L-TEC 250 HF tig pedal not working.

[chris1151]

i have a L-TEC 250 HF and i was using it today and i went to finish up a weld and then nothing. machine works. i can arc weld with it. but i use it for TIG. does anyone know of a place that does repair in Orange County CA?

i checked out the pedal a wire was broken, soldered it back together and still nothing on the TIG side. ARC ok. so it still puts out a load. so far no luck on the internet where to go.

[chris1151]

Forgive me if I i miss something doing this on my phone.
The wire I repaired was a wire in the pedal. It was just taped together before. The wire is to the rheostat on the pedal. Re-taped it after I soldered it
The wire had no prior evidence of arcing. I have not taken the welder apart. There was no smell of any electrical shortage. I do know that it can happen.

I have set the welder to panel and I do get an arc. I have set it to arc with the HF on and I can hear it. Works on stick weld also.

I have had pedals go bad before while on the job. That was
many years ago.

As of right now i have no evidence of shorting in the welder itself. My suspicion is that the rheostat is bad. But I could be wrong.

[vicegrip]

As of right now i have no evidence of shorting in the welder itself. My suspicion is that the rheostat is bad. But I could be wrong.

Your pedal should have a contact switch, a"Cherry" (brand) microswitch
when it was Linde. L-TEC may have changed that. That switch will eventually fail.
The variable should be a potentiometer not a rheostat, regardless both
the switch and the variable can be checked with a common V.O.M.

Set it on ohms and probe from center terminal to either outer terminal.
Then from center terminal to the other outer terminal.
Ohms should decrease in one direction and increase in the other.

The switch just test for open/closed continuity.
vg

[canoecruiser]

VG, you're a machinist? I wish the electronics engineers I work with had your methodical troubleshooting skills.

Some of those kids (compared to me LOL) should sue their high-priced universities for malpractice......

[vicegrip]

Thanks, but machinery is a great teacher.
When someone wants you to fix one.......

You need to grasp the fundamental that spells out "how it's sposed to work" first.
Only then can you deduce what's a miss in that fundamental.

I allways look over the shoulder of a good tech when one is called in.
The best ones are the one's that use mental logic to eliminate
the most to least likely Gremlins.

Cheers

[chris1151]

VG
I will check that at work with my VOM. I was unsure what to call it. But I know that part could fail anytime it wants to. Is that a hard part to find? Again sorry if i missed something still using my phone.

Thank you for the info.

[chris1151]

ok and update. i have continuity on my pedal. so that pretty much elimates that. i have scratched started when the machine in on "stick" not TIG side. i have taken the panels off the machine to see if there is anything out of place to the naked eye. i cannot smell anything burnt. but still nothing on the TIG side. i did go the local weld supply store and they gave me a number to a place in Downey CA. that does service welders. i will be giving them a call tomorrow and see when i can take it in to get it fixed. i don't have the time to troubleshoot the welder.

so right now i'm screwed on many projects and my side job that i do until i get this fixed.

[Pin Head]

There isn't much to the foot pedal: a microswitch and a rheostat. If you have ruled out a problem outside of the pedal, and it is not the microswitch, then the rheostat is either open or wired incorrectly.

Arc Products in San Diego fixes them.

[chris1151]

i was able to find a shop to take my welder in and it was the control rectitfier. as to what burned out on it is not known. the part was not hard to find and it was repaired at a reasonable price.

i doubt i would be able to troubleshoot this on my own and find that this part was bad.


i picked it up the last friday and used it friday night and works better than when i bought it 4 years ago.

thank you for all your input on troubleshooting this issue.