Two panelboards of one

[RUWired]

?designed to be placed in a cabinet or cutout box. . . .? Not two boxes; ?a box? (as in ONE box). So if you have to cabinets or two cutout boxes, you have two panels.

QED

Charlie,I think you are putting to much emphasis on the words "in a" cabinet,without keeping in mind the words "panel units" in the first sentence.It would be hard to put "panel units", "in a" single cabinet.It would be easier to,"put a single panel in a cabinet" or "single" units in a cabinet.It would be my opinion that as long as these maximum 42 cir panelboards are in single cabinets and grouped with the same feeder,(not tapped, but feed through) they are one panelboard.
Rick

 

[jim dungar]

... as long as these maximum 42 cir panelboards are in single cabinets and grouped with the same feeder,(not tapped, but feed through) they are one panelboard.

Rick,

How close do they have to be to be "grouped"? Why not on different floors it is the same thing electrically?
Why do they need to be feed-through? What if they are MLO can't they be tapped?

Charlie B, what if there are two back boxes but one trim? Square D offers a custom single trim for two individual back boxes joined with a 3" nipple.

 

[charlie b]

It would be hard to put "panel units", "in a" single cabinet.

I'm not sure that's true. But then, I don't know what a "panel unit" might be.

As I envision the situation, you have three vertical bus bars, a neutral bus, and a ground bus, and you have a number of breakers, all of which you can see by removing a single cover. That thing is what is limited to 42 circuits. IMHO, if you have another thing like it mounted on the same wall, with its own set of bars and breakers, and with a set of conductors (within a nipple) bringing electricity from one to the other, then you have a separate panel.

 

[RUWired]

Rick,

How close do they have to be to be "grouped"? Why not on different floors it is the same thing electrically?
Why do they need to be feed-through? What if they are MLO can't they be tapped?
.

Jim, I don't know if there is a maximum distance grouping can be extended.I would think on different floors would not be grouped though.In Websters dictionary,Group is defined as ; a number of individuals assembled together or having some unifying relationship.

If the inividual panels are feed through via double lugs or buss extensions, that would be IMO of the same.If the seperate panels where tapped, then they would require seperate ocp, and then be considered a seperate panel.
Rick

 

[RUWired]

IMHO, if you have another thing like it mounted on the same wall, with its own set of bars and breakers, and with a set of conductors (within a nipple) bringing electricity from one to the other, then you have a separate panel.

Charlie,From article 100,
A single panel or group of panel units designed for assembly in the form of a single panel, sounds to me like there saying it is o.k.to call it one single panel.
Rick

 

[smithacetech]

Charlie B, what if there are two back boxes but one trim? Square D offers a custom single trim for two individual back boxes joined with a 3" nipple.

I have a situation in an industrial plant that has these type of "stacked" panels. They are 2 seperate back boxes with 2 seperate trims/doors but the back boxes are bolted together, no nipples, no endwalls, one stacked on top of the other.
We are replacing one of these 84 ckt panels, But I was wondering about 408.35 & if these type of panels are considered a single cabinet or two???
(They are L&A panels).
These panels have been here for many moons so I dont know if they were manufactured this way or field installed. Iam checking with SQ D, but was wondering what you all thought?