NEC 225.33

[Johnhall30]

Is 225.33 stating that a sub-panel in a detached building cannot have more than 6 circuits without requiring a main breaker?

Or is it stating that a maximum of six feeders are permitted to supply a detached building per 225.30, and the disconnects must be grouped

 

[augie47]

The former (6 disconnect maximum in the panel)
225.30 still restricts the number of supplies to one with exceptions

 

[wwhitney]

Is 225.33 stating that a sub-panel in a detached building cannot have more than 6 circuits without requiring a main breaker?

Only for a subpanel that is serving as a disconnect for one of the permitted sources of supply to the detached building. A subpanel downstream of the disconnect is not subject to such a limitation.

Also for the case of multiple sources of supply under 225.30(B), I think that each source of supply requires a single disconnect.

Cheers, Wayne

 

[augie47]

Only for a subpanel that is serving as a disconnect for one of the permitted sources of supply to the detached building. A subpanel downstream of the disconnect is not subject to such a limitation.

Also for the case of multiple sources of supply under 225.30(B), I think that each source of supply requires a single disconnect.

Cheers, Wayne

I can't say I find the wording to be very definitive but would this not allow (6) per source ??
(225,33) There shall be no more than six disconnects per supply grouped in any one location.

 

[Johnhall30]

The wording of this section is very confusing and misleading.

It seems that this would be a very common installation scenario - running a feeder to a separate building, is a main needed at the separate building or not?

Its not clear at all

 

[wwhitney]

It seems that this would be a very common installation scenario - running a feeder to a separate building, is a main needed at the separate building or not?

Its not clear at all

For just one feeder to a building supplying a panel, the panel can be the disconnect if (a) it's outside or inside nearest the point of entry of the feeder and (b) it has a main breaker, or it has at most 6 circuit breakers. Otherwise, you need a separate disconnect.

Cheers, Wayne

 

[wwhitney]

I can't say I find the wording to be very definitive but would this not allow (6) per source ??

225.30(B) for multiple feeders originating at the same supply equipment says "the requirements of 225.33 shall not apply". (Edit: text deleted) And the first sentence of 225.30(B) specifies "each feeder terminates in a single disconnecting means." So you end up with at most 6 disconnecting means grouped in one location.

(Edit) When you have multiple supplies due to one of the other sections in 225.30, then you could have up to (6) per supply.

Cheers, Wayne

 

[jaggedben]

The wording of this section is very confusing and misleading.

It seems that this would be a very common installation scenario - running a feeder to a separate building, is a main needed at the separate building or not?

Its not clear at all

Generally, yes, a main is needed at the separate building. If you don't want to get into the qualifications and exceptions, that's the simplest way to comply. Provide a main breaker subpanel instead of a main lug subpanel.

You're right it's a common installation scenario. In my experience, the requirement for a main disconnect (or no more than 6, etc. etc.) is also frequently overlooked and not enforced.

That said, I don't agree the code isn't clear. It has a lot of words, sure, but read them carefully and the requirement is quite clear, at least for a typical situation where the outbuilding has one subpanel. It's as you initially said, with Wayne's clarification. "a sub-panel in a detached building cannot have more than 6 circuits without requiring a main breaker [unless it's downstream of another disconnect that's also at the detached building]."