Control Power Transformer

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Stonewall

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This is an industrial application. I have a small control power transformer (single phase 480/120) inside of a 480V motor operated valve. The 120V control power is used for the open close commands. The 120V control power is routed to a remote pushbutton station and the upstream 480V contactor. My question is does the NEC require that the 120V control power be tied to a local ground at the control power transformer (MOV location)? Where is this specified in the NEC?
 
Then look at 250.21(A)(3) and see if that applies. If it doesn't, then go back to 250.20(B).

And then go to 250.30 for grounding of seperately derived systems.
 
250.21 A3 gave me the answer as "not required"

250.21 A3 gave me the answer as "not required"

Thank you Crossman
 
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