THC hookup to raw voltage

[kaledobrohoczki]

I have a powermax 600 and I'm setting up a machine with linuxcnc. I'm using a Mesa 7i96 with a THCAD-300.

There is no divided voltage so I will need to wire the THCAD-300 inside the plasma cutter. Does anyone know where to wire is in? My understanding is that I need to wire it to the ground(work) terminal and either the electrode or the nozzle.
Thanks

[Rodw]

One wire goes to the work clamp and the other to the torch. If you have a HF start, wire it before the HF module. (The THCAD manual says do not use with HF start machines. I have seen a photo that explains why! Lots of charcoal on the THCAD board)

[kaledobrohoczki]

Do you agree with the advice given here?
https://forum.linuxcnc.org/plasmac/3951 ... per#174279

[Rodw]

There is no doubt that Tommy is an expert with plasma cutters. He has a vast knowledge of CNC and electronics. I trust his advice and he has been very helpful as I've built my machine. I've always spent the money to buy a plasma cutter with a CNC interface. Tommy lives in a war torn European country and is an expert at making things work on old surplus equipment becasue he can't source the gear you and I can. I call him the McGuyver of plasma cutting.

I thought I saw your 600 was HF start and if thats the case, the 25,0000 plus volts it generates in startup will smoke the high voltage side of the THCAD. There was someone who made this mistake recently but he was able to get it going again after replacing the 10 through hole resistors. Tommy's solution that did work for that guy was to pick up the voltage before the HF start circuit.

[kaledobrohoczki]

I also think Tommy's expertise is trustworthy. He's helped me a lot.

From the manual, I gather that my Powermax 600 is a pilot arc start. It has a pilot arc IGBT in the wiring diagram. Full disclosure, I don't know what an IGBT is, but I take it as evidence that it's pilot arc start.

The overwhelming consensus on the internet seems pilot arc is preferred for plasma. While my old machine doesn't have the interfacing for CNC it does seem to be well built and good quality. It's my understanding that HF is something many cheap plasmas use.