Page 147 - Handbook of Electrical Engineering

INDUCTION MOTORS 129

5.10.5 Part Winding Method

A special design of motor is used. The stator has two three-phase windings that are arranged in
parallel and wound in the same slots. If the two windings are the same then on starting and during
run-up one winding would provide half of the total torque at any speed. Hence one winding is used
for starting and both for running. The method is not suited to small or high speed motors. With two
equal windings the starting current and torque are half of their totals. This method is seldom used
in the oil industry because of the preference for standard motors, and the availability of satisfactory
alternative methods.

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