Electrical Fault

Fault in electrical equipment or apparatus is defined as an imperfection in the electrical circuit due to which current is deflected from the intended path. In other words, the fault is the abnormal condition of the electrical system which damages the electrical equipment and disturbs the normal flow of the electric current.

The fault reduces the insulation strength between phase conductors and earth or any earthed screen surrounding the conductors. It also reduces the impedance (property of circuit to oppose the flow of current) between the conductors and earth due to which the heavy short circuit current flows through the system and damage the power system equipment.

The probability of the failure or occurrence of abnormal faults is more on the transmission lines. About one-half of the fault occurs on the power system is the transmission line fault. Because transmission lines are broadly branched, have a greater length, operate under variable weather conditions and are subjected to the action of atmospheric disturbances of an electrical nature.