Lincoln AC/DC

I just got a new Lincoln AC/DC 225/125 for home use. Why is the duty cycle only 20percent on all taps? I thought that was the rating if maxed out. With my Miller I usually forget about a duty cycle and just weld until done with no problem. 20 percent doesn't seem like much welding and alot of waiting. Hope I didn't make a mistake.

I have one I have used for general farm repairs for at least two decades. It has worked fine. But, I use mostly Lincoln 6011 1/8". 90-100A. It seems to be "hot" and not take as much power as some others.

I'd say you got what you paid for.100% duty cycle machines are expensive.60% aren't cheap.I would say it has aluminum windings. I'd weld with it like I stole it, It should have a warranty. If it dies take it back.

For home use you should be just fine. I have the same welder and I've welded for long periods of time at fairly high settings without any trouble.

I wouldn't worry too much. I doubt you'll be using big rods but just do a weld, chip the slag and then do another weld. This will give a little cooling time between rods.

OK thank you everyone. I guess what threw me was the 20% duty cycle on all settings. I always thought as amperage goes up duty cycle goes down. And since I never need bigger than 1/8 rod for home figured I'd have plenty of duty cycle to work with. Anyway, I know they have a good reputation for durability and I feel better after listening to you all. Thanks for your help.
Bob

Bob,

If you open a Lincoln welder like the one you bought, you will see that the different amperage output settings are achieved by tapping different locations on the transformer with individual conductors which run to separate connection points on the back of the selector switch. Part of the reason that this welder has only a 20% duty cycle at every setting (except for the 75 amp setting which is 100%), is that the conductors are not all the same size. They run from the smallest conductors at the lowest settings to the largest at the highest. Since the duty cycle is a function of the amount of heat which is generated during use, using conductors which all generate approximately the same amount of heat per unit of time creates a situation where lower amperages do not result in a corresponding increase in duty cycle.

The situation is actually somewhat more complicated than I have described (a more complete explanation can be found in the archives of this site), but it is reasonably accurate---at least in its result. Lincoln 225 amp AC and AC/DC welders are famous for robustness. Many, many people report using them without regard to the duty cycle with no problems. While I wouldn’t go so far as to recommend that approach, I think you’ll find that the 20% duty cycle won’t pose a limitation for regular usage.

Stan

Thank you for the information Stan. I appreciate your help.
Bob

I don't think the 75 Amp setting is 100% duty cycle anymore.

My early 1970's era tombstone has the 75A setting circled, but new ones at Home Depot do not.

Lanse has a Longevity Stickweld 250 which has a 100% duty cycle up to 200 Amps if I'm not mistaken and 60% at 250 Amps. It's around $500, so not much more than a Lincoln AC/DC tombstone. It's made in China so if that's a problem for you it may not be an option.

My Lincoln has been pushed way past the 20% duty cycle on many occasions over the last 40 years and it's still kicking. The only problem it's had is the cooling fan went bad. I replaced it with a large 220V muffin fan from Mouser Electronics.

Thanks for the info. Good to know it seems alot of fellows say they are able to handle more than the 20 percent duty cycle. Ive read the owners manual and found it has a breaker protector for DC welding but not AC. So I guess if I push it too hard it will just shut off on DC. I see Lanse using the Chinese welders but can't bring myself to buy one.
Thanks Bob