Hi guys, FWIW, I am a Miller Certified Repair Tech.

Thats good, there have been quite a few people here looking for tech help with repairing welders. Thanks for joining,
MC

have much experience with the Econotig?

have much experience with the Econotig?

Using one, or repairing? I have yet to repair a TIG welder, I've used a Hobart TigMate for 2 years, what was the question? One of us can answer for sure.

Some. Whats wrong?

Some. Whats wrong?

from his introduction thread, figured I'd give you a jump start, I'm gussing bad earth ground...?

QUOTE: I'm a former welder looking for help diagnosing a problem with one of my machine's! I'm having trouble with my Miller Econotig! Seems like the high frequency transformer but I'm not a repairman! Any idea's? /QUOTE

If you have to scratch start there is a 99% possibility it is a bad HF unit. The HF unit in this machine is unique to the Econotig and is a small transformer about the size of your fist located behind the front panel. It is not repairable and must be replaced. I am not really sure of how it works to tell you the truth, Never took one apart. I dont recall them being very expensive either.

Did the HF ever work? If not, do you have a good earth ground, or a seperate ground rod for the machine? I've ran into that problem before.

I have never had a machine loose HF from a poor earth (frame) ground. The HF has nothing to do with earth ground. The coupling transformer is in series with the work lead. Bypass capacitors shunt the HF to keep it out of the machines electronics and complete the circuit to the ground lead. The entire secondary side of the welder is galvanically isolated from the mains. You will still get a HF arc to metal even without a ground lead, this is due to the bypass caps being attached to the frame of the machine. This spark is considerably weaker than one to work ground. On a machine like a Synchrowave which has a real HF unit you can expect a 3/4" to 1" spark in flowing argon.

A poor earth ground can cause excessive radio interference and other issues around the shop like stray high voltage.

My syncrowave never really worked right, and I bought it brand new. I called Miller, and one of thier engineers told me to put in a dedicated ground rod for the machine and to ground the welding table also. It's much better since I put the new ground rod in, but still not what I'm used to.

It's almost spuratic, it works, no doubt about that, there is HF there, no need to scratch start, but it's not a consistant arc of HF when the ground lead is hooked to the work piece. Without the ground lead on the work piece, it has a nice stream of HF to the earth ground.

Doesn't bother me on DC welding, just a little harder to get an arc initiated that what I've used in other shops and school, but my worry is the AC welding is suffering, it seems I should have more focus and control of the arc on AC welding, but I might be trying to compare it to a Dynasty also.

I already went through the manual and checked the gap of the points and what not, new ground rod helped a lot for some reason (42", came from the city electricians), but HF still acts funny.

Any idea's?

I would say a bad capacitor. Which synchro do you have? How old (first two letters of serial?)

If I were to guess I would say high voltage capacitor. Miller experimented with a poly-foil cap instead of the mica cap they have been using for the better part of the last century. They had a seemingly high failure rate as the number for the cap is superseded to a part kit that retrofits that cap to the old reliable mica cap.

I know for sure this cap was used in the Synchro 250DX. Not sure if it was in any other machine.

A modern square wave tig machine only needs HF for arc initiation. The reason for HF in old machine was the dead time when the single phase AC crossed zero in its wave form. The HF basically kept reigniting the arc each time it came up from zero.

With the advent of square wave HF is really not needed. In a square wave machine the rise and fall times of the square wave shaped AC are so short that the arc will not extinguish. HF is sometimes used to help stabilize an arc but in reality it can be turned off once the arc has started.

With the hybrid (big transformer mixed with inverter output) and inverters such as the Miller Aerowave and Dynasty Series the output square wave is so sharp due to the IGBT output stage that it is actually noisy. On the inverters there is no true HF. It is just a High Voltage pulse to start the arc. The Aerowave was one of the noisiest machines ever made. But it was a great machine. Waveform current was independently settable for each polarity shift. This didnt show up again until the Dynasty 700 and now the 350. The 350 also has several different waveforms you can choose from.

Yeah, I'd say you know your stuff!

It was bought brand new in 06, Syncrowave 200, shipped direct from Miller. Where is the serial number? I can check in the morning if it would make a difference.

I'm DYING to step up to a Dynasty 350! Full inverter machines are so nice, I just can't justify the cost at the moment.

Should I take it in for service, or would it not matter since I'm only worried about the AC cycle, and honestly, it lights off real easy on AC, just wished I could get a little more focus on the arc.

MC

hi to you all take a peek at my welding blog from stugod http://weldingace.blogspot.com/

This is not necessarily a repair question, bu tlooks like a good place to start.

I have a brand new Diversion 165. The problem is that I am currently in Germany. I am looking to adapt it to the European 220 plug. I am having trouble finding the 10ga minimum wire locally to replace the one on the machine. I want a temporary replacement until I move back stateside in 6 months. Does Miller have a European 220 power cord available as a replacement part?

Also, do you see too much problem using the machine with 50 hz instead of 60 on a hobby basis for 6 months?

My buddy has the same machine that he has been using fairly heavily for about a year now. He was able to find an american 220 receptacle that he made an extension and adapter from. The only problems he has experienced is that he cannot weld while the fan is running.

I have a maxtar (bought it used) 200 SD and came with no power plug.
It has 4 wires in the power cable. Does anyone knows how to hook these wires to a 220 plug (3 prong connector)
Thanks in advance. Joe.

According top the Miller owners manual, connect the white and black leads to the single phase 220, the green lead to the ground.
This is the way that mine is wired and it works just fine. While older transformer machines that were designed for 3 phase ran at about 70% of their nameplate rating that is not the case as stated in the miller owners manual. You can download the manual from Miller Electric's web site.