motors overload protection

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GoldDigger

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First confirm whether the overLOAD protection is already integral with the motor.
Often all you have to install is the short circuit and ground fault protection, whose size is specified in code tables based on motor nameplate HP.
The external overload protection, if needed, should be sized according to the specifications of the motor manufacturer, not the NEC.

Tapatalk!
 
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Jraef

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Not very many 10HP 460V* motors will have integral thermal protection. You will much more likely need an external overload relay. How you select heater elements or what you set it for will depend on the directions from the manufacturer of the relay that you buy. Some will build in a pick-up point that is ALREADY factored in at 115-125% of the set value, so you do NOT add it in those cases, others do not, so you DO add it if you want to. There is no valid answer that applies to ALL makes and models of overload relay. RTFM.

The NEC is not a design guide, it is a list of minimum requirements that must be met.
 
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