ECN Forum Forums General Topics of the Trade General Discussion Area Color codes revisited

Although this is generally true, it is not a requirement.
Some older panels have the breakers mounted vertically with the busses horizontal.
I haven't seen newer ones that way for awhile,tho.

Just about all domestic panels here have a horizontal busbar (usually at the bottom) and breakers or plug-in fuse carriers mounted vertically in a single row (only one hot leg remember).

Three-phase is generally two vertical rows of breakers mounted sideways with a main switch at the bottom.

>Although this is generally true, it is not a requirement.
1999 NEC 240-33?

240-33 says only that the enclosure must be mounted vertically if possible.

(I actually did see a service mounted sideways one time)

I hadn't thought of that way.

So does this just prohibit mounting it with the back against a floor, ceiling, and anything that isn't a vertical wall? But not which way the box itself has to be oriented?

Another word for "box" is "enclosure."