Red Seal Electrician Practice
MotorsQuestion 1299 of 1506

What opens the starting winding of a resistance split-phase motor?

  1. A thermal relay that opens at about 50% of the speed
  2. A push button held by the operator
  3. A fuse in the auxiliary winding
  4. A centrifugal switch near 3/4 of synchronous speed
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Correct answer: A centrifugal switch near 3/4 of synchronous speed

The starting torque is moderate, and the winding is cut out once the rotor is fast enough.

Source: Lessons in Electric Circuits II: AC (Kuphaldt), 13.9: Single-phase Induction Motors

Practice motors

Questions last reviewed: 18 October 2026