Electric to new garage ????

[ESwartz]

Hopefully I'll get started on my new garage in the very near future. I'm having difficulty planning the electric service from the house to the garage and looking for some help.

My main panel is a 200A, I'd like to have a 100A 240V service to the new garage.

My transformer, meter & main panel are on the south side of my house, the garage is going on the north side of the house. I've measured approximately 325' from the main panel outside to underground around a retaining wall and up to new garage.

If I could go through the house somehow I could cut the distance from the main panel to the garage to about 150'. Is there conductor made to run in a house like this? What size conductor would I need? Would I need to go from the house into a disconnect box of some sort then UG to the garage?

Any help is greatly appreciated.

 

[pattenp]

You can go straight from main panel to sub panel. You'll have a junction box where you transition from SER to MHF. The disconnect is the 100A breaker you put in the main panel and the 100A main disconnect in the sub panel. SER in the house does not need to be in conduit. MHF where inside or exposed outside needs to be in conduit. I recommend putting the MHF in conduit underground even though it's not required.

Use SER cable inside and transition to Mobile Home Feeder for going outside to under ground. For 100A, I suggest AL 2/0-2/0-2/0-1 of the two below listed cables.

SER: http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheet273

MHF: http://www.southwire.com/ProductCatalog/XTEInterfaceServlet?contentKey=prodcatsheet15

 

[ishiboo]

Hopefully I'll get started on my new garage in the very near future. I'm having difficulty planning the electric service from the house to the garage and looking for some help.

My main panel is a 200A, I'd like to have a 100A 240V service to the new garage.

My transformer, meter & main panel are on the south side of my house, the garage is going on the north side of the house. I've measured approximately 325' from the main panel outside to underground around a retaining wall and up to new garage.

If I could go through the house somehow I could cut the distance from the main panel to the garage to about 150'. Is there conductor made to run in a house like this? What size conductor would I need? Would I need to go from the house into a disconnect box of some sort then UG to the garage?

Any help is greatly appreciated.

I would run mobile home feeder/USE to the barn to a junction box on the outside wall of the house, and SER from the junction box through the house to the panel.

You could also use THWN in conduit the entire length, but that'll get pricey.

 

[Gary S]

You could also use THWN in conduit the entire length, but that'll get pricey.

I've done two garages. One in 1992, and the second one in 2004. I ran THWN copper to both of them. I know I'll never be sorry. It is worth a little more to do it right the first time.

 

[Charliekilo]

What ever you decide run it past the inspectors office and get it approved and signed.
When I was building my shop my inspector would say no and his office said yes. And around and around. Finally threatened a lawyer and the head of the dept and the guy that engineered the building had to get involved. It got worked out with hard feelings all around.

 

[ishiboo]

I've done two garages. One in 1992, and the second one in 2004. I ran THWN copper to both of them. I know I'll never be sorry. It is worth a little more to do it right the first time.

There is also aluminum THWN you can run, if you can find it locally. (Without minimums or needing an account somewhere!)

The USE/SER method is not "doing it wrong", the only thing I don't like about it is I don't like long runs of cable in the house fused at 100 amps you could easily put a nail/saw blade in. Plus, it takes a decent sized junction box on the outside of the house.

What ever you decide run it past the inspectors office and get it approved and signed.
When I was building my shop my inspector would say no and his office said yes. And around and around. Finally threatened a lawyer and the head of the dept and the guy that engineered the building had to get involved. It got worked out with hard feelings all around.

Very true, I'd recommend this any time you do permitted work that's any more complex than installing a single outlet Run the plans by the inspector. Use email if you can, it takes less of their time than a call and then you have it documented. Just review the materials/etc. you gathered you should use by your own reading of the code, and verify it's okay with them.