I looked through 430 to see if there were any exceptions for Adjustable Speed Drives. I could not find any. So, IMO 110.26 applies.
"430.120 General. The installation provisions of Part I
through Part IX are applicable unless modified or supplemented
by Part X."
I could not find anything in Part 1 through 10 to suggest anything with regards to working space. I would have hoped that it pointed you to 110.26 at some point but it does not.
Some people consider a VFD a motor control center and if you look at it that way you would need to comply with 110.26F. I don't believe that it is a MCC since there is a clear section in 430.120 specifically providing rules for Adjustable Speed Drives (VFD's)...
IMO 110.26 A as you suggest is the winner.
Last edited by tsolanto; 07/25/15 09:52 AM.
