Refer to the circuit shown in Figure 37–1. Assume that timer TR is set for a delay of 10 seconds. When the Start button is pressed, the motor starts in low speed. After a delay of 30 seconds, the motor is still in its lowest speed and has not accelerated to normal speed. Which of the following could not cause this condition? a. The Start button is shorted. b. Timer coil TR is open. c. Contactor coil R is open. d. Timed contact TR did not close after a delay of 10 seconds.

Refer to the circuit shown in Figure 37–1. Assume that timer TR is set for a delay of 10 seconds. When the Start button is pressed, the motor starts in low speed. After a delay of 30 seconds, the motor is still in its lowest speed and has not accelerated to normal speed. Which of the following could not cause this condition? a. The Start button is shorted. b. Timer coil TR is open. c. Contactor coil R is open. d. Timed contact TR did not close after a delay of 10 seconds.

Electric Motor Control

10th Edition

ISBN:9781133702818

Author:Herman

Publisher:Herman

Chapter43: About Dc Motors

Section: Chapter Questions

Problem 1SQ

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