THC Voltage

Hey Matt, leave the Hypertherm 45XP voltage divider set at 50:1.

I went back through the configuration we set up for your retrofit. The isolation amplifier and the 47k/22k resistor divider require an Arc Voltage Scale of 157. The JCM file I originally sent you had 157, but the generic StrikeCommand preset currently uses 230 and may have overwritten that value.

Your numbers line up almost exactly with that mismatch: a true 118V reading scaled by 230 instead of 157 would display about 173V.

In Machine Configuration, open Torch Height Control → Tuning and check Arc Voltage Scale. If it is 230, change it to 157, apply the configuration, and check the voltage again during the steady portion of a cut.

If it is already set to 157, let me know and we’ll verify the isolation amplifier output and the resistor placement on the THC connector next. The connector should have the 1µF capacitor across pins 1–2 with positive toward pin 1, 47k across pins 3–4, and 22k across pins 5–6.

It was set to 230, I think that fixed the issue.

Is there a way to see a live readout of the volts on the control? The readout on the pendant seems to have stopped working. So I'm not sure what my plasma is sending back to the control or if it is at all.

I thought I had it working, almost wondering if in adding some other wiring on the machine I accidently messed something up.

Matt, yes—there’s a live voltage readout in the ARC row directly below X/Y/Z in GcodePilot. The large number is the measured arc voltage; the smaller number to its right is the target.

Is the large ARC number showing voltage while the torch is cutting, or does it stay at zero? Zero with the torch off is normal.

If the main ARC readout works but the pendant doesn’t, we can focus on the pendant’s display settings. If both stay at zero with an established arc, a wiring or voltage-signal connection issue is more likely, especially given the recent wiring changes.

Let us know what that main ARC readout shows before changing any more settings.

The scaling must be way off, with scaling set at 157, the book voltage should be 132, it's reading out 32.