Explore BrainMass

Power factor

A single phase electric motor has an output power of 10 kW and an efficiency of 90% at full load. The motor is fed from a 240 V supply via a cable that has a resistance of 10 milli ohms per metre length. If the terminal voltage to the motor must not fall below 90% of the supply voltage, calculate the maximum return length of the cable for a motor power factor of:

A. unity

B. 0.8 (sketch a circuit diagram and phasor diagram, the motor and line voltages are no longer in phase)

C. The power dissipated in the cable for each of the above two cases.

© BrainMass Inc. brainmass.com July 21, 2018, 11:50 am ad1c9bdddf

Solution Summary

Step by step solution provided.