 3 is a schematic view illustrating the “trip” condition of the apparatus, in accordance with an embodiment of the present disclosure.
[0030] FIG. 4 is a schematic view illustrating the working condition of the apparatus from “trip” condition, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0031] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0032] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0033] The present disclosure relates, in general, to circuit breakers, and more specifically, relates to an apparatus to acknowledge fault state of the electrical circuit. The apparatus provided in the circuit breakers typically provide protection against persistent overcurrent and against very high currents produced by short circuits. The apparatus can be capable of differentiating between tripping due to any fault and tripping due to external signal given by any accessories as the fault acknowledgement mechanism of present disclosure is independent of main mechanism circuit breaker. The present disclosure can be described in enabling detail in the following examples, which may represent more than one embodiment of the present disclosure.
[0034] FIG. 1 illustrates exemplary representation of an apparatus for acknowledging fault conditions of circuit breakers, in accordance with an embodiment of the present disclosure.
[0035] Referring to FIG. 1, an apparatus 100 can be encased in a circuit breaker 126. Circuit breakers 126 of this type have an insulated case and cover that can house the components of the circuit breaker. The apparatus 100 may include an indicator 102 (also referred to as fault indicator 102, herein) and an operating unit 104 (also referred to as knob 104, herein), the indicator 102 and operating unit 104 can be extended to the front portion of the circuit breaker 126. The operating unit 104 can be extending through the cover that can provide the ability to turn the circuit breaker 126 “on” to energize a protected circuit (also referred to as an electrical circuit, herein), and turn the circuit breaker “off” to disconnect the protected circuit, or “reset” the circuit breaker 126 after a fault.
[0036] The circuit breakers 126 may include a pair of contacts to make and break the circuit. A mechanism can be used to make and break the contacts. In healthy circuit condition, contacts can carry a specified amount of current and can be opened or closed by manual or automatic means. In abnormal condition such as an overload condition or a relatively high-level short circuit or residual current fault condition, a protection release senses abnormality and can provide the trip command to mechanism in order to separate/open contacts to isolate the faulty circuit.
[0037] In an embodiment, the apparatus 100 can be encased inside the circuit breaker 126, in this example, the circuit breakers 126 can be provided with two stable states “on” and “off”, however, the present disclosure is not limited to this configuration but may be applied to other configurations, such as circuit breakers with three stable states and the like. When the circuit breaker is “on” the electrical contacts in the protected circuit can be closed thereby maintaining current flow through the circuit breaker 126, and when the circuit breaker is “off” the electrical contacts in the protected circuit can be opened thereby restricting the current flow through the circuit breaker 126.
[0038] In an embodiment, the indicator 102 provided in the circuit breaker 126 can be adapted to indicate the fault conditions of the circuit breakers. The circuit breaker 126 can be tripped by fault conditions that may include any or a combination of overcurrent, short circuit and ground fault. The circuit breaker 126may be typical three phase configuration, however, the present disclosure is not limited to this configuration but may be applied to other configurations, such as one, two or four pole circuit breakers and the like.
[0039] The apparatus 100 further include a contact element 120, a first latch element 114, a second latch element 112, C- link 122, U-pin 116, a solenoid 106, a slider 108,an actuation device 118. The actuation device 118 may include a solenoid plunger. The solenoid can be replaced by any electromechanical or any kind of actuation device to operate the main mechanism as well as fault acknowledgement mechanism and can be used in any application where this kind of interlocking can be required.
[0040] In an embodiment, the contact element 120can be configured in the electrical circuit of circuit breaker 126, the contact element 120 can be movable, the mechanism can be primarily responsible for operating the contact element 120 for closing and opening the electrical circuit. The operating unit 104 located in the electrical circuit can be coupled to the contact element 120,the contact element 120can be operated manually with the operating unit 104, the contact element 120 can be movable by the operating unit 104 to open and close the electrical circuit of circuit breaker during normal operations.
