View Full Version : Linde / Union Carbide UCC 305 HF trouble

12-29-2007, 01:33 AM
I have a Linde / Union Carbide UCC 305 power supply. I have been getting it set up with the HW-20 water cooled TIG torch. The HF arc start is not working properly. The Tesla coil like HF generator seems to be running steadily, but the HF energy on the electrode / torch tip varies so much it doesn't always start an arc. It seems to be better when I use a stick welding cable.

Any ideas on what is going on?

I have cleaned & adjusted the spark gaps acording to the manual. Tested the capacitors in the circuit. Checked for shorts & opens.

Thank you,

12-29-2007, 01:30 PM
Here is one place to start. From an earlier post:
A high percentage of the time in our business the complaint of low hi freq goes back to the machine having a welding lead attached even when tig welding. The situation is aggravated if the welding lead is coiled and lying against metal, say the side of machine. An easy fix is to add female terminal to output and male on welding lead so that the lead is attached only when stick welding. If hi freq is not restarting arc in the condition you describe, foot control is one likely culprit. The earlier Airco Heliwelder series that are obviously not Miller were built by Midstates with some being carried over to Esab. In any case you can still get some parts and information from Arc Products @ 800-770-0063 in San Diego. weldersales
Even coiling the torch lead itself can choke the high freq quite a bit, especially if the coils are close to metal. Keep in mind your machine has a rheostat to adjust somewhat the amount of high freq available. weldersales

12-29-2007, 07:42 PM
Ok, I'll try uncoiling the TIG cables. I have the 25' long ones. The cables are on the floor, don't know if the reinforceing mesh in the slab would be enough to bother the HF.

I only have the stick OR the TIG cable connected. I was already planning on making the plug / jack "switch".

The testing I have been doing is with the power control all the way to low, switched to "panel" on the panel control, to avoid pedal problems, and since I was testing the HF, I didn't want weld currect to get involved. The pedal switch on/off part does work.

I did measure some small leakage current (at a few hundred volts DC) from the TIG cable to ground / work clamp, with the hot cable unhooked from the welder. Maybe the current is going through the water cooler system? (dirty water?) I am not sure how the cable that supplies water and power to the torch is constructed.

Thank you,

12-30-2007, 10:01 PM
It seems to have been the coiled cables. I spread them out across the floor, and actually TIGed some thin steel today.

Thank you,

12-31-2007, 06:48 PM
It seems to have been the coiled cables. I spread them out across the floor, and actually TIGed some thin steel today.

Thank you,

Dave if you get half the use from your tig as I have from my Linde VI 400 CV/CC & VI 253 CV/DC Mig machines you will never regret owning it.

I Learned a good bit on a Lincoln 225 AC buzz box. But first welding job was on Hobart industrial welding equipment. Therefor sold on Hobart equipment.

I guess it's been near 5 years ago I bought the VI 400 & a VI 450 on Ebay. They were both equipped with Mig 35 feeders reg, & gun. I just couldn't pass them up for 75.00 ea. & about 300.00 freight. They were horribly dirty & my heart sank when I took the covers off to clean them. I figured there was no way they'd ever be good. Prooved me wrong & at least one of them gets run 8 hrs a day 5 per week.

Good luck with your machine.

05-14-2009, 12:52 PM
Hi Dave t, I have been reading your post and it sounds like you have a manual, I have cleaned & adjusted the spark gaps acording to the manual. if so hows chance of getting a copy? My name is Robert:

04-16-2015, 12:18 PM

Do you have a manuel for the Linde UCC-305 tig welder that you could send or I can download