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rahtreelimbs
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  • Joined:
    Mon Jun 14, 2010 10:39 pm

What exactly is a wild leg?

Would it be possible to just run a new dedicated line?
Poland308
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  • Joined:
    Thu Sep 10, 2015 8:45 pm
  • Location:
    Iowa

A wild leg has to do with a variable of how the power provider generates the the three phase. If you read between two of the legs with a good true rms meter you might be able to see it. It’s when one of the three legs varies substantially from the other two. That (wild leg) is often higher in voltage and if you are running controls of any kind it often also has a harmonic resonance of sorts that causes interference and surges. In three phase units where they often use single phase for the control power. It can stress electronic boards and cause premature failure. I’ve had to switch the legs that the control power transformer was on, to keep it from cooking electronics. If he’s tapped into power from someone else, and he just happens to have one of his legs of single phase power tied to the wild leg then it would explain why he cooked two inverters so fast. Since this is an issue caused by how the provider generates the power, this would also explain why the local dealers have seen a high rate of unit failures. Running the power through a transformer has a smoothing affect, probably why they have better luck with the transformer based machines. It’s not uncommon to see isolation transformers in controls where, it’s not a step down, or a step up, but the same voltage going into and out of the transformer. Especially in places with big power draws or lots of inductive resonance created from lots of motors.
I have more questions than answers

Josh
Poland308
  • Posts:
  • Joined:
    Thu Sep 10, 2015 8:45 pm
  • Location:
    Iowa

I have more questions than answers

Josh
wes gable
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    Sat Jan 06, 2018 6:15 pm
  • Location:
    northeast Ohio

Hi

Just to wrap this up here. First of all thanks, guys, for all your input here. I have had my Precision 225 for a week and a half and used it heavily for a couple of those days on a stainless steel project. Very happy so far. The arc control and starting seems to be every bit as effortless as the Squarewave, although admittedly we don't have a lot of TIG experience to draw comparisons from. Haven't tried any AC aluminum yet. The torch gets a bit warm after heavy use so down the road we may be looking at a cooler, but otherwise satisfied.

We are still using the same circuit that the original machines were on, and haven't been able to identify any problems or even hints of problems on that circuit or anywhere else in the electrical system. I would be delighted to fix something if I could just find something to fix! Someone here was opining about the possibilities of a wild leg in the 3 phase power. I don't have 3 phase in the shop and it's not even available at the road, so I didn't think it necessary to check into that option.
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