[0041] In another embodiment, the operating unit 104 can be rotated around its pivot with a pre-defined angle to operate the mechanism in order to close or open the electrical circuit. The first latch element 114 can be configured in the electrical circuit of circuit breaker 126, and the second latch element 112 can be pivotally coupled to the operating unit 104 through U-pin 116. During “on” operation/during activation of the circuit breaker 126, the second latch element 112, can be operated by the operating unit 104, to engage the second latch element 112 with the first latch element 114.
[0042] In another embodiment, the C- link 122 can be configured between the first latch element 114 and the second latch element 112, wherein the second latch element 112, the first latch element 114, C-link 122 and the contact element120 may act as a single component. The operating unit 104 can operate the moving contact element 120 combination through U-pin 116 to close and open the circuit during normal on-off operation.
[0043] In another embodiment, the indicator 102 can be coupled to the operating unit 104, the indicator 102 can be adapted to indicate the fault conditions of the circuit breaker 126. The slider 108 can be configured in the electrical circuit, the slider 108 can be adapted to latch and de-latch the indicator 102 from the slider 108. The actuation device 118 can be configured in the electrical circuit, the actuation device 118, upon detection of the fault condition, adapted to disengage the second latch element 112 with the first latch element 114.
[0044] In another embodiment, fault indication mechanism has two stable position, trip and reset state, in presence of fault condition, the actuation device 118 comes out and can rotate/disengage the first latch element 114 from the second latch element 112. After disengagement of the first latch element 114 from the second latch element 112, the first latch element 114, C-link 122 and moving contact element 120 combination can be brought to “off” position/deactivated position by a first spring 124 (also referred to as a mechanism spring 124), and the operating unit 104 can be brought to “off” position by a second spring (also referred to as a knob biasing spring).
[0045] In an implementation, in response to fault condition, e.g., overcurrent, the actuation device 118 can contact the slider 108 to de-latch the indicator 102 from the slider 108. The de-latched indicator 102can be rotated to reach a trip state, to restrict the flow of current, when the operating unit 104can be activated from the trip state, to acknowledge the fault condition, and upon acknowledging the fault condition, the indicator 102 can be latched with the slider 108 at the reset state, to be activated by the operating unit 104, to perform normal operation of the electrical circuit.
[0046] For example, when the fault occurs, the actuation device 118 can contact the slider 108 to de-latch the indicator 102 from the slider 108, the de-latched indicator 102 can be rotated to reach the trip state, and when the operating unit 104 can be operated from the trip state to “on” condition, the indicator 102 can be configured to exert force on the first latch element 114 to disengage the first latch element 114 from the second latch element 112 to restrict the flow of current. After acknowledging the fault condition of the electrical circuit, the indicator 102 can be latched with the slider 108 by the mechanical means, and when the operating unit 104 can be operated from the reset state to the “on” state, the first latch element 114 can be adapted to be engaged with the second latch element 112 to allow the passage of current to perform normal operation of the electrical circuit.
[0047] In another embodiment, the indicator 102 can be brought back to reset state manually by any mechanical means before turning the circuit breaker 126 to “on” position. For example, in reset state, the indicator 102 gets latched with indicator slider 108. If the operating unit 104 is rotated to operate the circuit breaker 126 from reset condition, the first latch element 114 cannot be restricted by fault indicator 102 and the circuit breaker 126 can be switched to “on” position normally. In this manner, during fault condition, the apparatus 100 can ensure fault acknowledgement by the operator before subsequent switching operation. The fault acknowledgement mechanism can be used in low voltage switchgears, low voltage circuit breakers and the like. The apparatus can provide extra safety measure incorporated by fault acknowledgement feature.
[0048] FIG. 2 is schematic view illustrating the “off” condition of the apparatus, in accordance with an embodiment of the present disclosure.
[0049] Referring to FIG. 2, the apparatus 100 can be encased in the circuit breaker 126, the apparatus 100 may include the indicator 102 and the operating unit 104, the indicator 102 and operating unit 104 can be located in the circuit breaker 126. The operating unit 104turn the circuit breaker “off” to disconnect the protected circuit, or “reset” the circuit breaker 126 after a fault. The “off” condition200 of the apparatus100 may include many of the same components introduced in FIG.1above. Those components that are unchanged in this embodiment retain their original element number and are not reintroduced.
