220v To 120v? Welding/Generator

[Gilly826]

Basically it's exactly as the title says, I'm looking to use the 30amp outlet on my generator to power my 120v welder.

I don't know much about electrical, and this is my first welder. Wish I spent the extra $100 a while back and got the welder with 120/240v plugs.. This has become a recent issue because I got a "new" generator and when using the 20amp plugs I am constantly tripping the breakers. Is there an adapter that would allow me to use the 30A plug on my generator?

I found a NEMA 6-50R adapter, but will that receive a standard 120v plug? TIA.

 

[bud16415]

I believe the 30a rating is 30a at 240v and splitting it out to 120v my thought is you will be getting 15a even if it works.



I could be wrong.



What kind of 120V welder do you have that’s tripping a 20a breaker?



I have a Harbor Freight 240v input mig that takes weld gas and I plug it into a 30a breaker in the garage and it works great. Mine is the lower grade one they sell. Now they have a better and best line.



I take it you want to go portable with it.

You could rig a 240v pigtail to 120v plug to try it out I guess. Just cap off the one hot.

 

[Snoonyb]

Or, better yet, buy a generator with the amperage rating sufficient to handle the power requirements of the welder.

 

[Gilly826]

I believe the 30a rating is 30a at 240v and splitting it out to 120v my thought is you will be getting 15a even if it works.



I could be wrong.



What kind of 120V welder do you have that’s tripping a 20a breaker?



I have a Harbor Freight 240v input mig that takes weld gas and I plug it into a 30a breaker in the garage and it works great. Mine is the lower grade one they sell. Now they have a better and best line.



I take it you want to go portable with it.

You could rig a 240v pigtail to 120v plug to try it out I guess. Just cap off the one hot.

I also have a harbor freight welder. It's the Titanium brand. I really like it actually, but since I got this new generator it can't handle it at high loads very long. What's weird is the other generator I used barely tripped ever, and the power ratings are the same and so are the breakers. Either the breakers are more sensitive, or the power rating isn't what it's advertised to be. I have tried running it of my 20A in my garage and that trips easily as well at higher loads.

 

[Gilly826]

Or, better yet, buy a generator with the amperage rating sufficient to handle the power requirements of the welder.

I don't believe that's the issue. The generator is 5500 running what's, the 120v outlets have 20A breakers. The welder is max 30A, but it's got a 120v plug. I realize now that is pretty dumb, should have spent another $100 and got the welder with 120/240 capabilities.

 

[bud16415]

I have an old timer HF back when they were blue. I bought it off an old farmer for 50 bucks and lengthened the power cord to about 25' with a heavy gage flex cord I had so I can roll it around the garage and out into the driveway. I also put a good ground clamp and lengthened it also. It will take the 10lb spool of wire.

As to your gen it sounds like you have enough power but the way they broke it up and sized the breakers is the problem. They all have different duty cycles and they kind of stretch the specs.

I wonder if you got inside it is you couldn't pick up power and add another external breaker that would work.

 

[Gilly826]

I have an old timer HF back when they were blue. I bought it off an old farmer for 50 bucks and lengthened the power cord to about 25' with a heavy gage flex cord I had so I can roll it around the garage and out into the driveway. I also put a good ground clamp and lengthened it also. It will take the 10lb spool of wire.

As to your gen it sounds like you have enough power but the way they broke it up and sized the breakers is the problem. They all have different duty cycles and they kind of stretch the specs.

I wonder if you got inside it is you couldn't pick up power and add another external breaker that would work.

I have never worked on a generator before, but I was having similar thoughts as well. I think the welder should have been rated at drawing higher amperages, cause it blows a standard 20A breaker in my garage pretty quick as well. What I did find was an adapter that goes from 220 to 2 - 120v plugs. Ones a 15A and ones a 20A. No clue if that would be any better.

Anyone have info on the NEMA 6-50R plugs? Will they receive a 120v plug or are they way different? I can only go off the pics I've seen.

 

[Gilly826]

Ok so a NEMA 6-50R is not compatible with a 120v plug.

I'm wondering if the plug on my welder can be converted into a 220v. If not I've got to figure out a way to swap out the breakers on my generator.

The other generator I used rarely tripped a breaker, and that had 20A just like mine does. PITA.

 

[bud16415]

I’m pretty sure those plugs are just gender changers and they just pass the 240 thru.



Without a wire diagram of your generator it is hard to say how the breakers and phases are divided up to be rewired. I assume there are a few 120v outlets and one 240v outlet. Is there a breaker for each outlet or are they paired together. By checking voltage between outlets some hot to hot will read zero as they are on the same leg and some would read 240 showing they are on opposite legs of the 240.



I would also want to study the welder a little and see if it doesn’t have an option for 240v input. It came with a 120v plug but still might have an option to run it off 240v.

What model is it?

 

[Gilly826]

I’m pretty sure those plugs are just gender changers and they just pass the 240 thru.



Without a wire diagram of your generator it is hard to say how the breakers and phases are divided up to be rewired. I assume there are a few 120v outlets and one 240v outlet. Is there a breaker for each outlet or are they paired together. By checking voltage between outlets some hot to hot will read zero as they are on the same leg and some would read 240 showing they are on opposite legs of the 240.



I would also want to study the welder a little and see if it doesn’t have an option for 240v input. It came with a 120v plug but still might have an option to run it off 240v.

What model is it?

I have 4 outlets for 120v between 2, 20A breakers. And one 220v at 30A.

Here's the welder I have. The bigger option is the 170Mig that comes with 120/240. They visually look identical.
https://www.harborfreight.com/mig-140-professional-welder-with-120-volt-input-64804.html
I found an adapter that goes from the 220v outlet and splits into 2, 20A 120v outlets. Might be a cheap/easy solution, but maybe not.

https://www.amazon.com/Conntek-YL1430520S/dp/B002MGJ2F4

 

[bud16415]

I have 4 outlets for 120v between 2, 20A breakers. And one 220v at 30A.

Here's the welder I have. The bigger option is the 170Mig that comes with 120/240. They visually look identical.
https://www.harborfreight.com/mig-140-professional-welder-with-120-volt-input-64804.html
I found an adapter that goes from the 220v outlet and splits into 2, 20A 120v outlets. Might be a cheap/easy solution, but maybe not.

https://www.amazon.com/Conntek-YL1430520S/dp/B002MGJ2F4

You could try the splitter cord as all it is doing is sending out a hot leg to each plug. What might happen is now you are being protected by a different breaker and that might let you work whatever leg you plug into a little harder than the dedicated 120v outlets. I’m not really sure how a 240v 30a breaker works or if just one leg hits 15a it trips both.



What would work I think is if you got a proper sized 240v to 120v transformer and built a box with the 240v plug coming out of it and then find a good quality 20a outlet. I think the breakers on the gen would protect it ok except in theory it would take 30a to trip them so maybe a 20a screw in slow blow fuse in the box as well on the secondary. Fuses would be nice as you could maybe push it up to a 25a if needed. Not really sure how many KVA the transformer rating would need to be or if you could scrounge up something used.



Maybe some of the pros here might offer some advice before we burn up your gen or welder or both.

I looked at a few sites where guys were getting inside their welders and doing stuff switching taps to change the input voltage and some welders can. The problem is the wire feed and gas shut off and such also has to be worked on as it is 120v.

 

[Gilly826]

You could try the splitter cord as all it is doing is sending out a hot leg to each plug. What might happen is now you are being protected by a different breaker and that might let you work whatever leg you plug into a little harder than the dedicated 120v outlets. I’m not really sure how a 240v 30a breaker works or if just one leg hits 15a it trips both.



