wiring for welding

[KubotainNH]

Hello, I recently was given a 30a-230a dual range Craftmans stick welder. The front says primary 230 volts 50 amps single. I assume this means I will need to wire it to a 2 pole 50amp breaker. What I don't get is that the original 6 foot cord is labeled as 12/3 which I didn't think would handle 50amps so why would I need such a large breaker? For the spikes in current when starting the arc maybe? Seeing wire is expensive I only want to do this once, any thoughts on the guage of the wire? I'm thinkin 8/3 but want another opinion seeing I don't have alot of extra money for overkill. This is all in my basement running about 35 feet. Thanks,

 

[kennyd]

The reason is duty cycle. The EL code treats welder outlets a little differently than your used to because the load is not constant like a oven or other appliance.

You could use 10/2 gauge wire for your feed, but 8/2 would be a better choice and would cover you if you got a new welder in the future. This is discussed A LOT on the welding boards like Weld Talk Message Boards - Powered by vBulletin

 

[Sleepy owl]

Hi my welder is supplied 60 amps from a 200 amp pnl with a 50 amp plug the plug is A foot from pnl.I run a miller 304 inverter and also a miller vintage 250 wire feeder also a 225 lincoln welder and use one welder at a time with no problem.they do make plugs like arc tite with a metal jacket but are very $$ for higher amp disconnects .I had a electrican wire it up.Sleepy owl

 

[MrJimi]

What does your manual say about it?
I would go by the factory manual first
Jim

 

[Sully2]

Hello, I recently was given a 30a-230a dual range Craftmans stick welder. The front says primary 230 volts 50 amps single. I assume this means I will need to wire it to a 2 pole 50amp breaker. What I don't get is that the original 6 foot cord is labeled as 12/3 which I didn't think would handle 50amps so why would I need such a large breaker? For the spikes in current when starting the arc maybe? Seeing wire is expensive I only want to do this once, any thoughts on the guage of the wire? I'm thinkin 8/3 but want another opinion seeing I don't have alot of extra money for overkill. This is all in my basement running about 35 feet. Thanks,

8/3 will definately work...but 10/3 would be OK.

 

[machmeter62]

MIKE: 10/3 would be safe, but 8/3 would be a better choice for future up-grades to prevent any wire heat-up; use that third wire as an additional ground! Use copper wire only!
LEE

 

[KubotainNH]

My future is a garage before another welder so I'm ok with not thinking about upgrading in the basement but I will price both ways. I did not get a manual but can order one if needed just haven't got that far yet. I want a bit more power than my little 110v cheapo stick welder, no huge jobs. The 12/3 on the cord still gets me. Thanks for all the replies.

 

[machmeter62]

MIKE: 10/3 would be safe, but 8/3 would be a better choice for future up-grades to prevent any wire heat-up; use that third wire as an additional ground! Use copper wire only!
LEE

The 12/3 wire on the 6' cord is plenty adequate for six feet; distance and a high AMP load creates heat in a small wire over a longer distance. It's like the difference in flow between a fire-hose vs a long garden hose. Of course you are only pulling a max of 50 AMPS at full power, and 25 AMPS per wire. Hope this helps?

 

[tommu56]

The 12/3 wire on the 6' cord is plenty adequate for six feet; distance and a high AMP load creates heat in a small wire over a longer distance. It's like the difference in flow between a fire-hose vs a long garden hose. Of course you are only pulling a max of 50 AMPS at full power, and 25 AMPS per wire. Hope this helps?

Note:: that each wire will carry the whole load not split as machmeter said>

What go's out one wire has to go back the other wire ground shouldden't be carrying any current.

tom

 

[kennyd]

The 12/3 on the cord still gets me.

As I said before, It's because of the duty cycle of the welder.

Take a look at the specs of THIS Lincoln welder, the specs are probably very similar to yours. You will see that has has a 20% duty cycle, which is explained HERE.
You can also download the manual from the Lincoln site, that's probably who made your Craftsmen unit anyway.


Also, you only NEED 2 conductor (w/ground) wire not 3. Like 10/2 or 8/2.

