stacked panelboards; overlapping dedicated space

[RossS]

I have more than one EC suggesting they can save wall space by installing one panelboard above another; in other words, installing a panelboard in the dedicated space of another panelboard. Best case scenario is both would be 225A 42ckt panels, but at least one configuration will be a 400A 42ckt panel beneath one of the 225A panels, and another configuration will be a 225A 54 ckt panel installed above one of the 42ckt panels.

I can't find anything in the NEC that clearly prohibits this. I'm assuming the panels, with respect to each other, would not be considered "foreign to the electrical installation" (110.26(E)(1)(a)).

I think it can safely be considered not a best practice, considering I can't remember ever seeing it done. But prohibited? I haven't been able to go that far.

Thoughts?

 

[charlie b]

The worst rock I could throw at it would be the "neat and workmanlike" rule, and the question of how you could run conduits neatly and without exceeding the 360 degree limit. That, and if I were the AHJ and I declared that the panel above is foreign to the installation of the panel below (and vice versa), it is a really good bet that you would not win an argument against me. But I have to agree with you. I don't think the words in the code prohibit this.

As a design engineer, I will add that a better idea than using this layout to save wall space is to push the architect into giving me more wall space. A fallback position could be to make more use of the space in the room by installing panels on unistrut in the middle of the room.

 

[oldsparky52]

Would you be able to reach all of the breakers w/out a ladder?

 

[jaggedben]

If one panel is not sticking out farther than the other then neither is in the working space of the other. I would see absolutely no problem with it if we were talking about small panelboards, e.g. 24 circuits or less.

With that said, along the lines of what oldsparky asked, I'm somewhat skeptical that the situation you describe could be compliant with 404.8. You're not allowed to have a circuit breaker handle more than 6ft 7ins above the floor.

 

[qcroanoke]

If one panel is not sticking out farther than the other then neither is in the working space of the other. I would see absolutely no problem with it if we were talking about small panelboards, e.g. 24 circuits or less.

With that said, along the lines of what oldsparky asked, I'm somewhat skeptical that the situation you describe could be compliant with 404.8. You're not allowed to have a circuit breaker handle more than 6ft 7ins above the floor.

+1
but I think that may apply to main breakers and disconnects and not so much to branch circuit breakers. Dunno....

 

[infinity]

We've done this many times in tight electric closets.

 

[oldsparky52]

+1
but I think that may apply to main breakers and disconnects and not so much to branch circuit breakers. Dunno....

I am of the impression it applies to the branch breakers too.