Arc-fault circuit interrupter
[3] In regions using 230 V, the combination of higher voltage and lower load currents lead to different conditions being required to initiate an arc fault that does not either burn clear or weld to a short circuit after a short time, and there are different arc characteristics once struck.
The Australian and New Zealand regulations – Wiring Rules (AS NZS 3000:2018) do not require installation of AFDDs in Australia.
AFCIs are devices designed to protect against fires caused by arcing faults in the home electrical wiring.
The AFCI circuitry continuously monitors the current and discriminates between normal and unwanted arcing conditions.
Once detected, the AFCI opens its internal contacts, thus de-energizing the circuit and reducing the potential for a fire to occur.
[7] The electronics inside an AFCI breaker detect electrical current alternating at characteristic frequencies, usually around 100 kHz, known to be associated with wire arcing, which are sustained for more than a few milliseconds.
This requirement may be accomplished by using a "combination type" breaker—a specific kind of circuit-breaker defined by UL 1699—in the breaker panel that provides combined arc-fault and overcurrent protection or by using an AFCI receptacle for modifications/extensions, as replacement receptacles or in new construction, at the first outlet on the branch.
These receptacles are designed to address the dangers associated with both types of potentially hazardous arcing: parallel and series.
AFCI receptacles offer the benefit of localized test and reset with such buttons located on the face of the device.
In 2002, the NEC removed the word "receptacle", leaving "outlets", with the effect that lights and other wired-in devices such as ceiling fans within bedrooms were added to the requirement.
The 2005 code made it clearer that all outlets must be protected despite discussion in the code-making panel about excluding bedroom smoke detectors from the requirement.
"Outlets" as defined in the NEC includes receptacles, light fixtures and smoke alarms, among other things.
[10] The Australian and New Zealand regulations – Wiring Rules (AS NZS 3000:2018) do not require installation of AFDDs in Australia.
For instance, lightning strikes provide voltage and current profiles that resemble arc faults, and vacuum cleaners and some laser printers trip AFCIs.
[12] AFCI circuit breakers include a standard inverse-time circuit breaker but provide no specific protection against "glowing" connections (also known as a high resistance connection), high line voltages, or low line voltages.
An AFCI does not detect high line voltage caused by an open neutral in a multiwire branch circuit.
Power fault circuit interrupters are designed to prevent fires from low voltage across loads.
