Elec to detached building?

[arthur1920]

I don't know anything. Can anyone explain rules about. power to a detached garage/barn near my single family home? Do I **have to** run the electricity in a trench from my home? Is there a limit as to how much electricity I can have? I have a main panel 200 amp and an accessory panel in the current garage 100 amp. I would expect to need at least 100 amp in the detached unit. Is it possible the electric company would bring in a separate line from a different pole to a separate meter on the detached structure? Which is the least costly way of doing it?

Please give a 6th grade, non electrician answer to a "customer" not an electrician.

 

[Innovate1]

Lots of ways to do it. You could run overhead or in the ground from the house. You could get a second meter on the garage but the power company may not want to do that and you have a second meter charge. Least costly way depends on a lot of details which you haven't given. What sort of permitting is needed (varies from simple and homeowner can do the work themselves to complex and not allowing the homeowner to do any of it). Do you want to do it yourself if you are allowed? Sounds like you probably shouldn't do that unless you plan to do a lot of getting up to speed or have a friend that knows electrical wiring. A sketch of the area showing where utilites are, distances between buildings and utilities, etc would help. What sort of things are you planning to do in the buildings? If it's just you then it's unlikely you will be loading things down in both buildings at the same time. Two 100A feeds from a 200A main panel seems like a lot but it really depends on how they are used. How much can you have? It depends on the utility but practically it is probably just a matter of how much you spend. I think most utilities would put a bigger transformer in if you justified the need and paid for it. You need to talk to your utility and the local AHJ (the people that issue permits).

 

[u2slow]

Have to talk to your utility if they allow a 2nd hookup of the same voltage to a single address. If they do, the billing rate may not be the same either.

For me, it was cheaper and easier to subfeed 100A from the house. One of these days I'll even bury the cable...

 

[TractorJeff]

My question is: How much of the 100 amps at the Garage is he using at the same time as the 100 amps at the New outbuilding?
I'm assuming there is no great thought to the ACTUAL Load consumption on a practical basis??

 

[Mike65]

When we had an electrician run the power for our detatched garage/shop he had a trench dug & ran the outdoor cable in the trench to the garage/shop. He ran the power off of our breaker box in the house.

 

[Poolshark314]

I would suggest spending a bit more time reading posts and watching youtube videos on the topic so you can come up with some more specific questions you want answered. A video (and there are plenty of them) will be much better to understand than trying to read super long replies that would come from describing the process overall. You will also need to know your local jurisidiction's electrical code compliance level (Ex. NEC 2008)

 

[Spud McGee]

This is one of the questions that falls under "every area is different. what is allowed one place may not be allowed in the next town over."

My local zoning rules dont allow a second power meter for accessory buildings. My town's rules probably dont apply to you.

I ended up renting a dingo with a ditch digging attachment and digging it myself. All the materials came from lowes and home depot.
I had a local electrician buddy looking over my shoulder for the planning and purchasing to make sure I was up to code and not doing anything dumb. I did a 100 amp breaker in the main panel feeding a panel in my shop, with direct burial cable.

 

[dcg9381]

To answer your question about "how much power is left over" (from the house) - I added a $100 power monitor to my existing panel. It measures peaks and is better than doing a "load calculation". I'd wager that MOST homes with 200A service likely have enough power available to do at least 60A to a garage/shop, but that's not good enough. In some places a load calc will be required. Some places nothing is required and you can simply run a feed from the house.

That simply leaves the question if you can do the run from the house or if you need "new service". We can't answer that for you without more information.

Where I am now, it's actually better to add a 2nd meter to the shop. They charge "agriculture rates" which are a fraction of what you pay for residential electric service. At home, it'd cost me $30 just to have the meter (assuming no use) and I'd get charged for residential power....

Hope that's enough of a non-answer, but gets you started.