THCAD-300 Jumper

I'm setting up a THCAD with raw arc voltage. What is the best jumper setting to use? My Hypertherm 600 is a pretty old machine and has no divided voltage. As far as the jumpers go I don't quite understand the rationale behind choosing what to use. I've read the Plasmac user guide and a few posts but I haven't quite figured it out. any links or explanations would be appreciated.

Kale, more info, please.
To what you are connecting the THCAD ?
If to a Mesa card, then 1/32 is the best option regarding noise immunity and resolution.
If to a parallel port, that will greatly depend on how good the latency of that PC is.
Also, be very careful where you wire the THCAD inside the plasma source, there is only one place inside it that the THCAD can be safely wired, otherwise it is very likely to mess up the card.
Pictures of the insides of the plasma source would help to pinpoint the location.
Or maybe your plasma has an output for THC with full voltage scale (no divider), so that is easy.

I'm using a Mesa 7i96. Here are some pictures inside the plasma:

Above,
The left screw terminal is the wire for the ground clamp. The middle with the red wire is labeled 500v. The white wires I can't say for certain what they are.




There is no plug for raw voltage.

The plug with the purple wires are for a relay to fire the torch. The blue wires are currently irrelevant.

I found the Schematic. This clears up what the wires from the screw terminal are. I still need to figure out whether the THCAD should be hooked to the electrode or ground.

Kale Dobrohoczki wrote: The left screw terminal is the wire for the ground clamp. The middle with the red wire is labeled 500v.

I really hope Hypertherm did not put that terminal there, that is a 16A/500V terminal, hence that is not a label for anything except the terminal block. The left wires (you said go to the clamp) should be yanked from that terminal strip and put on a 60A to 100A terminal.

Kale Dobrohoczki wrote:

Attachment not found

The SanRex part is the rectifier for 600V/60A, so you can attach the THCAD inputs to the + and - terminals on that rectifier, not on the ~ terminals. Use proper plugs for that and tighten the screws properly.

tommylight wrote: I really hope Hypertherm did not put that terminal there,

To my knowledge, Hypertherm did put that terminal there. I don't think the torch has ever been sent for servicing for a repair guy to rig up something screwy. The torch was brand new maybe 10 years ago and no one has done any DIY "repairing".

For clarity, the THCAD +IN should go to SanRex + and the THCAD -IN should go to SanRex -
Correct?

Yes.