Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
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Textbook Question
Chapter 2, Problem 10SQ
Select the best answer for each of the following.
Thermal overload protection
a. aids motor warm-up.
b. prevents motors from freezing.
c. protects motors and conductors from
d. provides overcurrent protection for motors.
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Students have asked these similar questions
1. It is a machine that converts mechanical energy to electrical energy.
2. It is a machine that converts electrical energy to mechanical energy.
3. It is cylindrical or drum-shaped where the coils are placed and can either be lap wounded or wave wounded.
4. It connects the commutator to the other parts of the DC machine.
5. It serves as the housing of the dc machine.
6. True or False: The shunt field winding is part of the armature.
7. True or False: The long shunt compound generator is when the armature is in series with the series field winding and parallel to the shunt field winding.
8-10. Your newly built house needs an elevator. Which from the following will be best to use- series, shunt or compound motor and why?
One type of failure that's more common with 200 HP motors than with 10 HP motors is
A. rotor bar failure.B. contactor failure.C. bearing failure.
D. stator failures.
a)Please explain the connection methods of Current and Voltage Transformers?
b) Control the DC motor speed and direction. Draw the circuit.
Chapter 2 Solutions
Electric Motor Control
Ch. 2 - If the contacts on a manual starter cannot be...Ch. 2 - If the handle of an installed motor starter is in...Ch. 2 - How may an automatic operation be achieved when a...Ch. 2 - What does the term trip-free mean as it relates to...Ch. 2 - Prob. 5SQCh. 2 - Prob. 6SQCh. 2 - Prob. 7SQCh. 2 - Prob. 8SQCh. 2 - Select the best answer for each of the following....Ch. 2 - Select the best answer for each of the following....
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- 6.a. When you're taking a PM motor apart you should exercise special care not to damage theA. end bells.B. commutator.C. permanent magnets.D. brush holders.6.b. A PM field servo motor may be equipped with a resolver that is used toA. excite the armature windings.B. create a voltage that increases with velocity.C. prevent the brushes from sparking.D. feed back position information.arrow_forward4.a. The stop control in a three-wire control scheme stops the motor byA. increasing the resistance in the run circuit.B. shorting the starter coil.C. tripping the thermal overloads.D. disrupting current flow to the coil.4.b. An across-the-line starter does not change the speed of a squirrel-cage motor because itA. varies the internal rotor resistance.B. does not vary the line voltage.C. varies the line voltage as the line frequency increases.D. varies the pole connections at each setting.arrow_forward9.a. The major failure area of a typical wound-field and wound-armature DC motor isA. a faulty commutator segment.B. open field windings.C. brush wear and failure.D. bearing failure.9.b. The magnetic material that's placed inside a coil of wire in a motor is called aA. concentrator.B. pole.C. form.D. rod.arrow_forward
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