a. A 55-hp, 550-V shunt wound motor draws a line current of 5 A at no load. The shunt field resistance is 285 Ω and the armature resistance exclusive of brushes is 0.35Ω. The brush drop at full-load is 4V. At full-load, the motor draws a line current of 88 A. Calculate the efficiency at full-load.b. The input and output powers of a 200 V shunt motor are 30 and 28 kW respectively. The field and armature circuit resistances are 40 Ω and 0.0125 Ω respectively. Determine the efficiency of the motor if the output power is reduced to 10 kW.

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a. A 55-hp, 550-V shunt wound motor draws a line current of 5 A at no load. The shunt field resistance is 285 Ω and the armature resistance exclusive of brushes is 0.35Ω. The brush drop at full-load is 4V. At full-load, the motor draws a line current of 88 A. Calculate the efficiency at full-load.

a. A 55-hp, 550-V shunt wound motor draws a line current of 5 A at no load. The shunt field resistance is 285 Ω and the armature resistance exclusive of brushes is 0.35Ω. The brush drop at full-load is 4V. At full-load, the motor draws a line current of 88 A. Calculate the efficiency at full-load.

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter33: Single-phase Motors

Section: Chapter Questions

Problem 35RQ

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