Sunday, January 19, 2014

What is AFCI (Arc Fault Circuit Interrupter)


What it is

AFCI (ARC Fault Circuit Interrupter) are the special circuit breakers inside the main Electrical panel which detects arching at the outlets in addition to performing as regular circuit breakers which offer protection against overload and short circuiting. They are very sophisticated devises which can detect special waveforms which are generated during arching at the outlet. AFCI can distinguish between the arching caused by regular operation i.e pulling out a cord and the one caused by an arc fault.

When the arc fault is detected the breakers opens the internal circuits within and thus stops the flow of current. Licensed Electrical contractor must be contacted to determine the cause of tripping before resetting it again.

What it an Arc Fault

We know that AFCI detects arc fault. But what exactly is an Arc Fault? To understand that first we need to know what is an arc? Arc is a luminous discharge of current that is formed when strong current jumps a gap (air) in a circuit or between two electrodes. The arc when generated produces heat and light which can burn the combustible material it comes in contact with. In houses arc fault is caused when loose or corroded connections make intermittent contact and causes arc. Arching should not be confused with short circuiting which is caused when a hot wire comes in contact with neutral or ground wire. If you ever heard buzzing or hissing sound at the outlets that is caused by arching.

Which circuits are protected with AFCI

After 2002 all 15 amp and 20 amp outlets in the bedrooms needs to be protected by AFCI breakers. In future more areas will be required to be protected. Every year many houses get burnt by fires caused by arc faults in the houses causing great deal of loss of life and property.