New Millermatic 211 - power plug question

[Aukai]

This is my 100 amp separate feed TIG welder circuit, with a 50 amp plugin next to it. So if my wife turns on a light while I'm welding at max output the house circuit will trip, I only have 100 amps available. 200 amps is digging a trench, and changing to 4" conduit for underground utilities.

 

[Papa Charlie]

I just finished up a 20' 10/3 extension cord to get the plasma cutter out the back door of the garage. I buzzed out the cord before I plugged it in, then checked voltage. Both ends are NEMA 6-50 style, as is the wall receptacle. Since the garage is fed from the main house panel, neutral and ground are connected in the panel, so I get 125V between G and X or Y, right? I get 250V between X and Y.

Correct.

 

[Papa Charlie]

This is my 100 amp separate feed TIG welder circuit, with a 50 amp plugin next to it. So if my wife turns on a light while I'm welding at max output the house circuit will trip, I only have 100 amps available. 200 amps is digging a trench, and changing to 4" conduit for underground utilities.

That plug must have set you back a bit. I played that game in my garage in our last house. If I was running anything of any size in the garage, and the wife would have a heavy load from too many appliances running at one time, I would pop the breaker. Did not make her happy when that would happen.

When we get our new property, I plan to have at least 200amps from the utility, 100 for house and 100 for shop. Don't know what the impact, financially will be to go above that and if I would use that much more in the shop at any one time. Basically assume lights (15 amps), compressor (15 amps), heater or AC (20 amps) and one machine (30 amps) at any given time. Rough guessing. Haven't planned it out much farther than that. But now that you got me thinking about it.

 

[Flyinfool]

Back when I bought my house it had a 120V 30A SERVICE coming in (NOT a typo) for a 4 bed, 2 full bath house. 40 years ago a Common service was 220V 60A I paid the extra for a 100A, now 40 years later I sure wish I had gone bigger. We have popped the main a few times. BUt back then there was not a lot of electric gadgets to plug in. If I were doing it now I would seriously consider bigger than 200A. Like it or not electric cars are coming and will need to be fed.

 

[Aukai]

The way I found out I needed to rewire the garage:
I was using a 7" diamond cut off wheel on my grinder, and it popped the circuit breaker 3 times, I switched to a 4 inch grinder, and the job took an hour longer. When I went in the house my wife told me she needs a new blow drier, her's kept turning off, and on

 

[General Zod]

I've studied the formulas within the NEC regarding welders. The duty cycle of a welder is what [sometimes] permits using conductors smaller than would otherwise seem necessary for a resistive load operating at 100% Duty cycle. This is why [some] welding machines themselves have conductors smaller than they would otherwise seem to need. My TIG welder when operating at 350A only consumes 50A of 240V AC current, but the cord coming from the welder sure isn't 6/3. 10 awg conductors inside the cord going into the machine. Why? Because the duty cycle is about 35% at that level. When the welder 'cools off' (should the thermal overload be exceeded), so do the conductors supplying power to the machine.

This is where the I1eff amperage rating comes into play. As I've mentioned before, the I1eff is the calculated value that solely relates to permissible down-sizing of conductors due to the welder's duty cycle. Hypothetical example, if I1eff is 20A, it doesn't matter that the I1max (peak current draw) is 50A. You are permitted to downsize the conductors (if you wanted to) to 12awg. This is an extreme example where the welder would have a very, very short duty cycle actually pulling 50A (perhaps 8-10% duty cycle). Most welders have an I1eff rating somewhat close to their I1max, but it all depends on the duty cycle and the peak amperage draw while welding at full capacity.

The downside of using the permitted smaller conductors is that even though they handle the current for the allotted duty cycle just fine, they exhibit more voltage drop than larger diameter conductors.

 

[ACHiPo]

This is what I would do. I made a 25 foot extension cord for my welder it isn't hard, you just need to put a plug and receptacle to match your wall and welder.

+1 I have one for my welder, and one for my mill.

 

[ACHiPo]

This is my 100 amp separate feed TIG welder circuit, with a 50 amp plugin next to it. So if my wife turns on a light while I'm welding at max output the house circuit will trip, I only have 100 amps available. 200 amps is digging a trench, and changing to 4" conduit for underground utilities.

Solar and a big PowerWall?

 

[AllenV]

My solution to plugging my new Millermatic 211 into my shop with NEMA L14-30P receptacles was an 18-inch adapter cord. Here is a link to similar one with your plug ends.

search amazon for "Nema 14-50P to 6-50R heavy duty # AWG8 STW 50 Amp Plug to50 amp (welder) socket adapter cable"

Thought I'd offer this even though preference was stated above for DIY.

BTW, I don't think the 211 uses more than 20A. See the chart in section 4-2 of the manual.

BTW again, I bought a UL-listed 10 ft NEMA L14-30P extension chord as well. My thinking is that most of the time the 211 is quite near a wall receptical and I'd rather not be tripping over a bunch of extra power cord. When I am in the far corner I can add the 10 ft extension.