Duty Cycle Graphs or Charts?

[JHC]

I know all the machines have a duty cycle listed for a specific current. But is there a graph or chart to show duty cycles at different currents? This would be very helpful, not only for selecting a machine but also for using a machine.
Thanks

[Slick]

http://www.kitcarinfo.com/welder/welder.htm


the guy is tonyF on here, I dont know if it would be the same for other machines or not.

[trackmaster]

Hey there JHC, ..... Ya know, i don't know if ya really need to get too isoteric about or with the duty cycles per say. They're really disclosed to more help you choose a machine that will handle your particular requirements, ie ( what is the MAXIMUM welding current you anticipate needing, along with, are you a hobbyist/light occassional fab work, or do you need those amps in a daily PRODUCTION situation.

If you buy a machine that has a 60% duty cycle at say a rated maximum 250 amps, and you almost always weld at 200 and below, or even far below that, and/or you are not doing piece work that someone is feeding you, pre-fitted and prep'd, you are simply not ever going to have to even think about the duty cycle because your going to be at or very near 100% all the time. Just weld away! Remember every time you shut off the arc the rest time is counting, and all the small pauses and repositioning your torch add up.

On the other hand if you anticipate doing production welding at or near 250 amps, then the take home point is that you need to buy a larger machine!
You see? It's really about making sure you have adequate margins. If your having to really break it down that finely, then you need a bigger or heavier duty unit! I've been welding professionaly 30 some years, and never given it that much thought. If your stuck money wise with a unit that is less capable than you really need, or you have a unit with a lower duty cycle % and your concerned about exceeding the duty cycle, then just assume your are at the maximum, and in my example unit, give the machine 4 minutes or so rest for every 6 of CONTINOUS welding. Then when ya can, go get you self a bigger welder!

[performance]

Which type unit were you considering? I can give you points of 60 and 100 amps.

[everlastsupport]

JHC,

Trackmaster summed it all up in post #3.

If you still have questions and want to call tech support, Mark or I can go over what we recommend for the type welding you will be doing. But as said, if you need 200 amps or less, get a 250 unit. You will have 100% or darn near at 200 all the time. Allow +25-30% for aluminum in your choice if needed. But 200 AMPs is a lot of power.

[patf]

Current = rated current squared x rated duty cycled divided by desired duty cycle then take the sq root of that to have the current.

try this, a 400 amp machine has a 25% duty cycle. What is the amp output at 50% duty cycle

(400A)2 x (.25) divided by(.50)duty cycle =160 x (0.5) =80,000 sq root = 282.8 amps at 50% duty cycle

Pat


note the (400A) 2 is 400A squared

hope this helps. I found this in a thermal arc owners manual

[performance]

And what mathematician figured that out?

[geezer]

Charts and graphs for duty cycles don't mean squat, assuming all manufacturers used ambient temperature (say 72F) to test their machine then the duty cycles have some meaning when comparing one to the other.
But a guy in Florida will always come up short in run time compared to me in Alberta, Why? cause last night it was -43 Centigrade with the wind chill, I could have welded all night at those temps and the machine would never have overheated.

Want to make you machine have a longer duty cycle park it infront of an airconditioner, want it have a shorter one put your tool box in front of the fan to restrict the air flow.

Heat is the killer when it comes to a duty cycle, get rid of the heat and the duty cycle gets better. Everlast welders have large heat sinks and large fans that pump out the heat, that's why they have a good duty cycle.

[woodchuck]

Charts and graphs for duty cycles don't mean squat, assuming all manufacturers used ambient temperature (say 72F) to test their machine then the duty cycles have some meaning when comparing one to the other.
But a guy in Florida will always come up short in run time compared to me in Alberta, Why? cause last night it was -43 Centigrade with the wind chill, I could have welded all night at those temps and the machine would never have overheated.

Want to make you machine have a longer duty cycle park it infront of an airconditioner, want it have a shorter one put your tool box in front of the fan to restrict the air flow.

Heat is the killer when it comes to a duty cycle, get rid of the heat and the duty cycle gets better. Everlast welders have large heat sinks and large fans that pump out the heat, that's why they have a good duty cycle.

Geezer that has to be the only good reason I've ever heard of for the winters we endure here in Alberta.

[geezer]

Wood Chuck, that's my point exactly, sure the nice people in Florida have the sun and the beaches with all the beautiful ladies. but they don't have the DUTY CYCLE we have up here, I think I will check to see if I plugged my truck in.

[woodchuck]

I think I'd exchange a little Duty Cycle for a few of those other things Geezer.

Stay warm, Chuck