A Ground-Fault Circuit Interrupter or GFCI is a protection device designed to turn off electricity to a circuit in the event of a ground-fault in as little as 25 milliseconds to help prevent electrical shock. These devices are found in areas prone to electrocution hazards like kitchens, bathrooms, and outside receptacles. Charles Dalziel invented the Ground-Fault Circuit Interrupter in 1961.
A/C voltage or alternating current cycles back and forth between the hot and neutral wires 60 times a second. A GFCI measures the outgoing and incoming current and looks for a difference of 5 or more milliamps which is evidence of voltage leakage in a circuit (Ground Fault). If an imbalance is detected the GFCI device will trip, opening the circuit to prevent further electricity flow.
Fact: A/C current as small as 100 milliamps can be fatal.
Manufacturers recommend you check your Ground-Fault Circuit Interrupter devices monthly, simply pushing the test button on devices or breakers should instantly turn the power off, then reset to restore power. If the GFCI doesn’t test correctly you are at risk, when was the last time you performed a test?
As of June 29, 2015 Underwriters Laboratories Inc (UL) has required all new GFCI’s to be manufactured with a self-testing feature because very few consumers ever tested their GFCI devices for correct operation.
Fact: The Equipment Grounding Conductor or GROUND has nothing to do with the function of Ground-Fault Circuit Interrupters. Ground wires do not need to be present, only the hot and neutral wired are being monitored.
There are few other devices similar to GFCI’s such as an Arc Fault Circuit Interrupter (AFCI), Immersion-detection circuit-interrupter (IDCI), and ground-fault protection of equipment (GFPE) but for general residential applications, GFCI and AFCI are the most common in use. Read more about AFCI Protection.
The NEC or National Electrical Code started requiring GFCI protection in 1971, since then GFCI Protection has been expanded to many different areas to provide maximum safety. Article 210 of the National Electrical Code covers Branch Circuits and will give you an in-depth guide to which areas require Ground-Fault Circuit Interrupter (GFCI) protection.
Fact: GFCI is not required for ceiling receptacles feeding garage door openers because this is not considered readily accessible.
Having GFCI and AFCI protection installed correctly are LIFE critical. If you are unsure about the locations that require protection or the correct installation of devices or breakers please consider Hiring an Electrician in Greenville SC.