MCC Cabling

[7carisfast]

Can anyone point to the NEC Code where it is illegal to do the following or is it simply legal to do this:

My MCC has a 400A Fused diconnect switch. I leave that switch through my ABB wireway, through the top and supply power to a wall mounted VFD. The output cabling comes back to my MCC and reuses the wireway to exit out the bottom of the MCC.

Isn't the reentry of the power cable back into the MCC a code violation?

 

[jraef]

Why would it be? The origination is within the MCC itself, so it is not a "foreign source". If you were going to work inside the MCC wireway and killed the main power disconnect to be safe, those cables would then be dead as well.

"Venditori de oleum-vipera non vigere excordis populi"

 

[advidana]

no

 

[jraef]

By the way, I hope you are using shielded cable for your VFD load connections. Otherwise you will likely have RFI and induction problems in that MCC.

"Venditori de oleum-vipera non vigere excordis populi"

 

[7carisfast]

You are correct. By the way, is there a place to post information on a design error of ABB VFDs?

 

[jraef]

You can post it here, but start a new thread. Several of the forum MVPs appear to be ABB employees or are closely connected to them around the world. They would likely appreciate hearing feedback.

But remember, what you may regard as an error was probably the solution to another problem!

"Venditori de oleum-vipera non vigere excordis populi"