Circuit protection device with timed negative half-cycle self test
First Claim
1. An electrical wiring protection device for use in coupling AC power through an AC power distribution system to at least one electrical load, the device comprising:
- an automated self-test circuit coupled to the AC power distribution system and configured to generate at least one simulated fault signal during a first predetermined half-cycle polarity of AC power;
a detector circuit coupled to the automated self-test circuit, the detector circuit generating a detection signal in response to the at least one simulated fault signal; and
an interval timing circuit coupled to the automated self-test circuit, the interval timing circuit being configured to enable the automated self-test circuit to generate the at least one simulated fault signal during a first predetermined interval and not enable the automated self-test circuit during a subsequent second predetermined interval, the first predetermined interval and the second predetermined interval being recurring time intervals.
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Accused Products
Abstract
The present invention is directed to an electrical wiring protection device for use in coupling an AC power distribution system to at least one electrical load. The device includes an automated self-test circuit coupled to the AC power distribution system. The automated self-test circuit is configured to generate at least one simulated fault signal during a first predetermined half-cycle of AC power. A detector circuit is coupled to the automated self-test circuit. The detector circuit generates a detection signal in response to the at least one simulated fault signal. An interval timing circuit is coupled to the test circuit. The interval timing circuit is configured to enable the automated self-test circuit to generate the at least one simulated fault signal during a first predetermined interval and not enable the test circuit during a subsequent second predetermined interval. The first predetermined interval and the second predetermined interval are recurring time intervals.
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Citations
71 Claims
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1. An electrical wiring protection device for use in coupling AC power through an AC power distribution system to at least one electrical load, the device comprising:
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an automated self-test circuit coupled to the AC power distribution system and configured to generate at least one simulated fault signal during a first predetermined half-cycle polarity of AC power;
a detector circuit coupled to the automated self-test circuit, the detector circuit generating a detection signal in response to the at least one simulated fault signal; and
an interval timing circuit coupled to the automated self-test circuit, the interval timing circuit being configured to enable the automated self-test circuit to generate the at least one simulated fault signal during a first predetermined interval and not enable the automated self-test circuit during a subsequent second predetermined interval, the first predetermined interval and the second predetermined interval being recurring time intervals. - 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, 53)
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25. An electrical wiring protection device for use in coupling an AC power through an AC power distribution system to at least one electrical load, the device comprising:
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a test circuit coupled between a hot conductor and a neutral conductor of the AC power distribution system, the test circuit being configured to generate at least one simulated fault signal during a first predetermined half-cycle polarity of AC power;
a detector circuit coupled to the test circuit, the detector circuit generating a detection signal in response to the at least one simulated fault signal;
an interval timing circuit coupled to the test circuit, the interval timing circuit being configured to enable the test circuit to generate the at least one simulated fault signal during a first predetermined interval and not enable the test circuit during a subsequent second predetermined interval, the first predetermined interval and the second predetermined interval being recurring time intervals;
a gate circuit coupled to the detector circuit, the gate circuit generating a gated test detection pulse in response to receiving the detection signal, the gated test detection pulse corresponding to the at least one simulated fault signal and having a duration not extending into a second predetermined half-cycle polarity of AC power subsequent to the first predetermined half-cycle of AC power;
a checking circuit coupled to the gate circuit, the checking circuit including a timer configured to initiate an end-of-life fault signal if the gated test detection pulse is not received within a predetermined period of time; and
a response mechanism coupled to the checking circuit, the response mechanism being actuated in response to the end-of-life fault signal. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47)
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48. An electrical wiring protection device for use in coupling an AC power distribution system to at least one electrical load, the device comprising:
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a test circuit coupled to the AC power distribution system and configured to generate at least one simulated fault signal during a first predetermined half-cycle polarity of AC power;
a detector circuit coupled to the test circuit, the detector circuit generating a detection signal in response to the at least one simulated fault signal;
a processor coupled to the test circuit and the detector circuit, the processor being programmed to, generate a self-test enable signal during a first predetermined time interval and not during a second predetermined time interval, the self-test enable signal enabling the test circuit to generate the at least one simulated fault signal, and generate a gated test detection pulse in response to receiving the detection signal, the gated test detection pulse corresponding to the at least one simulated fault signal and having a pulse duration not extending into a second predetermined half cycle polarity of AC power subsequent to the first predetermined half cycle polarity of AC power;
a checking circuit coupled to the processor, the checking circuit including a timer configured to initiate an end-of-life fault signal if the gated test detection pulse is not received within a predetermined period of time; and
a response mechanism coupled to the checking circuit, the response mechanism being actuated in response to the end-of-life fault signal. - View Dependent Claims (49, 50, 51, 52, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68)
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69. A method for automatically self testing an electrical wiring protection device for use in coupling an AC power distribution system to at least one electrical load, the device comprising:
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generating at least one simulated fault signal during a first predetermined polarity of AC power, the at least one simulated fault being generated during a test state interval and not being generated during a subsequent non-test state interval, the test state interval and the non-test state interval being recurring time intervals each of predetermined length;
transmitting a detection signal in response to detecting the at least one simulated fault signal;
generating an grated test detection pulse in response to the detection signal, the gated test detection pulse having a pulse duration not extending into a second predetermined polarity of AC power; and
initiating an end-of-life fault signal if the gated detection pulse is not received within a predetermined period of time. - View Dependent Claims (70, 71)
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Specification