[0050] In an embodiment, during “on” operation the second latch element 112 can engage with the first latch element 114. The first latch element 114, the second latch element 112, C-link 122 and moving contact 120 may act as a single component. The operating unit 104 can operate the moving contact element 120 combination through U-pin 116 to close and open the circuit during normal “on-off” operation.
[0051] In presence of fault, the actuation device 118 comes out and rotates/disengages the first latch element 114 from the second latch element 112, wherein, upon disengagement of the first latch element 114 and the second latch element 112, the first latch element 112, the C-link 122, and the contact element 120 can be deactivated by the first spring 124 and the operating unit 104 can be deactivated by the second spring.
[0052] After disengagement of the latches, the first latch element 114, C-link 122 and moving contact element 120 combination is brought to “off” position by the mechanism spring 124 and the operating unit 104 is brought to “off” position by the second spring (i.e. the knob biasing spring). The operating unit 104 pulls back the second latch element 112 to reset position so that it can be engaged with first latch element 114 during subsequent operation as illustrated in FIG 2.
[0053] For example, in reset state or “off” state, the indicator 102 can be in latched condition with indicator slider 108 with the help of fault indicator biasing spring 110 as illustrated in FIG. 2. Due to the latching condition of the indicator 102 with the slider 108, the first latch element 114 can be engaged with the second latch element 112 and the circuit breaker 126 can be operated normally from off-on positions.
[0054] In another embodiment, the actuation device 118 can be triggered by the solenoid upon detection of fault state. The solenoid can be replaced by any electromechanical or any kind of actuation device to operate the main mechanism as well as fault acknowledgement mechanism and can be used any application where this kind of interlocking is required. The operation of fault acknowledgement mechanism is completely independent of main mechanism. So, this fault acknowledgement mechanism can be used with any other kind of mechanism to provide interlocking and indication.
[0055] In the present invention, the circuit breaker 126 has to reset after tripping for subsequent operation. Operator has to reset the circuit breaker by mechanical means only after tripping and not after switching “off” to operate the circuit breaker 126. In this way any attempt to operate the circuit breaker 126 without acknowledging the unhealthy condition of the circuit is eliminated to enhance safety. The fault acknowledgement mechanism is capable of effectively indicating fault condition.
[0056] FIG. 3 is a schematic view illustrating the “trip” condition 300of the apparatus, in accordance with an embodiment of the present disclosure.
[0057] Referring to FIG 3, the apparatus 100 can be encased in the circuit breaker 126, the apparatus 100 may include the indicator 102 and the operating unit 104, the indicator 102 and operating unit 104 can be located in the circuit breaker 126. The circuit breaker 126 can be tripped by fault conditions that may include any or a combination of overcurrent, short circuit and ground fault. The operating unit 104turn the circuit breaker “off” to disconnect the protected circuit, or “reset” the circuit breaker 126 after a fault.
[0058] In an embodiment, in presence of overcurrent, short circuit and ground fault, the actuation device 118 hits the slider 108, it slides and de-latches the indicator 102. De-latched fault indicator 102 rotates anti-clock wise due to fault indicator biasing spring 110 and goes to trip state as shown in FIG 3. At the trip state, when the operating unit 104 is operated, the indicator 102 can be configured to exert force on the first latch element 114 to disengage the first latch element 114 from the second latch element 112 to restrict the flow of current. Disengagement of the first latch element 114 from the second latch element 112 does not allow the circuit breaker 126 to be turned “on”.
[0059] For example, when the short circuit condition occurs, the actuation device 118 can contact the slider108to de-latch the indicator 102 from the slider 108, the de-latched indicator 102 can be rotated to reach the trip state, and when the operating unit 104 can be operated from the trip state to “on” condition, the indicator 102 can be configured to exert force on the first latch element 114 to disengage the first latch element 114 from the second latch element 112 to restrict the flow of current.
