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A/C Tig Welder HF Interference

Posted: Wed Aug 18, 2010 8:09 pm
by sschefer
Hi, I just got my first TIG Welder. It's a new Lincoln Precision TIG 225 with all the bells and whistle including a add on water cooled torch. Yep, I'm a newbie to TIG but I've been gas, stick and MIG welding as a hobbyist for around 30 years.. And yes, I'm an old fart to boot. I've laid down about 10 practice welds and like what I'm seeing and that theory about learning gas, ... yep, it sure helps.

Anyway, I've got a 50 amp 220v circuit in the shop and last weekend while welding I heard the doorbell ring. I went to check and no one was at the door. On the way back to the shop I noticed the sprinklers had been on. I fired up the torch again and heard both the doorbell ringing and saw the sprinklers come on. It doesn't do it in DCEN, only in A/C. I'm speculating that it's the HF with the A/C and the wire is radiating it all over the wiring on it's way to ground.

The subpanel feeds the lights, pool filter pumps and one 20amp duplex outlet. Only the shop lights were on at the time. The pool pumps are frame grounded to a grounding rod that is separate from the rest of the wiring, (until it hits earth). The welder is grounded to the subpanel at the ground bus bar and the neutrals are isolated. Theres an old drill press that was plugged in to the duplex outlet at the time and it's about 5 feet from the welder. My welding table is not grounded and is on rubber casters.

I'm thinking I should run a separate ground from the ground rod that the pool pumps are on and tie the welder and the table into it via a buss bar.

I've got a pretty solid electrical/electronics background so when the weird unexpected stuff happens I ask questions first and try to avoid the easter egg hunts. Any thoughts?

Thanks

Steve Schefer
Santa Rosa, CA.

Re: A/C Tig Welder HF Interference

Posted: Thu Aug 26, 2010 8:07 pm
by sschefer
Problem solved - After crawling around in the garage attic for a couple of hours I finally figured out the problem. It was a phone line that my Pop's ran when he had his business phone in the shop. Pretty clever actually, he had it set up to ring the doorbells in the house so if he was in the house he would know his business phone was ringing. Later, after he retired, the phone went away but he used two of the pairs for 12vdc to one of the yard sprinkler valves. Of course that phone line was properly grounded and all so that was my Antenna and the source of the EMF that triggered both the doorbells and the sprinkler control. I removed it and everything is fine now.

Re: A/C Tig Welder HF Interference

Posted: Sat Jan 08, 2011 1:30 am
by Wobulate
S Schefer,

Steve, I thought I would strike up a conversation about your Lincoln Precision TIG 225, which I recently purchased from Indiana Oxygen Company. I am just learning the capabilities of this new welder, and so far I am impressed. Like you, I have been welding as a hobby since 1983, about 27 years+, mostly SMAW, GMAW and torch welding. This is my first TIG welder, which I have wanted for at least 10 years.

Since you have had yours longer have you learned any techniques or procedures that make the most of this extremely capable welder?
Using 11 gauge AL, I have been practicing running beads using Jody's techniques. And wouldn't you know, his technique works, imagine that. 8-)

So if you want to talk Lincoln or Miller, let's chat.

Wob

Re: A/C Tig Welder HF Interference

Posted: Mon Jan 10, 2011 5:29 pm
by Sarge
I love the Red ones! I tested the PT 375. WOW! Nice machine. Have not been able to justify the upgrade yet, but hope to have one in the next couple years! 8-)