Wire Length and Gauge

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yamiacaveman

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Looking to run a wire to the other side of by barn to run run a small stick welder rated at 27.8 amps. My question is; when all is said and done about 85 feet of wire is needed, would a 10/3 on a 30 amp breaker be OK? Or your suggestions.
 
I don't know much but I did a similar span and both electricians recommended a #10 for 220v?

Not questioning your experience but I'm wondering why the difference?
 
27.8A on a 30A circuit? Your going to have to up the breaker and wire size and then limit the ampacity with fuses in a disconnect.
 
I don't know much but I did a similar span and both electricians recommended a #10 for 220v?

Not questioning your experience but I'm wondering why the difference?

That's ok. I always budget for contingency, so, a 30A-240V is 15A each leg and 12ga. is 20A rated, which exceeds the 20% safety factor.
 
The wire length and the voltage drop is a factor because of the change in resistance. Knowing the real current draw is something I would want to know if trying to cut that close with a 30a circuit.
 
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I don't know much but I did a similar span and both electricians recommended a #10 for 220v?
Not questioning your experience but I'm wondering why the difference?

It is not the voltage that dictates the wire gauge but the amps. You can run 240v on #12 or even #14 gauge wire safely of course depending on the implementation/use.
 
Good info. Thank you afjes!
 
You are welcome havasu

Many people are confused or thrown off by that.
 
Why 110 volt at 27.8 amps ?
I would definitely run 220 volt at 15 amps .
you there could easily use # 12 wiring.
 
billshack
Why 110 volt at 27.8 amps ?
I would definitely run 220 volt at 15 amps .
you there could easily use # 12 wiring.

Even if it is a 120v welder you can't just hook it up for 240v so you can use a smaller gauge wire. That is unless it is stated on the nameplate that it can do dual voltage but even then you have to go according to the name plate rated amps. If it is dual voltage then you still have to go according to the amperage. Overall amperage dictates the size of the wires/conductors - not the voltage.

yamiacaveman still has not even confirmed that it is a 240v welder but we can assume it is.
Even if it is 240v at 27.8 amps using #12 is not wise and is dangerous.
 
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Ok for some reason cut and paste is not working today, lol.
Hobart 160i welder.
Input Welding Amp Range Rated Output Amps Input at
Rated Output

Power
120 V 20–80 A 65 A at 20% duty cycle 20.7
240 V 20–160 A 160 A at 30% duty cycle 27.8
 
Basically your welder has two power cords you can swap out 120v/240v when the 120v is plugged in it limits the output current to weld making the welder more versatile if you take it someplace and they only have 120v supply. You can still weld just not as heavy gage and rod.



I would think for a install where you will be mainly using it you want to run the 240v supply and that will draw 27.8a at a duty cycle of 30% and that will provide 160a draw at the weld rod for some pretty good welding ability.



A 30a 240v supply would be the minimum IMO. If you can jump to a 40a 240v supply sizing the wire up for that distance you will have larger safety factor and benefit from a lesser voltage drop with the larger wire, maybe a larger welder in the future etc.



If you wanted 30a protection at the end of the run you could fuse it at that end in a disconnect box. I would want a disconnect there anyway so you can kill the 240 before you plug in.



The pros here can review my suggestion.



Here is the PDF to the specs on your welder.

https://images-na.ssl-images-amazon.com/images/I/911NTbl-znL.pdf
 
So there is a ton of misinformation in this thread that is downright scary. The people giving electrical advice that aren't trained electricians need to stop before you create big problems.

Bud16415 and Afjes are giving you good info.

Here's what you are looking at : If you are running the wire in Romex the max amperage on a 10 wire is 30amps. If you run it in EMT or PVC and use THHN the #10 wire will give you up to 35amps. The diagram shows that it plugs in I think I saw, so that can act as your means of disconnect. Or you can put an actual subpanel/disconnect and you will be covered that way.

The first question that I'd ask you if you called me is "What are you comfortable spending? Is this something you will use daily or every now and then?"
I can give you more advice if you still need it but I'd want you to answer those two questions first.

Please don't do any electrical work that you aren't 100% confident in your ability to do. And please do not take electrical advice from just anyone. The posts above that were telling you that anything 240v can run on a #12 wire is so far from correct that I don't even know where to start. Like Afjes said above, the gauge of wire you use is purely based on the Amps being produced. Think of voltage like pressure in a water hose. More pressure the more water flows through the pipe. Except in electric it's electrons flowing through the wire. Amps are the "power" produced. We always see "High Voltage warning" on signs but actually it's the amps created that kill not the voltage.

Anyway, hopefully you can get everything working properly. I will try to check back in here and see if you need any help. Good luck.
 
Thanks for all replies.

So to try to answer your questions SlimSavage, it is not something I plan on using daily, it's basically for my farm equipment in case of a break down that needs to be welded and I would be happy to never use it at all. As far as the money part goes -- so if I was building a house and rafters were 2x8 which was OK but 2x 10's would be better, I'll pay for the the 2x10's knowing it would cost more but I would not have to worry in case of a heavy snow load, and 2x12 would be an over kill.
So I would rather go bigger than minimum, but not an over kill, suck up the cost, once and not have to worry it.
40 amp breaker, with an #8 or #6 or what other type of wire size or breaker?
Again, thanks for any help.
 
It sounds like you have a good idea what you need now.



If it was mine and again I’m not a pro electrician just a guy like you that does his own work with some electrical background.



I would put a 40a breaker in the main panel given you have ample capacity and an open slot for it, I would run my 85’+ of #8 AWG copper Romex to the location of the welder. There I would put a 240v safety disconnect switch with fuses sized at 30a. Coming out of that I would place a compatible outlet for the welder. These safety disconnect switches will allow you to have the power on at the main panel 85’ away and still have it shut off when you plug and unplug your welder. It will also allow you to put a padlock thru it in the off position to keep people you don’t want messing around with it if you want.



What isn’t clear is how long the cord is on your welder it looks like it has a short adapter that lets you select voltage. If it were mine I would make a long #8 extension cord. With working on farm equipment you will likely taking the welder to the work not the other way around. That cord you want stranded rubber flexible line that you can drag around and will stand up.



There are two ways to make the extension first a male/female extension and the second would be to connect it back into the safety disconnect switch and then coil it up and hang it on the wall when not used.



On mine I lengthened the welder ground and lead and made my long extension part of the welder and I have my welder mounted on a cart that I can roll around the shop and out into the driveway. On a rare occasion I will lift the welder off the cart to get close enough to my work, 99% of the time it stays on the cart with the rest of my welding tools.

Just a few things to think about how you want to be setup
 
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