Miller Synchrowave 350 LX Wiring and use Questions

Why are you running a 230 V welder on 208 V, when you have 240 V available?

240 is a lot closer to 230 than 208 is.

Does this "guy" know anything about TIG welding aluminum? I'm no expert, but these techniques sound way wrong. He should be putting a point on the electrodes. Is it the Lantanated electrodes are supposed to be the best for aluminum, now? Most people advise against pure (EWP) electrodes if you can avoid it. It is no surprise that a 3/8" ball at the end of the electrode is not working. Also, if you can't get a puddle, you don't have enough heat. Thick stuff like this really sounds like it needs to be pre-heated, or turn up the current on Lanthanated or Thoriated electrodes.

Of course, you'll get the REAL straight scoop from Ernie Leimkuhler.

That gas flow sounds ridiculously high. But, if you get gas lenses, you can turn down the gas flow even more. The gas is the most expensive part of TIG welding, so conserving the shield gas is worth a little effort. Of course, the wrong gas may not be helping the situation, although mostly He should make it a bit hotter. As for the Tungsten ball, that is probably a combination of not pointing the Tungstens, and using EWP (pure) tungsten at too high a current. I think if you look up the current range for EWP 1/8" electrodes, they shouldn't go over something like 175 A?

Jon

Reply to
Jon Elson
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Greetings all,

After much wailing and gnashing of teeth, the boss got us a new Miller Synchrowave 350 LX on demo to try out. We have an ESAB 252 which is a refurbished/remanufactured machine. I have asked for help here before with it and received some good advice, but it seems to be in its final throws. The ESAB has a bad habit of welding good on DC welding carbon and SS, but goes ignorant when welding Alum. We even installed a new PC board,(the old one had a burnt up resistor or capacitor) but to no avail. $500US, and they said it was a cheap one. Anywho, it is still not right, the high freq will "light", but it will not form an AC arc without scratching the tungsten. Welder is set at 250 on the dial(max), foot pedal being used, 1/8" pure tungsten with gas lenses, water cooled 250 amp torch, running straight Argon at times or 75Hel/25Arg at approx. 20-25 cfh, This was supposed to be 75Ar/25Hel, but Holox/Linde can't seem to get it right, they initially brought us 75Arg/25Co2. GGGRRRR!! Had to replace 400 amp torch(you _can not_ roll the welder over those coolant lines) with the 250, but it seems to be handling it, sort of, but I'll explain that later. Material being welded is 1/4" wall tubing(4x12) and 3"x3"x3/8"x6" long angle, both 6061, filler metal is 5556. The angles are lying flat onto the

12" side of the tubing, being welded on 3 sides. The person welding these is not pre-heating, he says the welder should get it hot enough. What can you do? As I mentioned above, the ESAB will weld after you scratch it, but it still is not "right", the arc sounds way too harsh, like the arc is about to destabilize. Hope that makes some sort of sense.

OK, on to the Miller. First the wiring question. Our shop has 3 phase power, meaning we have 240v, 120v and a 208v leg. There are 3 hot legs, between any 2 of the 3, you get 240v, from 2 of them to ground you get 120v but from the third to ground you get the 208v. Everybody still with me? I hope so. The wires feeding the Miller are the same that fed the ESAB, BTW, and one of them is the 208v leg. The welder is set up for 230v. QUESTION, finally. Could the 208v leg cause a problem with the Miller? More pointedly, is there anything in the welder that could be trying to run on

120v that this 208v leg could screw up?

Secondly, set up and use of the Miller. For whatever reason, we did not get the TIGrunner kit with this machine. We are using a QC brand(ESAB?) torch, Q20-25, which hooked up to the front of the ESAB and was plumbed out the back to a Pro-Cool(?) cooling rig sitting atop the welder. We were able to connect the cooling rig to the Miller successfully, after burning up one torch kit due to no circulation of coolant. GGGRRR!! Finally got everything plumbed right and used the following settings; Same torch, tungsten and gases as above, machine set at 250 amps, Balance seemed to work best at 3, but a later call to Miller advised 7 which did not seem to work. Using the straight Argon we were not able to form a puddle to begin welding. Using the Hel/Arg mix we could form a puddle, however the tungsten could not handle it. The guy welding would simply break off the end of the tungsten with a pair of lineman pliers and begin welding, the tungsten forms a ball atleast 3 times the diameter of itself and it is very unstable. It just sort of hangs there looking like it will fall off at any second until eventually either the cup explodes or the tungsten does fall off, I never really got that much information from the guy. I guess my QUESTION is, What could be causing the tungsten to ball up so big and be so unstable? The salesman suggested it could be that the gas is too hot, maybe? I know that the flow on the gas is too high, I tried to tell him that and turn it down but I think he turned it back up.

I realize this has gotten to be a huge post, I hope some of you can stay with it long enough to help me. I will check on it frequently tonight, Wednesday, as the boss has an electrician and another/more experienced salesman coming to look at it in the morning.

Thanks for any and all help, Jim C Roberts

Reply to
Jim C Roberts

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I suggest you ask this question in: sci.engr.joining.welding because lots of them fellows have forgotten more about welding than I have learned in 30 years of welding.

I am SURE someone there will be able to answer every question you have and get you on the right road. Some very very good welding information there, and a group of guys who mostly talk about welding, and don't bite on troll bait.

Steve

Reply to
SteveB

OK, I got home and looked up the info in my Lincoln TIG book. It says for 1/4" aluminum, the electrode should be 5/32", and for 3/8" Al the electrode should be 3/16". So, clearly your electrodes are too small. They recommand rounding the end of the electrode, not pointing it. They recommend 200-300 A for 1/4" material, and 330-380 A for the 3/8" material. They recommend a 1/2" cup for the 1/4" material, and a 5/8" cup for 3/8", and 25 CF/Hr gas flow with these cups. I'g go for a gas lens and cut the gas flow in half. Depending on the shape of the workpieces and the configuration of the welds, you may need back shielding on some of them. You need to protect the torch from drafts, which will blow the shielding gas away. Miller recommends pure Argon even up to 3/8" material thickness in Aluminum. The Lincoln book recommends Zirconiated tungsten electrodes, and so does Ernie Leimkuhler. I think that will help greatly over the pure Tungsten.

Jon

Reply to
Jon Elson

definatly use zircrom tungsten , pure argon should work and its going to take about 250 amps without preheat maybe a little more, a little less with preheat, 1/8 tungsten will be be marginal, 5/32 will work for sure . The ball on the end of the tungsten should never be more than a little larger than the dia. of the tungsten, one way on the balance is more penetration. A 330LX should do this easily, I think a 250 would probably do the job with a little preheat. We used to use pure tungsten, when we discovered zirc there is no comperison for amperage capicaty, arc stability and life.

Reply to
Jon Petrzelka

He doesn't have 208V service there - Sounds like he's got 120/240 V Open Delta "High Leg" service, which should run a welder just fine if the transformers and supply system isn't overloaded.

Between any two phases is full 240V, and two legs are 120V to ground (normally marked Black and Red) and can be used for 120V lighting and equipment loads. The "High Leg" is roughly 208V to ground - and does nasty things if someone screws up and puts a 120V load breaker on the Orange buss, lots of "Magic Smoke" popping out all over the place...

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Reply to
Bruce L. Bergman

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