240.4(G) and VFD

[infinity]

A VFD with an input current of 28 amps is fed with #10 THHN is a raceway. Is this code compliant based on 240.4(G)?

 

[augie47]

You always have the best questions
"G" does not include 430 Part X in it's listing so an argument could be made the Part G exceptions do not apply but I'm sure you know that or you would not have challenged us....

 

[wwhitney]

A VFD with an input current of 28 amps is fed with #10 THHN is a raceway. Is this code compliant based on 240.4(G)?

I assume you mean with an OCPD larger than 30A, as with a 30A OCPD there would be no issue.

As Augie points out, 430.130 on OCPD sizing for VFDs is in Part X, which is not referenced in 240.4(G). But 430.130 references 430.52, which is in Part IV, which is referenced in 240.4(G). So there a strong argument that when applying 430.52, as directed by 430.130, 240.4(G) applies.

Cheers, Wayne

 

[infinity]

I assume you mean with an OCPD larger than 30A, as with a 30A OCPD there would be no issue.

Yes you're correct sorry I left that part out. The conductors and the OCPD are 35 amps (28*125%=35)

"G" does not include 430 Part X in it's listing so an argument could be made the Part G exceptions do not apply

Yes that's the discussion we're having on the job.