Location of Service Main Disconnect

[larry1234]

Were the service equipment is two grouped disconnects, i.e. 2-200amp. Can both disconnects be inside a house were one is used to feed out to a seperate building (garage) and the other to serve the house.

[ March 07, 2003, 11:04 PM: Message edited by: larry1234 ]

 

[stamcon]

Re: Location of Service Main Disconnect

Larry, check with local code authority. Some cities require an exterior disconnect.

 

[russ]

Re: Location of Service Main Disconnect

I don't see why not.

Russ

 

[hornetd]

Re: Location of Service Main Disconnect

Under the US NEC they both have to be in or out. You cannot have one in and one out as it would violate
230.72 Grouping of Disconnects.
(A) General. The two to six disconnects as permitted in 230.71 shall be grouped. Each disconnect shall be marked to indicate the load served.
Exception: One of the two to six service disconnecting means permitted in 230.71, where used only for a water pump also intended to provide fire protection, shall be permitted to be located remote from the other disconnecting means.
--
tom

 

[david]

Re: Location of Service Main Disconnect

Interesting question

230.3 One Building or Other Structure Not to Be Supplied Through Another.
Service conductors supplying a building or other structure shall not pass through the interior of another building or other structure.

You would first have to define if these are in fact two separate services . Are these feed from two different meters? Are both the house and the garage under the control of one owner?

 

[amptech]

Re: Location of Service Main Disconnect

David, If the service disconnects were at the first building, as he stated, then any conductors from the disconnects to anywhere else would not be service conductors. They would be feeders. 230.3 would not apply to the situation the original poster described.

 

[david]

Re: Location of Service Main Disconnect

In a typical residential situation were you have a service for a dwelling and a feeder is taken to an out building a garage, which is most likely the case here. I agree. The garage could be just an out building or it could be a repair shop,

I just did not think that there was enough information to give a definite answer.

I was called to an inspection were the service conductor was taken to a two gang meter socket mounted on the main house. The two service entrances were taken into service disconnects ganged, in he basement of the first house. A feeder was taken from one to feed a second house located 200 feet behind the first house. It was explained to me by the father, that this used to be metered from one meter one panel. His daughter got married and now He wanted hers metered separately. I explained that his daughter?s service could not be supplied through his house.

[ March 09, 2003, 02:20 PM: Message edited by: david ]

 

[jxofaltrds]

Re: Location of Service Main Disconnect

David

Could he have been able to comply with 230.6?

 

[amptech]

Re: Location of Service Main Disconnect

David, You are correct. As far as I know, no utility would allow a disconnect ahead of their metering. Without a disconnect the conductors are service conductors and cannot pass through one building to another as you quoted in 230.3.

 

[david]

Re: Location of Service Main Disconnect

Mike

If it turns out to be in fact two separate services than the disconnect to the garage would be Code compliant if installed on he out side of the house.

 

[hornetd]

Re: Location of Service Main Disconnect

Originally posted by david:
In a typical residential situation were you have a service for a dwelling and a feeder is taken to an out building a garage, which is most likely the case here. I agree. The garage could be just an out building or it could be a repair shop,

I just did not think that there was enough information to give a definite answer.

I was called to an inspection were the service conductor was taken to a two gang meter socket mounted on the main house. The two service entrances were taken into service disconnects ganged, in he basement of the first house. A feeder was taken from one to feed a second house located 200 feet behind the first house. It was explained to me by the father, that this used to be metered from one meter one panel. His daughter got married and now He wanted hers metered separately. I explained that his daughter?s service could not be supplied through his house.

I don't see that the daughters "service conductors" pass through the fathers house. I see nothing about that installation that violates the letter or even the spirit of the US NEC. There is nothing in the code that prohibits the power for one building to pass through wiring mounted in another building only that the service conductors for one building may not pass through another building. I would understand the concern if the conductors did not terminate to service equipment in the first building.

Imagine a multiple occupancy office park with nine buildings. The service entry conductors enter an electric room and terminate in multi meter equipment were each meter has a disconnect to protect a feeder to one of the buildings. By this reasoning this installation is unlawful.
--
Tom

 

[iwire]

Re: Location of Service Main Disconnect

Posted by David

"the service conductor was taken to a two gang meter socket mounted on the main house. The two service entrances were taken into service disconnects ganged, in he basement of the first house. A feeder was taken from one to feed a second house located 200 feet behind the first house"

"I explained that his daughter?s service could not be supplied through his house."

I do not understand your position on this, you said it was a feeder so why can it not pass thru?

2002 NEC 230.3 says service conductors can not pass thru the interior of another building.

As soon as the service conductors hit the disconnect they became feeders, so they did not pass thru, they terminated, which is not addressed by 230.3

[ March 11, 2003, 04:35 PM: Message edited by: iwire ]

 

[david]

Re: Location of Service Main Disconnect

NEC:
230.3 One Building or Other Structure Not to Be Supplied Through Another.
Service conductors supplying a building or other structure shall not pass through the interior of another building or other structure.


