Electrical Help needed. Add power to detached garage. (1 Viewer)

[se2000]

I don't think there is any circumstances where you can run romex in conduit.
I run masonry string through the conduit as I build it as opposed to trying to blow or suck it through. When I pull wire, I also pull a string along with the wires. For a long run, a larger rope.

If you have grass or dirt next to the sidewalk on both sides, there are easy ways of tunneling underneath, no concrete work needed.
I am not an NEC expert but double tapping is a no no if we are talking about the same thing.
I also like to put a caution tape in the trench well above the pipe.


I don't see the number on the main breaker but with so few breakers, I am thinking 60 or 100a. You can go 100A subpanel on a 100a main service so don't be afraid to wire for it.

 

[LAMBCRUSHER]

when I said double tap the main, I did explain how to do it properly, without landing 2 wires into a breaker lug designed for only one conductor> which IS a no-no.

caution tape is a great idea for any underground ute...

 

[TLC76]

You may have room to lug right off the bus, and run a 100A (assuming that's what your main is) over to your garage if you don't have breaker space. If your main was say 200A, you could land on a 100A fused disconnect next to your existing panel then run over to the garage.

 

[LandCruiserPhil]

I don't think there is any circumstances where you can run romex in conduit.

You can run romex in conduit when inside or where physical protection is needed. NEC 336-10

NM romex as a whole or with casing stripped is not permitted because the wire is not rated for wet/damp location, including and not limited to outside and underground use.NEC 334.12-b-4

For wet location and conduit use UF is permitted

As other have said double conductors on a single lug is not permitted.NEC 110-14

 

[daito]

Cool there is lots of good information to guide me along. Now the only fun part is getting money and buying parts that I need to get going.

 

[TLC76]

Just remember, you can never have too much available power in the shop...

 

[daito]

Ok will this stuff work? It's 4/0 awg use ul. Does that mean its quad aut? It's pretty big aluminum wire for direct entry it says. It seems pretty huge like jumper cable size from what I see in the pic.

 

[TLC76]

4/0 aluminum is good for around 180 amps in SE I believe, you will be plenty safe. You probably wont be able to land it on a 100A breaker though, you will need to get a reducing lug or splice in a smaller conductor on either end.

http://www.cerrowire.com/ampacity-charts

 

[daito]

One more bit of info on the wire. It had 2 wires at 4/0 then one at 2/0. I assume the 2/0 is smaller in gauge than the 4/0 and would assume that is a ground or would I need to run a separate ground cable from the panel to the stake?

 

[TLC76]

That doesn't include a neutral, it would normally be used from the utility to your service panel, where the 2/0 would tie to your ground and neutral bus. If you want 120/240 you need to pull an additional conductor for a neutral to the garage. If you are only feeding it with a 100A breaker you could use the 2/0 for the neutral and pull a separate ground since you are oversize anyway.

 

[daito]

Yeah i would want my garage box to support 110/220. Does the neutral wire have the smallest load requirement? Meaning I could use these 3 big wires on

 

[TLC76]

For shop use yes, you can use the smaller in this case because you are oversize. If you were running the full 4/0 ampacity you wouldn't want to do that.

 

[LAMBCRUSHER]

if you're set on using that wire, then you'll need a 2" conduit. do not add any conductors in the conduit for ground; instead, use a driven ground rod at the garage and run a #4 copper bonding wire from the ground rod to the new sub panels neutral bus. I would pass on that Al wire...

 

[daito]

Well my 4/0 wire fell through. I was going to get the 100' for $90 so I felt like it was a good deal.

Weird question for ya now. Would it be possible to use a 6/3 wire doubled over? So I'd have 2 wires for each?

 

[se2000]

Dude, get the right stuff.

 

[daito]

Maybe I should try to get the right stuff. Just to make sure I'm not being taken by Home Depot, how much should 3awg cost me to run 100' of wire or what would it cost you guys for wire only?

 

[se2000]

I don't buy wire at HD. Too pricey. My local electrical supply place is way cheaper, better selection and helpful advice.

 

[sggoat]

I have never run into a more complete answer than lambcrusher offers--he must be an electrical Guru for sure!!

 

[LAMBCRUSHER]

I have never run into a more complete answer than lambcrusher offers--he must be an electrical Guru for sure!!

guru NO, but i am electric call around and find the right wire...copper # 3 is going to be about 1.50 a foot if your #6 is copper, it'll carry 50 amps for ya, but you list it as 6/3; so is it romex?(no the right stuff) If you can live with only 50 amps at the shop, you can run #8 copper or #6 aluminum and cut your wire cost in about 2. I try to find ways of saving costs on parts all the time. 2 area I don't try to compromise on are breakers and wire. the wire is the single most important part of any electrical system; every other part needed or each bit of code applied to the methods of installation are to ensure to safety of the wire both during installation and for the span of its service life.