wiring for welding

[KubotainNH]

Another interesting tidbit for those thinking a ground is needed, I just removed the cover to look inside the unit. The ground from the plug is screwed to the case. As far as I can see there is no ground attaching to the transformer unit.

 

[MikeD74T]

KubotainNH, I have a welder similar, possibly identical, to yours. Had it since 1967. Many facets to your question. The size of your projects is less important than the size electrodes you'll be using. That determines the output range. My welder is wired with 8/3 cause I got the wire for free. If you never burn bigger than 1/8" rod you can get by with 10/3 on a 30 amp breaker forvever and stay in the 100% duty cycle. If you buy bigger rods they just won't work very long without tripping the breaker. You're right about the neutral/ground. The welder doesn't need it but you run the risk of a short energizing the cabinet & zapping whoever touches it.
If you buy an ohm meter to check voltage, buy two because it'll burn up on the first attempt unless it's a good one, get a voltage meter to check voltage. I suspect you already knew that.
Absolutely set up good ventilation in your basement. Welding fumes can cause serious health issues. Cartridge respirators are cheap and effective but don't protect the rest of the household. MikeD74T

 

[machmeter62]

Wow, this brought alot of viewpoints to this thread. Let me answer some things and make some points. First of all my house was built in 2003 with me as the GC and doing a bunch of the work. I have been doing electrical work for 25 years or so and went to school for electronics so am not clueless when it comes to this stuff. I've never wired a 220 line for a welder which is why I started the post. BTW, I would never put a breaker that is rated for more amperage than the wire. My welding projects are small so by no means will I max the thing out. It does seem funny to me that the welder has 12 guage wire but to be safe I need to use 6. Lastly, who's time is this site set to?

GMT.....It's based on the zero merdian that passes through London, England, or close to(GREENWICH MEAN TIME)....subtract 5hrs for Eastcoast. and 8hrs for the Westcoast this time of year. It is also used for all navigation too, and is the absolute correct time for the entire world for all the time zones with the atomic clock, I think?

 

[SPIKER]

NEC article 630 specifically refers to welding machines and shows tables about how the de-rate conductors for use with them. I will say again, it has to do with duty cycle.
PM member "inspector507" if you don't believe it

I think you may be correct but is he going to wire the welder into the box directly? he is putting a plug in that will be used to weld with today, tomorrow someone may plug a oven/stove or ?? into it when there is a outlet installed only items able to plug into that outlet have that type of plug on the end of them. if it is a 20 amp 120 volt device it has a plug that has one of the poles (hot lead) turned 90 degrees from a standard 15 amp 120 volt plug.

same goes for any DEVICE a welder is a device what is plugged in. that welder manufacture determines what it is rated at for usage and has to put a/an appropriate plug onto that device. if they put a 15 amp plug on it the device needs LESS THAN 15 amps. If they put a 20 amp plug on it it means it needs 15 to 20 amps if there is a 30 amp plug it means 20 to 30 amps are required... get my drift... that is WHY there are different plug designs with different prongs so you can't plug a 50 amp device into a 120volt 15 amp wall outlet....

NOW ask any welder person out there if they have EVER followed the duty cycle warning on the machines they are running??? I've done a fair bit of welding (as in welded for a job for years.) SO if you are welding you keep going until you are done, stopping & starting only when rod is out or you need to move to get a better angle...


mark m

 

[tommu56]

In 220 volts the sine wave is positive on one wire and negitive on the other leg at one instance (note the polarity changes 60 times a second (hence 60 hertz)and will switch polarity on the next cycle.


The current moves from negative to positive all the time (this is electron flow)
so actually the same electron keeps being pushed and pulled as the sine wave advances in time.

http://www.sprags.com/images/mainpower_sine_wave.jpg
tom

 

[SPIKER]

In 220 volts the sine wave is positive on one wire and negitive on the other leg at one instance (note the polarity changes 60 times a second (hence 60 hertz)and will switch polarity on the next cycle.


The current moves from negative to positive all the time (this is electron flow)
so actually the same electron keeps being pushed and pulled as the sine wave advances in time.

http://www.sprags.com/images/mainpower_sine_wave.jpg
tom

one correction, while in theory this is correct in most applications the sign wave is out by 1/3 not 1/2 as in most power situations the system is derived from a 3 phase power each of the phases being out by the 1/3.

even most homes are powered from incoming power that has a 3 phase/legs and one neutral/ground wire system.

