Correct Answer - Option 1 : Open conductor fault
Electrical faults in three-phase power system mainly classified into two types, namely open and short circuit faults.
Open circuit faults: These faults occur due to the failure of one or more conductors. The most common causes of these faults include joint failures of cables and overhead lines, and failure of one or more phase of circuit breaker and also due to melting of a fuse or conductor in one or more phases.
Type of open circuit faults:
- Single phase open circuit fault
- Two phase open circuit fault
- Three phase open circuit fault
Open circuit faults are also called as series faults. These are unsymmetrical or unbalanced type of faults except three phase open fault.
Shunt faults:
The shunt fault involves short circuit between conductor and ground or short circuit between two or more conductors.
The shunt faults are characterized by:
- Increase in current
- Fall in voltage
- Fall in frequency
Shunt faults are classified as follows:
- Single line to Ground fault (LG fault)
- Line to Line fault (LL fault)
- Double line to Ground fault (LLG fault)
- Three phase faults
