Chapter 14, Problem 1SQ

What is the purpose of phase failure relays?

To determine

State the purpose of phase failure relays.

Answer to Problem 1SQ

The purpose of phase failure relay is to disconnect the loads on the event of phase failure.

Explanation of Solution

Phase failure relay:

Phase failure relay are the type of protective relays. When the three-phase motor is running, if a fuse blows or the wire connected to motor breaks, the motor will operate in single-phase but the serious over-heating might occur. To prevent the motor from these situations, phase failure relay is utilized.

The main purpose of phase failure relays is to disconnect loads, like motors, from the power supply in the event they fail.

Conclusion:

Thus, the purpose of phase failure relay is to disconnect the loads on the event of phase failure.