Valid Arc Lost, Thcad 300 config & Plasmac override

Good day, Gentlemen.

I already measured yesterday the output you suggested but in Idle it showed approx 580V, so I didn't mention it.
Didn't go for arc start either due to High DC?
Even on the control board the Voltage appears. The two connectors shown have a short with each other.
To the output (clamp, torch) I have only a short beep then it stops which I guess some circuit blocks then.


I found an old dvm which I can use to blow up, unfortunately Max 600V :woohoo:
Have to find batteries for this thing.


Definitely I will record! and I put my rubber boots on... Safety first!

And there is another one on the other side.

You are getting 580V as it is high frequency and causes all kinds of trouble for measuring equipment, but a true RMS DVM might work to measure it properly, but they tend to be north of 300$.

I did some measurements with the cheapest DVM as you suggested which goes up to 600V and it survived all the measured points even when the arc start was triggered.
The points you suggested do not give a proper dc reading, but make more sense since there is nearly 0 Volts when not triggered.


Since I never thought of measuring true Rms dc+AC I did and voila, when torch is on I got..




I still don't know if the arc ignition hig voltage appears there too since Rms is not that quick to show.

Further the question is since only true Rms shows proper voltage would the thcad 300 see the same? Is it also true Rms?

And sorry nothing went into flames so far!

TOMMYLIGHT... Thx for your suggestions!

If you fired the torch while measuring and the DVM did NOT go up in smoke, you are good to go!
All this cheap Chinese stuff has gotten me to think of buying one of those plasma cutters just to see how they are made and how they do things.
I have already gotten a MIG welder, 400A one, measured the output current while pushing it to the max aaaand got 196A ! Still not conclusive since i do not have wire thicker than 0.8 for it (small spool), so it might just do more.
BUT ! at that max it does not even get hot and can go on for hours without stopping so it does look that they are getting much better at it.
Then they go and give us this tinny virus! Thanks a lot, di#s !
BTW, does any one know where do i address the subpoena to the Chinese government for the loses in ..... everything due to their F...... ?
Thank you.

I didn't find a double shielded cable not even easy obvious in my B&W TV from the 70s?:silly:

So I guess I will use my beloved cat5 cable again. Or satellite cable. :laugh:

Use that from the TV, it has quite the isolation, just check if that isolation is intact.
NO cat5 or 6 or 834727734 for plasma arc voltage !

Older dvd cable, cd player, casete deck, laptop, radio ?

Found rg6 cable.... Does not work... Measurement tells me 29kHz..
True rms shows voltage but not thcad.
Regards&thank you..

:woohoo:
Hello Everybody, I fixed it ..somehow..first seems the filter capacitors I installed (on the flammed thcad 300) did not work, changed it to smaller ones and single ones!
I get readings!!!

The point where to connect , if somebody is interested I can show those points...Please don't mention the cables I used...I soldered so many different ones on...
My problem I think the voltage is a bit to high ...at the moment still works only with pulse. as soon as I try run a programm (automatic) it says valid arc lost...
again ...so I am seeking help to solve that problem now I have voltage readings..hurraaayyyyyy






many thanks for your patience ...

when the program runs it is just like I would snip with my fingers on the trigger, the arc has not even a spark..and the error message appears.

this video shows how to hook up a thc for an unknown system, at 5:00 they shortly mention what to do when it has a HF start!

hope that helps others as well to understand not to make my mistake.