Electric Motor Control
10th Edition
ISBN: 9781133702818
Author: Herman
Publisher: CENGAGE L
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Textbook Question
Chapter 10, Problem 9SQ
Refer to the circuit shown in Figure 10–6. Assume that when the thermostat contact closes the compressor does not start, but the condenser fan and evaporator fan do start. When troubleshooting the circuit, a voltmeter connected across the compressor contactor coil CC indicates 0 volts. A voltmeter connected across the high-pressure switch indicates 0 volts, and a voltmeter placed across the thermostat contact indicates 0 volts. When the voltmeter is connected across the low-pressure switch it indicates 24 volts. Which of the following conditions could cause this problem?
a. The refrigerant pressure is too high.
b. The compressor contactor coil is open.
c. The refrigerant pressure is too low.
d. The thermostat contact is open.
Fig. 10–6 Pressure switches are often used in air-conditioning circuits.
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Students have asked these similar questions
A.With the aid of a diagram, describe fringing, and explain the impact that it has on the relevant magnetic circuit parameter.
B. A coil of 1500 turns give rise to a magnetic flux of 2.5 mWb when carrying a certain current. If this current is reversed in 0.2 s, what is the average value of the e.m.f. induced in the coil?
C.Define Mutual Inductance.Two coils are connected in series and their total inductance is measured as 0.12 H, and when the connection to one coil is reversed, the total inductance is measured as 0.04 H. If the coefficient of coupling is 0.8, determine:The self-inductance of each coil, and the mutual inductance between the coils.
comparing Lenz's law and the left hand generator rule, which of these is the more important fundamental principle?
Example: Electric Field and Potential Inside a Charged Sphere
Problem: A sphere of radius R = 0.2 m is uniformly charged with a total charge Q = 5 μC. The sphere
is made of a dielectric material with relative permittivity € = 4. Calculate:
1. The electric field intensity E(r) inside and outside the sphere.
2. The electric potential (r) at any point inside the sphere.
Solution:
Step 1: Given Data
Radius of the sphere: R = 0.2m,
Total charge: Q-5 μC=5× 10° C.
Step 2: Electric Field Inside the Sphere (<
Using Gauss's Law:
Chapter 10 Solutions
Electric Motor Control
Ch. 10 - Describe how pressure switches are connected to...Ch. 10 - What type of pressure switch is generally used to...Ch. 10 - A pressure switch is set to cut in at a pressure...Ch. 10 - A pressure switch is to be installed on a system...Ch. 10 - A pressure switch is to be installed in a circuit...Ch. 10 - Refer to the circuit shown in Figure 105. If the...Ch. 10 - Refer to the circuit shown in Figure 105. Assume...Ch. 10 - Refer to the circuit shown in Figure 106. Assume...Ch. 10 - Refer to the circuit shown in Figure 106. Assume...Ch. 10 - Refer to Figure 106. When the thermostat contact...
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