ground-fault circuit interrupter
- Its abbreviation is GFCI. A special type of circuit breaker which continuously monitors the current flowing in both the hot and neutral wires. Normally, this amount would be equal, but if even if a slight current leaks to ground, be it through the ground wire or through a person being shocked, there will be more current in one than the other. The GFCI detects this, and shuts off all current flow within about 0.025 seconds, which should be fast enough to prevent any real harm to a person. Some GFCIs detect current differences of less than 0.001 amperes. There are various types of GFCIs, including the receptacle type, which replaces a conventional outlet, and those installed in a circuit-breaker panel. Also called ground fault interrupter.