Electrical Transformers and Rotating Machines
4th Edition
ISBN: 9781305494817
Author: Stephen L. Herman
Publisher: Cengage Learning
expand_more
expand_more
format_list_bulleted
Textbook Question
Chapter 19, Problem 10RQ
Assume that a nine-lead dual-voltage motor is being tested with an ohmmeter. The meter indicates resistance values as follows: T7–T8 = 6Ω, T7–T9 = 6Ω, and T8–T9 = 10Ω. What would these readings indicate?
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
The working current has a power of 100 kW and a power factor of 0.50. After a capacitor of 75 KVAR is installed, what does the
power factor become?
A 0.84
B 0.71
C 0.63
D 0.78
E 0.92
What is the peak voltage of an AC circuit which has an RMS voltage of 115V?
4. A circuit contains a 20-2 resistor and
an inductor with an inductance of
0.093 H. If the circuit has a frequency
of 60 Hz, what is the total impedance
of the circuit?
5. An R-L series circuit has a power
factor of 86%. By how many degrees
are the voltage and current out of
phase with each other?
6. An R-L series circuit has an apparent
power of 230 VA and a true power of
180 W. What is the reactive power?
7. The resistor in an R-L series circuit
has a voltage drop of 53 V, and the
inductor has a voltage drop of 28 V.
What is the applied voltage of the
circuit?
Chapter 19 Solutions
Electrical Transformers and Rotating Machines
Ch. 19 - Why is it necessary to keep lubrication records...Ch. 19 - Why is it necessary to pick between the commutator...Ch. 19 - What are the effects of improper brush tension in...Ch. 19 - What instrument is used to test the insulation of...Ch. 19 - How do you check for an open armature winding?
Ch. 19 - What instrument is generally used to test an...Ch. 19 - Prob. 7RQCh. 19 - Prob. 8RQCh. 19 - Prob. 9RQCh. 19 - Assume that a nine-lead dual-voltage motor is...
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- What is the peak voltage of a 120V RMS AC voltage?arrow_forwardThe following data were obtained on a 50 kVA 2400/120 V transformer: Open circuit test, instruments on low voltage side: Waltmeter reading = 396 Watts Ammeter reading = 9.65 amperes Voltmeter reading = 120 Volts Short circuit test, instruments on high voltage side: Waltmeter reading = 810 Watts Ammeter reading = 20.8 amperes Voltmeter reading = 92 Volts Find the efficiency when rated kVA is delivered to a load having a power factor of 0.8 lagging.The following data were obtained on a 50 kVA 2400/120 V transformer : Open circuit test, instruments on low voltage side: Waltmeter reading = 396 Watts Ammeter reading = 9.65 amperes Voltmeter reading = 120 Volts Short circuit test, instruments on high voltage side: Waltmeter reading = 810 Watts Ammeter reading = 20.8 amperes Voltmeter reading = 92 Volts Find the efficiency when rated kVA is delivered to a load having a power factor of 0.8 lagging.arrow_forwardIn a given DC motor, the output power is 45 HP, and the copper losses are 2.005 KW. If the rotational losses is one tenth of the output power, find the converted power and the efficiency of the motor. Select one: O a. None O b. Pcony = 33.57 KW and % efficiency = 89.2 % %3D O C. Pcony = 39 KW and % efficiency = 75.8 % O d. Peony = 36.927 KW and % efficiency = 86.2 %. !! n dunlay I AP-wound armature whicharrow_forward
- Find the value of the currents I1 and 12. 100 ohm 5V 5V 100 ohm 12 O a. 1=-0.3A, 12=-0.1A O b. 11=0.3A, 12=0.1A Oc. 11=0.05A, 12=0.1A O d. 11=0.1A, 12=0.2Aarrow_forwardIn a given DC motor, the output power is 20 HP, and the copper losses are 1.1 KW. If the motor is operating at 87 % efficiency, find the converted power and the rotational losses. Select one: a. Pconv = 16.05 KW and Prot = 1.13 KW b. Pconv = 17.15 KW and Prot = 3.11 KW c. Pconv = 14.92 KW and Prot = 1.35 KW d. Nonearrow_forwardWhat does the voltage measurement across the conductor indicate? HAL 3.01 v The wire has high resistance. The wire is okay. The wire is open. The wire condition can't be determine.arrow_forward
- A 480-volt three-phase load is rated at 34.5 kVA. It is to be supplied with variable three-phase voltage. Because the load is continuous, the transformers ratings are to be increased by 1.25% of the rated load. Three variable autotransformers are used to supply this load. Refer to Table 4-2 and determine the standard size of each transformer that should be used to make this connection.arrow_forwardGiven the following Resistances and Inductors in Series and Voltage Source: R1 = 1,664 ohms R2 = 1,999 ohms L1 = 2 Henry L2 = 2 Henry Vs = 3 Volts Frequency = 92 Hz What is the Total Impedance (Amplitude) in ohms?arrow_forwardQuestion 2 A 29 kW, 262 V DC shunt generator has an armature and field resistance of 0.05 ohms and 82 ohms respectively. Find the armature voltage. • 2 decimal places • No need unit Round your answer to 2 decimal places. Add your answe answerarrow_forward
- For the circuit shown below, calculate the Thévenin's equivalent circuit to the left of the resistor R. R1 10Ω 10Ω E 10 V R3 R2 10Ω O . Rth= 15 0, Van = 5 V O b. Rth= 30 0, Vah = 10 V O c. Rth= 15 0, Veh = 10 V O d. Rh= 30 Q, Vah = 5 Varrow_forwardA 10 kVA transformer has a primary voltage rating of 240 volts and a secondary voltage rating of 480 volts. The transformer is connected to a circuit protected by a 100 ampere circuit breaker. The secondary is protected by a 25-ampere fuse. Does the primary require separate overcurrent protection?arrow_forwardName three factors that determine the amount of induced voltage.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
- Electrical Transformers and Rotating MachinesMechanical EngineeringISBN:9781305494817Author:Stephen L. HermanPublisher:Cengage LearningUnderstanding Motor ControlsMechanical EngineeringISBN:9781337798686Author:Stephen L. HermanPublisher:Delmar Cengage LearningRefrigeration and Air Conditioning Technology (Mi...Mechanical EngineeringISBN:9781305578296Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill JohnsonPublisher:Cengage Learning
Electrical Transformers and Rotating Machines
Mechanical Engineering
ISBN:9781305494817
Author:Stephen L. Herman
Publisher:Cengage Learning
Understanding Motor Controls
Mechanical Engineering
ISBN:9781337798686
Author:Stephen L. Herman
Publisher:Delmar Cengage Learning
Refrigeration and Air Conditioning Technology (Mi...
Mechanical Engineering
ISBN:9781305578296
Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson
Publisher:Cengage Learning
Mod-01 Lec-16 Basics of Instrumentation; Author: nptelhrd;https://www.youtube.com/watch?v=qbKnW42ZM5c;License: Standard YouTube License, CC-BY