Overstuffed main service panelboard

[donf]

I was asked by a neighbor (with a rather large can of Foster's in hand) to take a look at his panelboard because he needs to add a BC.

The cabinet is a 150 amp, singe phase, three wire. Manufacturered by GE.

This panelboard itself is filled to capacity with slim-lines. The neutral bus, has at least 5 pigtailed (3 wire) connections to a single hole in the top neutral bus. I could not find a ground bus, nor were any egc's connected to the neutral bus bar.

There is enough wire in this panelboard to do a full hospital (albeit a small one).

I remember reading somewhere in the NEC that there is a 70% maximum fill for a panelboard, but because I am looking for it, I cannot find it. Can anyone help me find that citation please?

 

[infinity]

Look here. IMO it's just about impossible to exceed the maximum fill in any cross section.

312.8 Enclosures for Switches or Overcurrent Devices.
Enclosures for switches or overcurrent devices shall not be used as junction boxes, auxiliary gutters, or raceways for conductors feeding through or tapping off to other switches or overcurrent devices, unless adequate space for this purpose is provided. The conductors shall not fill the wiring space at any cross section to more than 40 percent of the cross-sectional area of the space, and the conductors, splices, and taps shall not fill the wiring space at any cross section to more than 75 percent of the cross-sectional area of that space.

 

[Finite10]

75% is pretty generous considering auxiliary gutters and wireways are only 20% fill. I've seen some small old panels that were so full they made me squint putting the cover back on. Usually with old solid wire wadded up in there.