Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
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Textbook Question
Chapter 36, Problem 6SQ
Referring to Figure 36–4, why is it not possible to remove all of the resistance from the secondary circuit?
Fig. 36–4 Automatic acceleration of wound rotor motor using a simplified frequency relay system.
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K-1)The speed of a 3-phase wound-rotor induction motor can be changed by varying the amount of resistance in the rotor circuit. a) true b) false K-2). Which of the following statements are true about a 3-phase synchronous motor? a) It is a constant speed motor even under varying loads. b) It runs at the same speed the magnetic field rotates on the stator. c) It can correct its own, and the supply line's power factor d) all of the above K-3. A) What determines the speed of a 3-phase synchronous motor? a) the number of poles b) the frequency of the supply c) both "a" and "b" d) neither "a" nor "b" K-3)B) From a technician's standpoint, which of the following is the most practical method of providing a wide range of speed control for a 3-phase synchronous motor? a) by changing the frequency b) by changing the number of poles c) both "a" and "b" d) neither "a" nor "b"
1. Explain the working Principle of Single Phase Induction Motor.
2. What are the different types of Starters to control AC-Motor. Explain briefly.
3. Explain DOL starter of Single Phase Induction Motor briefly.
4. What is the purpose of the magnetic contactor?
5. What is the use of auxiliary contact in the magnetic controller?
6. What happens when the holding coil gets the supply in the magnetic controller?
7. Explain the working principle of a relay.
4.a. The device which responds to the heat developed within the motor is theA. shading coil.B. short-circuiter.C. bimetallic protector.D. current-operated relay.4.b. How is a rotating magnetic field produced during starting in a split-phase motor?A. A capacitor is inserted in the auxiliary-winding circuit.B. A low resistance coil is placed around a portion of each pole.C. Brushes are shifted off the hard-neutral position.D. An auxiliary winding is made with a high ratio of resistance to reactance.
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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Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.Similar questions
- A three-phase, six-pole, 60 Hz, 230-volt wound rotor motor has its stator connected in delta and its rotor in star. There are 70 percent as many rotor conductors as stator conductors as stator conductors. Calculate the voltage and frequency between slip rings if normal voltage is applied to the stator when, a, the rotor is at rest, b. the rotor slip is 0.04arrow_forward__________induction motor is an AC motor that provides variable speed control by varying the resistance of its rotor. a. Synchronous b. Squirrel-cage c. Wound-rotor d. Split-phasearrow_forward14. Under line voltage control of induction motor the speed regulation occurs: a) by change of the slip of the motor. b) by change of the synchronous speed of the motor. c) by adding additional resistance in the rotor circuit. d) by changing the stator resistance of the motor.arrow_forward
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- 53. A 200 W, 230 V, 50 Hz capacitor-start mo- tor has the following winding parameters: Main winding: R = 4·5 Q2 ; X₁ = 3·7 Q What should be the angle between input voltage and starting winding current to give maximum starting torque? (1) 38.2⁰ (iii) 50-4⁰ (ii) 24-6° (iv) 32.7°arrow_forwardExplain how dc shunt motor is working with relevant circuit diagramarrow_forwardWhich is the answer for Question 12?arrow_forward
- Q4arrow_forwardElectrical engineering subject of electrical machines/ I need a correct and accurate solutionarrow_forward(a) Draw and explain slip-torque characteristics of 3-phase induction motor. (b) No load and blocked rotor test of a 440 V, three phase 55 HP, star connected induction motor gave the following results No-load (line values) : 440 V, 5 A , 230 W Blocked rotor test (Line values) : 130 V, 15 A , 1800 W Stator resistance per phase is 1.2 Q. Calculate the parameters of exact equivalent circuit and draw the exact equivalent circuit referred to stator side.arrow_forward
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