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Up Topic Welding Industry / General Welding Discussion / Hybrid wave Tig & auto helmets.
- - By awill4wd (**) Date 05-03-2002 12:15
When using our new OTC tig on hybrid wave, we often get a problem with our Esab auto helmets switching off during the welding process.
It seems to happen on the negative cycle mostly and flashes off and on during welding and I was wondering if anybody has similar problems with any other hybrid wave machines. Miller's aerowave comes to mind.
As you may guess, it's a bit unnerving not knowing when it's going to happen and I'm loath to stop using the helmets as a lot of our welds are very short so they are a necessity.
If anyone else has had this problem and a possible solution it would be much appreciated.
Regards Andrew.
Parent - By Dave (**) Date 05-03-2002 14:03
Andrew,

I can only offer a general suggestion about auto darkening lenses, not anything specific about the products that you are using. At times the operator will have a clear view of the weld yet the lens still switches off. This is often caused by the sensor being in the shadow of the electrode, weld gun or the welder's hands. This would be the first thing to check out and the easiest to fix.

Dave
Parent - By airweld (**) Date 05-03-2002 16:42
I encountered the same problem when I went to an inverter TIG machine. I could not trust the auto helmets any more and went to a chin-operated helmet that I have used since. It works great for me, but I hear there are so-called "second generation" sensors that solve the problem. Call 1-800-658-4443 to find out more about the chin-operated hoods and no, I don't get a commission, I just like to see what I'm welding and hope it may save some aggravation for others also. Good luck, Scott
Parent - - By aircraft (**) Date 05-04-2002 02:33
I was having the same problem and my welding supply let me use a Jackson 3N1 next/gen with four new generation sensors. problem went away....so I bought the helmet.
Parent - - By Lawrence (*****) Date 05-06-2002 15:55
It's not your Imagination,

Our Miller Aerowaves have been known to deactivate several brands of Auto Darkening hoods. This phenomenon occurs during DC Straight polarity (DCEN) operations in a variety of amperages. We went straight to Miller on this and discovered they too had encountered this problem and had come up with a fix.

A standard helmet <snort>

At least with the Aerowave, Arc initiation is accomplished by a combination of Superimposed high frequency in conjunction with a DC Reverse Polarity (DCEP) pulse measured in milliseconds. It is my belief that during welding operations when the tungsten electrode comes very close to the work the machine can sense this via an Arc Voltage meter and in response makes an attempt to re-initiate the arc. During this arc iniation attempt the afore mentioned pulse may be the culprit, somehow turning off the helmets.

What I am talking about may also tie into another more disturbing phenomena which only the Aerowave is known to produce, that is the changing of polarity in mid weld which sometimes occurs... Yes Straight polarity DC to Reverse Polarity DC right in the middle of the weld. The Electrode just balls up and you are left with a fouled weld and a nice little etched circle to prove your not going mad.

Does this make sense? Don't Light sensors activate these hoods? If so than how can they turn themselves off during operations over 70 amps?

The Crack team at Miller (and they are a crack team) did not confirm or deny my theory. It's doubtful that it's profitable for them to spend the time necessary to discover and make a fix for this. Nonetheless for the sake of safety this quirk outta be mentioned, especially in product literature.

I bet OTC uses many similar circuit boards in their machines so we are most likely talking about the same thing.
Parent - - By billvanderhoof (****) Date 05-08-2002 04:58
Sure it makes sense. In order to get from dcen to dcep you have to go through a period of time when there is no current flowing. A wild guess is that this period would at least be a millisecond perhaps as much as 8 1/3 milliseconds if they switch on zero crossing to keep radio noise down. Insignificant to the eye but giant amounts of time for electronics. Easy to see how this could confuse a helmet if the designer was not aware of this situation. You could ask the helmet manufacturer if there is a way to delay the appearance of the "arc is off" condition in the electronics but I wouldn't hold out too much hope.

Luck to you

Bill
Parent - - By Lawrence (*****) Date 05-08-2002 13:20
Bill,

I like your reply-- But the remaining mystery for me are the times when the Aerowave is operating in NON-Hybred mode (DCEN) and still shuts off the hoods. I can Grok at least on a peripherial level how it might cause havoc during AC Hybred ops. But the DC effects on AutoDark lenses is a real mystery.
Parent - - By BP Maas (**) Date 05-08-2002 15:20
Unfortunately, I can't explain why some helmets don't function well in that mode, but, I use a Speedglass 9000X which has two modes.
One for GWAW and SMAW, and a mode for GTAW. Additionally there is a sensitivity adjustment knob, if you "tweek" the setting so it just turns on with existing light conditions, I have yet to have the "flickering" problem. If I am in an area with multiple welding arcs (field work), that can be a problem, then I just turn the sensitivity all the way up, finish my weld and go find a welding curtain, safety issue anyway. I use this helmet mostly with Miller Dynasty's, but have had significant hours on the bench with Aerowaves; no problem so far. One of our welders has an Optrel that seems to work well for him also. I'm guessing you have tried a 9000X, just wanted to point out that sensitvity adjustment, it matters a lot.

Best regards, Brad
Parent - By awill4wd (**) Date 05-09-2002 13:02
Thank you for all your answers everybody. In my circumstances, the only time we have problems is when we are using hybrid wave welding mode where DC electrode negative is added to modified square wave AC.
It happens on the transition of wave to DC neg. and the helmet is turned off during the DC neg component. It turns on during the AC component. Changing the Hertz frequency simply makes it flash on and off either faster or slower depending on which way you turn the dial.
I might try and borrow another auto helmet to see if it happens to different brands, apart from that, I don't know there's much more I can do.
Many thanks for all your answers.
Regards Andrew.
Up Topic Welding Industry / General Welding Discussion / Hybrid wave Tig & auto helmets.

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