New service at detached garage already served by branch circuit.

[Greentagger]

I have an existing detached garage with existing branch circuit from primary residence which serves lights, receptacles, etc.
No disconnecting means was noted.
New 120/240V 200A service was installed at detached garage for EV chargers. Main disconnecting means on exterior. GES installed.
Does 225.30 not permit this?
If so does 225.37 Exception No.2 relate?
What about 230.2(E)?
Seems like an odd installation.
Thanks.

 

[packersparky]

I have an existing detached garage with existing branch circuit from primary residence which serves lights, receptacles, etc.
No disconnecting means was noted.
New 120/240V 200A service was installed at detached garage for EV chargers. Main disconnecting means on exterior. GES installed.
Does 225.30 not permit this?
If so does 225.37 Exception No.2 relate?
What about 230.2(E)?
Seems like an odd installation.
Thanks.

225 says only one branch circuit or feeder, and 230 says only one service (unless one of the conditions in each article is met), but nothing in the NEC prohibits a building from being supplied by a branch circuit and a service.

 

[ptonsparky]

Sounds like a ground loop at birth to me.

Yes,
Yes.
Odd indeed.

As an EC, the BC would have disappeared, but that would have been me.

 

[ptonsparky]

Is the original BC with no GES now required to be connected to the newly established one?

 

[roger]

IMO the wording of 225 would prohibit the addition of a service.

225.30 Number of Supplies. A building or other structure
that is served by a branch circuit or feeder on the load side
of a service disconnecting means shall be supplied by only
one feeder or branch circuit.

Barring the specific allowances the words "Shall be supplied by only one feeder or branch circuit" means exactly that.

So if the building was already supplied by a branch circuit that is all that is allowed to supply it.

 

[retirede]

IMO the wording of 225 would prohibit the addition of a service.

225.30 Number of Supplies. A building or other structure
that is served by a branch circuit or feeder on the load side
of a service disconnecting means shall be supplied by only
one feeder or branch circuit.

Barring the specific allowances the words "Shall be supplied by only one feeder or branch circuit" means exactly that.

So if the building was already supplied by a branch circuit that is all that is allowed to supply it.

Playing the devils’s advocate, how does explicitly prohibiting additional “feeders and branch circuits” also prohibit a service?

A service is neither a feeder or a branch circuit. Charlie’s rule and all….

 

[Greentagger]

IMO the wording of 225 would prohibit the addition of a service.

225.30 Number of Supplies. A building or other structure
that is served by a branch circuit or feeder on the load side
of a service disconnecting means shall be supplied by only
one feeder or branch circuit.

Barring the specific allowances the words "Shall be supplied by only one feeder or branch circuit" means exactly that.

So if the building was already supplied by a branch circuit that is all that is allowed to supply it.

Kind of the line of thinking I originally thought……….but…………what about 225.37, 230.2(E). That seems to allow?

 

[roger]

Playing the devils’s advocate, how does explicitly prohibiting additional “feeders and branch circuits” also prohibit a service?

A service is neither a feeder or a branch circuit. Charlie’s rule and all….

It says Supplies, it's not specific to feeders or branch circuits. In as much as a service would be a supply it would mean the feeder or branch circuit would be the only allowed supply.

 

[roger]

Kind of the line of thinking I originally thought……….but…………what about 225.37, 230.2(E). That seems to allow?

IMO 225.37 and 230.2 would both be addressing special conditions/exceptions such as

"(A) Special Conditions. Additional services shall be permitted
to supply the following:
(1) Fire pumps
(2) Emergency systems
(3) Legally required standby systems
(4) Optional standby systems
(5) Parallel power production systems
(6) Systems designed for connection to multiple sources of
supply for the purpose of enhanced reliability"

 

[Greentagger]

And 225.30 (A)(7) applies to feeder run from detached structure back to original building or dwelling from existing branch circuit which now supplies detached garage? Not from or related to new service built on detached garage for EV chargers.

 

[wwhitney]

Barring the specific allowances the words "Shall be supplied by only one feeder or branch circuit" means exactly that.

But that's not the same meaning as "shall only be supplied by one feeder or branch circuit." I'd say that wording rules out other types of supplies, while the language you quoted is silent on non-feeder, non-branch circuit supplies.

