electrical requirements for Miller 211

[yomax4]

If you read the plate on the front of your 211 you will see that the output is not 211 amps. It's more like 150. I think a 40 would do it. Miller over rates most of it's integrated mig units.

 

[_RaT_]

Miller 211 rated is 150A at 30% duty cycle welding range is 30-210A. What this means is that the duty cycle is for 150A. The duty cycle will probably be less at full rated load which is what the maximum current draw is based on. A 240V/30 amp cicuit will be more than sufficient when you use the NEC duty cycle % table for computing wire size for welders. Yes, you can de-rate the wire when the wire is not continuously loaded. The maximum circuit size or breaker is determined by the manufactuer. Breakers today will withstand a short overload duration. Old breakers like the Zinsco style did not.

It would be interesting to put an amp probe on the 211 and look at the current draw for various current settings. Based on its duty cycle, I doubt you will ever get a #10 wire remotely warm.

Miller - MIG Welding - Millermatic® 211 Auto-Set? with MVP?

If you read the plate on the front of your 211 you will see that the output is not 211 amps. It's more like 150. I think a 40 would do it. Miller over rates most of it's integrated mig units.

 

[dstig1]

With a 24.3 A draw (per the OP) a 30A 240V circuit you could argue is technically overloaded as the continuous load allowed is 80% = 30x.8 = 24A, but that's splitting hairs pretty severely as it is only 0.3A over, and there is no way you could argue the welder is continuously loaded at that level as it has a duty cycle much lower than 100%.

If you have a special situation that you can't do properly with the correct outlet (like in your friends garage), make yourself a new plug for the welder or an adapter that you keep locked up so some moron or clueless individual can't use it for the wrong purpose. Then when you can finally bring the welder home, take the adapter apart so it never gets misused, and wire in the proper circuit and plug. This would be the practical solution, but make sure nobody else gets their hands on that adapter as fireworks will ensue (Murphy's Law and all that...).

Make your peace with what you are comfortable doing.

 

[_RaT_]

In the post above you can see the duty cycle is 30% for the Miller 211 at full operating current. This breaker is not going to trip even at full load. The 80% is a guide to ensure continuous load with no issues, that's 24 hours a day, 7 days a week. Even if the welder were rated 100% at the max load chances of tripping the breaker are small and its a simple issue of resetting the breaker and if nothing else modifying your weld time. On the other hand, I have yet to meet a welder so prepared he welds more than that! :laughing:

With a 24.3 A draw (per the OP) a 30A 240V circuit you could argue is technically overloaded as the continuous load allowed is 80% = 30x.8 = 24A, but that's splitting hairs pretty severely as it is only 0.3A over, and there is no way you could argue the welder is continuously loaded at that level as it has a duty cycle much lower than 100%.

If you have a special situation that you can't do properly with the correct outlet (like in your friends garage), make yourself a new plug for the welder or an adapter that you keep locked up so some moron or clueless individual can't use it for the wrong purpose. Then when you can finally bring the welder home, take the adapter apart so it never gets misused, and wire in the proper circuit and plug. This would be the practical solution, but make sure nobody else gets their hands on that adapter as fireworks will ensue (Murphy's Law and all that...).

Make your peace with what you are comfortable doing.

 

[dstig1]

Yeah.....like I said. I ran the math for the worst case code, and it is pretty much a no-brainer (unless your inspector is total puckerbutt). I suppose I could have said precisely that earlier, but I thought it was clear

You overstate your case for the 80% load rule. It is to allow start up in-rush current for some motor loads and random undervoltage in the mains, as well as just plain old safety margin, especially when you know exactly the fixed load that will be attached. It does not imply 24/7, though that won't be a problem following the rule.

 

[_RaT_]

Good points, with welders, you are allowed to oversize a breaker compared to the wire size based on the duty cycle and the chart the NEC book provides based on those duty cycles. Sort of the same idea behind running a larger breaker on a HVAC compressor. Maximum fuse size/minimum circuit size. One is for the breaker and the other for the wire size respectively.

Yeah.....like I said. I ran the math for the worst case code, and it is pretty much a no-brainer (unless your inspector is total puckerbutt). I suppose I could have said precisely that earlier, but I thought it was clear

You overstate your case for the 80% load rule. It is to allow start up in-rush current for some motor loads and random undervoltage in the mains, as well as just plain old safety margin, especially when you know exactly the fixed load that will be attached. It does not imply 24/7, though that won't be a problem following the rule.

 

[shade tree welder]

Miller over rates most of it's integrated mig units.

Unfortunately for the smaller consumer marketed units all welding manufacturers
have gotten into my D*** is bigger than yours rather than rating machines
being rated at 60% or 100% duty cycle as most industrial machines are.
I do not agree with it but it has been driven by the market.

Years ago most industrial machines were rated at 100%, they have gotten
away from that as no person or even robot can weld at 100% duty cycle in
a typical a production environment; 40-60% duty cycle is more realistic.

So even as a hobbyist or occasional user you need to look at what you want to
weld and size your machine accordingly.

40-60% duty cycle range
MM 211 - 100-125 amps
MM 212 - 150-188 amps
MM 350P - 300-350 amps
Deltaweld 302 - 300 amps at 100% duty cycle

The other thing to keep in mind that duty cycles are measured/rated at 40C
or 104F ambient temperature. So if you are welding in the cooler weather
and the ambient temperature of you shop is 60F you duty cycle will be
increased.

Like the others are saying, you don't pay for amps used, you pay for watts.

Watts = Amps x Volts

There are no deals when dealing with the electric company...

 

[beppington]

Watts = Amps x Volts

There are no deals when dealing with the electric company...

Well darn it :laughing:

I'm enjoying this discussion; I'm a noob who will be in the market for a welder soon, & will of course also want to connect it/ power it correctly.

 

[Luremaker]

Oh, I don't know about that. I don't see where generating your own would beat out 8-10 cents per kilowatt residential, to say nothing of overhead for equipment. I've been to some places in the Yukon where they would love such a deal.

Here in Ontario if I could buy electricity for 8-10 cents per kilowatt hour residential it would be a deal.

 

[_RaT_]

Your not tiered, that is, the more you use the higher the rate goes over each tier level? Do you not pay distribution and transmission charges? We start at about 10 cents a kilowatt hour, that does not include distribution and transmission charges and if your a big user, you can get as high as about 45 cents a kilowatt hour into the 4th or 5th tier. Its what they call "progressive rates" Reminds me of certain attitudes that permeate this state. I guess the good thing about huge electricity costs is that you can really justify installing solar power or you learn ways to conserve. My electric bill is about $170/month. I use far less than many of my neighbors. Very few folks use electric to heat their homes or their hot water, out here its just to costly. We use NG.

Oh, I don't know about that. I don't see where generating your own would beat out 8-10 cents per kilowatt residential, to say nothing of overhead for equipment. I've been to some places in the Yukon where they would love such a deal.

Update: I looked at my last bill and the basic rate was $ .070923 per kilowatt. With taxes and fees, it came out to $ .116844 per kilowatt. Sorry about the gross error of a penny and a half.