Help with shop electrical

[PaladinReed]

Hey guys, got a 220v welder a while back from my GF. My shop only had 110 so the welder took a back seat to a couple other projects.

I wanted to get some experience with electrical so I've been reading up a little and am going to tackle this by myself.

I went to my local Lowes yesterday and purchased the following.

25' insulated 10-3 wire. (4 wires, red hot, black hot, white neutral, and bare ground)
30A double pole breaker for my Square D box
30A 3 post plug in (welder side)
30A 3 post receptacle (wire side)

I purchased a 3 post plug in because I have 3 wires in the cord coming from the welder (hot, neutral, ground) and figured I'd use a plug in to accommodate that.

However, I ran into an issue last night installing the receptacle to the 10-3 wire. The receptacle box has terminals to install only 3 wires, the two hots and the neutral and no where for the bare ground.

My box will accept the 4 wire cord but my questions is, where do I install the ground on the receptacle end?

I realize I could buy a 4 prong plug in and receptacle but then would be faced with not knowing how to install the plug on the welder side.

Thanks for the help

[PaladinReed]

Like this but add a ground to the cord of wires between box and receptacle

[twistednut]

In your case you need to use the bare grounding conductor.

Your illustration is for old ranges and dryers which carry a small amount of current through the 3rd conductor to the neutral bar of the electrical service for timers and lights.

[Kevinl]

240v in this case does not use neutral so hook up your 2 hots and ground

[flyboyx]

"I purchased a 3 post plug in because I have 3 wires in the cord coming from the welder (hot, neutral, ground) and figured I'd use a plug in to accommodate that."



this is 220v. you do not have hot neutral and ground. you have two hots and a ground. for all practical purposes the neutral and ground are the same. when you take the front cover off and look in your square d load panel, you should see that the neutral and ground buses are connected together.

so with that said, i assume the wire you purchased has two insulated conductors and a bare ground? the two insulated wires(i assume one is black and the other is white) will be connected to the circuit breaker as is shown in the diagram posted above. the bare wire will go to the ground bus in the panel. on the outlet/plug end, the bare ground wire goes to the more rounded ground slot. the insulated wires go to the flat slots. it doesn't matter which is which.

with all this said, just so you know the three prong 220v system really isn't up to current electrical code but is more than adequate for your task at hand. if you really want to comply, you will need to pretty much return everything you purchased except the breaker and buy 3 conductor wire with a bare ground. you will also need to change the wire and plug on your welding machine. i wouldn't worry about this if i were you though. if you have more questions, send me a pm.