multiple sources in one Enclosure

[smarteng]

We have a Control Panel Enclosure which has mostly control circuits. Customers also wants to have two breakers for couple of their loads into same panel. These new load fed by a different distribution panel. so now basically that control enclosure has breakers with power coming from two different panel. ( tried to show in the diagram) Breakers will be physically isolated from each other, but since they are in same nclosure will it be NEC non-compliant. Or is there NEC code which does not permit that.


Thank you.

 

[roger]

See 300.3(C) and take note of the Informational Notes.

Roger

 

[Jraef]

When you have multiple circuits entering the enclosure, you must have a permanent label on the outside identifying the location of the disconnects for each circuit, 110.21 and 22. That can get kind of messy on what you show there. Then if your panel would need to follow NFPA79 for "machinery controls", the "foreign" sources would need to be wired in yellow wire, which would mean ONE of the circuits would be the "main" circuit, but the others are all "foreign".

The issue is that anyone who would need to work on that panel would need to know, VERY CLEARLY, that turning off one or even all of those breakers will not remove all power from that panel.