One more time - duty cycle.

[firedog]

Had to have another discussion with my 20 year old son about duty cycle.
He's been taking welding classes at the local college, working toward his certificate.
Been thru stick 1 & 2 plus some other classes. Now taking a TIG class. I bought a Miller Thunderbolt when he started and told him it would be his to keep when he got his certificate. He also has access to my Lincoln Ranger and 140 MIG machines.

He came and told me the other day he would have to by me another MIG machine. The gun lead caught fire at the machine.
Well, the machine is OK, I'll just have to replace the gun.
I knew exactly what he had done. Went out to practice laying bead on some 1/2" plate and had the machine turned all the way up. the cable burnt up right where it attaches to the sheath coming out of the machine.


Very important. I'm no professional by any means. Mostly self taught. But if your looking for a welding machine, it's something you need to consider. It's basically the amount of time in a ten minute period you can actually weld. My MIG has a rating of 20% at full bore. It's considered a hobbyist machine at best.
When looking to purchase, it's usually a balance of what you need and what you can afford. Typically, the cheaper the machine, the lighter the components, the lower the duty cycle. The machine may serve you well at first, but as you progress, and become more proficient at welding, the machine hasn't. Keep an eye on that duty cycle.

 

[Shield Arc]

For general fab work around the house, where you're cutting fitting, welding, cutting fitting welding, etc, etc, I would think 60% is OK. I've been on jobs where all you did for 8 to 10 to 12-hours a day for 6 to 7-days a week was pull the trigger, burning 70 + pounds of wire a day, now this is where you want 100% duty cycle. :laughing:

 

[Rock knocker]

Sounds like the gun was made poorly. Have you taken it back to the vendor? Most times the duty cycle of the guns appreciably exceeds that of the power source. They want the thermally protected machine to shut off prior to the gun melting in your hands

 

[Gary Fowler]

Unless you were pulling more current than the gun was rated for, the machine would normally shut down first. You shouldn't be using a gun rated for 100 amps on a 140 amp machine. Next time get a gun rated for 200 amps and you should be OK on the gun as long as you don't upgrade the machine.

 

[firedog]

Sounds like the gun was made poorly. Have you taken it back to the vendor? Most times the duty cycle of the guns appreciably exceeds that of the power source. They want the thermally protected machine to shut off prior to the gun melting in your hands

I've had the machine for several years. Very well could have been a defect in the gun, I just don't push the machine that hard. The machine protection did trip, but I agree it should not have burnt the lead up. The new lead came in Friday, haven't put it on yet.
My son was attempting to make multiple passes with a light duty wire feeder that just wasn't designed for that.

@ShieldArc. I agree, for my application this mig is quite adequate. Anything heavier, I break out the Ranger, its D/C is 100%.

 

[Gary Fowler]

If that gun was what came with the machine, I would go back to the vendor and try for a free replacement. It should have been rated for maximum use at the machines rated output.