What is the difference between an arc fault breaker and and a ground fault breaker?

Answer 1

A ground fault circuit interrupter is as its name implies, a device (circuit breaker or special receptacle) which interrupts (shuts down) a circuit when it detects a ground fault (current flowing to ground). When a small amount of current (4 to 6 milliamperes) is detected flowing to ground by the electronics within the device it trips so that no more current can flow, thereby possibly saving your life. Example: you are listening to the radio while having a bath and it falls into the tub--- the circuit will turn off before you can be harmed. GFCI's as they are commonly called are required by the Electrical Code to be installed in bathrooms, kitchens where the receptacle is within one meter of the sink, any outdoor location (rain and snow) and any other wet or damp locations. (refer to code book) An Arc Fault Circuit Interrupter is a device( I've seem breakers but am unsure whether there is a special AFCI receptacle) which shuts off a circuit when it detects an arcing condition in the circuit. An example of arcing would be when you pull the plug out of a wall receptacle when the device plugged in is under load (turned on) and you see a little (sometimes big depending on the size of the load) bluish or yellowish flash or "arc". Receptacles on AFCI circuit breakers are required by the electrical code to be installed in bedrooms. It has something to do with the flammability of linens and blankets I believe, but here again for detailed info please consult the official Electrical Code book for your location.

Answer 2

A ground fault breaker, or outlet can tell when the current leaks to a different ground.

These are used when or in the area of water.

An ARC fault breaker can tell when an Arc occurs, such as the hot line contacting the neutral, which causes an ARC and has lead to sparks and fires. Most new construction homes have ARC fault breakers for bedrooms.

Answer 3

Simplified, an arc can occur without tripping a breaker. An arc is often the result of a poor connection or a worn contact on a switch. Equipment plugged in to an outlet will draw current. While drawing current, an attachment screw on the outlet may be loose. This is high resistance. Volts equal amps x resistance. While the equipment is drawing current, the poor contact surface at the screw will slightly arc, often barely perceptible but extreme local heat is generated. The small, high temperature arc can cause a fire over time. These are sneaky little trouble makers. The AFCI breaker detects the noise associated with arcing and will trip.

GFCI breakers simply compare line current to load current. When 5mA or more is unaccounted for, the breaker trips.

Arc fault breakers were first required for bedrooms because so many fires were created by bedroom extension cords and lamp cords that shorted and arced. A GFCI would not detect that fault.

Answer 4

They are totally different. The GFCI is used to protect you from an electrical shock but an AFCI is used to prevent a fire. A GFCI will detect any measurable difference in the voltage returning to the circuit and shut the circuit off when it is detected. A AFCI breaker will detect a spark or arc which causes overheating of the outlet or wiring. It will turn the circuit off when it detects a spark or arc.