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Old 02-26-2005, 12:07 AM
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X-ray X-ray is offline
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Default Duty Cycle #'s

At 300 amps load current:

Powermig 350MP 60%
Linde VI-206 44%
Migmaster 250+ 35%
Powermig 255 28%
Millermatic 210 17%
Hobart 210 10%



I do not know if all of these machines can produce a load current of 300 amps I am just plugging #'s into a formula.

Last edited by X-ray; 02-26-2005 at 12:29 AM.
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Old 02-26-2005, 12:26 AM
Franz Franz is offline
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First, the damn yellow numbers are hard to read when yer an old fart.

Duty Cycle= very simply put, is the number of minutes you can actually weld at full machine output in a 10 minute time period. 20% would be 2 minutes out of 10 and 90% would be 9 minutes out of 10.
At lower settings than full output, the duty cycle of the machine increases, in large part because the machine is creating less internal heat that has to be carried off to the atmousphere by the cooling system.

Unless you're running production, Duty Cycle rarely comes into play. Someplace in the long ago distant past, I read something that said if a weldor is actually welding 30% of the time in a given day, he's doing well.
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Old 02-26-2005, 12:33 AM
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Yeah sorry about that Yellow color thing Franz, just playing cute.
Dug up a formula that I think helps even the playing field when doing 'paper comparisons'.

Here is the formula in case I got an F for the math.

% Duty cycle= [(rated current)² ÷ (load current)²] x (rated duty cycle)
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Old 02-26-2005, 01:40 AM
Franz Franz is offline
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Just what in the he!! are you trying to figure out?
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Old 02-26-2005, 02:02 AM
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Quote:
Originally Posted by Franz
Just what in the he!! are you trying to figure out?
Me nothing, no $$ to buy any new welders, just another tool that the welding consumer can use to form a more objective 'competitive comparison'.

I just scrounged this %duty cycle formula up, because over on the 'mig bead' thread a point came out where one machine was rated at 100% and the other at 60%.
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Old 02-26-2005, 02:03 AM
Mike W Mike W is offline
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Damn Franz, my back is killing me and you made me laugh.
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Old 02-26-2005, 02:17 AM
Franz Franz is offline
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Quote:
Originally Posted by Mike W
Damn Franz, my back is killing me and you made me laugh.
Have you ever tried sneezing, or coughing, with your brest bone wired together?
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Old 02-26-2005, 02:20 AM
Mike W Mike W is offline
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No, you got me beat there. I am real careful of coughing.
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Old 02-26-2005, 02:21 AM
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Franz, Took me over a month to be able to wear a shoulder belt without looking to kill something/someone. Used to sleep on my left side...been close to 14 months now and I still can't get comfortable on that side. Least the leg they "jerked" the vein out of doesn't hurt like the devil anymore. Good luck and hope you have a speedy recovery.
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Old 02-26-2005, 11:09 AM
JTMcC. JTMcC. is offline
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Quote:
Originally Posted by Franz

Duty Cycle= very simply put, is the number of minutes you can actually weld at full machine output in a 10 minute time period.

I have to disagree, duty cycle isn't tied to "full machine output", it's rated at a "given" output.

A machine will have duty cycle at any output from it's minimum up to max output. And I'm not aware of a machine that is rated for a duty cycle at it's max output. For example my old Classic II is called a 250 amp machine and is rated at 60% duty cycle @ 250A. The machine will put out somewhere around 325A with the dials twisted up all the way. The duty cycle on the machine @ 200A is 100%, @300A it's 40%. That's usefull information. I know I'll never strain the machine running in the 200A area but is I have much work in the 300A range I'd better be carefull, and maybe look at a bigger machine.

You can't put a number on what percentage of the day a welding machine is actually welding unless you consider the job being done. There is no across the board figure that will be acurate in varying trades/situations. You may not have need to run a machine but 30% of the work day but I certainly do.


NEMA sets the standards, or used to, in rating machines.


JTMcC.
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Last edited by JTMcC.; 02-26-2005 at 11:24 AM.
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