wiring shop; have Q

[P&T Jeeps]

while doing some searching I ran across this statement:

One thing I thought of AFTER the fact.. was to put in a 3+G outlet, at 50amps. That'll get you 220V plus the neutral so you could get a 110 branch from it.

can someone more fully explain this to me. My plan: use 8GA w/ a 30A breaker on a 75' run for a Millermatic 175. The variable is that my compressor runs on 120 on a circuit that is too small for it. It can kick on at 0-20psi but if it tries to cycle above that it'll trip the breaker so I'd like to run a deticated 120 as well.

so, that said, can I run a 3+G (is that just a 4-strand wire?) using 2 of the strands for the 220 & 1 for the 120 & share the ground? am I full of shit, I have no clue?

[preach]

I cannot fully answer your Q but I can shed a little light maybe:

3+ is:
black power
red power
white nuetral
bare ground

2+ is:
black power
white power
bare ground

3+ is requiered by most code now.

Personally I would not jump a 110 off of a 220 but that is just me.

What is the rest of your power situation like?

[steveh]

You should not try and share 1 leg of a 220 run as 110 and a 220 off the same breaker. Whay you should do is set up a 50 to 100amp subpanel at the end of theat 75' run, and insatll dedicated breakers for the 200v welder and a the 120 volt compressor

Check out this thread, we really hashed it out on how to do a good job with subpanels a couple weeks ago.

/forum/shop-tools/259692-electrician-tech-inside-question.html

[junkyardjeep]

If you are running conduit which I assume you are, you would be better with probably 1" and just pull 6 10 gauge wires.3 for each circuit,You can run into problems with sharing the nuetral.I am sure the 8 guage can handle it but you may run into the breaker tripping when both run if they do at the same time.Might as well separate them at the beginnig rather than fish wires later.Check a code book [NEC] and see if theres anything in there.

[P&T Jeeps]

part of the problem is that I live in a different city as the Jeep which stays at my parents so I'll be doing this at their house. I already had to jump through some hoops to let them let me to dig up their backyard so a new junction box will really be pushing it. they have quite a few empty slots in the main breaker box for additional circuits.

what I want to accomplish the cheapest yet effectively is a dedicated 120 on a 20A breaker as well as a 220 on a 30A. it sounds as if I just need to run two seperate wires. I don't quite understand why I need a 3+, what does the fourth strand connect to?

[junkyardjeep]

Basically the 3 wires would be[assuming you have red white and black;standard for romex and simple to identify:]Dont use romex wire though just using as color reference, use individual stranded wire both circuits will have different size wire though. black [HOT] red [HOT] white is the neutral and the copper is the ground.If using conduit then the conduit or bx becomes the ground.For the 20 amp 120v you only need the black and white using the conduit as the ground.If you ran all the wires through the conduit you would have a total of 5 wires 3/for 220 and 2 for the 120v but you have to ground all metal boxes to a ground screw and have all of the conduit connections tight,remember these will be the ground for both circuits.But again your local code may call for more than that.These are standard in the NEC [National Electric Code] But your state may require more.Good luck

[junkyardjeep]

Also did you use a junction box or a sub panel?That will help.What is your setup?Do you have a garage that you ran power to.Or do you just have one circuit?Give some more info on your setup I or others may be able to help you better.

[steveh]

My advice to you from reading this is get an Electrician to help you. Electricity is not something to be taken lightly, it will kill you and can burn down your house if you don't understand it. IMO, a sub-panel is the easy way to solve this problem and it allows for easy expansion down the road.

The reason for 4 wires is this:

A home is fed with 2 hot legs, each one, when connected separately to a Neutral/ground yields 110Vac

When both are used together you get 220vac

So, to set up a 220-volt circuit, you normally run 2 hot’s, 1 neutral, and 1 ground.

Did you at least read the other thread I posted about? Anyway, don’t do anything yourself until you fully understand what is you need to do and why. If it just does not make sense, then for safety’s sake, either don’t do it or have an Electrician do it.

Bottom line is, you need 2 dedicated breakers, 1 110v for the comp, 1 220v for the welder.

[P&T Jeeps]

I guess I should have disclosed that I've planned from day one having an electrican hook up the wires at the box & end but simply want to run the wires the 75' underground to save $$. All I really need to know is what wires to run...

[steveh]

Originally Posted by P&T Jeeps

I guess I should have disclosed that I've planned from day one having an electrican hook up the wires at the box & end but simply want to run the wires the 75' underground to save $$. All I really need to know is what wires to run...

Simple, ask the Electrician what to run, and ask the Electrician how it should be done as well.

[junkyardjeep]

Is it a garage?Or is it Two receptacles on a pole.If it is in a garage then run a sub panel.You can very easily go to home depot or a local electrical dist. and they will tell you what size to run for either a sub panel or two separate circuits.There is nothing complicated about it.You can run underground feeder [UF Cable] without conduit.But I would seriously run the sub panel if you could.Having an electrican hook it up is not a bad idea if you are unsure, but then again its not that hard to do yourself,as long as you check with the codebook or some else that is qualified.