Installing a 220V circuit for a 220V welder - need help. Options

[GlennCMC70]

there is no 220V service in my garage - thats about to change.

i picked up a 250V 30A outlet (3 slots arranged in a circle w/ one looking like a "L") which matches the plug on the welder.
i have a 30A breaker that takes up two slots in the breaker panel for the house (located in the garage!)
i have some new 10 gauge 3 conductor wire (black, white, and green conductors).
snap the breaker in place - make sure its switched off.
install a black and white conductor in one of the two set screw slots in the 30A breaker.
connect the other ends of the black/white to the outlet and the ground to the ground on the back of the outlet and inside the breaker panel (metal box).


to be honest here, the only thing i know about A/C electricity is it can kill you. other than that, i don't know jack. i can replace a bad outlet/socket/switch, but i couldnt wire any 110v circuit from the box to the wall if i had to.

so does the above sound right? i know there should normally be a red wire to use in place of the white, but i've read thats really only required for 4 prong plug/outlets.

looking for the FRAXX guidance here oh wise one's. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/drink.gif)

[trackbird]

Sounds about right. Make sure you run the ground lead to the ground/common in the breaker panel. Then, check everything with a volt meter, you should see 116-123 volts between each of the main plug prongs and the ground socket and 220-240 volts between the two main prongs. If so, you're ready to rock n' roll.

You should be on your way!!!

[GlennCMC70]

good.
now any advice on running a temp run across a wall from the panel to a spot about 6-10 feet from the panel? i have to go buy wire anyways since the wire i have turns out to be 14-3 and not the 10-2 i need. 10-2 has 2 conductors and a bare ground wire in it, right? should i get get something i can place inside a PVC conduit or soething that comes w/ that spiral metal jacket? i'm not intrested in running it inside the wall.
thoughts?

[trackbird]

I ran mine through the studs. If not, I'd put it in a conduit if it's not behind the wallboard. The spiral stuff has been the cause of a few fires in the phone company (the jacket becomes a big heating element in a short circuit condition). Check the local code and use conduit accordingly.

[sgarnett]

I used metal conduit and a metal outlet box for my outside-the-wall run. The breakouts and the fittings available make it pretty easy to work with. When I looked at the spiral metal stuff, it looked like it would be a pain to work with, and I was also concerned about sharp edges, in spite of the bushings available.

[GlennCMC70]

i plan to use the PVC outdoor stuff. thanks guys.

[Wayno]

Is you're panel mounted between the studs "in" the wall or is it mounted "on" the wall

[GlennCMC70]

between two studs "in" the wall.
i was thinking of knocking out a knock-out plug and going out the top and to the top of the wall. there i will come out of the wall into a "box". conduit across the wall to another "box" and then half way down the wall to the outlet box.

[FBody383]

When I ran mine I had about 20' of wire left over that I made into a 220V extension cord - comes in real handy.

[GlennCMC70]

this used welder came w/ a 20' plus cord on it. very nice high grade cord and it looks very new.

[Torque]

Not an electrician but I can tell you how I most recently ran my 30 amp 220 and 50 amp 220 in my recent remodel (as I was guided to by my electrician). For 30 amp, I was told to use 10-3. The 10-3 Romex I used has an orange outer sleeve and contains 4 wires. 1- Neutral- white, 1- Red and 1- black (both hot) and 1- bare ground. The way I understand it, any 220 has 2 hot leads and one neutral. What concerns me is if I read what you posted correctly, you are hooking up 2 hot leads to the breaker (one to each of the 30-amp dual breakers) and you are either hooking up the neutral to the ground or you are not using a neutral.... or not using a ground. You should have 2 hot wires (I believe one to each breaker) a neutral (white) to the neutral bus bar and the green or bare goes to ground. Sounds like you are using an ungrounded receptacle (3 prong) which would only have 2 hots and a neutral. If this is the case, you may be hooking the neutral to the neutral bus bar and calling it ground which is ok but you'll not be properly grounded as most current code would require. If you can, I'd get the 4 prong 30 amp receptacle (the 30 amp also has an L shaped prong, the 50's do not) which should allow you to properly ground. You'd have the 2 hots going to the breakers (red and black), the white to neutral bus bar and the green/bare to ground.

Romex can be run through studs and I suggest using the nailing plates to cover them so you don't accidentally find them with a drywall screw, etc. down the road. With Romex, my local code does not require them to be pulled through any metal shielding indoors. Obviously, check local codes by you to ensure you are ok.

Hope this helps.

[Torque]

the wire i have turns out to be 14-3 and not the 10-2 i need. 10-2 has 2 conductors and a bare ground wire in it, right?
[/quote]


14-3 is for lighting, NOT for powering outlets of any type. 14-3 does have 4 wires in it, one neutral/white, 1-ground (bare or green) and 2 hots (usually one black and one red). The way you use it would be to have each of the hots (red and black) support a separate service/circuit utilizing the common neutral and ground. In a sense, this is similar to the way you'd run a 220 circuit like the 30 amp you are trying to run, they should also be hooked up to a double breaker (2 15 or maybe 20-amp breakers bridged together so that you can't kill one thinking you killed the circuit and then cut it only to learn the other circuit was still hot... etc.). In this case however they would be supporting 2 separate circuits (i.e. 2 separate lighting fixtures or arrays of can lights in a kitchen). 14 gauge is way to thin for 220.

10-2 will have 3 wires which are intended for hot, neutral, and ground. 10-2 will not get you what you need for your application. You need 2 hots, 1 neutral, and one ground and 10-3 should provide that for you.

