Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
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Textbook Question
Chapter 12, Problem 6SQ
When the thermostat contacts close, the blower motor does not start. During troubleshooting of the unit, a voltmeter placed across the bottom terminals of the circuit breaker indicates a voltage of 240 volts. When the voltmeter is placed across the secondary of the transformer it indicates a voltage of 24 volts. When placed across the thermostat contacts it indicates 0 volts. When the voltmeter is placed across the coil of CR relay it indicates 24 volts. When the voltmeter is placed across the flow switch contacts it indicates 0 volts. When placed across the coil of HR contactor coil it indicates 0 volts, and when placed across the coil of BMR contactor it indicates 0 volts. Which of the following is the problem?
- a. CR coil is open.
- b. BMR coil is open.
- c. The thermostat is defective.
- d. The flow switch is defective.
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Chapter 12 Solutions
Electric Motor Control
Ch. 12 - Prob. 1SQCh. 12 - Draw a line diagram to show that a green light...Ch. 12 - Draw a one-line diagram showing a bell that will...Ch. 12 - To answer the following questions refer to Figure...Ch. 12 - When the thermostat contacts close, the blower...Ch. 12 - When the thermostat contacts close, the blower...Ch. 12 - When the thermostat contacts close the blower...
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