When measuring voltage you have 2 ways to measure it, True RMS (root mean square) voltage and PEAK TO PEAK voltage. On a home system you will have ~175 volts peak to peak, but only 120 volts RMS (RMS is basically the AVERAGE of the power under the curve) that is Line to Neutral/ground voltage.

you are 100% correct on the electron flow from - to +, but that is in a DC system, in AC system it doesn't go any where just back & forth wonder that thing don't wear out the rug lol... besides that why do I have to pay the electric company if I'm only using the same electrons??? Maybe they should call it rental fee instead of a consumption charge hahaha...

mark

 

[tommu56]

Mark around here there is only single phase wiring in most houses.
and it is 180 degrees out of phase


Single-phase power systems : POLYPHASE AC CIRCUITS


Scroll down to the bottom of page for single phase picture text is very good too

I haven't found a good 3 phase (120 degrees shift) diagram on line but I will keep looking

found it
Three-phase power systems : POLYPHASE AC CIRCUITS

after looking at this whole page it is impressive ther is alot of information on them.

Volume I - DC : All About Circuits

tom

 

[Inspector507]

Mike,
Check your PMs

 

[KubotainNH]

Phew, I walk away for a little while and wow.... I do not plan on using rod any larger than 1/8". I think the plug is the same as my range and that is wired with a 40 amp breaker done professionally for the local code. When I have some time I will verify the plug and maybe post a picture. The welder will not be directly wired to a breaker panel, it will use the plug that came with it. Thanks for all the posts.

 

[Rebel]

Wow, not to step on anybodies toes but there is a lot of bad advise here.

One of the purposes of a circuit breaker is to prevent the wiring from overheating. If you use #10 wire and land it on a 50 Amp breaker, at high current draw the wire will overheat before the breaker trips, and you have a potential fire.

Always size the wiring to the breaker, consult the tables in the NEC for proper sizing.

 

[gemini5362]

Wow this has me confused and I have been working with electricity for almost 40 years now.

1. dont worry about the plug being 50 amps and someone putting a 50 amp device on it. If you have the money and want to do it the proper way then you can run the right size wire and a 50 amp breaker. If you want to be cheaper then run 10 gauge wire and a 30 amp 220 breaker. As long as the breaker is sized correctly for the wire it will be safe.

You really really need that ground wire. I did not notice anyone mentioning safety as the reason for it. If something were to short to the case, such as a winding in the transformer and you touch the case at the same time you touch something that has a good ground ( pipes, another piece of equipment that is only 110 volt but has a ground wire going to its case etc) you are going to complete the circuit between your welding case and ground. If that circuit goes across your heart you are most likely going to die. That is the main reason you have a ground cable is for SAFETY.

I am under the impression that most home wireing is actually 180 out of phase. I am not 100 per cent sure of that. I do know that if you want three phase wireing the electric company has to run leads from the nearest three phase power they have available.


To the original poster. There are some facts in these posts you really need to be aware of. 1. A lot of cities, counties and I believe some states will not let DIY people run electric power because of the danger involved if it is not done right. Not only to the original user but to others ( I. E. If your house catches on fire and burns up the neighborhood. ) 2. A lot of insurance companies have a fit if they find out that you have run your own house wiring. ( IE such as cancel your insurance.) If you have a lot of electrical experience and you dont have legal restrictions against it then go ahead and run your own cable just make sure whatever cable you use is 2 conductors and a ground. The ground can be a bare copper wire with no problem.



The last thing I want to mention is that you probably dont want to use an ohm meter in a HOT electrical panel if you go across energized power lines with it something is going to melt more than likely the meter and probably the leads you are holding. I would recomment a VOM (Volt Ohm Meter) that has a setting for measureing volts.

 

[mopacman]

I tried welding using 1/8 rod and a 30 amp breaker but ever time I would stick the rod to the metal it would blow the breaker. I know none of you have ever done that......Larry

 

[Inspector507]

I tried welding using 1/8 rod and a 30 amp breaker but ever time I would stick the rod to the metal it would blow the breaker. I know none of you have ever done that......Larry

Nope never tripped the breaker yet. But it is installed per the manufacturers instructions and the NEC. #10 wire on a 50A breaker.

 

[gemini5362]

Nope never tripped the breaker yet. But it is installed per the manufacturers instructions and the NEC. #10 wire on a 50A breaker.

I am confused why would you ever have a 50 amp breaker on #10 wire. Inspector 507 I thought you were an electrician.

 

[Inspector507]

I am confused why would you ever have a 50 amp breaker on #10 wire. Inspector 507 I thought you were an electrician.

NEC says it's okay, UL says it's okay and the manufacturer says it's okay. And no I'm no longer an electrician, just a code official enforcing the NEC.

