Maximum VFD mounting height

[Mr. Bill]

I just heard an EC asking if he could mount a VFD (with integral disconnect switch) about 8' to 10' AFF so the wall space below could be used for storage. Is this even allowed per NEC?

430.107 states that at least one motor disconnect needs to be readily accessible.

While 404.8 Exception 2 allows motor disconnects to be mounted higher than 6'-7" and accessible by a portable ladder.

I consider a VFD to require a working space as defined in 110.26(A). But I don't see anything here that says the working space needs to be readily accessible. Just that the working space cannot be used for storage.

I personally don't like seeing a VFD mounted that high but is it permissable by the NEC?

 

[petersonra]

I think a good argument could be made that in this case the working space would start at the front of the VFD and extend down to the floor. That would allow you to use the space under the VFD for storage (shelves perhaps), but the storage could not extend past the front of the VFD.

As for the disconnect being accessible, its not. BUT, if it was fed from a panel board that is accessible, a lock on the CB would be an accessible disconnect.

I think it is a bad idea, but potentially allowable.

 

[boater bill]

Storage under the VFD is bad for service access.
I can't find an exact reference but my gut says don't do it, you will regret it later.

I have put small VFD's for air handlers above the ceiling but I think you are describing something else.

Can the VFD be located in another part of the room?

I hope this helps.