 

[2manyrocks]

If I recall correctly, Miller cautions that a welder can throw sparks 35 feet. So welding in the basement or around anything that will burn is not good. I assume you'll be welding outdoors with this and the fumes will be carried off in the outdoor air. Also, you can get poisoned if you breathe the fumes from welding anything coated with zinc including zinc chromate primer. Have fun, but stay safe.

 

[SPIKER]

I suggest not listening to some of the posts here. You HAVE to by code wire the (in this case welder) per the plug being used. MOST welders use the 220v 3 prong 50 amp plug. (hot lead hot lead and ground no neutral.) also used to be referred as a stove plug. This is a 50 amp plug and the wiring feeding that plug MUST be approved to handle 50 amps continuous! if the welder needs it or not!

depending on the wire used you more than likely will need to use 6 GA wire. 8 ga is rated usually to 45 amps ONLY...

Mark M

p.s. I guess you don't HAVE to do anything, but if there is a fire and the insurance finds that there is something wired wrong that YOU did you are finishing paying the mortgage not them . also if you were ever SELL the place and the next inspector found this plug (this is a place that most home inspectors see a 50 amp plug they will WILL look to make sure the wiring to that plug was correct. it is same if you put in 20 amp outlets you have to by code use 20 amp rated wire (12 gauge that is)
so if you want to risk burning down the place then by all means wire the plug as you see fit. I say this only because most people think that doing electrical work is some thing that any tom dick or harry can do. and that is why every home needs to have an independent inspection done by the people LOOKING at buying it not the person selling it or the Realtor as the Realtor only gets paid if the place sell...

 

[machmeter62]

Note:: that each wire will carry the whole load not split as machmeter said>

What go's out one wire has to go back the other wire ground shouldden't be carrying any current.

tom

Not to create any confusion to the gentleman with the welder........this is basic "electricty 101".....the welder requires 220V! The least expensive way is to use two 110V lines (correct), so one can double the flow of amps from two sources to meet the welders requirement??? VOLTS=pressure/AMPS=flow

 

[machmeter62]

I suggest not listening to some of the posts here. You HAVE to by code wire the (in this case welder) per the plug being used. MOST welders use the 220v 3 prong 50 amp plug. (hot lead hot lead and ground no neutral.) also used to be referred as a stove plug. This is a 50 amp plug and the wiring feeding that plug MUST be approved to handle 50 amps continuous! if the welder needs it or not!

depending on the wire used you more than likely will need to use 6 GA wire. 8 ga is rated usually to 45 amps ONLY...

Mark M

Distance/volts/amps should determine the minimum wire size for a 35' run; and a #6 wire may not fit into the female receptable to match the welders....#10 wire is safe, but I would use #8. With a 50 AMP outlet at 220V-240V will handle 12.000 watts (Volts x Amps= Watts).

 

[tommu56]

Not to create any confusion to the gentleman with the welder........this is basic "electricty 101".....the welder requires 220V! The least expensive way is to use two 110V lines (correct), so one can double the flow of amps from two sources to meet the welders requirement??? VOLTS=pressure/AMPS=flow

Would you please explain to me how wire two 110v lines to get 220

When I went to schook it would requite a 2 pole breaker in the panel as it is a common source to a single receptical (both must be disconnected at the same time).
Take a curent reading on any 220v line on an item and the current Sill be the same on both legs.

Most homes that have 220v are center tapped to ground so ground to a leg would be 110v

so the current would go out one leg of the 220 and back the other 220v .

tom

 

[machmeter62]

Hello, I recently was given a 30a-230a dual range Craftmans stick welder. The front says primary 230 volts 50 amps single. I assume this means I will need to wire it to a 2 pole 50amp breaker. What I don't get is that the original 6 foot cord is labeled as 12/3 which I didn't think would handle 50amps so why would I need such a large breaker? For the spikes in current when starting the arc maybe? Seeing wire is expensive I only want to do this once, any thoughts on the guage of the wire? I'm thinkin 8/3 but want another opinion seeing I don't have alot of extra money for overkill. This is all in my basement running about 35 feet. Thanks,

MIKE: If you are still following this thread, this is what I would do first, depending on the vintage of your home. Check your main house electrical panel and see if there is space for a 220V/50AMP double circuit breaker....this will require two single spaces in the panel. If your panel is already full, the only safe alternative is to add a sub panel somewhere close to the main one. Then go from there, and ask further questions from others, including the electrical supplier for self confidence, if required? This should help you on the decision for the job?

