question about duty cycle

[HCJtractor]

I have a Miller 211 Mig that I am learning on . I understand the concept of duty cycle, but am unsure what happens to this particular welder when it is exceded. Does the arc just weaken and you just sense a lack of power? Or does the machine have an automatic cut-off or signal that it is time to stop and let things cool? In other words, how do I know it is time to slow down and wait? I hate to ask stupid questions but hey, I admit I am clueless. Thanks to you guys who are willing to share your knowledge!

 

[dcyrilc]

I have a Miller 211 Mig that I am learning on . I understand the concept of duty cycle, but am unsure what happens to this particular welder when it is exceded. Does the arc just weaken and you just sense a lack of power? Or does the machine have an automatic cut-off or signal that it is time to stop and let things cool? In other words, how do I know it is time to slow down and wait? I hate to ask stupid questions but hey, I admit I am clueless. Thanks to you guys who are willing to share your knowledge!

If I remember correctly, it should have an automatic cut-off.

Yep, it does. Found it on my spec sheet:
"Thermal overload protection shuts down the unit and activates over temperature light if airflow is blocked or duty cycle is exceeded. Automatically resets when fault is corrected and unit cools."

 

[dcyrilc]

How do you like your 211? I keep bouncing back and forth on buying a Millermatic 211 or an Everlast I-Mig 200.

 

[JD Greg]

How do you like your 211? I keep bouncing back and forth on buying a Millermatic 211 or an Everlast I-Mig 200.

I've got the 211. I love it.
Had a Lincoln 135P, 110v prior to the 211.
There is no comparison. The 211 will do most
everything that I will ever want to do with it.
I have welded 5/16" steel with no problems. I
know that I could even do heavier steel, just haven't
had that opportunity. I mostly just make my own
repairs and some light fabrication.

Greg

 

[JB4310]

I've had inexpensive, low duty cycle stick machines all my life, never paid any attention to the duty cycle, never stopped welding cause I thought I was going over. No worse for the wear as far as I can tell? I'm sure the modern MIGs may be more susceptible and have some type of built in protection.

JB

 

[Soundguy]

all my machiens cut out when duty cycle is exceeded.

soundguy

 

[IXLR8]

How do you like your 211? I keep bouncing back and forth on buying a Millermatic 211 or an Everlast I-Mig 200.

[Hijack]
I am going through the same debate. Everybody who has the 211 loves it, all who have the I-Mig love it. I suspect you can't do wrong with either. For me it comes down to... do I want have a relationship with a local vendor for supplies/service (Miller) or save money, have more features, 1/2 the weight, but need ship unit out for service if needed, mail order consumables. (Everlast) I'm getting tired of doing the pros/cons, I am about to toss a coin.
[/end Hijack]

 

[MrBobcat230]

I also have a Miller 211 and I can say I love it also. I had a lincon sp 100 it was a nice little welder but nothing compared to my 211. Glad I bought the Miller. On the question of duty cycle as others have said it will shut down but, leave the power on so the fan keeps running. I welded up a tube for my bucket 68'' long almost continuously. The ground cable got a little warm but, it never shut down.

 

[yomax4]

If you read your manual on the 211 or any other welder it will tell you what your duty cycle is. The 211 is probably 20-30% at 211 amps or 30-40% at 150. It just means how many minutes out of 10 you can weld before the machine starts to heat up internally. 30% = 3 minutes out 10 arc time. Dont worry about duty cycle until it gives you a reason to. Then you will live with what you get or you will buy a more industrial type machine.

 

[dcyrilc]

If you read your manual on the 211 or any other welder it will tell you what your duty cycle is. The 211 is probably 20-30% at 211 amps or 30-40% at 150. It just means how many minutes out of 10 you can weld before the machine starts to heat up internally. 30% = 3 minutes out 10 arc time. Dont worry about duty cycle until it gives you a reason to. Then you will live with what you get or you will buy a more industrial type machine.

150A at 23.5VDC, 30% Duty Cycle (230V)
90A at 20VDC, 20% Duty Cycle (120V)

 

[Mark @ Everlast]

At max amps, I think that the duty cycle fades to about 10% on the 211.

 

[HCJtractor]

The reason I asked is that I was welding recently (on 120 V as there was no 230V available) and it seemed to start losing power, still arcing, but just weak. I guess I needed to wait, but I just wondered if there was any indication (other than loss of welding power) like a overheat light, machine cut-off, etc. that would alert the user to wait. The manual is vague in this respect, and my machine was still running, no lights were on, so I was not sure if what I was experiencing was a duty cycle issue. The manual states that exceeding the duty cycle can damage the welder, but how do you know you have exceeded it if no warning lights come on or the welder does not have a shut off? When I am welding in a stop and go manner, it is hard to tell how many minutes are spent welding vs. how many minutes rest time. I understand duty cycle and know duty cycle is lower on 120V, but just wondered on my specific welder, if the machine protected itself automatically.

 

[Soundguy]

duty cycle tripping should stop the machine.. not make it limp...

soundguy

 

[Mark @ Everlast]

It is possible that the sensor was not working. It has a very low duty cycle at low amps while on 110V. But if they unit does not have a separate sensor, depending upon how it is setup, it may not be tuned for the 110V specifically...though you would expect it to from Miller. IF you were welding on an extension cord or something, the cord could be heating up and power input could have dropped. Or if your circuits were wired with aluminum, the same could happen.

 

[fabberd]

The reason I asked is that I was welding recently (on 120 V as there was no 230V available) and it seemed to start losing power, still arcing, but just weak. I guess I needed to wait, but I just wondered if there was any indication (other than loss of welding power) like a overheat light, machine cut-off, etc. that would alert the user to wait. The manual is vague in this respect, and my machine was still running, no lights were on, so I was not sure if what I was experiencing was a duty cycle issue. The manual states that exceeding the duty cycle can damage the welder, but how do you know you have exceeded it if no warning lights come on or the welder does not have a shut off? When I am welding in a stop and go manner, it is hard to tell how many minutes are spent welding vs. how many minutes rest time. I understand duty cycle and know duty cycle is lower on 120V, but just wondered on my specific welder, if the machine protected itself automatically.

That's not duty cycle that is doing that.

Mark hit on the head in his post. It's your wiring.
You're exceeding or at the limit of your electrical wiring or extension cord.

When you exceed duty cycle, the machine will stop welding. The fans will run to allow cooling, but you'll get no arc until it resets.

 

[HCJtractor]

thanks for the info!!

 

[Ford tractor]

duty cycle tripping should stop the machine.. not make it limp...

soundguy

"should" is the operative word. I've used several that would limp and give poor penetration for a while before finally stopping. It's VERY frustrating to have to go back and grind of the last 5 min of weld.

 

[Soundguy]

weird.. almost sounds like a thermal overload in the wireing.. vs a limp mode.

soundguy

 

[Mark @ Everlast]

As older transformer machines with out duty cycle interupts and units like the tombstone stick welders, the hotter they get, the weaker the spark.

There is another factory possibly, the contact in the switch could be corroded. The place where there is possibly the most resistance to flow of electricity is at the contacts in the voltage selector. If the unit is in a humid or corrosive environment, this could cause a weak spark once the contacts start heating up.

 

[Shield Arc]

This duty cycle thread is very interesting to me. I've never hit the duty cycle in any machine I've run. I must have lead a very sheltered life. I do pay attention to the duty cycle when buying a machine, but never hit it, and I've run machines at 500 to 600-amps for 10 to 12-hours days for months at a time. Had to replace the Tweco fittings in the leads every morning, and still didn't hit the duty cycle! :laughing: