4 prong 220v to 3 prong 220v HELP!!

Chingon619

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Ok guys, I look to you for help on this little mystery. Sure I can Google and yadda but need confirmation. I am going to be setting up a tig welder at home but my house has the 3 prong wall socket, and the welder is a 4 prong. Is this doable by just switching out the plugs at the cable ends. I'm trying to use the one on my mig welder but do I not use a wire or do I join ground and neutral? I get the whole hot, hot, ground theory and I believe the 4 prong is a neutral added? Who knows this stuff?? @Sausage450r @L.R.S. @Fullthrottleguy @Rockwood and @buff < for some entertainment 😆

Forgot the pics. 

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4 prong is to run off genny or osha crap there are adapters available or

A32DBFA9-1FC1-40ED-AFA3-AB9B57CBE4B8.jpeg

 
the 4 prong has ground and neutral. most welders dont use the neutral you can just put a jumper between the neutral and ground not the best way tho. the ground and neutral are on the same bus bar in your panel but the ground wire may be a smaller gauge than the hot leads. the only reason the welder would need a neutral would be for the electronics or if it has a outlet for a water cooler 

 
the 4 prong has ground and neutral. most welders dont use the neutral you can just put a jumper between the neutral and ground not the best way tho. the ground and neutral are on the same bus bar in your panel but the ground wire may be a smaller gauge than the hot leads. the only reason the welder would need a neutral would be for the electronics or if it has a outlet for a water cooler 
I guess that is my question, can I just put the ground and neutral on the same ground peg of the 3 wire plug. Thanks for the input! 

 
I made a cord for the welding cart: NEMA 30 dryer plug on one side, 8-3 stranded between, NEMA 50 receptacle for the welder on the other bolted to the cart (along with a 2 way 110v NEMA 15). No neutral hooked up. I’ll snap a picture when I get home of the inside of the 50 and 30. 

Or I’ll forget. One of the two. :biggrin:

 
I guess that is my question, can I just put the ground and neutral on the same ground peg of the 3 wire plug. Thanks for the input! 
You can but its both illegal and you are defeating a safety feature.   You are bringing Darwin into play. 

 I’d get the correct wall receptacle and install it.       

 
i would check the welder again they usually don't require a neutral.  the only reason i think it would have 4 wires is if it was 3 phase 

 
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After a 2nd look at OP’s photo, it looks like a NEMA 15-50P.   Buy and install the correct receptacle.   (15-50R)

 
After a 2nd look at OP’s photo, it looks like a NEMA 15-50P.   Buy and install the correct receptacle.   (15-50R)
I get ya, but what if the welder doesn't require a neutral? Can I get  away with it? I will get a picture of the welder faceplate but as I looked at it, it's small suitcase type. No real digital electronics on it. Super simple looking machine. It's a temporary job to weld a small crack and reinforce a Bimini top aluminum frame on a center console boat. Not my machine. It's coming from a boat yard where I'm sure everything plugs into that 15-50R. I fully appreciate your input and I'm definitely not looking to burn my house down lol

 
i put that plug on all my stuff because you can buy real nice RV extension cords with molded ends and its a very common plug so there is a good chance they did the same thing

 
I get ya, but what if the welder doesn't require a neutral? Can I get  away with it? I will get a picture of the welder faceplate but as I looked at it, it's small suitcase type. No real digital electronics on it. Super simple looking machine. It's a temporary job to weld a small crack and reinforce a Bimini top aluminum frame on a center console boat. Not my machine. It's coming from a boat yard where I'm sure everything plugs into that 15-50R. I fully appreciate your input and I'm definitely not looking to burn my house down lol
I’m an electrical contractor.  My customers hate me because I don’t do shortcuts but they keep calling me back for decades because I don’t do shortcuts and over the long haul it saves them money and makes them money and it safer.  

You can do what we used to call a Mexican adapter and just stab #12THHN into the socket and wrap it around the blades of the plug (insulating electrical tape optional) and you will get your welder to make an arc.   Just keep a sharp eye out for old Darwin  

If it’s a dead end circuit (most likely) it wouldn’t be all that much trouble to replace the original box with a 2 gang deep and put one of each receptacle or a 2nd box with one of each receptacle, just don’t run both machines at the same time or you will pop your breaker assuming it’s sized correctly.    

My advice will almost always be to adhere to the NEC, CEC, NFPA, UBC and your AHJ. 

 
4 wire is for 3 phase... 3 wire is 2 phase. Make sure to change and or check the connections inside the welder also. It may only be a 3 phase welder.

 
4 wire is for 3 phase... 3 wire is 2 phase. Make sure to change and or check the connections inside the welder also. It may only be a 3 phase welder.
Looks like the label on the back has an amperage draw table for 120/240/480. 

 
Here is some forum boards info... those in favor Yay or Nay?

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According to the manual for your welder, Dynasty 200 DX, your machine can use an input voltage of 120 to 460 volts single or three phase and will auto sense whatever input voltage you are connecting so no internal wiring changes are necessary.  Since this is a residential setting, it is most likely that you have either 120 volt single phase or 240 volt single phase available for power. The four prong plug you have is a three phase plug and should be removed and replaced with a 120 or 240 volt single phase plug. 120 and 240 volt plugs (actually rated at 125 or 250 volts)  are available in many amperages. Can you post a picture of the face of the existing receptacle you want to use and a picture of the circuit breaker handle? This will clarify what you actually have installed and determine if you have the correct amperage receptacle and circuit breaker installed for your machine and that will tell you what amperage and voltage plug you need to install.

 
so it does not need a neutral just need to open the plug and see if they use the red wire . looks like the red wire is to run it on 3 phase

 
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