Delmar's Standard Textbook Of Electricity
7th Edition
ISBN: 9781337900348
Author: Stephen L. Herman
Publisher: Cengage Learning
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Textbook Question
Chapter 34, Problem 5RQ
A squirrel-cage induction motor has a nameplate full-load current of 78 amperes and a marked temperature rise of 30°C. The motor requires a NEMA size 4 starter. Using the overload heater chart in Figure 34-8, what size overload heaters should be used to protect this motor?
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Chapter 34 Solutions
Delmar's Standard Textbook Of Electricity
Ch. 34 - Which NEC table is used to determine the full...Ch. 34 - A 5-HP single-phase motor is connected to 208...Ch. 34 - A 10-HP single-phase motor is connected to 240...Ch. 34 - A 75-HP synchronous motor is connected to a...Ch. 34 - A squirrel-cage induction motor has a nameplate...Ch. 34 - A squirrel-cage motor has a nameplate current...Ch. 34 - A 100-HP three-phase squirrel-cage induction motor...Ch. 34 - A 60-HP synchronous motor is connected to 240...Ch. 34 - Prob. 9RQCh. 34 - Both the motors and the feeder in Question 9 are...
Ch. 34 - A 30-HP squirrel-cage induction motor is connected...Ch. 34 - Refer to the preceding Practical Application. When...Ch. 34 - Refer to the first Practical Application in this...Ch. 34 - A 10-HP single-phase motor is connected to 240...Ch. 34 - A 500-HP synchronous motor is connected to 2300...Ch. 34 - A 30-HP three-phase squirrel-cage induction motor...Ch. 34 - A 75-HP synchronous motor is connected to a...Ch. 34 - Prob. 5PPCh. 34 - A 350-HP squirrel-cage induction motor is...Ch. 34 - Three squirrel-cage motors are connected to a...
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- What happens to a series connected direct current motor if its field winding opens at full load?arrow_forwardA 460VAC rated, 60 Hz, 125-Hp Three-phase induction type motor is to be connected for across-the-line starting. The nameplate indicates the motor’s maximum ampere rating, 160A. It has a NEMA code letter B. The ambient temp of the installation place is and TW copper will be used. Short-circuit protection device that will be used is Inverse Time Breaker. Calculate the Motor Starter Size.arrow_forwardA 50-horsepower, 460V, 60Hz, 3-phase induction motor has a Nameplate Rating of 60 amperes. The nameplate also shows a temperature rise of 30°C. What is the overload size for this motor?arrow_forward
- A 460VAC rated, 60 Hz, 125-Hp Three-phase induction type motor is to be connected for across-the-line starting. The nameplate indicates the motor’s maximum ampere rating, 160A. It has a NEMA code letter B. The ambient temp of the installation place is and TW copper will be used. Short-circuit protection device that will be used is Inverse Time Breaker. Calculate the Thermal Overload Protection.arrow_forwardon the plate of the star-connected ring induction motor; It is written as 7.5kW, 16A, 380V, 1430 rpm, CosQ=0.82 and f=50 Hz. Find the rated (nominal) torque of the motor?arrow_forwardDraw the circuit diagram for the squirrel cage motor and name all the components too.arrow_forward
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- 10 kW, 400 volt 3 phase star connected synchronous motor has negligible armature resistance the synchronous reactance per phages 10 ohms. Determine induced emf if the motor draws minimum current with excitation variable. The full load efficiency of motor is 80%. 10 minute fast please answerarrow_forwardA single phase induction motor is rated 5 hp, 75% power factor and 220 volts. What approximate size of capacitor is necessary to raise the power factor to about 90%?arrow_forwardHow to avoid the effect of the high current at starting of the Motor? a. variable resistor is connected in series with Armature circuit b. variable resistor is connected in parallel with Armature circuit c. variable resistor is connected in series with field circuit d. None of the above Clear my choicearrow_forward
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