Is this one industrial electrical panel, or two?

Status
Not open for further replies.
Shackled Designer

Shackled Designer

Member
Location
Decatur, AL USA
If in designing an industrial panel enclosure with a smaller enclosure mounted on the side to house the disconnect, mains circuit protection, and mains power contactors for the larger panel, is the smaller enclosure considered part of the larger panel, or is it considered its own panel?

Putting this question in other terms, do I need to provide markings for two industrial panels, or just one?

Thanks,
Shak
 
Ahah! Great question, Bob.

It did not cross my mind that there would be a difference considering that one of the marking requirements in article 409 is that I provide SCCR for the panel I design, and the only method I know of for determining SCCR apart from UL-witnessed testing is that found in supplement SB of UL508A. I guess then I would need the definition according to UL508A, just so long as me treating it that way does not mean I am in violation of the NEC.

Is it possible, by virtue of compliance with one standard, to be in violation of the other?

Regards,
Shak
 
If the power circuits are only in the one panel and the second one is only lower (non-line) voltage controls, only that power panel would need an SCCR listing. But if they are separate boxes, each would need their own listing, unless the door of the controls-only box is mechanically linked to the door of the power box so that you cannot open it without disconnecting the line power in the first one. For example, Hoffman (and others) sell multi-door cabinets, each with their own side walls, but where all of the doors have a mechanical linkage to the first one, so to open any door, the first one must be opened, and it has the main disconnect that kills all power. In that case, the entire lineup can be listed as one panel.
 
Status
Not open for further replies.
Top