 

[gemini5362]

NEC says it's okay, UL says it's okay and the manufacturer says it's okay. And no I'm no longer an electrician, just a code official enforcing the NEC.

Yeah that is what i thought you actually did but I figured I would be safer just saying electrician.

Please dont take this as an argument you know a lot more about code than I ever will in my entire life. I understand that it is ok because basically the welder is not pulling that much current. The problem I see is twofold. What if you get a partial short across the wiring behind the receptacle the 10 gauge is going to get hot enough to melt before the breaker trips or, if you decide to plug something in there that will fit and draws more than 30 amps lets say something that draws 40 or even 50 amps at that point you have a problem with the 10 gauge wire getting rather warm. ( for some reason this discussion is very familiar must be deja vue)

 

[Inspector507]

Yeah that is what i thought you actually did but I figured I would be safer just saying electrician.

Please dont take this as an argument you know a lot more about code than I ever will in my entire life. I understand that it is ok because basically the welder is not pulling that much current. The problem I see is twofold. What if you get a partial short across the wiring behind the receptacle the 10 gauge is going to get hot enough to melt before the breaker trips or, if you decide to plug something in there that will fit and draws more than 30 amps lets say something that draws 40 or even 50 amps at that point you have a problem with the 10 gauge wire getting rather warm. ( for some reason this discussion is very familiar must be deja vue)

gemini,
The first scenario deals with short circuit current and has little to do with the amperage of the breaker. If something shorts out behind the receptacle, it will trip.
The second is why I recommend a NEMA 6-50R receptacle. It is dedicated for welders and is what is recommended by probably every welder manufacturer. You can't plug a range into a NEMA 6-50R receptacle.

Deja Vu? Yep and I wonder why I even commented here. Would you like to read what I copied out of the manual for my welder?

 

[gemini5362]

LOL

No I dont need to read what your manual says. I missed where you recommended a different kind of receptacle. Since I am not familiar with that receptacle please enlighten me I might want to switch the one for my welder. One of the plugs that came with my welder fits into the plug in for a range perfectly. ( I have a miller DVI with multpiple adapter plugs)

As far as Deja Vu I am not going to restart that whole thread again. I am going to just hopefully agree that we disagree. I will point out that you have mountains of experience with code versus my basically no code experience. I just am of the simple opinion that you never ever put a bigger breaker than the wire is rated for. I do however acknowledge your superior experience with code and home electrical wiring. I just basically disagree in this one particular instance.

 

[Inspector507]

LOL

No I dont need to read what your manual says. I missed where you recommended a different kind of receptacle. Since I am not familiar with that receptacle please enlighten me I might want to switch the one for my welder. One of the plugs that came with my welder fits into the plug in for a range perfectly. ( I have a miller DVI with multpiple adapter plugs)

As far as Deja Vu I am not going to restart that whole thread again. I am going to just hopefully agree that we disagree. I will point out that you have mountains of experience with code versus my basically no code experience. I just am of the simple opinion that you never ever put a bigger breaker than the wire is rated for. I do however acknowledge your superior experience with code and home electrical wiring. I just basically disagree in this one particular instance.

First, I think it's wrong for a manufacturer to include a plug that will fit into a range outlet. One is a NEMA 6-50R the other is a 10-50R. The 6-50R is the correct one. Most welder supply houses will have it if you ask for a welder outlet. Is it more convenient to install a range plug? Yes. Because they are more readily available. And people don't know there is one dedicated for a welder.

If you look at Table 310-16 of the current NEC, there is an asterick on #10 wire. The asterick directs you to Article 240-4(D) which directs you to 240-4(G) for Special Conductor Appilcations. That in turn says to look at Article 630 for Electric Welders, which says for one welder on the circuit, you can fuse the feed for the welder at 200% of the conductor ampacity. #10 THHN/THWN is actually rated for 40 amps, so if I fuse it at 200%, it's good for 80 amps for a welder.

But we can agree to disagree.

BTW I didn't make a recommendation in this thread on the receptacle, just the previous ones.

 

[RobJ]

I run a hobart and Lincoln 230a ac welder on 10 guage wire. Also run a 30a breaker. One is here and one is at the weekend place. Both have NEVER popped the breaker. Why, I never need to run 230a welding, I can't lift 1" plate you know. Last project I ran 60a max. I think the most I've ever run is 120a. My cord is also 30' long. The 30a breaker protects the 10 guage wire I guess. And I've never burnt down a house!!

Actually after welding or using an O/A set, I never leave the house for 30 minutes. Mainly for a rolling piece of steel or slag.

Good Luck,
Rob