ECN Forum Forums Code Related Discussion NEC & other Code issues Grounding in Control Panels

Section 409.60 of the 2005 NEC refers to "Multisection industrial control panels", but there is no definition. What would be an example of a Multisection industrial control panel? Would it be multiple sub-panels in a common enclosure?

Also, the second sentence of 409.60 seems ambiguous. Is a grounding bus required for a Multisection industrial control panel?

In a previous life, I used to be control panel assembler. On big assembly lines, we could have 6 Hoffman 4' wide by 6' tall enclosures bolted together to make 1 long-ass control cabinet. I think that would qualify as a "Multisection Industrial Control Panel."

Also look at multi-cabinet control consoles for control rooms at large industrial facilities, nuclear plants, etc.

Larry C

I believe they're referring to large switchboard-style cabinets.

409.2 defines "Industrial control panel" and refers to pretty much anything, including breaker panels, switchgear, MCC, pushbuttons, etc. 409.60 just wants to make sure you properly bond them all together if they're installed as a single multisection unit. If you mount individual industrial control panels 1" apart, I do not believe 409.60 applies.

Edit: 409.2 was re-written in 2008, but doesn't appear to really change the definition, just presents it differently.