Motor controlsQuestion 94 of 1506

Why is a time-delay relay used in a reduced-voltage motor starter?

To keep the motor at reduced voltage for its whole running time
To open the overload contact after a delay, so the motor can restart by itself
To reverse the motor after a set time, so it brakes quickly
To apply full power after a set time, which lowers the inrush current on start

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Correct answer: To apply full power after a set time, which lowers the inrush current on start

Soft starts use reduced voltage first, then full power after the delay.

Source: Lessons in Electric Circuits IV: Digital (Kuphaldt), 5.3: Time-delay Relays

Questions last reviewed: 18 October 2026

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