Need help with wiring confusion

[Pilvr83]

Hello,

I am new to this forum. Last year, I had a 16 x 24 foot barn/garage built in my backyard. My intentions are to use this as a woodshop some day.

Previously, I had a metal shed that I ran 14/2 UF wire (15 amp breaker) to supply lights. When I had this new garage built (on concrete) I moved the same wire over to supply electric.

For over a year, this line has worked great for lights and outlets. I have a Shopsmith wood working setup that I can run with the lights on. I cannot run the dust collection system. Occasionally, the lights do dim.

Sorry for the long story...now my dilemma...

I purchased 2 rolls of 250' 10/2 UF wire, a 30 amp breaker, 160' of RIGID galvanized 1.5" conduit, an inside subpanel box for the barn, etc. I am thinking of replacing my 15 amp breaker (last slot I had avail) with the 30 amp breaker, running one 10/2 wire (run second roll for reserve), from my breaker in my attached garage to a subpanel in the barn. I would jump the hot wire in the subpanel (120 volts) to enable me to put in 2 20 amp breakers for two separate circuits. One for the lights, one for the tools.

Or would like to add a second breaker box from garage with 2 30amp breakers, use both rolls of my 10/2 line to barn. Put 4 20 amp breakers in subpanel at barn (240 volts) for 4 circuits.

If I did the second option, would that be a 30 amp circuit or a 60 amp circuit?

Does either one sound safe/logical? I only want to run the conduit/line once in my life time!

Thank you in advance,

Greg

 

[G_P]

I dont think code allows you to have 2 separate power feed cables to the outbuilding. You would be better off returning the 2 rolls of wire and buying a different wire so that you can just run a 60a subpanel in the shop fed by a 60a breaker in your home panel.

 

[pattenp]

NEC doesn't allow 2 power feeds to a detached structure. Also how far is the barn from the attached garage panel that you plan to get power from? #10 may be a little small depending on the distance. Also you will be limited to 120V with 10-2. You need 3 conductors plus ground (10-3) to get 240V.

 

[Charles (in GA)]

You also need to return the conduit. You should be using PVC glued together for underground. The steel conduit will corrode and the connectors are not water tight, it will fill with water. You really do not need a conduit at all for UF, just to get it down in the ground and back out (for protection where it is exposed).

You would run one wire, such as 10-3 w/grd or 6-3 w/grd and this will give you 240v capability at the building, you can split it in a small panel in the shop.

If you are out of spaces in your home panel, you probably can find two low use, low draw circuits that can be combined on the same breaker, and then move/remove breakers to make for two adjacent (above/below) breaker slots to install a double pole breaker to provide the 240v/120v to the building.

On a budget, I would get 6-3 w/grd UF and run it without conduit except to exit the building and house and go underground. Breaker it at 50 amps and then install 20 amp breakers in your shop to run your woodworking tools.

Last thing you want to be doing is the same job twice because you didn't give yourself enough power the first time.

 

[Norcal]

PVC will fill w/ water just due to temperature differences, so the water is no big deal unless it were to drain somewhere it shouldn't. That being said, PVC conduit would be a lot easier to install then rigid steel,& a lot cheaper, also as said above only one circuit is allowed to be run to a outbuilding....

 

[MTW]

Seal both ends of the conduit with duct seal, to prevent moisture buildup from condensing. Air traveling thru the conduit from one building to the other (pressure differential) is the real source of moisture. No airflow means no condensation, provide the pipe is glued properly.