Welder / Wiring for Small Garage

[MAX-24-Dean]

From the 2020 NEC the section you would like to look at in article 110.14.(C) is titled "Temperature Limitations".
Also, along with article 110.14.(1) titled "Equipment Provisions".
You will want to flip between the "Equipment provision" section and the Ampacity Tables at article 310.16 and pay attention to the columns of "temperature ratings for conductors".

 

[UncleW]

From the 2020 NEC the section you would like to look at in article 110.14.(C) is titled "Temperature Limitations".
Also, along with article 110.14.(1) titled "Equipment Provisions".
You will want to flip between the "Equipment provision" section and the Ampacity Tables at article 310.16 and pay attention to the columns of "temperature ratings for conductors".

Thanks! I see where you’re coming from. I always thought “equipment” terminations applied to stuff like pumps, motors, etc. I took that into account when I had to upsize my wire to my irrigation pump due to high ambient temperature and the temperature rating of the terminals on the pump.

So I was thinking that a receptacle that’s 6’ away from a heat source like a welder would be rated on the temperature of the receptacle (=ambient as long as the connections are properly torqued) vs the connection of the power cord to the welder, which would get hot. But hopefully the manufacturer took care of that

I didn’t wade through the whole chart in 310.16, but at least for 8ga wire, it looks the the Cerrowire chart. Not looking at it right now, but I don't think the Cerrowire chart accounted for ambient over 86F. I try to avoid welding any time it’s over 86F, but I’ll ponder that

Interesting stuff. Terminal temperature might explain some of the the code stuff around hard wired EV chargers, cause for sure they’re “equipment” and all that power conversion magic is bound to generate some heat

Thanks again!

 

[grsthegreat]

Unless the termination point has printed 75c rating stamped on it, you have to assume its 60c rated.

 

[UncleW]

Unless the termination point has printed 75c rating stamped on it, you have to assume its 60c rated.

Good point! I looked up the specs on the 6-50 outlet (Leviton IIRC but might have been Hubble) and it was 75C. Other ones from Home Depot, Lowes, Amazon may not be 75C rating so you do have to check! Same with the breaker!

 

[grsthegreat]

The breakers are usually the sticking point in older panels. Heck, even some new breakers arnt rated 75°c.

 

[DaBear3428]

heat dissipation is the issue and the termination lugs have to stand up to the heat transfer as well as the junction between the conductor and the lug. in this case the insulation on the wire is just fine at 75C and will stand up to the current flow but the lug will overheat and become a high resistance point causing more heat to be generated etc. bottom line is a run away event where the end of the conductor loses insulation and the lug becomes unusable leading to a thermal failure.

 

[DaBear3428]

Thanks! I see where you’re coming from. I always thought “equipment” terminations applied to stuff like pumps, motors, etc. I took that into account when I had to upsize my wire to my irrigation pump due to high ambient temperature and the temperature rating of the terminals on the pump.

So I was thinking that a receptacle that’s 6’ away from a heat source like a welder would be rated on the temperature of the receptacle (=ambient as long as the connections are properly torqued) vs the connection of the power cord to the welder, which would get hot. But hopefully the manufacturer took care of that

I didn’t wade through the whole chart in 310.16, but at least for 8ga wire, it looks the the Cerrowire chart. Not looking at it right now, but I don't think the Cerrowire chart accounted for ambient over 86F. I try to avoid welding any time it’s over 86F, but I’ll ponder that

Interesting stuff. Terminal temperature might explain some of the the code stuff around hard wired EV chargers, cause for sure they’re “equipment” and all that power conversion magic is bound to generate some heat

Thanks again!

it is not the welding heat that is the issue it is the resistance of the wire in combination with the thermal insulating/conduction of the insulation. welders are not as big of an issue do to the fact that most do not support 100% duty cycle (duty cycle for a welder is the percentage of time in a 10 min window that the welder can perform at a specific load, most being 60% or less at full load so most circuit breakers are 80% rated leading to some engineering margin.
EV chargers are not subject to this and operated at rated power for hours on end so a 50A EV charger outlet is a lot more serious than a 50 welder outlet

 

