13 The following details are known about a 250 hp, 230 V, 435 r/min de shunt motor: nominal full-load current: 862 A insulation class: H weight: 3400 kg external diameter of the frame: 915 mm length of frame: 1260 mm a. Calculate the total losses and efficiency at full-load. b. Calculate the approximate shunt field exciting current if the shunt field causes 20 percent of the total losses. c. Calculate the value of the armature resistance as well as the counter-emf, knowing that 50 percent of the total losses at full-load are due to armature resistance. d. If we wish to attain a speed of 1100 r/min, what should be the approximate exciting current?

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...
icon
Related questions
Question

I need some help in question 13

13 The following details are known about a
250 hp, 230 V, 435 r/min de shunt motor:
nominal full-load current: 862 A
insulation class: H
weight: 3400 kg
external diameter of the frame: 915 mm
length of frame: 1260 mm
a. Calculate the total losses and efficiency
at full-load.
b. Calculate the approximate shunt field
exciting current if the shunt field causes
20 percent of the total losses.
c. Calculate the value of the armature
resistance as well as the counter-emf,
knowing that 50 percent of the total losses
at full-load are due to armature resistance.
d. If we wish to attain a speed of 1100 r/min,
what should be the approximate exciting
current?
Transcribed Image Text:13 The following details are known about a 250 hp, 230 V, 435 r/min de shunt motor: nominal full-load current: 862 A insulation class: H weight: 3400 kg external diameter of the frame: 915 mm length of frame: 1260 mm a. Calculate the total losses and efficiency at full-load. b. Calculate the approximate shunt field exciting current if the shunt field causes 20 percent of the total losses. c. Calculate the value of the armature resistance as well as the counter-emf, knowing that 50 percent of the total losses at full-load are due to armature resistance. d. If we wish to attain a speed of 1100 r/min, what should be the approximate exciting current?
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 4 steps

Blurred answer
Knowledge Booster
Direct Current (DC) Motor
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
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,