What would work I think is if you got a proper sized 240v to 120v transformer and built a box with the 240v plug coming out of it and then find a good quality 20a outlet. I think the breakers on the gen would protect it ok except in theory it would take 30a to trip them so maybe a 20a screw in slow blow fuse in the box as well on the secondary. Fuses would be nice as you could maybe push it up to a 25a if needed. Not really sure how many KVA the transformer rating would need to be or if you could scrounge up something used.



Maybe some of the pros here might offer some advice before we burn up your gen or welder or both.

I looked at a few sites where guys were getting inside their welders and doing stuff switching taps to change the input voltage and some welders can. The problem is the wire feed and gas shut off and such also has to be worked on as it is 120v.

Yea, I think I'm gonna try the splitter first. A part of me was wondering if I could "merge" the two legs into one and "technically" have a 240v in a 120v outlet application. I assume it's probably dangerous/not recommend but it crossed my mind. If that's a no-no, I'll try the splitter/adapter as is. And if it doesn't work I'll have to look into adapting my generator, or selling my welder and buying one with 220v capabilities. Just kinda sucks cause I'm just a "hobbyist" really and don't necessarily need a big time welder for my needs/skill level.

 

[bud16415]

Yea, I think I'm gonna try the splitter first. A part of me was wondering if I could "merge" the two legs into one and "technically" have a 240v in a 120v outlet application. I assume it's probably dangerous/not recommend but it crossed my mind. If that's a no-no, I'll try the splitter/adapter as is. And if it doesn't work I'll have to look into adapting my generator, or selling my welder and buying one with 220v capabilities. Just kinda sucks cause I'm just a "hobbyist" really and don't necessarily need a big time welder for my needs/skill level.

Ya you defiantly a no-no you don’t want to attach the two 120v legs together because they are 180 degrees out of phase and it would be a major short circuit. The splitter is cheap enough and even if it doesn’t work it wouldn’t be a bad thing to have around as it gives you two more 120v sources for using the gen for other reasons.



I do think it will likely trip around 15a or half the rating of both legs.



Are you using the gen just because your garage power wont handle the tripping or do you want to take the welder out and about and use it like a portable? Do you have a sub panel in your garage where you have 240v available?



There are 25a and 30a 120v breakers. People use them mostly with the plugs and sockets that have the curved prongs in a circle. It would be easy enough to switch your welder plug out to that if you just wanted to weld in the garage with an extra long power cord like I do, and if you have a sub panel in the garage to add a new breaker to power just the welder plug. It sounds like you just need a little more current than what you have now a 25a might get you there.



Like you it’s just a hobby with me I worked 43 in industry that was metal fabrication and it wasn’t till I retired I gave it a try. I wasn’t too impressed with flux core and last fall I used up what I had left fixing up my snowplow before winter. It wasn’t pretty but got the job done. Once I rigged mine to pull the big spool of MIG wire I doubt I will do any welding without gas. What I need to do though is step up the size of my bottle and keep the little bottle full as a backup when I run out in the middle of what I’m working on.



Here is a thread on my old 240v HF.

Welder questions.

Again I’m not a pro electrician closer to an Amish electrician as they say around here. Take my suggestions as food for thought and don’t get in behind the panel unless you are sure you can do it safely.

 

[Gilly826]

Ya you defiantly a no-no you don’t want to attach the two 120v legs together because they are 180 degrees out of phase and it would be a major short circuit. The splitter is cheap enough and even if it doesn’t work it wouldn’t be a bad thing to have around as it gives you two more 120v sources for using the gen for other reasons.



I do think it will likely trip around 15a or half the rating of both legs.



Are you using the gen just because your garage power wont handle the tripping or do you want to take the welder out and about and use it like a portable? Do you have a sub panel in your garage where you have 240v available?



