Powering up an out building

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Old 12-13-15, 09:05 PM
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Powering up an out building

I have a garage and a building on my property. The building is being turned into a tiny house. I will be running power first to the garage and then to the building.

The garage is 150' from the house and the building is 20' from the garage.
The garage will have lighting and 110 outlets for power tools. The building will have a 220 hotwater heater, 110 window unit, microwave, refrigerator, lighting, and of course outlets for TV, George Forman grill, etc....

100 amp panel for each building?
What direct burial cable should I use from house to garage(150')?
What over head cable should I use from garage to building(50')?
Do I need to bond a ground at both boxes?

Thanks in advance
 
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Old 12-13-15, 09:25 PM
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The NEC specifies a minimum 100 amp service for a dwelling unit.

Does the garage already have a service?
 
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Old 12-13-15, 10:00 PM
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There was once upon a time, but not currently.
 
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Old 12-14-15, 08:33 AM
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I'd use #2/0-2/0-1-4 or #2/0-2/0-2/0-4 aluminum mobile home feeder (MHF) cable (whichever you can get from your supplier). It must be in conduit inside the buildings, buried at 24" deep when underground conduit is not required. You could also use this cable for an overhead service if you securely lash it to a steel support wire. The overhead would need a mast and weatherhead on each side. The attachment points should be at least 12' high and the lowest point of the cable should be no less than 10'.

Both buildings would need ground rods. Ground and neutrals must be unbonded in both panels.
 
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Old 12-14-15, 10:53 AM
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There is a crawl space under my house. Do I need to have PVC pipe under there?
 
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Old 12-14-15, 11:57 AM
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Yes, conduit is required from the panel to a 90 degree sweep at the bottom of the trench. Same on the other side from the trench up to the panel. I'd use 1-1/2" conduit for that size cable.
 
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Old 12-14-15, 03:22 PM
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Seems everyone around here carries #2 or 4/0. Since #2 is probably underrated, that leave me with 4/0. Will I be able to get that in the lugs from the 200 panel?
 
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Old 12-14-15, 03:30 PM
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Can you order the #2/0? #4/0 will be a monster to work with and you would probably need to splice down to a smaller size at the panels which adds significantly to the expense. Home Depot and Menards usually have access to that product if you have either of those nearby. You could also try an Internet vendor like Platt.
 
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Old 12-14-15, 07:50 PM
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4/0 fits in a 200 amp lug.
 
 

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