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Can a 3p QO breaker be used to directly control a motor?

Issue:  
Can you use a QO breaker to protect a high-efficiency motor?

Product line:  
Miniature circuit breakers

Environment:  
QO circuit breakers

Resolution:  
Yes, as long as the motor will start with the breaker as protection.  The inrush current must be lower than the breakers instantaneous trip level and the motor's start-up time/current characteristic must be below the trip curve.  A high-efficiency motor will have a much higher inrush current than a typical motor so a QO breaker is much more likely to have nuisance tripping if used on one.  

Normally it would be preferable to use a contactor between the breaker and motor.  If this is not possible, then a breaker with an adjustable instantaneous/magnetic trip is recommended.  
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