There are 25a and 30a 120v breakers. People use them mostly with the plugs and sockets that have the curved prongs in a circle. It would be easy enough to switch your welder plug out to that if you just wanted to weld in the garage with an extra long power cord like I do, and if you have a sub panel in the garage to add a new breaker to power just the welder plug. It sounds like you just need a little more current than what you have now a 25a might get you there.



Like you it’s just a hobby with me I worked 43 in industry that was metal fabrication and it wasn’t till I retired I gave it a try. I wasn’t too impressed with flux core and last fall I used up what I had left fixing up my snowplow before winter. It wasn’t pretty but got the job done. Once I rigged mine to pull the big spool of MIG wire I doubt I will do any welding without gas. What I need to do though is step up the size of my bottle and keep the little bottle full as a backup when I run out in the middle of what I’m working on.



Here is a thread on my old 240v HF.

Welder questions.

Again I’m not a pro electrician closer to an Amish electrician as they say around here. Take my suggestions as food for thought and don’t get in behind the panel unless you are sure you can do it safely.

For the most part, yes. I am using the generator because my 20A circuit in my "garage" can't handle the load. Speaking of amish, you might appreciate this - my garage is actually a box truck body on a cement slab. I ran conduit from the garage through the ground to our barn, which has a 50A power supply. So I suppose there is a possibility I could add a bigger 120v breaker/wire which would be nice for sure. I assume the electrician used 50A wire to the barn because of the long distance from main power supply. It isn't heavily used so it should be able to handle a 25/30A breaker - I would think.

It would still be ideal if I can figure out a solution for the generator as well because it has been nice to bring the welder wherever it's needed. It's a nice and light welder and I have a smaller bottle of argon I can bring along with it.

 

[bud16415]

For the most part, yes. I am using the generator because my 20A circuit in my "garage" can't handle the load. Speaking of amish, you might appreciate this - my garage is actually a box truck body on a cement slab. I ran conduit from the garage through the ground to our barn, which has a 50A power supply. So I suppose there is a possibility I could add a bigger 120v breaker/wire which would be nice for sure. I assume the electrician used 50A wire to the barn because of the long distance from main power supply. It isn't heavily used so it should be able to handle a 25/30A breaker - I would think.

It would still be ideal if I can figure out a solution for the generator as well because it has been nice to bring the welder wherever it's needed. It's a nice and light welder and I have a smaller bottle of argon I can bring along with it.

I had a similar idea but would need a gen unit. I would like to have a portable gen for if the power goes out as well to keep the furnace going and the fridge maybe a microwave, couple lights and a TV. So using it for other things like welding or a building project out where I wouldn’t have power would help cost justify it. But I haven’t done that yet.



My idea with the welder was to not have it tied down to the 240v wall outlet that is next to my 100a sub panel in the garage that is right by the garage door. I thought the cord that was on it looked cheap and too small anyway so when I lengthened it I made it long enough to reach all the garage and my attached workshop and it normally just sits next to the bench I do smaller welded projects on. With the long cord I can take it out in the driveway for working on cars or tractors, snow plows etc. So when a neighbor wants something welded I tell them bring it up and drop it in front of the garage. I have a couple windbreaks I can set up if the gas is blowing away and lights I can drag out with stands if it needs done after dark. Doing that covered 95% of my needs anyway.



If I was you and again I hope one of our pro electricians pop in to check my thinking out here. I would make an extension cord out a 30a (RV) extension cord like this one.

https://www.amazon.com/Conntek-1436...t=&hvlocphy=9006390&hvtargid=pla-435238500840

I would cut off the female end and replace it with the best quality industral replacement plug that will match your welder. Then I would get the mating (RV) plug setup for the other end and connect that back into your panel to a 25a breaker for starters.



Doing this you wont be changing anything with your welder and the longer cord won’t have to stay with the welder like mine does.

I use my breaker shutting it off before I connect my welder making sure my welder is off also. After the welder is safely plugged in I flip the breaker on and then power my welder up. Doing that there is no way I’m messing with the plug under power.