[ChiefBDT]

Hello All. I'm stuck so I thought I'd come to the experts with this.

I have a welder that has a 3 prong plug but I have to plug it into a 4 prong outlet. I purchased the 4 prong plug to replace the original one but I'm not sure what wires go where. Currently the 3 prong has a Green (Top) and black and white wires on the bottom two prongs. My logic is that my welder wire doesn't have enough wires to use on a 4 prong plug in?? Of course that's just my "Simple" logic as I don't know much at all about wiring things.

I'm going to be running my welder on my Genrac 25,000 watt generator. That is what has the 4 prong plug. The generator 4 prong plug says 50 amp and my welder says 40 amp so, again with my logic, the generator should be big enough to run the welder?

Thanks in advance,

Brad

[hvac1000]

Welders are tuuf on electrical supply normally in a residential home. They are really ruff on a generator. I suggest you check around to make sure the generator will hold up to the surges that the welder will put it through before frying the generator. The amp rate is one thing the inrush is another.

[ChiefBDT]

Thanks a lot for getting back to me. I do have 240 in the house that I could use, but it has a 4 prong as well. Can someone tell me if and how to convert this over?

Thanks,

Brad

[hvac1000]

There is not much to the conversion. A 4 wire has two hot legs of 120 volts each which makes 240 volts to the machine The third wire is a common and the 4th wire is a ground. All you need to do for 3 wire is switch the two hots and the ground wire. The neutral will not be used on a 3 wire setup. While you could use the neutral on a 3 wire setup the ground is a safer bet.

4 wire setup with color wires

Wiring A Range Power Cord - Connecting An Electric Stove




3 wire



Y and X are the hot legs on both type receptacles

I hope you can figure it out now.

[ChiefBDT]

I don't want to sound thick headed here but just to make sure I have it right, don't want to blow anything up, including myself. Currently the Green is on the top prong, the white is bottom left and the black is on the bottom right (as you are looking at the plug). Can you walk me through where I need to swap out the wires? Maybe it would be easier and less of a bother if you could e mail me? [email protected]

Thanks so much for your help,

Brad

[hvac1000]

The green is the color for ground.

Now the white and black is a different issue

Normally black and red are used as the two sources of 120 volts and when they are combined for use they produce 240 volts.

Now you said that the bottom left is white and white is the color for the neutral and not a power carrying conductor color. This is confusing to me as well as you. The only way to tell for sure if the white is a 120 volt power wire or if it is acting as a neutral is to use a electric meter and sound them out.

I will mention that it is possible the white has been used by the installer or the manufacturer for one of the legs of 120 volts but to be safe it needs to be sounded out with a meter.

A normal 120 volt circuit has a black,white,and a green or bare wire.

A normal 240 volt circuit has a black,red,white as neutral and a green as ground.

So as you can see with the wiring you have that contains the white wire it could be considered possibly used for a neutral or was wired incorrectly and a hot leg. Since I am not positive of the white wire I cannot tell you exactly how to wire your plug without the possibility of a short circuit which you and I do not want to happen.

Use a meter to sound it out properly. Sorry but that is the best I can do from here.