About two months ago we started experiencing lock-ups while using the 2nd torch on this machine, only on piercing. Immediately it was assumed that there was a grounding issue being that a high frequency voltage is used during the pilot stage of the arc. After speaking with Koike for weeks trying to get this resolved we had two techs from Thermal Dynamics come down and look at the machine. They eventually gave up and left that evening.

So far we've re-seated all the ground cables on the tank, grounding rods, insidew the controller, swapped power supplies, stand-off controllers and even ran the second torch on the number one torch port on the controller. It always locks up.

After the first attempt at fixing this problem the machine ran great for about 4 days and then began locking up again. This consisted mainly of re-seating ground cables. Since then additional ground cables have been run from the torches themselves to the star ground on the side of the table, and even from the power supply chasis to the grounding rods.

The problem seems to lie somewhere between the tip of the second torch and it's connection to its power supply. I checked the mesh inside the sheath on the torch and it looks fine, and tested good with a meter.

If anyone has had similar problems with a Koike table using Thermal Dynamic torches I'd greatly appreciate any input. So far Koike and Thermadyne have basically given up on us.

One long shot is to check the continuity of the HF pilot arc wire.
I had a similar instance on a MG table with TD torches.
The HF wire had a small fracture from flexing in the cable track, it was close enough to make contact for the arc to jump across, but eventually it started to fail completely.
Al.

I will definitely check this out. Thanks a bunch for responding.

One long shot is to check the continuity of the HF pilot arc wire.
I had a similar instance on a MG table with TD torches.
The HF wire had a small fracture from flexing in the cable track, it was close enough to make contact for the arc to jump across, but eventually it started to fail completely.
Al.

Bang on.

If you manually fire the plasma torches does the controller lock up? Are the input and output signals from the plasma to the controller electrically isolated from the controller? What is the model of the plasma? Have this system been used right along with 2 plasmas?