How Do Primary Resistance Starters Work

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The Answer is The milling machines are equipped with primary resistance starters. For this type of starter or controller, the heavy starting current results in a voltage drop while it passes through the primary resistors; thus, there is a lower voltage value at the motor terminals. The motor accelerates gently with less torque than is the case when line starters are used. When the motor has almost reached its normal speed, a time-delay relay (set for about 5 seconds) closes a second contactor to short out the primary resistors. At this point, the motor receives the full line voltage and accelerates to its normal speed.

How Do Primary Resistance Starters Work

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