METHODS AND APPARATUS TO FACILITATE GROUND FAULT PROTECTION AND SELF TEST WITH A SINGLE SWITCH
First Claim
1. A ground fault detection device comprising:
- a ground fault detector to receive a signal indicative of current in a line conductor and a neutral conductor; and
a single switch to simulate a fault during a self test and to cause a relay to activate in response to at least one of a real fault or a failed self-test.
1 Assignment
0 Petitions
Accused Products
Abstract
Methods and apparatus to facilitate ground fault protection and self test with a single switch are disclosed. An example ground fault detection device includes a ground fault detector to receive a signal indicative of current in a line conductor and a neutral conductor, and a single switch to simulate a fault during a self test and to cause a relay to activate in response to at least one of a real fault or a failed self-test. An example method to self-test a ground fault detection device includes monitoring a self-test indicator for an indication to initiate the self-test, and when the indication to inititate the self-test is true, activating a switch to cause at least one fault diode to conduct for a predetermined self-test duration. The example method also includes monitoring at least one of a sense coil or the switch for a signal indicative of the self-test.
30 Citations
41 Claims
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1. A ground fault detection device comprising:
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a ground fault detector to receive a signal indicative of current in a line conductor and a neutral conductor; and a single switch to simulate a fault during a self test and to cause a relay to activate in response to at least one of a real fault or a failed self-test. - View Dependent Claims (2, 4, 5)
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3. (canceled)
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6. A ground fault detection device comprising:
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a sense coil to detect current in at least one of a line conductor or a neutral conductor; a ground fault detector connected to the sense coil to monitor a current in the line conductor and the neutral conductor; a switch to conduct a fault simulation current in at least one of the line conductor or the neutral conductor, the switch fault simulation current to simulate a fault signal detected by the sense coil; and a relay coil connected to the switch to at least one of allow at least one of the line conductor current or the neutral conductor current during the fault simulation, to disconnect at least one of the line conductor current or the neutral conductor current to a load during a real ground fault, or to allow at least one switch test. - View Dependent Claims (7, 8, 12)
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9. (canceled)
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10. (canceled)
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11. (canceled)
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13. A method to self-test a ground fault detection device comprising:
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monitoring a self-test indicator for an indication to initiate the self-test; when the indication to initiate the self-test is true, activating a switch to cause at least one fault diode to conduct for a predetermined self-test duration; and monitoring at least one of a sense coil or the switch for a signal indicative of the self-test. - View Dependent Claims (14, 16, 18, 19)
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15. (canceled)
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17. (canceled)
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20-28. -28. (canceled)
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29. A ground fault detection device comprising:
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a sense coil to detect current in a line conductor and a neutral conductor, the line conductor and the neutral conductor passing through the sense coil at a first location, and a ground fault detector circuit connected to the sense coil; a first power tap connected to the line conductor and the neutral conductor at a second location preceding the first location to provide power to the ground fault detector circuit; a second power tap connected to the line conductor and the neutral conductor at a third location after the first location to provide power to the ground fault detector circuit; a first fault tap connected to the second location; and a second fault tap connected to the third location. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 38, 39, 40, 41)
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37. (canceled)
Specification