General rule I was told by my electrician-

14 = lighting (usually white romex casing)
12 = 110 outlets/power sources (usually yellow romex casing)
10 = 220 applications- 30amp, etc. (usually orange romex casing)

2nd number depicts number of non-ground wires- -2 is hot and neutral, -3 is 2 hots, 1 neutral. Both will have a ground as well.

Hope this helps.

[sgarnett]

220V dryers and ovens get a neutral, because they may have a few 110V parts (like light bulbs). That's why they have a 4-prong plug. Devices that are purely 220V (like water heaters and welders) do not use or need a neutral, so welders typically have a 3-prong plug.

I did run a neutral wire in mine just in case I ever need to add a 4-prong outlet for some reason, but it's just capped with a wire nut inside the box.

BTW, the difference between a neutral and a ground is that the neutral is intended to carry load current in normal operation and the ground is not. That's why metallic conduit can be used as the ground but not as the neutral. There may be several volts difference between neutral and ground at some outlets depending on how well the loads are balanced.

Neutrals and grounds must be tied together at the main panel ONLY. They should never be connected at the outlet or in subpanels. So, a main panel may have one big ground bus for all the grounds and neutrals, but subpanels must have separate ground and neutral buses with the neutral bus isolated from the enclosure.

[GlennCMC70]

accually the way i understand it is the neutral is not used at all. i use two hots and a ground. thats the way the outlet is set-up. it has two brass colored screws and a green one. most all 110v outlets have a brass and a silver and a green. the silver is neutral. brass is hot.

[GlennCMC70]

220V dryers and ovens get a neutral, because they may have a few 110V parts (like light bulbs). That's why they have a 4-prong plug. Devices that are purely 220V (like water heaters and welders) do not use or need a neutral, so welders typically have a 3-prong plug.

I did run a neutral wire in mine just in case I ever need to add a 4-prong outlet for some reason, but it's just capped with a wire nut inside the box.

BTW, the difference between a neutral and a ground is that the neutral is intended to carry load current in normal operation and the ground is not. That's why metallic conduit can be used as the ground but not as the neutral. There may be several volts difference between neutral and ground at some outlets depending on how well the loads are balanced.

Neutrals and grounds must be tied together at the main panel ONLY. They should never be connected at the outlet or in subpanels. So, a main panel may have one big ground bus for all the grounds and neutrals, but subpanels must have separate ground and neutral buses with the neutral bus isolated from the enclosure.

excatly how i'm gonna do mine.

[nape]

I AM an electrician and Sean's advice is correct.

I'm not sure what the codes are down there, Glenn, but make sure all the lock nuts and set screws on your fittings are tight when you run it in pipe. Up here in Chicago, the raceway (pipe, greenfield (spiral metal conduit you spoke of), seal-tight, wire mold, etc) is your ground. If you do not tighten the fittings, you have no ground and a very dangerous situation.

In normal residential situations not taking de-rating or special applications into mind, the rule of thumb is:

#14 = 15A
#12 = 20A
#10 = 30A
#8 = 50A

As far as Romex, it's illegal in Chicago and the surrounding suburbs and I won't use the stuff. You're basically running extension cords through your walls, no thanks. On top of that, if it ever does go bad or you want to upsize the conductors, then you're screwed. Time to tear down the drywall.

[Torque]

Out of curiosity, what's the safety issue with Romex? Vulnerability to being found by screws, etc? Curious as I just ran about 700+ ft of it in my recent re-model and I'm about to run another couple hundred feet in my garage makeover.

[GlennCMC70]

got it done. usd the black and red to the 30A breaker. connected the white in the panel to the neutral strip and the bare wire to the ground strip. at the outlet i connected the blackand red to the outlet and bare wire to the ground.
used the welder for a bit. works fine.
it has 23 wire in it now. i need to get some 35 in it for stuff like cage tube and then use my 110v welder w/ the 23 or set it up for aluminum.

[nape]

Out of curiosity, what's the safety issue with Romex? Vulnerability to being found by screws, etc? Curious as I just ran about 700+ ft of it in my recent re-model and I'm about to run another couple hundred feet in my garage makeover.

Other then the typical nail/screw through it, since most builders don't put the nail plates over where they drill the studs:

Circuit breakers are mechanical contraptions that can freeze/rust/stick over time and when combined with Romex can present a dangerous situation. If a splice/device/wire goes bad (or someone decides to plug in 3 space heaters...) and the draw goes up and the breaker doesn't trip, the wire can get hot enough for the insulation to melt off and set the insulation/studs on fire. The chance of this is lessened in conduit because if the wire gets hot enough to melt the insulation off, it will then find ground and be a dead short which will either trip the breaker or blow the wire.

You'll probably be fine since you just wired everything new, but in areas where houses have been around for a long time, these situations creep up and are starting to cause fires.

Conduit makes sense in areas where urban sprawl is happening and people are living in older and older houses. The house doesn't need a complete gutting when technology changes or new devices come out where the homeowner might need more recepts/draw. It makes even more sense in condos/apartments/townhomes. You can just pull new wire if you need more ampacity.

The biggest benefit in my eyes is that if something does go wrong, you don't have to chop the wall to fix it. What is usually pitched is safety since most people don't know more then they hit the switch and it works.

This post has been edited by nape: Nov 9 2008, 09:43 PM

[nape]

got it done. usd the black and red to the 30A breaker. connected the white in the panel to the neutral strip and the bare wire to the ground strip. at the outlet i connected the blackand red to the outlet and bare wire to the ground.
used the welder for a bit. works fine.
it has 23 wire in it now. i need to get some 35 in it for stuff like cage tube and then use my 110v welder w/ the 23 or set it up for aluminum.

.023 is nice for sheet metal work.

I'm jealous, I still don't have 220v to the garage and run my welder off a generator.

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