ELECTRICAL WIRING:RESIDENT.-TEXT (PB)
19th Edition
ISBN: 9781337116213
Author: MULLIN
Publisher: CENGAGE L
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 28, Problem 10R
Using the method shown in this unit, what is the approximate short-circuit current available at the terminals of a 50-kVA single-phase transformer rated 120/240 volts? The transformer impedance is 1%.
- a. Line-to-line
- b. Line-to-neutral
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
A dc compound motor having a rating of 10 kW,
1150 r/min, 230 V, 50 A, has the following losses at
full-load:
bearing friction loss
40 W
brush friction loss
==
50 W
windage loss
=
200 W
(1)
total mechanical losses
=
290 W
(2)
iron losses
=
420 W
(3)
copper loss in the shunt field
=
120 W
copper losses at full-load:
(4)
a. in the armature
b. in the series field
c. in the commutating winding
total copper loss in the
500 W
25 W
70 W
armature circuit at full-load
=
595 W
4 What determines the power rating of a ma-
chine?
-5 If we cover up the vents in a motor, its out-
put power must be reduced. Explain.
-6 If a motor operates in a cold environment,
may we load it above its rated power? Why?
An electric motor driving a skip hoist with-
draws 1.5 metric tons of minerals from a
trench 20 m deep every 30 seconds. If the
hoist has an overall efficiency of 94 percent,
calculate the power output of the motor in
horsepower and in kilowatts.
Chapter 28 Solutions
ELECTRICAL WIRING:RESIDENT.-TEXT (PB)
Ch. 28 - What is the minimum size service for a one-family...Ch. 28 - Prob. 2RCh. 28 - Prob. 3RCh. 28 - Prob. 4RCh. 28 - Prob. 5RCh. 28 - Prob. 6RCh. 28 - Prob. 7RCh. 28 - List the standard sizes of fuses and circuit...Ch. 28 - Prob. 9RCh. 28 - Using the method shown in this unit, what is the...
Ch. 28 - State four possible combinations of service...Ch. 28 - Which Code section states that all overcurrent...Ch. 28 - All electrical components have some sort of...Ch. 28 - Arc-fault damage is closely related to the value...Ch. 28 - The utility company has provided a letter to the...Ch. 28 - While working on the main panelboard that is...Ch. 28 - Repeat problem 16 for a main service panel that...Ch. 28 - NEC ______________________________ generally...Ch. 28 - Prob. 19RCh. 28 - Prob. 20RCh. 28 - Overcurrent devices must be accessible. (True)...
Knowledge Booster
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
- The efficiency of a motor is always low when it operates at 10 percent of its nominal power rating. Explain.arrow_forwardA dc motor connected to a 240 V line pro- duces a mechanical output of 160 hp. Knowing that the losses are 12 kW, calculate the input power and the line current.arrow_forwardA 115 V dc generator delivers 120 A to a load. If the generator has an efficiency of 81 percent, calculate the mechanical power needed to drive it [hp].arrow_forward
- A machine having class B insulation attains a temperature of 208°C (by resistance) in a torrid ambient temperature of 180°C. a. What is the temperature rise? b. Is the machine running too hot and, if so, by how much?arrow_forward1 Name the losses in a dc motor. 2 What causes iron losses and how can they be reduced? -3 Explain why the temperature of a machine increases as the load increases.arrow_forward20. A tractor weighing 14 kN with a wheel base of 3m carries an 8 kN load on its rear wheel. Compute the maximum bending moment and shear when crossing a 4.5 span. Consider the load only at the wheels.arrow_forward
- A 110-V, three-phase, Y-connected, 8 pole, 48-slot, 6000-rpm, double-layer wound chronoun anı vonorotor boo 10 +1 urn or oilarrow_forward-7 Name some of the factors that contribute to the deterioration of organic insulators. -8 A motor is built with class H insulation. What maximum hot-spot temperature can it withstand?arrow_forwardCalculate the full-load current of a 250 hp, 230 V dc motor having an efficiency of 92 percent.arrow_forward
- Assignment #2 A 110-V, three-phase, Y-connected, 8 pole, 48-slot, 6000-rpm, double-layer wound, synchronous generator has 12 turns per coil. If one side of the coil is in slot 1, the other side is in slot 6. There are 4 parallel paths. When the generator delivers the rated load at a line voltage of 110 V, the voltage regulation is 5%. What is the flux per pole? Draw two consecutive phasegroups of one of the phase windings and connect them (a) in series and (b) in parallel showing the Start (S) and Finish (F) of both connections. (A separate drawing for each connection)arrow_forward3-4 Transmissiva Live of 120km has R= 0.2 ~2/15 X= 0.8 -2/km Y = 15H/6 5/km The line is supplies a load of 45 kV, SOMW, 0.8 lead p.f find sending voltage, Sending Current p.f. Sanding Voltage Regulation ⑨Voltage 5 Ⓒ charching coming! изу usy π cct लेarrow_forwardA (medium) single phase transmission line 100 km long has the following constants : Resistance/km = 0.25 Q; Susceptance/km = 14 × 10° siemen ; Reactance/km = 0.8 Receiving end line voltage = 66,000 V Assuming that the total capacitance of the line is localised at the receiving end alone, determine (i) the sending end current (ii) the sending end voltage (iii) regulation and (iv) supply power factor. The line is delivering 15,000 kW at 0.8 power factor Lead Draw the phasor diagram to illustrate your calculations.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Power System Analysis and Design (MindTap Course ...Electrical EngineeringISBN:9781305632134Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. SarmaPublisher:Cengage Learning
Power System Analysis and Design (MindTap Course ...
Electrical Engineering
ISBN:9781305632134
Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma
Publisher:Cengage Learning
TRANSFORMERS - What They Are, How They Work, How Electricians Size Them; Author: Electrician U;https://www.youtube.com/watch?v=tXPy4OE7ApE;License: Standard Youtube License