Cheers, Wayne

 

[roger]

But that's not the same meaning as "shall only be supplied by one feeder or branch circuit." I'd say that wording rules out other types of supplies, while the language you quoted is silent on non-feeder, non-branch circuit supplies.

Cheers, Wayne

Yeah, I'd expect you to somehow nitpick the wording. Regardless of how you want to interpret it I see it as being the same and if I were the inspector I would enforce it that way.

 

[wwhitney]

Yeah, I'd expect you to somehow nitpick the wording.

Often otherwise known as Charlie's Rule.

In this case I think the English language construction is just a little too ambiguous and the distinction I'm pointing to is a bit too subtle. It would obviously be clearer if the sentence were instead, say, "shall have at most one source of supply, be it branch circuit, feeder, or service," assuming that is the intention.

Although in keeping with the scope of the article, it should really be phrased along the lines of "if the building has a service, then there shall be no branch circuit or feeder supply."

Cheers, Wayne

 

[wwhitney]

It says Supplies, it's not specific to feeders or branch circuits. In as much as a service would be a supply it would mean the feeder or branch circuit would be the only allowed supply.

So then why are the permissions granted in the rest of 225.30 only for additional "feeders or branch circuits"? Surely for all of those purposes a service would also be fine. Your interpretation creates the situation where a building might be allowed to have two feeders supplying it for one of the allowed purposes, but it wouldn't be allowed to have a feeder and a service supplying it for that same purposes. That makes no sense.

What makes more sense is that given the scoping of Article 225 as per 225.1, 225.30 doesn't regulate services at all. Any such regulation would be in Article 230.

As an example of that idea, take a look at 225.37. It contemplates that a building may be supplied by both a feeder and a service (which would be an unnecessary breadth if 225.30 prohibits that arrangement) and requires that plaques be put up describing the multiple sources of supply. But it makes that plaque requirement only on the feeders and branch circuits supplying the building--not on the services. Because per the scoping, 225 can only regulate the feeders and branch circuits, not the services. The requirement for plaques at services is in 230.2(E).

So the idea that Article 225 can regulate or limit the number of services just doesn't work.

Cheers, Wayne

 

[retirede]

It says Supplies, it's not specific to feeders or branch circuits. In as much as a service would be a supply it would mean the feeder or branch circuit would be the only allowed supply.

If the intention was to limit the building to a single supply, there would be no need to specifically call out branch circuits and feeders without mentioning services.

But I can see your point, too.

 

[roger]

So then why are the permissions granted in the rest of 225.30 only for additional "feeders or branch circuits"?

Cheers, Wayne

This is where you have to expand your reading and remember Charlies rule too. Go to 230.2(E) and read it closely. You will see where combinations of feeders, branch circuits, and services can be allowed.

 

[roger]

If the intention was to limit the building to a single supply, there would be no need to specifically call out branch circuits and feeders without mentioning services.

But I can see your point, too.

As in my previous post, 230.2(E) allows it but for the aforementioned reasons of Special Conditions and I don't see where the OP's situation is one of those.

 

[Sea Nile]

225.30 is under Part II which is titled buildings and structures supplied by feeders or branch circuits. So I don't see the answer being found in this section.

However, 230.2 says a building can be supplied by only one service.

If the garage has its own service, then I don't think it can be served by a branch circuit or feeder originating from another service at the main residence per 230.2

 

[Sea Nile]

230.2 (E) can not apply. Because 230.2 specifies (A) through (D).

They stopped before reaching (E)

 

[wwhitney]

Go to 230.2(E) and read it closely. You will see where combinations of feeders, branch circuits, and services can be allowed.

230.2(E) is about Identification (signage). It does not grant or deny permission on the topic of number of supplies or types.

Again, your interpretation yields the unreasonable result that a building might be allowed to have two feeders for one of the allowed reasons (225.30), or two services for that same reason (230.2), but one service and one feeder would be prohibited.

Per the scope and the structure of 225, it can not and does not regulate services. While the title of 225.30 is "number of supplies" without immediate qualification, the title of Part II just above that is "Buildings or Other Structures Supplied by a Feeder(s) or Branch Circuit(s)." That qualifies the meaning of the word "supply" in 225.30 only to supply by a feeder or branch circuit.

Cheers, Wayne