[metlcre8or]

I have a Miller Synchrowave 200 TIG that only works part-time. When I took it to the local Miller repair shop, they said,"why didn't you get a Synchrowave 250?". After they went through it and found nothing wrong, I used it for a few hours and it was back to giving a very weak arc. I know there is nothing wrong with my shop power, and my grounds, settings, tungsten, and metal are good because they haven't changed. Just all of a sudden the damn thing quit melting metal -- wouldn't even melt the filler rod! This has happened with AC, DCEN, Pulsed, Non-pulsed, mild steel, aluminum, and stainless, and amperage changes have no effect. After setting for a few days, it will work for an hour or two before dying (usually in the middle of a weld). I have other trouble-free Miller, Lincoln, and "brand X" welders in my shop, but this unit has me pulling my hair out (and I don't have that much left). After talking with other Miller TIG users, I find that this isn't a rare experience.

Has anyone else had this problem? If so, what was the (or is there a) fix?

[Sarge]

Buy a Red one??? Is your cooling fan running when it kicks off?

[metlcre8or]

Sarge,

That's the conclusion I have come to. I have had next to no trouble with any of my Lincoln welders, but all of my other Miller welders work great too. This one has really soured me against Millers though.

The fan does still run. It's as if it is in pulse and stuck in an "off" state where it gives an arc but no heat. This happens whether in pulse mode or not.

Thanks,
Bill

[Sarge]

I have tested the syncorwave 250 and it was ok, but it kept shutting down for overheat due to duty cycle. (I had a LOT of long aluminum welding with long beads to do) I could weld for about 40 minutes on the first bead then about 10 minutes at a time between thermal shut downs after that. So then I tested the Lincoln 375. NICE MACHINE! I will push for that to be my next unit. But hey... I weld LOTS of aluminum and up to 3/8 6061.

Anyway...side tracked....It sounds like a power supply problem to me.

[Otto Nobedder]

You running this thing with remote amperage control? (I use a Miller SW 250, and am not familiar with the 200.) Try setting amperage control to "panel" and weld some scrap to see if it fires full-power consistently. It could be as simple as a problem in your foot pedal/thumb control.

Good luck,

Steve

[sschefer]

The duty cycle is 10 minutes. If the machine is running at a current range that allows it to run for 10 minutes before needing a rest then that would be running at 100% duty cycle. The higher you set your current, the lower the duty cycle %. At 100amps it might run for 10 minutes before it would need a 10 minute cooling off period (100% duty cycle). At 200amps it might only run for 6 minutes before needing a 10 minute cooling off period. (60% duty cycle).

If you read your manual it will explain this in detail and you'll understand why the Miller rep say's there's nothing wrong with it. The 250 duty cycle is also 10 minutes but you might be able to run 150amps and get 100% duty cycle.

I think what's going on is that your simply hitting the end of the duty cycle and not allowing it to cool. Eventually you hit the wall and it forces you to let it cool off.

By the way, running below the 100% duty cycle (lets say 40 amps) does not extend the amount of time (10 min) in the duty cycle. It's 10 min no matter what. So run for 10 or less and cool for 10 or more. When I have a lot of stuff to do I plan my welds and switch from TIG to MIG and back again. I just have be carefull to keep from melting down the project then.

[ogorir]

that's not quite right, steve. duty cycle is % of 10 minutes the welder can be welding. 100% means you can weld for 10 out of 10 minutes, no waiting, ect. %60 duty means 6 minutes on 4 minutes off for every 10 minute cycle.


not tryin to be an ass, but other people read the board who never ask questions. I like to keep the record straight. 'course, if I'm full of shit, please let me know