Instructables

wiring a building up with a 10 awg stranded wire

i have recently bought a repoed amish rent to own building.  it was getting wired in the middle of the repo.  i have some stranded 10awg stranded wire with an extension cord male plug on one end.  i would like to have it to where i can easily disconnect the power by unplugging it from my outside outlet of the house.  inside the building is a complete breaker box with a 60 amp breaker and a bunch of 30's as secondaries.  i have read that 30 amp is max for the 10 awg stranded wire.  is there any way that i can have the other end of the wiring put in the breaker box with a 30 amp breaker as the main and 15's and possibly a 20 here and there for breakers.  it has about 6 outlets and one flourescent light in there.  i will have only a small air compressor, small miter saw, couple lights, and a drill battery charger in the building, but never all running at the same time.  can someone give me a couple pointers on this?  by the way, this is industrial warehouse wire, and not no cheap stuff.

caarntedd1 year ago
You should be able to wire the building as you have said.
Connect the cord into the same place in the breaker box as the mains would normally be connected, and plug it into your house. Don't worry that the main breaker in the box is 60A. Everything will be dependent on the breaker for the power circuit in your house.
If that for example is a 20A breaker, then your new building coupled with whatever else is running on that circuit in your house will be limited to a maximum draw of 20A.

Just make sure that if your new building has mains cables running into the breaker box that may be hanging out somewhere waiting to be connected to the grid, that you disconnet these from the box before connecting your cord into the main breaker, or you will have live mains wires hanging out somewhere every time you plug the building into your house. 

Extension cords are ususlly manufactured to the right length to gauge ratio. If your cord is a "store bought" heavy duty type, the length should be OK. I am in Australia and we don't use AWG, but an average heavy duty industrial cord would only be 2.5 mm squared cross sectional area per wire, and no longer than 30 metres (close to 100 feet). AWG 10 is over 5 mm sq, so you should be good to go.
Vyger1 year ago
You gave a good description except you left out a few important details. What kind of distance are you talking about, how far is the building from the source of power? Is the inside wiring complete? Are you asking just about how to plug it into the main?

An outside outlet probably has a rating of 15 to 30 amps depending on the wiring and the breaker. Where is your power coming in from?

If your going to try and tap it off an outlet then the most you can get from that outlet and everything else on the circuit is probably 20 amps.

The proper way to do something like this is to add a breaker to your main box and run an auxiliary feeder line off that. Or if you are like me, tap a line into the box at the meter on the pole which is where my meter is.
To connect the power source to the breaker box in the building there are several options.

You can get a "Pigtail" like what is used on some mobile homes. This is a very heavy cable with a very stout plug that plugs into the box at the meter. For short distances it works fine. But it is very expensive cable. So more than a few feet is not recommended. The next choice is regular cable. The kind of stuff you see connecting houses to incoming transformers. It is much less expensive and is rated for outside use. You CANNOT use regular inside cable outside or underground. The sun will eat up the insulation and it will fall apart and short out. Outside cable is water proof and sun resistant. Getting regular aluminum cable and hooking it into a breaker box is the only real way to go. You can run it overhead or bury it in the ground. Extension cords are not going to work.
welderman02 (author)  Vyger1 year ago
yeah i did leave a few things out i see. this out building is about 70 feet from the source of power. the cable i have reads ( CME WIRE AND CABLE E102470 S UL MTW OR THHN OR THWN-2 OR AWM OR GRII 10 AWG 5.26mm CU 600V) for green gire and the other read the same all but it says gasoline and oil resistant. hell i dont even have to use the breaker box if i dont' have to. id really like to just have two dang outlets and thats all id need really. the wiring is complete inside. all but one light switch to go up to a shop light i put up but i can do that myself. i just didn't know if it would be possible to actually hook a buiding up by a drop cord i guess i am asking.
As long as your power use is not going to exceed the rating of the outlets circuit you can use just a cord.
I have a small mobile home that was given to me in exchange for some work I did and I am now just using it for storage. I have it plugged in with a heavy extension cord so I can get lights in it. But that is all I have on. Someday I hope to hook it up the right way and even have the cable for doing that but its not yet in its final location. What I did was to cut off the end of 2 computer power cords and splice them together so I have 2 pronged ends. Plug one end into the extension cord and the other end into an outlet in the trailer. The power goes through the outlet to the breaker panel and then to the rest of the existing trailer wiring. For a few room lights it works fine. If that is all you are intending to do then its fine as a temporary setup. The temptation is to turn on to much. If you do that your breaker in the house will trip. They often set up camper trailers this way and for limited use it does work. If the cord is going to be in place for any length of time I would run it through some PVC pipe for protection so it doesn't get run over with a lawn mower or something like that.
You have a cord with prongs on both ends? Super dangerous.
welderman02 (author)  Vyger1 year ago
i was thinking something like that but wasnt sure if it would work correctly. awesome.....you have saved the day. thanks so much
frollard1 year ago
Depending on where you are, you need a building permit to modify the electrical system. Generally, you need a licensed electrician to get this permit - and its for your protection as well as everyone who will ever set foot in your shed.

Long story short - Get a qualified technician for your area. Advice from the internet is worth what you pay for it, especially when it is advice that stops you from burning down a building and killing your family. (seriously, not just being cynical here, I've seem some REALLY hack electrical jobs and they are just plain unsafe).
welderman02 (author)  frollard1 year ago
i dont care what it takes i need a couple outlets in my building today even if i have to do it myself and do without the breaker box