A 20-hp, 200-V, shunt wound DC motor has an armature resistance of 0.7 2 and a field resistance of 100Q. The adjustable resistor, Radj can be adjusted from 50 Q to 350 2. Figure 1 shows the motor's circuitdiagram, and Figure 2 illustrates its magnetisation curve.RARaliRrFigure 1: Equivalents circuit of a de motor300280260Speed = 1500 rpm24022020019016014012010080604020o 01 02 03 04 05 06 0.7 08 09 1 11 12 1.3 14 1.5 1.6 1.7 1.8 19 2Figure 2: Magnetization curve of a dc motor. (a) Describe two main differences between a DC shunt-wound and separately-excited motor.(b) Calculate the starting current of this motor if Radj is set to 50 2.(c) Calculate the no-load speed (rpm) using the starting current obtained in (a) above.

GIVEN: a circuit diagram RA=0.7ΩRF=100ΩRadj=50 to 500Ω FIND: (a) two main difference…

2. The adjustable resistor, Radj can be adjusted from 50 2 to 350 2. Figure 1 shows the motor's circui diagram, and Figure 2 illustrates its magnetisation curve. RA Figure 1: Equivalents circuit of a de motor 300 280 260 Speed = 1500 rpm 240 220 200 180 160 140 120 100 80 60 40 20 0 01 02 03 04 05 06 0.7 08 09 I LI 12 13 14 1.5 16 1.7 18 19 2 Figure 2: Magnetization curve of a de motor.

2. The adjustable resistor, Radj can be adjusted from 50 2 to 350 2. Figure 1 shows the motor's circui diagram, and Figure 2 illustrates its magnetisation curve. RA Figure 1: Equivalents circuit of a de motor 300 280 260 Speed = 1500 rpm 240 220 200 180 160 140 120 100 80 60 40 20 0 01 02 03 04 05 06 0.7 08 09 I LI 12 13 14 1.5 16 1.7 18 19 2 Figure 2: Magnetization curve of a de motor.

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter32: Three-phase Motors

Section: Chapter Questions

Problem 6RQ: Name three factors that determine the torque produced by an induction motor.

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