Electrical wiring device with protective features
First Claim
1. An electrical wiring device for use in an electrical distribution system including a plurality of line conductors coupled to a source of AC power and a plurality of load conductors, comprising:
- a plurality of line terminals configured to terminate the plurality of line conductors and a plurality of load terminals configured to terminate the plurality of load conductors, the electrical wiring device being in a properly wired condition when the plurality of line conductors are terminated to the plurality of line terminals and in a miswired condition when the plurality of line conductors are terminated to the plurality of load terminals;
a circuit interrupter assembly including a plurality of moveable contacts, the plurality of movable contacts being configured to be latched into a reset state in response to a reset stimulus whereby the plurality of line terminals are electrically coupled to the plurality of load terminals, the movable contacts being configured to be driven into a tripped state in response to a tripping stimulus whereby the plurality of line terminals are electrically decoupled from the plurality of load terminals;
a protective circuit assembly including at least one power supply coupled to the plurality of line terminals, the at least one power supply being charged in the reset state and in the tripped state when the device is in the properly wired condition, the protective circuit assembly including an automatic test circuit configured to introduce a test fault condition during a predetermined test interval when the device is in the reset state or when the device is in the tripped state and in the properly wired condition, the protective circuit assembly also including at least one fault detector deriving power from the at least one power supply and configured to generate a fault detection signal based on electrical perturbations propagating on at least one of the plurality of line terminals and a test fault detection signal in response to the test fault condition if the protective circuit assembly is operable and the at least one power supply is substantially charged; and
a device integrity evaluation circuit coupled to the plurality of load terminals, the device integrity evaluation circuit including a timing circuit configured to provide a time measurement and the tripping stimulus when the time measurement exceeds a predetermined threshold, the test fault detection signal resetting the time measurement in the properly wired condition before the time measurement exceeds the predetermined threshold but does not reset the time measurement in the miswired condition.
1 Assignment
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Accused Products
Abstract
The present invention is directed to an electrical wiring device for use in an electrical distribution system. The device includes a plurality of line terminals configured to terminate the plurality of line conductors and a plurality of load terminals configured to terminate the plurality of load conductors. The protective circuit assembly includes at least one fault detector configured to generate a fault detection signal based on electrical perturbations propagating on at least one of the plurality of line terminals or at least one of the plurality of load terminals. A device integrity evaluation circuit includes a timing circuit coupled to the source of AC power by way of the plurality of load terminals and configured to generate a time measurement. The device integrity evaluation circuit is configured to reset the time measurement if the protective circuit assembly generates the fault detection signal during a predetermined test interval in the properly wired condition. The device integrity evaluation circuit is configured to generate a device integrity fault signal when the time measurement exceeds a predetermined threshold. A circuit interrupter assembly includes movable contacts configured to be latched into a reset state in response to a reset stimulus. The movable contacts are configured to be driven into a tripped state in response to the fault detection signal or the device integrity fault signal.
235 Citations
53 Claims
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1. An electrical wiring device for use in an electrical distribution system including a plurality of line conductors coupled to a source of AC power and a plurality of load conductors, comprising:
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a plurality of line terminals configured to terminate the plurality of line conductors and a plurality of load terminals configured to terminate the plurality of load conductors, the electrical wiring device being in a properly wired condition when the plurality of line conductors are terminated to the plurality of line terminals and in a miswired condition when the plurality of line conductors are terminated to the plurality of load terminals; a circuit interrupter assembly including a plurality of moveable contacts, the plurality of movable contacts being configured to be latched into a reset state in response to a reset stimulus whereby the plurality of line terminals are electrically coupled to the plurality of load terminals, the movable contacts being configured to be driven into a tripped state in response to a tripping stimulus whereby the plurality of line terminals are electrically decoupled from the plurality of load terminals; a protective circuit assembly including at least one power supply coupled to the plurality of line terminals, the at least one power supply being charged in the reset state and in the tripped state when the device is in the properly wired condition, the protective circuit assembly including an automatic test circuit configured to introduce a test fault condition during a predetermined test interval when the device is in the reset state or when the device is in the tripped state and in the properly wired condition, the protective circuit assembly also including at least one fault detector deriving power from the at least one power supply and configured to generate a fault detection signal based on electrical perturbations propagating on at least one of the plurality of line terminals and a test fault detection signal in response to the test fault condition if the protective circuit assembly is operable and the at least one power supply is substantially charged; and a device integrity evaluation circuit coupled to the plurality of load terminals, the device integrity evaluation circuit including a timing circuit configured to provide a time measurement and the tripping stimulus when the time measurement exceeds a predetermined threshold, the test fault detection signal resetting the time measurement in the properly wired condition before the time measurement exceeds the predetermined threshold but does not reset the time measurement in the miswired condition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44)
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45. A method for electrical power to a load via an electrical distribution system including a plurality of line conductors coupled to a source of AC power and a plurality of load conductors, the method comprising:
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providing an electrical wiring device including a plurality of line terminals configured to terminate the plurality of line conductors and a plurality of load terminals configured to terminate the plurality of load conductors, the electrical wiring device being in a properly wired condition when the plurality of line conductors are terminated to the plurality of line terminals and in a miswired condition when the plurality of line conductors are terminated to the plurality of load terminals, the plurality of line terminals being electrically coupled to the plurality of load terminals in a reset state, the plurality of line terminals being electrically decoupled from the plurality of load terminals in a tripped state; charging at least one power supply when the device is in the reset state, and when the device is in the tripped state and in the properly wired condition; introducing a test fault condition during a predetermined test interval when the device is in the reset state, or when the device is in the tripped state and in the properly wired condition; generating a test fault detection signal in response to detecting the test fault condition if the at least one power supply is substantially charged, the test fault detection signal indicating that the device is operable, a failure to generate the test fault detection signal within a predetermined time period indicating that the device is at end-of-life; measuring elapsed time when the test fault condition is introduced; and providing a test failure signal and a tripping stimulus if the elapsed time is substantially greater than the predetermined time period, or resetting the elapsed time measurement in response to generating the test fault detection signal, the elapsed time not being reset when the device is in the miswired condition. - View Dependent Claims (46, 47, 48, 49, 50, 51, 52, 53)
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Specification