Electrical Transformers and Rotating Machines
4th Edition
ISBN: 9781305494817
Author: Stephen L. Herman
Publisher: Cengage Learning
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Chapter 18, Problem 6RQ
To determine
The phase angle made by the start and run winding currents in a resistance-start induction-run motor.
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3. The design of a pump and pipe system has been completed, except for the valves. The system
is used to transpor10t water at 120°F through 2 nom sch 40 commercial steel pipe at a required
flow rate of 85 gpm. Without the valves, the pump selected has the capability to overcome an
additional 18 psi of pressure drop due to the valves and still provide the required flow rate. The
pipe/valve joints are threaded. Determine how many 2-inch globe valves can be installed in this
pump and pipe system.
4. Figure 1 shows a pump and pipe network being used to transport heptane at 120°F to a large,
elevated, closed storage tank. The tank is pressurized and maintained at 18 psia. The volumetric
flow rate of the heptane is 500 gpm.
a. Specify the nominal diameter of the check valve.
b. Determine the pump discharge pressure required (psia) to move the heptane
through the discharge pipe.
Plank
=
18 psia
Liquid level
Large pressurized
storage tank
40 ft
All pipes are 6-nom sch 40 commercial steel
Standard 90° elbows and 180° bend
Total length of straight pipe = 115 ft
Class 300 swing
check valve
INH
Pump
Figure 1: Pressurized storage tank system
2. In a particular section of a fluid system, a 30% ethylene glycol mixture is flowing through a 6-
nom xs cast iron pipe at a temperature of 0°C. In this section of piping, the velocity must be
maintained in the range 1.5 m/s
Chapter 18 Solutions
Electrical Transformers and Rotating Machines
Ch. 18 - Prob. 1RQCh. 18 - Prob. 2RQCh. 18 - Prob. 3RQCh. 18 - Prob. 4RQCh. 18 - What is the advantage of the capacitor-start...Ch. 18 - Prob. 6RQCh. 18 - Prob. 7RQCh. 18 - Prob. 8RQCh. 18 - Prob. 9RQCh. 18 - Prob. 10RQ
Ch. 18 - Prob. 11RQCh. 18 - Prob. 12RQCh. 18 - What type of single-phase motor develops the...Ch. 18 - What is the principle of operation of a repulsion...Ch. 18 - What type of commutator is used with a...Ch. 18 - When a repulsion-start induction-run motor reaches...Ch. 18 - Prob. 17RQCh. 18 - Prob. 18RQCh. 18 - Prob. 19RQCh. 18 - How is the speed of a consequent pole motor...Ch. 18 - Why can a multispeed fan motor be operated at...Ch. 18 - What is the speed of operation of the Warren...Ch. 18 - What is the speed of operation of the Holtz motor?Ch. 18 - Prob. 24RQCh. 18 - Prob. 25RQCh. 18 - What does the term bifilar mean?
Ch. 18 - Why do stepping motors have teeth machined in the...Ch. 18 - Prob. 28RQCh. 18 - Prob. 29RQCh. 18 - Prob. 30RQCh. 18 - Prob. 31RQCh. 18 - What is the function of the compensating winding?
Ch. 18 - Prob. 33RQCh. 18 - Prob. 34RQCh. 18 - Explain how to set the neutral plane position of...Ch. 18 - Explain how to set the neutral plane position by...
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