Underground wire size question

buickanddeere · Apr 9, 2017

100 amps is plenty for the shop but a 200 amp can be routed from the house's 200 amp supply to the shop via the feed through transfer switch I posted earlier. There will be less light dimming when an arc is struck or when a compressor starts with the heavier 200 amp supply. Not going to be operating a 10HP compressor, plasma cutting 1" steel plate, welding at 250 amps, running a 4.8KW water heater and a 5 ton AC unit simultaneously.

zoedog2012 · Apr 9, 2017

Thank you everybody! We have enough information now to make the correct decision.

buickanddeere · Apr 10, 2017

The other alternative is to bury the high voltage from the road to the house and locate the 4800V to 120/240 service transformer in the back yard.

RNeumann · Apr 10, 2017

buickanddeere said:
The other alternative is to bury the high voltage from the road to the house and locate the 4800V to 120/240 service transformer in the back yard.

I said the same thing. It may be cheaper and would be a better option in the long run. It's just a matter of getting the utility to go along with that plan.

zoedog2012 · Apr 10, 2017

RNeumann said:
I said the same thing. It may be cheaper and would be a better option in the long run. It's just a matter of getting the utility to go along with that plan.

the transformer also services the adjoining property

RNeumann · Apr 10, 2017

It comes down to cost. Some utilities wouldn't charge much to install a transformer while others would charge tens of thousands. I'm betting you will have around 10k in wire and conduit alone. If the utility charged that much or less I'd do that instead. I think what a few of us are saying is it's worth asking.

zoedog2012 · Apr 10, 2017

We will certainly ask the electric co-op what they can do. There will be 8 other folks in the same boat and I have a feeling electric company is going to say sorry unless you all go all electric.

RNeumann · Apr 11, 2017

For reference I did a very similar project in North Idaho about a year ago. Power at the road, the house and shop about 500' off the road. The utility allowed us to place the conduit and junction box. They charged about $3000 for the transformer and $3/ft for wire. They also charged a connection fee of about $2000. So for $6500 the project ended up with a transformer and meter between the house and shop- making both runs from there very manageable. The other nice aspect with this setup (besides voltage drop and cost) is the fact the utility owns and maintains everything on their side of the meter.

Either way you have the info needed to make it happen. Good luck with the project and enjoy the new home!

pinetree10 · Apr 15, 2017

bfisherman11 said:
I have a small building i want to run about 20-30amps in 110V to. My run is 180 feet from my electrical panel to the building.

I have searched "electrical" and gone back 8 pages to no avail.

I won't be welding etc. All i want are about 6 light fixtures (LED) and a couple outlets for a drill or hand saw.

I don't have any 220v needs....

Would say #10/2 with a ground work? I was having trouble looking at charts and understanding on line. I am not an electrician.

Thank you!
Bill

I had a similar situation to yours a few years ago. I built a detached garage/oversized shed and wanted just some lights and receptacles for basic equipment maintenance. The building is about 60 feet from the house and the main panel is another 50 feet away at the other end of the basement. I ran 10-2 Romex wire inside the house from the main panel to the outside wall at the opposite end of the house, then transitioned to 3/4" conduit and ran #10 stranded wire underground to the new building. Once I got to the new building I transitioned to #12 Romex and put a bunch of T8 fluorescent lights and receptacles in. The place is well lit and I have no complaints. Everything is fed from a 20 amp GFCI breaker and the main in the new building is just a heavy duty single pole switch, which code required at the time. I also ran a separate 3/4" conduit to the new building for phone and fire/security alarm system wires.

I started the run with 10 wire because I wanted to prevent voltage loss, and I've had no problem with dimming lights or voltage drop over that distance. I've run a compound miter saw and a bench grinder while running the space heater with no problem either. It's always nice to have a small sub panel in accessory buildings but if you're serious about needing just the basics then keep it simple. You know what you need there. Let us know how you make out.

bfisherman11 · Apr 15, 2017

Thanks Gus, I was looking at wire and wanting #8 but only saw stranded wire not solid copper. I was not sure I could use stranded wire but see you did. Looks like I can. I was at Home depot so not sure if that was the best place for wire, I have always thought it was decent. Funny, they did have the sold copper ground wire.

Bill