capacitor wiring on a three phase motor

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holteen

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What is the Proper wiring of power factor cap on a three phase motor, before the starter or after the starter? pros or cons for either ?
 

jim dungar

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holteen said:
What is the Proper wiring of power factor cap on a three phase motor, before the starter or after the starter? pros or cons for either ?

There is no one proper way.

If the capacitor is located after the starter the overload relays may need to be re-sized based on the new current flowing through them.

If the capacitor is wired before the starter it does not automatically cycle with the motor.

Many manufactures of NEMA size 3 and larger starters provide a method to connect the capacitor between the contactor and the overload relay thus overcoming the these two negatives.
 
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