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

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

Product line:  
Miniature circuit breakers

QO circuit breakers

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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