OT: Alarm and TIG welder???

[Conrad_Turbo]

Sooo I have been having an issue with my alarm system in my shop since the day it has been put in. It's a DSC alarm system with a keypad in the garage for the part of the alarm system that monitors the garage. The only problem I have is that when I'm TIG welding (normally AC or sometimes the high frequency arc start on DC) it will trip the alarm. The keypad panel will beep for a minute straight and then shut off after I am done welding.

Any of you have an issue like this? I let my installer know and he suggests to shut the keypad off while I am welding (ie: put an inline switch on the power wire to the keypad), seems like the *easy* way out...

[Sberry]

It could have a lot to do with the alarm wiring routing? It might need to be piped?

[FM117]

My tig unit will trip the alarm also.
I have a old tig, power feeding it is in metal
conduit, case grounded to a ground rod at the welder
....etc.
Still trips the alarm. I had to install a shut off.
My panel and key pads are close to 100 feet from the
welder.
Dave P.

[hankj]

Conrad,

RF energy is wierd! The high freq is leaking somewhere that is the right distance from the alarm wiring to allow the alarm wiring to act as an antenna. The induced current is whacking the alarm system.

One solution I can think of is to replace the alarm wiring that is exposed on the surface of the garage walls with shielded cable, and then grounding one end of the shield. That will pass any induced energy from the HF radiation to ground (at least, it's supposed to!).

Hank

[gmc1999]

I have almost the same problem, but it's with
my electric overhead doors. I have to unplug
then plug them back in.

[glockdoc]

friend of mine installs security systems for a living and he always uses shielded cable. he claims that if someone (police, firetruck) keys a radio transmitter and is close enough to the alarm that it can be enough to trip the alarm. false alarms are not good for business. Guess he can add tig welders to that list.

[klworks]

I had a similar problem with a gfi circuit. Every time I hit the pedal the hi frequency would trip the gfi. Turns out that there was a small cut in the insulation. The cut was near a the steel conduit and would "leak" during the high frequency blast of the tig welder and blow the circuit. The puzzling thing was the other than at the circuit breakers the only thing the circuits have in common is the conduit. Hi frequency likes to dance where it likes to dance. I fixed the wire and life is good again.

Klworks

[acx780]

Keypad Trip

If you could supply some more specifics about your DSC system I think I might be able to help you. Can you tell me what model the keypad is and what security devices you have in the garage. Do you have motion detectors or just door switches in the garage? When the keypad goes into alarm what does it say (other than beep) Where is the panel and what model is it. Is the cable used in this install (devices and keypad) shielded? Does the wire have an uninsulated wire in the cable bundle and if it does is it attached to anything anywhere. I solved this problem at a local shop by running a wire from the board inside the keypad to building steel. In this instance the panel was also mounted to the building and that provided a common reference. If you do have motions can you get the model and manuf. info. Some dual-tech type motion detectors use microwave frequencies.

[burninbriar]

A quick fix might be to move you're welding to a different spot in the shop until you get a permanent fix. Mine was opening the garage door, now I just don't weld directly under the garage door opener any more.

[cruizer]

2 Ways of fixing this problem, the first is to run the primary ground from your machine out of the back of the machine into a outside ground rod. You will have to disconnect the green ground wire from where ever it's presently connected, & connect it to a 4' rod.

Shove a 4' rod into an outside ground position. Probably make sure your not shoving the rod into some other line, like a gas line first.

Now, if your in a industrial shop, you have to run a ground wire direct to the buss (the place where the power comes in to your shop) What is likely is that you have a conduit ground. And conduit grounds go everywhere, computers, telephone lines, and alarm systems. HF likes to go everywhere as well. So best to isolate it's travel back to the buss

You might get away with running the ground to a waterpipe, providing that pipe is going underground. The problem with this method is the mesh in the concrete, which transfers frequency back to the alarm system, computers and whatnot.

Or, twist tie the work lead to the tig torch for the first 2' from the machine end. You can try this, usually works well but best on non squarewave machines.

Either of these should take care of your problem.

[Conrad_Turbo]

AWESOME REPLIES!

Okay to answer a few questions, this is the alarm system I have:

Partition 1: House
2 - motion detectors
2 - door switches
5 - glass break sensors
1 - keypad (PK5501)
1 - control panel (PC5010)

Partition 2: Garage
2 - door switches (1 for garage door, other for man door)
1 - keypad (RFK5501)

All wiring I believe is unshielded (just standard alarm install wire) and the TIG welder is about 20ft away from the keypad in the garage. I am situated as far as possible from the alarm system as I can be when using the TIG, however in the future I will be moving the whole welding station and it will end up being closer to the keypad.

I have suggested swapping the keypads (the one in the garage has a RF receiver for a keyfob), so the one in the garage would go in the house and vice versa. The alarm is disarmed when I am in the shop (obviously) and the door chime feature is left on. When I am welding (mostly AC) it will trip the alarm, sounds similar to the entry delay when you first go into the garage when it's armed, the buzzer going off alerting you to disarm the keypad noise. That's the only thing that happens...I guess the easy way would be to remove that buzzer haha...because it doesn't seem to affect the alarm in any other way. I can arm and disarm it like normal, even though the entry delay sound is still going off. Usually it's about 1min in duration that the buzzer goes off for, but it's not consistant.

So really the big issue is just the fact of replacing the unshielded cable (acting as an antenna) with a shielded varient and making sure the shield is properly grounded. Correct?

[cruizer]

Doesn't matter where your keypad is, could be 300' away, won't matter. Shielded or unshielded, it is still grounded to a ground somewhere. Won't matter where you stick your machine either. Just follow my instructions and your problem will go away.

I trouble shoot and fix machines for a living........

Lincoln/Miller warranty tech

[Wheelchair]

I know this sounds crazy but when I am in my electric power wheelchair if I forget to turn it off it will start acting wierd. This only happens with tig. The lights on the control will go into a flashing mode and then it takes a few minutes to level out.

Wheelchair

[burninbriar]

I know this sounds crazy but when I am in my electric power wheelchair if I forget to turn it off it will start acting wierd. This only happens with tig. The lights on the control will go into a flashing mode and then it takes a few minutes to level out.

Wheelchair

You better watch out, get that rascal all charged up on high frequency and its liable to start popping wheelies and doing donuts on ya.

[cruizer]

Seems nobody with this hf interferance follows jeff's instructions, HF goes everywhere, hunting for it's mate, thats why you tye the work to the torch. Ends the hunting and HF signal is stable. The HF does not effect anything once the arc is kit.

Power source case is also hf charged needs a place to go, and must be drained on it's own line direct to a potential ground, like the incomming Buss, or directly to a ground source

Anyhow, been t-shooting this stuff for like 20 years, follow it or forget it.