Extension cord form my welder

I just purchased a new Miller Millermatic 140.

It is a 120v unit.

I only have one 110 outlet in my garage.

I have heard horror stories about using a welder on an extension cord. But I have to have one to reach all the way around my work area.


I need advice on what to use so I don’t burn up my new investment.

Here are the welders specs.

It’s a 120v wire feed welder.

RA SPECS:
Volts 18
Amps 90
Duty Cycle 20%
Max OCV 28
Amp Range 30-140


CSA SPECS
Volts 21
Amps 63
Duty Cycle 20%
Max OCV 28
Amp Range 30-140

 

call miller, thats what i did..come too find out that you can run 94 feet on a 220 unit

 

Your welder requires a 20 amp circuit to run it. Check the breaker feeding your single outlet in your garage and make sure it doesn;t also feed something large like your refrigerator or something. Make sure it is wired with #12 wire. It should say on the romex. If you don't have at least that don't worry about an extension cord! Call an electrician and have some outlets added in your garage. If you do buy a heavy duty #12 extension cord. Max 20 feet long. Nice welder it would be a shame to screw it up or burn down your place!

 

Something to consider is the size of the wiring inside the wall going to the plug.

The closer the wall plug is to the panel box the better as you get more usable voltage.
IF the wall has small 14g wire and its 20' from the Panel box...AND you then still need a 20' extension...It might actually be better to run a 40' 10g extension cord and plug in as close to the Panel box as possible!

 

I have the same welder myself. I used it a lot on 15amp with a 20' 14 gauge cord. I did end up running a 20amp breaker, dedicated 20 amp outlet and a 20amp 20' 12gauge cord. I don't know if I can tell there is a difference but I feel better about it. The welder only has a 14 gauge cord on it from the factory so I would think that is a limiting factor anyways. Peter

 

run a heavy wire from one side of the dryer plug, it has a higher amp capability and also the wires to it are heavier.

 

I agree with what has been said here so far. I wouldn't go crazy with your extension cord length. Longer cord lengths means more resistance which translates to excess heat and voltage drops. 15 or 20 feet should be okay. Check the outlet, wire size, and breaker for that circuit in your garage. They all should be all rated for 20 amps. If everything checks out then you should be okay. If it's a dedicated circuit, that's even better. If not, unplug anything else that uses that circuit while running your welder.

Sizes for rated current loads:

15 Amps - 15 Amp Outlet, #14 Wire, 15 Amp Breaker
20 Amps - 20 Amp Outlet, #12 Wire, 20 Amp Breaker
30 Amps - 30 Amp Outlet, #10 Wire, 30 Amp Breaker
40 Amps - 40 Amp Outlet, #8 Wire, 40 Amp Breaker
60 Amps - 60 Amp Outlet, #6 Wire, 60 Amp Breaker

Residental Load Centers (Service Entry And/Or Sub-Panel)
100 Amps - 2 OT Wire (Aluminum), 100 Amp Breakered
200 Amps - 4 OT Wire (Aluminum), 200 Amp Breakered

 

According to the National Electric Code (NEC) 20 amp circuits should be wired using a minimum of #12 wire. If your circuit is wired according to code, then it should have #12 coming from the panel to the receptacle. The capacity of wire is rated by amperage not voltage. #12 wire is actually rated for 30 amps and limited by the NEC to 20 amps for safety. If your panel is not over 50 feet from the outlet you want to use, and the other loads are limited, tv, ect, you probably won't have any issues if your use a good heavy duty drop cord with #12 conductors. (tv will probably act crazy). The shorter the better. 20 foot max for your situation. Make sure the receptacle is in good condition (plugs are tight when plugged in). Voltage drop is what will kill your welder. Longer the cord, more possibility of voltage drop. Feel the cord at the plugs occasionaly. If it feels hot, you may have problems. One last thing, most modern garages have GFCI protected outlets (reset buttons on the receptacle). It will probably not hold up to welding. They do make 20 amp GFCI units but I am not sure how the welder will affect it. Please don't try the dryer plug idea (safety issues). Call an electrician. Probably have a HAMB guy in your area who is an electrician. Call Miller. Electrical work is not a hobby.

