40 amp breaker for a Millermatic 210 welder?

[RockcrawlingTJ]

Sorry if this is noobish, but I only know a little about electrical.

Can I use a 40 amp breaker for my Millermatic 210 welder? At my previous house I used a 50 amp, but the new place (until I upgrade my service) has a 40 amp breaker. I believe the wiring is 6 guage so I could upgrade to a 50 amp breaker though. I'm going to sandwich one of the 220v slots in the box (range/stove is the current 40amp). By sandwich I mean take out the 3" breaker and replace it with two 40 amp (or 50 amp) breakers. Or can I just leave one 40 amp for the range, and put a 50 amp for the welder? I'm going to run the wiring directly from the new breaker in the box to the garage.

Thoughts?

Thank you.
Justin

[Brandon]

I have 2 plugs in my wall, one is 30 and one is 50, both work fine

[jelbehai]

IIRC, the MM210 draws 30A - I believe that's what I used for my garage breaker, while I had a 50A for the line running from the main. Haven't tripped it yet anyways...

[RockcrawlingTJ]

Cool, from the sounds of it I should be okay so far. Would it hurt the box if I put a 40 and a 50 and used the 50 to run to the garage?

[PAToyota]

Not quite sure that I understand your term of "sandwich" with the breakers. If you mean pull out the current "double space" 40amp and put in two "single space" breakers in its place, that won't work because you are pulling out a 220V breaker and replacing it with two 110V breakers. You need the "double space" breakers for 220V.

[RockcrawlingTJ]

Thanks for mentioning that, it jarged my memory. I remember I cannot put two seperate breakers in its place, but they do make a dual double 220v breaker (if that makes sense). You pull the "double space" out and replace it with a "double space dual"...

[PAToyota]

Most of the dual breakers are 110V because each "position" on the panel only accesses one of the two hots. So you can get dual 110V breakers and then they are both on the same hot. But to have 220V you have to access both hots, which is why they are double width.

As a rule, I don't use the dual breakers so I must admit that I have not looked closely at all the variations available. Depending on your panel, you may be able to do a dual 220V breaker.

[willyswanter]

Thanks for mentioning that, it jarged my memory. I remember I cannot put two seperate breakers in its place, but they do make a dual double 220v breaker (if that makes sense). You pull the "double space" out and replace it with a "double space dual"...

Yes you can run a quad breaker. You will get 2 220 circuits out of the single "2 space" breaker. I use them almost daily. Just make sure you keep the common trip pieces in place and that your combined load won't pass the rated buss load.

[DarkEternal]

I ran mine on a 30 amp until just recently, I was only able to trip it when I had it cranked ALL the way up and used it to the max of its duty cycle.

[RockcrawlingTJ]

UPDATE:
Directly from Miller - the 210 is to be connected to a 30 amp breaker, as anything larger will not trip if something is wrong.

Justin

[Travis Waldher]

UPDATE:
Directly from Miller - the 210 is to be connected to a 30 amp breaker, as anything larger will not trip if something is wrong.

Justin

Really:

http://millerwelds.com/om/o1325j_mil.pdf
Reference Page 15

They recommend a 40A Breaker, UNLESS it's a time delay style circuit breaker, in which case 30A is ok.

[jasonmt]

Really:

http://millerwelds.com/om/o1325j_mil.pdf
Reference Page 15

They recommend a 40A Breaker, UNLESS it's a time delay style circuit breaker, in which case 30A is ok.


Even your linked manual recommends a 30 Amp BREAKER, the 40A recommendation is for a Normal Operating3 FUSE. Notice that application notes 2 & 3 are referencing FUSES.

[PAToyota]

Ummm... If you'll read the notes in the picture above you will see that for normal operating circuit breaker OR standard fuse you want 40amp at 230V. If you use a time delay circuit breaker or time delay fuse, then you can use 30amp...

They put the little numbers with the reference statements at the bottom there for a reason... :)

[jasonmt]

Ummm... If you'll read the notes in the picture above you will see that for normal operating circuit breaker OR standard fuse you want 40amp at 230V. If you use a time delay circuit breaker or time delay fuse, then you can use 30amp...

They put the little numbers with the reference statements at the bottom there for a reason... :)

The normal everyday HACR rated circuit breaker you buy for residential/light commercial use IS a time delay or inverse time type due to it having a thermal-magnetic trip element with the thermal element providing the delay.

Generally a circuit breaker that has ONLY a magnetic sensing element is a non-delay instantaneous trip type and doesn't work well with transformer based equipment due to the inrush currents associated with energizing the transformer.


Once you know and understand this the intention of the reference statement(s) is clear.

[u2slow]

What jasonmt said.

I have a Century mig machine with the same specs as the Millermatic 210. I run it on a 20A breaker with #12 wire to a plug right next to my sub-panel. I haven't been able to trip it yet. Your mileage may vary...

I know my wallet... and it doesn't like to buy #8 or #6 wire if it doesn't have to.

[jasonmt]

My electrical background isn't the strongest but I do wonder if some of the above posters fail to understand the difference in operation between a fuse and a circuit breaker why they post? It certainly adds no value and doesn't help RockcrawlingTJ at all.

[PAToyota]

You have three types of circuit breaker time delays: instantaneous, short time delay, and longtime delay. You also have delays on fuses: very fast acting, time delay, rejection type...

What's your point?

[Brandon]

I run my 210 on a 50' 10/3 wire, it won't trip the 30 or the 50 amp breakers but I thought they had built in protection? I was told by the tech guy at miller either breaker will be fine, they are for the spikes not for continuous operation and any spike will pop both a 30 and a 50. This topic is all over the millerwelds bulletin board though..