Need for Protective Systems & types of faults

To prevent the equipment from short circuits and other abnormal conditions often occur on power system.

Types of faults

1) Symmetrical faults: 3 phase fault 

2) Unsymmetrical faults: Single phase to ground fault. Short circuit between anyone of the phase        conductors and earth

a) Two phase to ground fault: Short circuit between any two phases and earth

b) Phase to phase fault: Short circuit  between any two phases

c) Open circuited phase fault: Caused by a break in conducting path occur when one or more phase            conductors break or cable joint

d) Winding fault: Circuit circuiting of turns

3) Simultaneous faults: Two or more faults occurring simultaneously