 

I have a Millermatic 135. I think that it is a 2003 model. I had it on a dedicated 20 amp breaker and it kept throwing it. An electrician friend came over and did a voltage check on it. Not every time but every now and then when you turned it on it would spike and draw 24 volts for a split second, just enough to trip the breaker. I had big enough wire feeding the outlet so I went up to a 30 amp breaker. This solved the problem. Has anyone else had this happen?

Like rhew5r said “voltage drop will kill your welder.” At the college I work at, they burnt up a Hobart 135 because they were running it on a skinny extension cord. I was told that the Miller welders have a relay that will trip before you damage the machine, but the cheaper Hobart’s do not. They burnt up the board in the welder and the board is almost as much as a new welder.

I use a 20’ 12g extension cord with mine.

 

.Dryer's in houses are 30 which is perfect .Rule of thumb You can always go bigger not smaller. Here's an example Your wiring your house and all you have is 12 guage. That's ok to install 15 amp outlets With a 15amp breaker But to run 14 guage and a 20 amp breaker is a no no .Fire hazard Make up an extension cord about 6 guage and use dryer outlet if electric.If not use a designated 20 amp outlet and run 10 guage or less depending on length of run I started out like you Depending if something was on in my house I use to trip breakers and was left fumbling around in the dark in my garage.

 

I thought Rusty was your friend ? Isnt he a ELECTRICAN ? WTF !

 

Please don't use the dryer outlet trick. Yes, it is probably #10 wire & 30amps. It is also 240 volt. If it is a 3 wire dryer outlet, it does not have a neutral wire, only a bare ground wire and there is a difference between a neutral and a ground wire. Neutrals have return current and grounds only have current on them in an emergency situation. Get between a neutral and ground wire in right situation and you will understand...

 

I have a 175 on a 30 amp breaker and a 275 on a 100 amp breaker.

 

I tried calling. He didn't answer.

 

Look at the gauge wiring on the units plug. You will be fine using a short extenion cord of the same gauge or if you can find an extention cord one size bigger, all the better. 110-120 volt is the same just different verbage. Just like 220-240. Same thing.

 

I've never had a problem with my 30'er and my lincoln 110v It'll flip every breaker in the house exept for a plug in the kitchen when i'm doing frame stuff but other than that no problem

 

It is true that bigger wire is better. It is NOT true that "you need 20 amps!" Standard household outlets are 15 amps, PERIOD. 20-amp outlets look different and any device that requires 20 amps will have a plug with the extra little tab that won't allow it to plug into a standard 15-amp outlet. Miller and Hobard 140-amp welders are made to plug into any standard 15 amp outlet.
Putting a 20-amp breaker in there will just mask some problem until bad things happen elsewhere!
As for extension cords, use the shortest you can and make sure it's of the gauge recommended in your owner's manual. (My Hobart calls for 14-gauge and up to 20 or 30 feet - mine is only 15 feet and I only use it when I gotta.)
If you need it longer than 10 or 15 feet, I'd go 12-gauge or even 10 if you can find it. Don't buy the extension cord at Harbor Freight.

 

True, every "normal" household outlet (in the US) would be a NEMA 5-15, which has the hot and neutral plug blades parallel to each other. A NEMA 5-20 plug has one blade which will be turned 90 degrees to the other. Most NEMA 5-20 receptacles will accept a 5-15 plug, but no NEMA 5-15 receptacle will accept a 5-20 plug. Go here for more info:

http://www.elect-spec.com/nema_plgsokt.htm

 

i wound up with 2 10/3 cords for my 110v mig. i got them from work, ive never seen them in stores, but i guess a welding supply or ebay would be a good place. i forget if they are 25 or 50'. for my 220v mig i forget if i bought a #6 or #8, its a real nice cord though. definitely worth spending a few bucks on.

 

Where is your fuse/breaker box?

It is cake to drop a new breaker and an outlet... and cheap enough to have an electrician wire up if you don't feel comfortable doing so yourself.

That said a good heavy wire in an extension cord (10 GA is plenty big!) and you won't have any problems.

 

Using your existing circuit for your welder is a crap shoot due to it's unknown quantity. You're allowed a 2% voltage drop. You need to get a base line of the voltage without anything connected and then again with a load to get the amount of voltage drop. You don't need to go too far before you start to run into problems. I wouldn't be surprised if you've already exceeded maximum voltage drop right at the existing outlet.

