The contacts of a current starting relay are:

• A. Normally closed.
• B. Normally open.
• C. Changeover.
• D. Shorted.

Answer: (B)

The contacts are normally open because a current starting relay is designed to energize the start winding only during the initial startup. At rest, the start winding should be disconnected, so the contact remains open. When startup current flows, the relay coil is energized and the normally open contact closes to connect the start winding, providing the extra torque needed to start. As the motor comes up to speed, the current in the start winding drops, the relay releases, and the contact opens again to remove the start winding from the circuit.

If the contacts were normally closed, the start winding would stay connected all the time, wasting energy and causing overheating. A changeover contact would imply switching between circuits in a more complex way than needed for starting, and a shorted contact would keep the circuit closed permanently.