going from 220 large wire to 220 small?

bonedoc

Ok, this may not make sense. But I have a 220V supply that goes to my barn from my house. The wires are the same size as my pinky. They are large. They run about 300 feet. Well, I have 12/2 guage wire that goes to a 220 light half way between my house and barn. I wanted to somehow connect the 12 guage wireds to the large wires. I there a way to do this outdoors and/or underground. Right now, all wires are in PVC underground. I dont mind puttig a fuse box in, but prefer to do it at the light I am installing. I need to get power in the 12/2 wires without treching, and by using the current wires.

SecretSquirrel

If you were to tap into the larger conductors, what would the distance be from that point to the nearest vertical surface that a small fuse box could be mounted to, to feed the lights?

bonedoc

about 100 ft.

SecretSquirrel

That's too long of a length to run any wiring that is unprotected. Would there be any way to set a post at the the tap point to set a fuse box? You could tap into the larger conductors for a feeder to the box, then go back undergound with the branch circuit to the lights. Would that be possible?

bonedoc

I should have clarified that. The large wires are actually protected by a 220v fuse in my house...which goes to a small box in the barn. The large wires are protected. If this was considered safe. How could I tap a 12 guage wire to a huge wire? Thanks!

SecretSquirrel

The large wires are protected by fuses that are rated accordingly for the amount of current that the wire can safely carry for its size. That takes care of the feeder to the barn. If you were to tap into the large wires with 12 gauge wiring then you would have to provide 20 amp fuses or breakers within 10' of the tap to protect that particular circuit. Does that make any sense?

bonedoc

so, I can put a fuse box between the to wire sizes. Then I can run the wire way out there. I guess I will have to see how much the 12/2 wires can handle, stick a fuse box in, and splice the big wire in the box. Is there a special name for a fuse box that can run big wires straight in and out of it?

SecretSquirrel

Here's the complication. The "big wire" is in underground conduit. The conduit will have to be cut along with the wiring and an underground junction box will have to be set in place and splices will have to be made to rejoin the wires and this will also allow you an opportunity to make the tap there. From the new underground junction box you will extend the new tap wiring to a small breaker panel (2 circuit) within close proximity. From there you can feed your lighting. The 12 gauge wiring for your 220V lights will require a 2-pole 20 amp breaker.

Here's my candid opinion; That's a lot of work, a lot of expense, and a lot of electrical downtime at the barn. I know you initially didn't want to do any ditch work but it seems to me that the best and least expensive option is to run a circuit either from the barn or from the house, whichever is most practical. It would take rental of a DitchWitch and some 1/2" pvc conduit to accomplish this or the running of some underground rated wire. You could do it at your leisure and you don't incur any inconvenience from an extended electrical interruption and the nuisance of obtaining all the materials required to perform this major piece of electrical surgery. Not to mention that it does require some knowledge and skill to do what you're asking. I always hesitate at coming out of the gate with the suggestion of "hiring a professional" but in this case, if you insist on pursuing your original idea then I will have to leave you with that recommendation. There's some other electrical expertise floating around this forum and perhaps they could offer some insight as well. I regret not being able to do a better job at helping you.