The GFCI Breaker

A ground-fault circuit interrupter (GFCI) is used to prevent electrocution.It installed where electrical circuits are exposed to contact with water. These can be found in kitchens, bathrooms, laundry and such places where electric equipments and water is used together.

Electricity always wants to find a path to the ground. Ground fault means a conducting connection between any electric conductor and any conducting material that is grounded. Ina ground fault, electricity has found a path to ground, but causing a danger through a person’s body.

To save human from this shock, GFCI breaker protection is used. Other circuit breakers and fuses only protect equipment—they will not protect people.When a human body is receiving a shock; the GFCI senses this and cuts off the power before any injury is caused.

It is advised that GFC breaker be installed in areas where appliances and power tools are used in close exposure to water. Tap water or wet objects are able to conduct electricity very easily and can connect your body to a ground potential.This increases your chances of receiving a shock from a ground fault. Appliances that have built-in GFCI breaker protection, as now required for hair dryers, may not need additional GFCI protection, but there are still many appliances not equipped with GFCI protection.The GFCI will recognize the difference in the amount of electricity flowing into the circuit to that flowing out, even in amounts of current as small as 4 or 5 milli amps. As soon as this is identified, The GFCI reacts quickly (less than one-tenth of a second) to trip or shut off the circuit.

It is very important to check the functioning of these circuits every month. Being electronic devises, they can wear out. Using the test button on Fixed GFCI it is easy to test whether it is working or not. However, the portable GFCIs should be tested every time before using them. 

The trouble with GFCI is it takes only 5 mA (0.005 A) of current leakage from the hot wire to the ground to cause a GFCI to trip. A small amount of leakage current may be difficult to avoid in some normal circuits. Hand-held power tools maintained in good condition do not cause a tripping problem. Also permanently installed motors or fluorescent lighting fixtures can produce sufficient leakage to cause nuisance tripping. Another problem may be a long circuit with many splices. It is suggested to consider the effects of loss of power to a circuit before installing GFCI protection.