Homework Help is Here – Start Your Trial Now!
Engineering
Electrical Engineering
b. The braking power [kW] when the motor We wish to stop a 120 hp, 240 V, 400 r/min motor by using the dynamic braking circuit shown in Fig. 17. If the nominal armature current is 400 A, calculate the following: a. The value of the braking resistor R if we want to limit the maximum braking current to 125 percent of its nominal value 14 has decelerated to 200 r/min 50 r/min.

b. The braking power [kW] when the motor We wish to stop a 120 hp, 240 V, 400 r/min motor by using the dynamic braking circuit shown in Fig. 17. If the nominal armature current is 400 A, calculate the following: a. The value of the braking resistor R if we want to limit the maximum braking current to 125 percent of its nominal value 14 has decelerated to 200 r/min 50 r/min.

Introductory Circuit Analysis (13th Edition)
Introductory Circuit Analysis (13th Edition)
13th Edition
ISBN:9780133923605
Author:Robert L. Boylestad
Publisher:Robert L. Boylestad
Chapter1: Introduction
Section: Chapter Questions
Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...
See similar textbooks
icon
Related questions
Question

Stop ducking the question and just answer it.

Number 14 letter a. 

12 A separatel otor turns at ng. c. Compare the brak 200 r/min to the in voltage required 1500 r/min. At 100 r/min. dissipated in resis 16 The armature of a 2: tor has a diameter o length of 235 mm. C a. The approximate knowing that irc kg/m³ b. The kinetic ener when it turns at Advanced level nd make a erator ef- insulation class: H d polarity weight: 3400 kg external diameter of the frame: 915 m c. The total kineti parts at a speed the windings an the J calculated length of frame: 1260 mm re volt- . Calculate the total losses and efficiency at full-load. ary the exciting current if the shunt field canse 20 percent of the total losses. c. Calculate the value of the armature resistance as well as the counter-emf. 17 If we reduce the n practical shunt me speed increases, b Explain why, bea of the iron under a shunt tes. ing a 18 The speed of a se ing temperature, increases. Expla of ro- d. If we wish to attain a speed of 1100 r/min what should be the approximate exciting na- current? Industrial Application 14 We wish to stop a 120 hp, 240 V, 400 r/min A permanent ma cobalt-samarium motor by using the dynamic braking circuit shown in Fig. 17. If the nominal armature current is 400 A, calculate the following: a. The value of the braking resistor R if we want to limit the maximum braking [M che magnetism per I ture. The motor 2500 r/min whe in an ambient te the speed if the where the ambi current to 125 percent of its nominal value pa has decelerated to 200 r/min, 50 r/min, 0 r/min IC A. 15 a. The motor in Problem 14 is now stopped Answers to Pr Calculate the new braking resistor R so the maximum braking current is 500 A. Note: The following rounded off to an a are preceded by the 1S 9a. 221 V 9b. 13 800 W 10b. 1 85 O
Transcribed Image Text:12 A separatel otor turns at ng. c. Compare the brak 200 r/min to the in voltage required 1500 r/min. At 100 r/min. dissipated in resis 16 The armature of a 2: tor has a diameter o length of 235 mm. C a. The approximate knowing that irc kg/m³ b. The kinetic ener when it turns at Advanced level nd make a erator ef- insulation class: H d polarity weight: 3400 kg external diameter of the frame: 915 m c. The total kineti parts at a speed the windings an the J calculated length of frame: 1260 mm re volt- . Calculate the total losses and efficiency at full-load. ary the exciting current if the shunt field canse 20 percent of the total losses. c. Calculate the value of the armature resistance as well as the counter-emf. 17 If we reduce the n practical shunt me speed increases, b Explain why, bea of the iron under a shunt tes. ing a 18 The speed of a se ing temperature, increases. Expla of ro- d. If we wish to attain a speed of 1100 r/min what should be the approximate exciting na- current? Industrial Application 14 We wish to stop a 120 hp, 240 V, 400 r/min A permanent ma cobalt-samarium motor by using the dynamic braking circuit shown in Fig. 17. If the nominal armature current is 400 A, calculate the following: a. The value of the braking resistor R if we want to limit the maximum braking [M che magnetism per I ture. The motor 2500 r/min whe in an ambient te the speed if the where the ambi current to 125 percent of its nominal value pa has decelerated to 200 r/min, 50 r/min, 0 r/min IC A. 15 a. The motor in Problem 14 is now stopped Answers to Pr Calculate the new braking resistor R so the maximum braking current is 500 A. Note: The following rounded off to an a are preceded by the 1S 9a. 221 V 9b. 13 800 W 10b. 1 85 O
50 Speed +, DIRECT-CURRENT MOTORS 110 75 dyna R. 25 plugging 0. Figure 17b Armature on open circuit generating a voltage E.. Figure 18otor Speed versus tin ors to vinulo E, E R reversing the a minals of the L- Under nor 41 rent I is give Figure 17c Dynamic braking. where R, is t In practice, resistor R is chosen so that the initial braking current is about twice the rated motor cur- rent. The initial braking torque is then twice the nor- mal torque of the motor. As the motor slows down, the gradual decrease in E, produces a corresponding decrease in I,. Consequently, the braking torque becomes smaller and smaller, finally becoming zero when the arma- ture ceases to turn. The speed drops quickly at first reverse the t acting on th The so-calle longer cour supply volt an enormo greater tha current wo
Transcribed Image Text:50 Speed +, DIRECT-CURRENT MOTORS 110 75 dyna R. 25 plugging 0. Figure 17b Armature on open circuit generating a voltage E.. Figure 18otor Speed versus tin ors to vinulo E, E R reversing the a minals of the L- Under nor 41 rent I is give Figure 17c Dynamic braking. where R, is t In practice, resistor R is chosen so that the initial braking current is about twice the rated motor cur- rent. The initial braking torque is then twice the nor- mal torque of the motor. As the motor slows down, the gradual decrease in E, produces a corresponding decrease in I,. Consequently, the braking torque becomes smaller and smaller, finally becoming zero when the arma- ture ceases to turn. The speed drops quickly at first reverse the t acting on th The so-calle longer cour supply volt an enormo greater tha current wo
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 2 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Analog to digital converters
Learn more about
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
  • SEE MORE QUESTIONS
Recommended textbooks for you
Introductory Circuit Analysis (13th Edition)
Introductory Circuit Analysis (13th Edition)
Electrical Engineering
ISBN:
9780133923605
Author:
Robert L. Boylestad
Publisher:
PEARSON
Delmar's Standard Textbook Of Electricity
Delmar's Standard Textbook Of Electricity
Electrical Engineering
ISBN:
9781337900348
Author:
Stephen L. Herman
Publisher:
Cengage Learning
Programmable Logic Controllers
Programmable Logic Controllers
Electrical Engineering
ISBN:
9780073373843
Author:
Frank D. Petruzella
Publisher:
McGraw-Hill Education
Fundamentals of Electric Circuits
Fundamentals of Electric Circuits
Electrical Engineering
ISBN:
9780078028229
Author:
Charles K Alexander, Matthew Sadiku
Publisher:
McGraw-Hill Education
Electric Circuits. (11th Edition)
Electric Circuits. (11th Edition)
Electrical Engineering
ISBN:
9780134746968
Author:
James W. Nilsson, Susan Riedel
Publisher:
PEARSON
Engineering Electromagnetics
Engineering Electromagnetics
Electrical Engineering
ISBN:
9780078028151
Author:
Hayt, William H. (william Hart), Jr, BUCK, John A.
Publisher:
Mcgraw-hill Education,
SEE MORE TEXTBOOKS