[0060] The indicator 102 needs to be brought back to reset state manually before turning the circuit breaker 126 to “on” position. Thus, the resetting button/mechanism also indicates the fault condition by changing its position. The apparatus 100 do not require additional components and hence additional hardware cost can be reduced and can improve safety by eliminating unwanted reclosing of circuit on fault. The apparatus 100 can achieve independent mechanism for contact system and fault acknowledgement.
[0061] FIG. 4 is schematic view illustrating the working condition 400 of apparatus from “trip” condition, in accordance with an embodiment of the present disclosure.
[0062] Referring to FIG 4, in presence of fault, when the actuation device 118 comes in contact with the slider 108, it de-latches the indicator 102 from the slider 108. De-latched fault indicator 102 rotates anti-clock wise due to fault indicator biasing spring 110 and goes to trip state as shown described above in FIG. 3, when the operating unit 104 is rotated to switch the circuit breaker 126 to “on” position from the trip condition, the first latch element 114 contacts the indicator 102 after certain rotation.
[0063] In another embodiment, in case of further rotation, fault indicator 102 can exert force on the first latch element 114 and disengages from the second latch element 112. Disengagement of the first latch element 114 from the second latch element 112 does not allow the circuit breaker 126 to get turned “on”. The indicator 102 needs to be brought back to reset state manually before turning the circuit breaker to “on” position. At the reset state, the indicator 102 can be latched with the slider 108, and when the operating unit 104 can be activated from the reset state, the first latch element 114can be adapted to be engaged with the second latch element 112 to allow the passage of current.
[0064] For example, upon acknowledging the fault condition, the indicator 102 can be latched with the slider 108 by the mechanical means, and when the operating unit 104 can be operated from the reset state to the “on” state, the first latch element 114can be adapted to be engaged with the second latch element 112 to allow the passage of current to perform normal operation of the electrical circuit.
[0065] In reset state, for example, the fault indicator 104 gets latched with indicator slider 108 as shown in FIG. 2. If the operating unit 104 is rotated to operate the circuit breaker 126 from reset condition, the first latch element 114 cannot be restricted by fault indicator 102 and the circuit breaker 126 can be switched on normally. In this way an extra safety measure is incorporated by fault acknowledgement feature. Thus, the apparatus 100can operate the circuit breaker by acknowledging the unhealthy condition of the circuit to enhance safety. The apparatus in which the complicated mechanism of three stable state “on”, “trip” and “off” is not required. Capable of differentiating between tripping due to any fault and tripping due to external signal given by any accessories as the fault acknowledgement mechanism of present disclosure is independent of main mechanism circuit breaker.
[0066] It will be apparent to those skilled in the art that the apparatus 100 of the disclosure may be provided using some or all of the mentioned features and components without departing from the scope of the present disclosure. While various embodiments of the present disclosure have been illustrated and described herein, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the disclosure, as described in the claims.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0067] The present disclosure provides an apparatus that can ensure fault acknowledgement by operator before subsequent switching operation.
[0068] The present disclosure provides an apparatus in which the complicated mechanism of three stable state on, trip and off is not required.
[0069] The present disclosure provides an apparatus in which same fault acknowledgement mechanism is capable of indicating fault condition.
[0070] The present disclosure provides an apparatus that do not require additional components and hence additional hardware cost can be reduced.
[0071] The present disclosure provides an apparatus, which can improve safety by eliminating unwanted reclosing of circuit on fault.
[0072] The present disclosure provides an apparatus in which independent mechanism for contact system and fault acknowledgement can be achieved.
[0073] The present disclosure provides an apparatus that can operate the circuit breaker by acknowledging the unhealthy condition of the circuit to enhanced safety.
[0074] The present disclosure provides an apparatus in which the resetting button/mechanism indicates the fault condition by changing its position.
[0075] The present feature provides an apparatus that is designed to acknowledge fault and eliminate any unintentional circuit re-closer on fault.