For any welder, I would run a dedicated circuit and for your 120 volt MIG, like mine, I'd run at least #10 AWG and use a spec grade outlet, not a Home Depot special $.97.

For general purpose circuits, breakers are sized by wire and visa versa. But for definite purpose circuits, you can end up with what appears to be an over sized breaker for the gauge of wire it's connected to

The amount of current a wire can carry varies on many factors. The temperature of the area it's installed, the amount of wires in a conduit, the temperature rating of connection points, type of insulation and so on.

To sum it up, you've got some good advice by others my opinion is to bite the bullet and run a dedicated circuit with a minimum of #12 on a very short run measure right from the panel but would really like to see you use #10.

To put things into perspective, wattage = voltsXamps voltage = ampsXresistance. For a given resistance, reducing the voltage to half, you'll end up with 25% of the original wattage. That's food for thought on how long your circuit or extension cord is!

 

I have the same welder the eletrician at work made me up a 20' # 10 cord works great good luck. Rick

 

hard wire it straight into the pannel

 

Yes, but the comment I was reacting to was not someone who wired in a 20-amp circuit, but someone who put a 20-amp circuit breaker on a 15-amp circuit! That's a big difference. Depending on when his house was built he could have 14-gauge wire with a 20-amp breaker on that circuit!
I have 10-gauge wire on my shop outlets that I use for welding and a 15-amp breaker because (as I said) the welder is a 15-amp device, NOT 20 amps. A 20-amp breaker will just allow things to go more wrong before blowing, and if a 15-amp breaker is blowing then something is WRONG.

 

After reading all this I am going to run a 220 service line from my box to my garage. From there I will have a 220 hookup and a few 110. For now I'm just going to shut the house down when I weld.

I have a 20 amp breaker and 12g wire to the garage. It's about 35-40 feet from the box if you count the actual wire length. I shouldn't have any problems doing sheet metal work. No heavy welding as of now. Just patch panels.

Thanks for the tips.

 

My dad (who is a certified electrician with over 40 years experience) and I upgraded my house service from 100 amps to 200 amps. We used my old 100 amp panel (that feed the whole house) in my garage which is now sub-paneled from the new 200 Amp panel in the basement. We installed two dedicated 30 amp circuits with twist-lock recepticles, and one 20 amp dedicated for welders and air compressors to plug into. They are less than 30 feet from the sub-panel and I've never had any problems with any of it. A friend of mine has a similar setup in his garage and he has never had a problem either. Just food for thought...

 

Damn...now I remember why I bought a 220v welder....

 

Just do it right and run some more outlets in the damn garage! One outlet will cover your radio and cordless charger. You already know an electrition to bribe.

 

The wires that supply your house travels a long way from the transformer to it. Not only does it supply the plug you're thinking of plugging your welder into, it also supplies the air conditioner, dryer,oven, every other plug in the house and all the lights. That's a lot of electricity! It's many times more than your measly welder could ever hope to use. How do they do that??? They use BIG WIRES between your house and the light pole.

The point is, if you use a big enough wire, it will handle all the electricity your welder requires no matter how long you make your extension cord. With a big enough wire, your welder will "think" it is plugged directly into the outlet because the cord won't have any resistance. Make your extension cord as long as you like. Make it reach down the driveway or into the back yard if you like.

Go to Home Depot and buy some #10 two-conductor house wire. (It would be better to buy multi-strand if you can afford it. It won't wear out from bending and moving quite as fast. But the house wire will last a good long time (years) if you don't roll it up in too tight of a circle when you put it away.) Attach regular three-prong plugs on each end of your #10 wire. You can get them at Home Depot also. Plug it into the existing outlet. Plug your welder into your home-made extension cord. Done!

It won't hurt your welder. It won't be a fire hazard. As far as your welder and your house are concerned, it will be "invisible" to the electricity. It will "think" it is plugged directly into the outlet.

The dryer oultet trick will also work. Most motors in dryers are 110Vac. (So are the timers, the drum light, the door switch, and everything else except the heater element.) They all pull electricity off one leg of the 220V and send it down the common/ground leg. Your welder will do exactly the same thing except that it will use less electricity than the dryer. Use #10 wire there too. You can also buy a dryer plug end at Home Depot or Ace or Lowes.

Good luck, Sparky!