THC detects active voltage with straight cut, but not when using THC

So I’ve been trying to figure out my THC for a minute now.

I have it on non divided voltage, set at .060 off the material and went to calibrate and when doing a straight cut it’s registering a solid and consistent 0.60v

So I set the THC to that instead of smart volts. But when I go to do a cut the torch fires, then shuts off showing 0v detected and the THC not registering voltage or pierce delay is too long when it’s not.

What gives, how does it detect voltage for everything else then not when using THC.

THC has been giving me issues since day one and I’ve had this for almost 8 months now. Longest it worked was for 3 weeks no issues but then refuses to work.

Is that a typo, or is it really showing 0.60v? It should be showing somewhere between 80 and 130 volts during a cut.

What plasma cutter are you using?

Nope a constant .60 volts.

That’s just some background voltage from the USB or something like that. Cutting voltage should be much higher.

Where is it connected to the raw voltage and is the raw voltage plugged into the PV input on the VIM box?

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Raw voltage (torch & clamp) and PV output

Is the polarity correct?

:black_circle:Black is negative and it is the electrode (torch)

:red_circle:Red Is positive and it is the work clamp (ground clamp)

A plasma cutter is a constant current electrode negative power supply.

I’m pretty sure. Per primeweld instructions pin 5 is red, pin 7 is black.

1 and 2 are on off.

So you are taking your raw from the CPC instead of directly from the terminals from inside the machine.

So what you’re saying is if I swap the red and black inputs to the THC it should read voltage?

Woah there, nobody is suggesting that you do anything yet. We’re just asking questions so we can get a good picture of your setup.

This might be a good place to start, however. It’ll tell us what voltage is going into the VIM.


Only if you currently have them in the incorrect locations.

Here’s the pinout on the CPC port for the primeweld.

Your description sounds like you’re hooked to the right terminal at the CPC port

Ideally I would hook up raw voltage straight from the terminals with inside the machine.

Here are the instructions on how to hook up raw voltage with inside the machine.

And remember to unplug the power