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NEC definition of torque motor

NEC definition of torque motor

NEC definition of torque motor

(OP)
I am looking for a definition or application of a torque motor per the NEC. I work at a valve actuator manufacturing facility and I am have a problem rating citcuit protectors, etc.. According to the NEC a torque motor should be rated at its locked rotor current instead of the full load current.In my application the motors have torque switches in the circuit to keep the motor from seeing the full locked rotor current. But I also see starting currents that are sometimes above locked rotor. My problem is that other manufaturers suggest ratings per FLA only and I can't justify that to myself. I need to know if the motors are in torque applications are they considered torque motors?

RE: NEC definition of torque motor

If one could use MCB(miniature circuit breaker)as a circuit protector, the said problem can easily be solved. In such case rating of MCB shall be just equal to full load current. Now even if starting current is even higher than full load current, MCB will not cut-off the suply instantaniously as it takes some time to operate. And stating current is always momentary which can actuate the MCB to operate in such a smll duration.

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