This is, if you still are interested in (do-it-your-selfer?) I don't know your electrical experience; but would invest in an ohm meter before digging into main panel to verify the electricity is off!!! Turn it off at the meter for adding the CB or sub-panel.

The route of the wire will also be a factor. If you are running it through the exposed ceiling of the basement; Romex maybe legal for code there? If the wire is going anywhere else, and exposed; conduit may be needed, requiring stranded wire. Good luck, and I hope you didn't get more info than needed, or wanted?

 

[SPIKER]

Distance/volts/amps should determine the minimum wire size for a 35' run; and a #6 wire may not fit into the female receptacle to match the welders....#10 wire is safe, but I would use #8. With a 50 AMP outlet at 220V-240V will handle 12.000 watts (Volts x Amps= Watts).

yes 50 ams at 240 is 12000 watts. it has nothing to do with electrical code, I refer you to NEC 2008.

Wire ratings regardless of length of run require 6 ga wire for 50 amps in conduit. While free air ratings are different rarely will FREE AIR tables be used for any building wire... only wire which stands in "FREE AIR"

LENGTH of RUN does factor into the problem if he is running long distance from the power feed point then you must de-rate the wires listed in the NEC per foot of run per amperage through the wire only to get the voltage drop NOT amp load rating of the wire. Those are for allowable voltage drops per the run of cabling.

as for your 10 gauge wire it is only rated at 30 amps load and 8 ga wire at 45 amp load that is for THHN/THWN which has a better heat resistance than other types of insulation. More than likely the wire type used in home/bld construction is not THHN/THWN ect but Romex type materials. with both wires tightly wound inside a 2nd layer the heating can become worse when both legs are heating the same amount of insulation therefore the ratings for it are reduced. Again rating of the wire is per the item being wired, (in this case a 50 amp plug) just because he is probably not going to ever use the full 50 amp load does not negate the fact that the wire MUST be able to handle the load. also a 50 amp breaker can and will hold when it has 50 amps load on it the breaker is there to protect the wiring NOT the device plugged into the outlet...

thank you for helping though.

 

[machmeter62]

Would you please explain to me how wire two 110v lines to get 220

When I went to schook it would requite a 2 pole breaker in the panel as it is a common source to a single receptical (both must be disconnected at the same time).
Take a curent reading on any 220v line on an item and the current Sill be the same on both legs.

Most homes that have 220v are center tapped to ground so ground to a leg would be 110v

so the current would go out one leg of the 220 and back the other 220v .

tom

Tom: YES, a 220V CB has two poles/ also a common on/off switch. I agree with your thoughts for ground too.

All electricity, as I know must have a ground, or return to earth, our magnetic field too!

I am confused on one side of a 220V CB that returns electricity only.......please explain further on your thoughts? Both 110V lines are pushing
and the ground line is (pulling) returning it to earth.

 

[KubotainNH]

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?

 

[kennyd]

I suggest not listening to some of the posts here. You HAVE to by code wire the (in this case welder) per the plug being used. MOST welders use the 220v 3 prong 50 amp plug. (hot lead hot lead and ground no neutral.) also used to be referred as a stove plug. This is a 50 amp plug and the wiring feeding that plug MUST be approved to handle 50 amps continuous! if the welder needs it or not!

depending on the wire used you more than likely will need to use 6 GA wire. 8 ga is rated usually to 45 amps ONLY...

Mark M

p.s. I guess you don't HAVE to do anything, but if there is a fire and the insurance finds that there is something wired wrong that YOU did you are finishing paying the mortgage not them . also if you were ever SELL the place and the next inspector found this plug (this is a place that most home inspectors see a 50 amp plug they will WILL look to make sure the wiring to that plug was correct. it is same if you put in 20 amp outlets you have to by code use 20 amp rated wire (12 gauge that is)
so if you want to risk burning down the place then by all means wire the plug as you see fit. I say this only because most people think that doing electrical work is some thing that any tom dick or harry can do. and that is why every home needs to have an independent inspection done by the people LOOKING at buying it not the person selling it or the Realtor as the Realtor only gets paid if the place sell...

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