Circuit protection arrangements using ground fault interrupter for overcurrent and overvoltage protection

摘要

An electrical protection system which uses a ground fault interrupter (GFI) to protect a circuit from (A) ground faults and (B) overcurrents and/or overvoltages. For overcurrent protection, a control element may be coupled in series with the line or return input to the GFI, and a bypass element may be coupled in parallel with the control element and the GFI. In case of an overcurrent, the control element causes current to be diverted through the bypass element, thereby creating a current imbalance in the GFI circuitry causing the GFI to open the circuit. For overvoltage protection, a bypass element (e.g. a varistor) may be coupled between, e.g., the line sense input of the GFI and the return sense input of the GFI. In case of an overvoltage, the bypass element conducts current, thereby creating a current imbalance in the GFI circuitry causing the GFI to open the circuit.