Melting Tungsten Electrod - Dynasty 200DX

Try setting the machine for DCEP. If that works, you've got the torch and ground connections switched. A less likely scenario is the welder's internal wiring is reversed, or it's outputting AC instead of DC.

I'll try the DCEP tomorrow. I checked the ground and torch connections and they match the manual. How would I check the welder's internal wiring?

Thanks,

Dave

That should work fine. Sounds like the machine is wired backwards or your lead connections are reversed. What tungsten? RichD

Dave, I was going to say put a DC meter on it, but the high voltage high frequency won't do it or you any good unless you can turn it off. The symtoms are definetly DCEP especially at such a low amperage. RichD

The Tungsten rod has an Orange tip so it should be Cerium. How can the machine be wired backwards? I have followed the instructions for the plug with black and white wires to the AC lines, and the green to the ground or white wire. The electrode connections are correct in front of the unit. Ground is plugged into the ground terminal, and the torch is plugged into the electrode weld output. Should I call Miller for assistance? I've never been able to weld with this unit yet, but this is the first time I have tried TIG welding.

Thanks!

Luds

The Dynasty has a Polarity Control with two settings. One for DC and one for AC. I selected the default DC. The manual states "Machine is set to DCEN (direct current electrode negative) for TIG weldign, and to DCEP (direct current electrode positive) for Stick welding. I selected DC, but how do I know if Stick or TIG is selected? I assumed TIG is default.

Thanks,

Luds

I have the Process Control set to TIG HF Impulse so this should provide DCEN.

Are you SURE the argon is on and the bottle HAS argon in it? Can you hear the gas blowing at the torch when you push the pedal down? NO argon = a mess when trying to TIG weld. Richd

Definitely check the gas flow, though the original description "the tungsten keeps melting into a ball" is more consistent with incorrect polarity. Without gas the tungsten will erode irregularly in a blackened mess.

As Rich says, don't check polarity with a meter unless you're sure the hi-freq is off.

I'm not familiar with this machine, but it sounds as though polarity is determined by the machine based on the setting of a process selector switch? In that case, try setting the machine for stick welding DCEN (straight polarity). If you still melt the tungsten, try DCEP. Presumably that will disable the hi-freq start, but you can still scratch start, and perhaps get some clues as to what's going on.

I check the electrode voltage and its negative 16VDC. The maximum Amp set is 70. The diameter of the electrode is 3/32. Am I just using too small of an electrode. The sheet metal thickness is roughly 0.065. Argon is flowing with a 7 second post setting.

Thanks,

Luds

Under what conditions? 16V is very low. I'd expect to see 60V to 80V open circuit, perhaps 30V while current is flowing.

Luds, OK, I think I see your problem. That small of electrode can only handle very small current. Too small for 1/16 steel sheet. I hate to disagree with Ned, but a 1/16" tungsten is awfully small. For most work the 3/32 size thoriated or cerium is best. Keep it well sharpened to a point for welding steel. About 30* is fine. Anytime you are melting the tungsten, the current is way to high for that size. For welding aluminum, use pure (green) tungsten. Form the ball on a blunt end. Typically 1 size larger than steel. I am a student at a Tech College, but have been welding for many years. Owner Miller Syncrowave 250. RichD

No harm in disagreeing, but you're way off here. A 1/16 thoriated tungsten is good to well over 100A on DC, at least twice what's necessary for welding 16 gauge steel. For stock thinner than 16 gauge, I'd be thinking about switching to a .040 tungsten.

There's a chart on this page:

Better go at least two sizes larger if you're using pure tungsten.

I made my living TIG welding for many years.

I'd say try a different tungsten.

I did some welding last week on 3/16" steel using a 3/32" lanthanated tungsten, running well over 150 amps to "get 'er going" because I wanted to be done in 15 seconds and quench before the heat got to plastic about 1.5" distant. No problems at all with the tungsten. (No problems with the plastic either.)

Miller Dialarc 250 HF, DCEN.

I like zirconiated tungestens much better than pure tungsten for AC on ally.

Hello,

The electrode I have been using is a 3/32" 2% Thoriated. Do you think the Dynasty 200 DX unit is malfunctioning? Here are the specifics:

Input power is Single Phase 220VAC on 50Amp circuit (Upgraded from

Thanks!

It's certainly possible that your machine isn't working right. 16 volts sounds quite low even with an arc running and way low for open circuit voltage. That sounds more like a MIG machine at a low setting.

Thanks for all the help! Finally figured out the problem! The Dynasty

Luds

IOW the whole problem was a loose nut behind the torch.

Been there, Done that, Have the book, Saw the movie, the book was better, the movie was totally mis-cast...

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