Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
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Textbook Question
Chapter 36, Problem 4SQ
If one of the secondary resistor contacts (S2) fails in Figure 36–1, what will happen?
Fig. 36–1 Typical control circuit for accelerating a wound rotor motor with three steps of speed.
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4- A 3-phase A -connected 220-V (line-to-neutral), 60-Hz 6-pole induction motor has the following parameter
values in O/phase referred to the stator: R1 = 0.294, R2 = 0.144, X, = 0.503, X2 = 0.209, Xm= 13.25. The total
friction, windage, and core losses may be assumed to be constant at 403 W, independent of load. For a slip of
5%,
a. Output torque
b. Stator current,
c. Power factor,
d. Converted power
e. Efficiency.
A 220 V shunt motor driving its normal load draws an armature current of 50 A from a 220 V dc source. The armature resistance of this motor including brushes is 0.25 ohms. How much armature current (minimum) Will this motor draw from a 200 V DC source when driving the same load with the field adjusted to maintain the same speed.
Name three factors that determine the amount of voltage induced in the rotor of a wound-rotor motor.
Chapter 36 Solutions
Electric Motor Control
Ch. 36 - Are the secondary resistors connected in three...Ch. 36 - Do secondary resistors on starters with three or...Ch. 36 - Does reversing the secondary rotor leads mean that...Ch. 36 - If one of the secondary resistor contacts (S2)...Ch. 36 - In Figure 362, how many different interlocking...Ch. 36 - Referring to Figure 364, why is it not possible to...Ch. 36 - Prob. 7SQCh. 36 - If there is a locked rotor in the secondary...Ch. 36 - Why is it necessary to remove the jumpers in...Ch. 36 - Prob. 10SQ
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