Can I convert 3 wire stick welder to 4 wire plug

[hunterridgefarm]

I have my Dads old stick welder that has the 3 prong plug and would like to convert it to 4 wire plug to run off the generator.

I know I cannot replace the plug only and was looking to replace the entire cord. I took the cover off the welder and not sure if I can since there is only a 2 wire connection, plus ground.

Is this possible?

I would like to be able to transport to the other farm when needed, no power there, and run with the generator.

Thanks,
David

 

[buickanddeere]

You can make a short patch cable and run the ground and two live lines to the welder plug. 4 to 3 , no problem. 3 to a 4 is a problem.

 

[Silvic]

Do yourself a short little pig tail. Use the two hots and the ground on the male 4 prong twist lock and do not connect the common. One male twist lock plug with a female 3 prong (correct [plug/receptacles for the purpose) and a 18-24 inch 3 wire cord of # 8 and you are good to go. Then you still have the earlier flexibility of plugging into your previous receptacle.

He typed faster than I did:laughing:

 

[Ed of all trades]

I just put a 4 prong plug on the end of my welders cord. I just hooked up the three wires and it worked well.

 

[hunterridgefarm]

Okay, I talked with the welding supplier that supplies all on welding stuff at work. He said cut the 3 prong off and wire it to the 4 prong plug, I just won't have a neutral wire connected to the plug.

Good/bad idea??

I am in the dark on this one.

 

[George2615]

Yes you can put a 4 prong plug on the welder to fit the generator. Just need 2 hots and a ground, 4th terminal (neutral) wouldn't be used. It will work fine.

 

[aczlan]

Okay, I talked with the welding supplier that supplies all on welding stuff at work. He said cut the 3 prong off and wire it to the 4 prong plug, I just won't have a neutral wire connected to the plug.

He is correct. The 4th wire is only needed if you have something that uses 120V. If everything runs off of 240V, and the ground just attaches to the case, the 4th wire is unneeded and you can just replace the 3 wire plug with a 4 eire one.

Aaron Z

 

[hunterridgefarm]

Hopefully this will be my last question

Most of the box stores only carry a 30 amp plug and I figured I would need a 50 amp which I can get. However, this got me to think about the amp on the receptacle on the generator, I check and it is rated for 30 amps and has two 30 amp beakers.

Can I put a 30 amp plug on this welder and it work? It is 30-200 amp welder and I was planning to use 1/8" rods, pictures attached.

If I can use the 30amp plug I assume I will need to run the welder at the lower settings?

Or, just trash it and buy another

 

[tomcat7359]

I think you could use a 30 amp plug on your welder, since your generator is only going to supply 30 amps before the circuit breaker "opens" The data plate on your welder says it needs a total of 42 amps, but that would be when you have it cranked all the way up to 200 amps.. If you are only going to use 1/8" rods, you probably are going to be below 140 amps of welding amperage..

 

[buickanddeere]

Do it right with a 50amp three prong instead of pharting around . Then your welder is up to standard and will plug into any welding receptacle.

 

[arlen4720]

Even if you were welding at max 200 amps, and the welder was drawing 42 amps, your welder (and most humans) is only rated for a 20% duty cycle. I would bet that you still wouldn't be able to pop the breaker.
I ran a sears stick welder like yours for years on a 15 amp circuit before I finally got around to running bigger wires.

 

[hunterridgefarm]

Just to update:

I put the 30 amp plug on and plugged it into the generator to make sure it would work, no problems. I welded a arm on the box blade that had broken just to test it out.

I may put a 50 amp on it once I have the workshop wired.

THANKS for all the help!

David

 

[rjkobbeman]

Unlike other discussions where someone wants to eliminate a 4th wire (which is usually a safety concern because the 4th wire being removed is a ground or neutral when one is required), your welder only has three wires because it is 240v ONLY. There is no neutral wire because there is no need for 120v.

Wiring up your existing three wire (hot-hot-ground) to a four wire plug (hot-hot-neutral-ground) so that it fits in a four wire receptacle is fine. You will simply NOT use the neutral lug in the four wire plug (you will use the hot-hot-ground lugs).

 

[rjkobbeman]

With regards to 30 amp vs 50 amp cord/plug.

A 30 amp 4 wire cord/plug will be for an electric dryer. You should be able to find them very easy in the box stores. A 50 amp 4 wire cord/plug will be for an electric range. Again, should be easy to find.

If you want to put a 30 amp 4 wire cord/plug on your welder, it should be fine. Only in extreme cases would you pull more than 30 amps and trip the breaker.

If you are concerned about wire gauge in the 30 amp cord, don't. If you are plugging it in a 30 amp receptacle, you would simply trip the breaker if you exceeded 30 amps. In addition, due to duty cycle of most welders (unless yours is a higher duty cycle), a lot of welders have like 12 gauge wire for a 50 amp plug.

 

[IslandTractor]

Just to update:

I put the 30 amp plug on and plugged it into the generator to make sure it would work, no problems. I welded a arm on the box blade that had broken just to test it out.

I may put a 50 amp on it once I have the workshop wired.

THANKS for all the help!

David

Can you take a better picture of that weld? It looks to me like you may not have very good penetration as the bead has a convex contour. I'm not a very experienced welder myself but I increase the amperage if my beads are proud (high) like that.

 

[buickanddeere]

Can you take a better picture of that weld? It looks to me like you may not have very good penetration as the bead has a convex contour. I'm not a very experienced welder myself but I increase the amperage if my beads are proud (high) like that.

You are correct. I'm no pro welder but those beads of rod metal are sitting on top of the steel. Instead of the rod metal being melted into and alloyed with the steel.

 

[hunterridgefarm]

Guys, I am no pro either However the bead you see is the second pass. I ground V slots or champers all the way around the piece that was welded on and the part of the box blade that was welded to. I was able to get deep penetration, ground the weld down some and ran another bead.

 

[IslandTractor]

Guys, I am no pro either However the bead you see is the second pass. I ground V slots or champers all the way around the piece that was welded on and the part of the box blade that was welded to. I was able to get deep penetration, ground the weld down some and ran another bead.

Understood. However, if your welder was at the same settings for the root passes, you might still have poor penetration despite the chamfering. Again, I am a rank amateur welder but I recall my welding instructor always pointed at raised beads as evidence of poor penetration. I think most of us who do not weld regularly are prone to err on the side of under penetration.

We have a few very experienced welders here who would be happy to comment if you can get a better photo.