Leakage current detection interrupter extension cord with cord diagnostics and/or inadvertent ground-to-neutral detection
First Claim
1. An electrical extension cord comprising:
- an electrical cable including separate, insulated phase, neutral and ground conductors surrounded by a conductive sensing shield wherein said cable is electrically connected at first ends of the phase, neutral, ground conductors and conductive sensing shield to a receptacle, an electrical plug comprising a plug housing, phase, neutral and ground plug blades, and a fault circuit interrupter wherein the fault circuit interrupter is electrically connected at load end phase, neutral and shield ports to the cable at second ends of the phase, neutral and shield conductors, and at line end phase and neutral ports to the phase and neutral plug blades and wherein the ground conductor is electrically connected to the ground plug blade, such that leakage current is collected by the shield enabling protection of the extension cord by the fault circuit interrupter.
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Accused Products
Abstract
With prior art Immersion Detection Circuit Interrupters (IDCI), the firing of the trip coil to open the contacts which interrupts the flow of current to a load uses the neutral conductor as the return path when leakage is detected. If, however, the neutral conductor should become open, there is no return path present to fire the coil. An unsafe condition because the voltage that is present cannot be disconnected from the load. With this invention the SCR, which is used to fire the coil, now uses the ground conductor and diodes as the return path to fire the coil to interrupt the voltage from the load. A fully shielded cord is used to detect a break in a conductor. An LED indicator in either the plug or the receptacle of the extension cord verifies that protection is available. A test button is provided to test shield continuity and to verify proper circuit operation.
27 Citations
20 Claims
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1. An electrical extension cord comprising:
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an electrical cable including separate, insulated phase, neutral and ground conductors surrounded by a conductive sensing shield wherein said cable is electrically connected at first ends of the phase, neutral, ground conductors and conductive sensing shield to a receptacle, an electrical plug comprising a plug housing, phase, neutral and ground plug blades, and a fault circuit interrupter wherein the fault circuit interrupter is electrically connected at load end phase, neutral and shield ports to the cable at second ends of the phase, neutral and shield conductors, and at line end phase and neutral ports to the phase and neutral plug blades and wherein the ground conductor is electrically connected to the ground plug blade, such that leakage current is collected by the shield enabling protection of the extension cord by the fault circuit interrupter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification