I am changing 3 220v receptacles in my garage so I can plug my new welder in. The welder has a NEMA 6-50R plug so I bought 3 new NEMA 6-50R receptacles (and one new NEMA 6-50R plug for my old arc welder so it can be plugged into the new receptacles).
The NEMA 6-50R receptacles have 3 prongs.
My old receptacles had four.
The wires to the old receptacles were, Red, Black, White, and one naked copper.
Which is the ground and what do I do with the naked one?
The NEMA 6-50R receptacles call for a green to be the ground in the center. I don't have any greens, but a white one goes to the center prong in the old receptacle so is tha ground and the red and black hot?
I don't like electrical very much but I would like to learn.

 

Red and black are hot, white is neutral and bare is ground.

 

Here is a link to Lowe's "How To" article for installing 220V outlets:

http://www.lowes.com/lowes/lkn?actio...220outlet.html

Between Home Depot's, Lowe's, and DIY Network's web sites, I think you can find write-ups & videos covering most things that any home owner would be willing to undertake.

 

The lowes site is confusing me. It says some appliances only require 2 hots and a ground(no neutral ?, but in the picture it shows hot, neutral, and ground. Wouldn't that only be 110v?
Since the receptacles I have are only 3 prong, do I not use the neutral? Use two hots and a ground?

 

I think the neutral and ground are combined, like on a dryer.

 

I think you can/should leave the neutral completely disconnected. Lowe's instruction step #4 states that if you are only using a three pronged plug that you can skip the step...which tells you to connect the neutral (white) wire. While they do not tell you to cap the wire & leave it disconnected, they also do not tell you to connect it anywhere else.


Here is my overly crude explanation (as I understand it). The electric company sends out 220 triple phase. The three phases of ~220V current are ready to be split out to three different wires before being handed off to your house. Somewhere between the pole and the utility meter, one of the phases is generally blocked/dropped...however in the hell they do that. Depending on where your house sits & how the electric provider has your neighborhood setup, you share a phase with each neighbor. When your house is wired, the standard wiring & colors are used so that there is no question which are hot & neutral wires.

Hypothetical example, I will just call the phases 1, 2, and 3, and I will refer to houses A, B, and C...with B being our/your house. House A would get phases 1 & 2...so the third wire would be neutral. House B would get phases 2 & 3...first wire being neutral. And, House C would get phases 1 & 3...with the second wire being neutral.


A buddy of mine--with an electrical degree--went into an explanation of why/how neutral is different from ground & how that plays into how electric motors, transformers, etc. are built, but that explanation made my head hurt a little bit.

 

Doing a bit of researching, there seems to be some variances in answers....but...I did find that connecting the ground & the neutral/natural wires can only be done at the breaker box itself. Anywhere else, and it breaks National Electric Code.

It is crucial that the ground is connected to the third (likely rounded) plug of the 220V outlet. This screw/push-hole should be green, have some lettering to indicate that it is specifically for ground, or have the three, parallel, horizontal lines to indicate ground.

That seems to lend credence to putting a wire nut on the neutral (to cap it) & leaving it disconnected.




Kind of glad that I looked that up. I have been contemplating something similar, and I found a decent article on what the "professional" suggestion was for that situation.

 

I just finished and did not do this.
I hooked the red and blacks to the outside blades and the white neutral to the center rounded blade. I did not use the bare copper ground wire.
It worked fine with both welders, but I will research some more and disconnect the white neutral, leave it off, and connect the little bare copper ground wire, if need be.

 

The neutral and the ground terminate from the same point in your main electrical panel. For a welder a 3 wire outlet is fine. For an appliance such as an electric dryer the NEC mandates that a 4 wire outlet to be used. This is because the electric motor that spins the drum is 110V and for safety reasons you do not want the motor to use the grouund as the neutral source. It has been done for years and due to some accidents it was changed.

 

So do I use the ground or the neutral???

 

I'm far from the expert that megawatt is, but the ground should go to a ground screw in any metallic part.

The ground is there so that any hot wire that hits a metal part will blow the breaker, and there will not be any voltage on an exposed metal part.

If the round pin on the welder side gets connected to the case, then you should wire it to the ground and not the neutral. In any normal situation, it probably doesn't matter, but I think that would be the correct way.

Perhaps megawatt can enlilghten us on this.

 

Sorry guys I spaced out this post. You are 100% correct here. If inside the welder the, we will call it the non hot wire, goes to the case or if a jumper is installed from where that wire terminates, and goes to the case then use the ground wire as the 3rd wire.

 

I know for a fact that it does on my Lincoln 225 Arc welder. I switched the cord out for a much longer one and it has the two hots (black, white) and a green that goes to the case.
Now the new welder that will also use the outlets, I am not sure about. I haven't taken it apart, yet...

 

Ok.
I figured it all out.
At the electrical panel, on the left edge is a vertical strap with all the naked solid core copper "ground wires" going to it.
On the right edge is a vertical strap with all the white "neutral wires" going to it.
The "ground" strap is connected to the "neutral" strap by a horozontal strap.
So they all connect together at the box.
So what is the difference?
Is the "ground" wire preferred because it is a naked?

[/IMG]

 

The only spot in a residential electric service that the grounded conductor(white)and the grounding conductor(green or bare) are connected is in the service switch (which can be in the electric panel).This is to help a circuit breaker trip in a minimal amount of time(6 cycles or .1 of 1 second I believe).
The reason you have black white and green on a 220 v welder is that flexible cord comes in standard colors for the inner conductors.2 cond. bla+wh,3 cond. bla+wh+green
4 cond. bla+wh+red+green.