NEC Handbook:
Service conductors are permitted to be installed along the exterior of one building to supply another building. However, service conductors supplying a building are not permitted to pass through the interior of a building. Each building served in this manner is required to be provided with a disconnecting means for all ungrounded conductors, in accordance with Part VI, Service Equipment?Disconnecting Means.
For example, in Exhibit 230.14, Building No. 2 service is not to be supplied through Building No. 1 service. The service disconnecting means shown for Building No. 1 and Building No. 2 are located on the exterior walls. A disconnecting means suitable for use as service equipment is required to be provided for each building.

Let me make it clear at that the deed to the second house changed hands at the time of the daughters marriage.

Tom
I have seen services as you described at state parks. I never inspected a service for cabins at state parks, and I would have assumed these buildings were under control of one owner on the states property. I will have to look into this more.

In the handbook illustration combined with the commentary it is clear that the author is saying the service conductors to the second building have to stay on the exterior of the first building.

I read the rule to first say one building or structures service shall not be supplied through another.

Second I read the rule to also say that the service conductors of the second building cannot pass through the first building.

you say because the conductors entering the first building are service conductors and because they leave the first building as feeders, (after passing through a service disconnect) to the second building, the service conductors have not passed through the first building.

You still cannot get away from the second building service being supplied through the first building.

The rule does not address feeders and the rule does not address service conductors alone. the rule addresses a building service as a whole

[ March 11, 2003, 06:11 PM: Message edited by: david ]

 

[david]

Re: Location of Service Main Disconnect

After rereading this thread I want to make it clear that I have no problem with a feeder passing through one building to another under the control of one owner.

 

[iwire]

Re: Location of Service Main Disconnect

I agree it makes sense about the control of one owner but where do I find a reference to that in the code, 230.3 makes no such distinction?

I ordered the NEC handbook on CD-ROM but it has not arrived.

 

[david]

Re: Location of Service Main Disconnect

Service. The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served.

230.3 One Building or Other Structure Not to Be Supplied Through Another.

Service conductors supplying a building or other structure shall not pass through the interior of another building or other structure.

I have concluded the following:

Service conductors include service entrance conductors and any and all other conductor that deliver power from the utility to the premises served.

So according to 230.3 service conductors can only enter a building if the are serving a part of that buildings electrical system.

I further conclude that according to 230.3 if you enter a service disconnect in building # 1 that is only a service disconnect to serve building # 2 you are in violation of 230.3

If I was to inspect your job that you brought the service entrance conductor to your garage into your residence through a service only disconnect then took a feeder to your garage I would pass it even though I think this set up is a violation according to 230.3. If you want to call that special permission then I would give special permission.

I also conclude I do not see any thing wrong with the way service are set up in state parks to distribute power from one service location to each of the cabins. I do not see how this complies to 230.3 so if special permission is needed I would also give it.

[ March 12, 2003, 12:17 PM: Message edited by: david ]

 

[jkllm5]

Re: Location of Service Main Disconnect

This topic has garnered much debate were I work at and from the postings on this and it is still subject to debate. It boils down to how you read the NEC book-was it the intent that no building will be supplied thru another building or is it referring to Service Entrance conductors only. I would guess there are plenty of outbuildings that have a feeder run to them and I don't think the code was trying exclude that from occuring.

 

[david]

Re: Location of Service Main Disconnect

230.1 Scope.
This article covers service conductors and equipment for control and protection of services and their installation requirements.

Remember keep the scope of article 230 in your debate :

230.3 One Building or Other Structure Not to Be Supplied Through Another.

Service conductors supplying a building or other structure shall not pass through the interior of another building or other structure.

230.3 One Building or Other Structure ( service) Not to Be Supplied Through Another.

The word supplied is limited by the scope of 230 to dealing with service supplied

Remember also to keep the definition of service in your debate

?Service. The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served.?

Call the serving utility point A and the premise point B. Until you get from point A to point B all conductors and equipment used between those two points are service conductors and equipment

[ March 12, 2003, 11:52 PM: Message edited by: david ]

 

[bphgravity]

Re: Location of Service Main Disconnect

David, I think you are reading too much into the defintion of service and attributing too much wiring and equipment to it. The ponit at which you no longer call the premise wiring service wiring is at the supply side of the service OCD. The load side of this OCD is either a feeder or the buss of a loadcenter. In the case of two or more metered occupancies, there is still only one service to the the building. The service entrance, disconnects and OCD's will all be at this point. After this, the wiring is either a feeder or branch circuit and can pass through other buildings or structures. 230.3 is prohibiting the service entrance conductors from passing through a separate building or structure before it lands at the meter enclosure or disconnect at the building it will serve.

 

[david]

Re: Location of Service Main Disconnect

______________________________________________________
It boils down to how you read the NEC book-was it the intent that no building will be supplied thru another building or is it referring to Service Entrance conductors only.

jkllm5
Service entrance conductors are the conductors that enter a premise they are only a part of the service conductors.

There is a distinction being made here between a feeder coming out of a distribution panel from building 1 to building 2. a distribution panel also serving the premise wiring system in building 1. Verses a feeder going out of a service only disconnect in building # 1 this feeder would also be classified as service conductors until the feeder enters the service disconnect in building # 2 the premises being served.