Voltage unbalance is the unbalance that occurs when the voltages at different motor terminals are not equal. This is a big problem for power companies generating, and other facilities using three phase power. If left in this condition this can cause transformer and motor windings to prematurely burn open. Using a DMM you are troubleshooting a 480 volt, 3 phase power feeding a fused disconnect connected to a 3 phase, 1 H.P. motor. Your findings are as follows: Phase A/B = 441 volts, Phase A/C = 479 volts and Phase B/C = 457 volts Find the voltage unbalance and determine if this is acceptable.

Voltage unbalance is the unbalance that occurs when the voltages at different motor terminals are not equal. This is a big problem for power companies generating, and other facilities using three phase power. If left in this condition this can cause transformer and motor windings to prematurely burn open. Using a DMM you are troubleshooting a 480 volt, 3 phase power feeding a fused disconnect connected to a 3 phase, 1 H.P. motor. Your findings are as follows: Phase A/B = 441 volts, Phase A/C = 479 volts and Phase B/C = 457 volts Find the voltage unbalance and determine if this is acceptable.

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter10: System Protection

Section: Chapter Questions

Problem 10.27P

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