Circuit interrupting device with lock out and reversible wiring
A resettable circuit interrupting device such as a GFCI that is immune to the problem of reverse wiring and, therefore, has load-line terminals that can be interchangeably connected to either at least one load or to a power source. Regardless of how the load-line terminals are connected, the resettable circuit interrupting device operates properly and retains leakage current fault protection. The circuit interrupting device includes an interrupting portion disposed within the device configured to cause electrical discontinuity in either the phase and/or neutral conductive paths between the line side and the load side upon the occurrence of a leakage condition. A reset portion disposed at least partially within the device is configured to initially establish or, after the detection of a leakage current fault, reestablish electrical continuity between the load and the line. The device comprises two differential transformers, one to detect leakage current when the load is connected to the load terminals, and the second coupled to detect leakage current when the load is connected to the line terminals. Separate rectifiers coupled to the differential transformers operate to power a solenoid to disconnect the line from the load upon the detection of leakage current in the load path.
1. A circuit interrupting device comprising:
a first pair of terminals adapted for connection to line and neutral terminals of a power source or a load circuit; a second pair of terminals adapted for connection to line and neutral terminals of a power source when said first pair of terminals is connected to a load circuit or for connection to a load circuit when said first pair of terminals is connected to line and neutral terminals of a power source, or adapted to be left unconnected when the first pair of terminals are connected to line and neutral terminals of a power source; and a third pair of terminals adapted for connection to a load provided by a user, and
detection circuitry coupled to the first, second and third pair of terminals.
2. The device of claim 1 wherein the detection circuitry comprised at least first and second differential transformers each coupled to detect leakage current in the load circuit.
3. The device of claim 2 wherein the first differential transformer is coupled to detect leakage current in a load circuit coupled to the first pair of terminals and the third pair of terminals.
4. The device of claim 2 wherein the second differential transformer is coupled to detect a leakage current in a load circuit coupled to the second pair of terminals and the third pair of terminals.
5. The device of claim 2 wherein the first differential transformer is coupled to detect leakage current when a load circuit is coupled to the first and/or third pair of terminals and the second differential transformer is coupled to detect leakage current when a load circuit is coupled to the second and/or third pair of terminals.
6. The device of claim 5 wherein the first and second differential transformers are coupled through a four pole double throw latch to at least one rectifier.
7. The device of claim 6 wherein the first differential transformer is coupled through first and second poles of the four pole double throw latch to a first rectifier and the second differential transformer is coupled through third and fourth poles of the four pole double throw latch to a second rectifier.
8. The device of claim 7 wherein the first rectifier is a one-half wave or a full wave rectifier.
9. The device of claim 8 wherein the second rectifier is a one-half wave or a full wave rectifier.
10. The device of claim 9 wherein the four pole double throw latch has at least four wiper arms each of which makes contact with a first of two contacts when in a first position and the second of the two contacts when in a second position.
11. The device of claim 10 further comprising:
a reset button, when depressed, is coupled to move the at least four wiper arms to their second position to contact their second contacts.
12. The device of claim 11 further comprising a spring coupled to urge the reset button to its up position.
13. The device of claim 11 further comprising a solenoid activated by one of the rectifiers when either the first or second differential transformer detects leakage current to open the connection between the wiper arms and their contacts to break the electrical connection between the line and the load circuit.
14. The device of claim 11 further comprising a second spring coupled to the reset button to urge the four pole double throw latch to couple the load circuit to the line when the reset button is pressed.