Oversized Motor Starters

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Pitt123

Senior Member
I know that NEMA starters are broken into sizes according to motor HP, and a 50HP motor will require a size 3 starter.

My question is weather or not you can use a larger starter such as a size 4 starter on such a motor as long as the breaker and overloads met the the requirements of 430? Can a larger size contactor be used as long as breaker and overloads were sized per the motor?
 
As Jim says, no problem. It is not uncommon when motors have numerous jogging or plugging use.
 
You just have to watch the capabilities of the OLR that it is capable of being adjusted low enough to a value that protects the motor.
 
You just have to watch the capabilities of the OLR that it is capable of being adjusted low enough to a value that protects the motor.

good point... I'm still accustomed to the bi-metal OL heaters where that was not much of a problem. Over a wide range, one size fil all.
 
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