[UncleW]

it is not the welding heat that is the issue it is the resistance of the wire in combination with the thermal insulating/conduction of the insulation. welders are not as big of an issue do to the fact that most do not support 100% duty cycle (duty cycle for a welder is the percentage of time in a 10 min window that the welder can perform at a specific load, most being 60% or less at full load so most circuit breakers are 80% rated leading to some engineering margin.
EV chargers are not subject to this and operated at rated power for hours on end so a 50A EV charger outlet is a lot more serious than a 50 welder outlet

This particular Lincoln 50 amp welder has a 20% duty cyle. The instructions below say to use 10 ga wire with a 50 amp breaker. I looked at section 630 of the NEC, and that’s allowed because of the arc welder duty cycle adjustment. Would be a disaster waiting to happen if an EV got plugged into that installation

I ended up putting my welder outlet right next to the panel in the garage. 50amp, 75C or better components & 3 feet 6ga wire. EV code requirements keep changing, but at least it wont melt anything if one gets plugged in

Found an 8 ga extension cord that was cheaper than wiring all the way to the garage door. Will be fine with my particular welder amp draw and duty cycle

 

[5030]

Understand a couple things... The 210 is a transformer machine (I happen to own a pair of them) and they will certainly operate at full output on a 30 amp 220 circuit. The drawback is they are heavy. The advantage of a transformer based machine is a very smooth wire feed arc and excellent wet out. In fact, both of mine are excellent machines and I run them hard in a semi production environment.

Having said that, there are better and less expensive choices out there today. Would I sell mine? Not a chance but if I was in the market for a new MIG welder, I wouldn't buy them in as much as there are better choices out there today.

The multi process welder is an IGBT inverter machine, you can tell that by it's weight. IGBT inverters eliminate the heavy transformer and are much more electrically efficient but that comes at a price and that is, running in MIG, they won't be as user friendly concerning wet out and arc stability when running in MIG mode.

I also see the multi process welder don't come with a foot pedal, you need that to run TIG and neither of them have what I consider a good gas regulator. I much prefer a ball type regulator where you can actually see the gas flow over a needle gage and neither of them are 'fan on demand' which today is basically an industry standard. The issue with any machine where the cooling fan runs constantly is dirt getting sucked in by the cooling fan and getting deposited inside the cabinet and eventually causing issues. I take t he covers off both my Hobarts and blow them out inside regularly. What I did to mitigate the issue somewhat is, I added external filters over the fan intakes. That helps but they still suck in some dirt in the shop when running.

I will at some point, convert them both to 'fan on demand'. I have the adjustable snap thermostats on hand, just have to modify them both.

30 amp 220-1 will run them both no issue. Cannot speak for the wire gage as I had my electrician do my wiring.

I will say that neither machine will run satisfactorily on a 110-1 circuit.

Efficiency wise, the IGBT inverter machine will be much more economical to run but then I would not purchase that machine anyway as there are much better machines out there that will include everything, including the foot pedal for a much better price point.

I have no idea why you favor the Hobart and really don't concern me. All I know is that Harbor Freight offers a much less (and more complete) multi process machine(s) that are IGBT inverter based and have things like fan on demand and come complete with everything for a lot less jack.

I have 2 of the HF machines, one multi process and one TIG only and both have a 3 year warranty on them.

If you are going to run flux core, then no shielding gas is required but if you going to run solid core wire and are contemplating TIG, you need a shielding gas bottle for the MIG (75-25) as well as a 100% argon bottle to run TIG.

I suggest buying the bottles rather than renting them. Weld fabulous sells full bottles of both on their website and I have them in both flavors, 120 cubic feet. They are somewhat costly to buy but that beats any rental fee in the long run plus my LWS fills them no issue. I actually have 2 120 Cubic Feet 75-25 and 2 120 cubic feet argon bottles in the shop. One bottle of each on the welding cart and 2 spare bottles in the corner. Nothing worse than running out of gas in the middle of a job.

 

[UncleW]

I’m surrounded by opportunities

I have the AC welder, a DC inverter stick welder, and an oxy-acetylene rig. Gave my MIG/argon welder to my son in law cause I didn’t use it much with all the other options. The AC welder will do 220 amps if I need it for really thick stuff, which my inverter won’t, so it’s worth keeping around.