Question

The relay which is connected in series with the running winding is:

• A. Voltage starting relay
• B. Hot wire relay
• C. Current starting relay
• D. Both (A) and (B)

Hint:

Voltage and hot wire relays = series with running winding!

Answer 1

The Correct Option is D

In single-phase induction motors, relays are used for starting and protecting windings.
A voltage starting relay and a hot wire relay are both types of starting relays connected in series with the running winding.
These relays sense the motor’s operating conditions and help disconnect the starting winding once the motor reaches the required speed.
The voltage starting relay works by responding to the back EMF generated in the running winding.
The hot wire relay uses the heat generated by current to operate a bimetal strip or wire.
The current starting relay is generally connected in series with the starting winding, not the running winding.
Therefore, both (A) and (B) are correct.