Live voltage too low?

I just went through the support page again, didn’t find what I was looking for, could be there or I’m just missing something else.

But, book specs show 130v for my powermax 45xp. Live voltage is reading 32. I set nominal to 130, but live is still 32. Is that right?

What am I missing?

The reason I’m looking into this is I just created new tool sets off book specs and 48ipm per the book does not cut reliably. The THC is hunting all over the place, torch goes really high. Slow it down to 35, things are good. Just wondering if something is up with the voltage discrepancy.

Believe I may have found my own issue. I had sporadically had the IHS start position error, which I though was odd since my setup had been great before. (I shortened my whip to fit under my storage loft and have been paranoid about it).

The further I pressed on into my night of cutting, the more I got the IHS error. I though I was clearing it by blowing out the z axis with and air gun, but finally reached the point where it kept binding and would not even travel down to IHS. It would sometimes under manual jogging, but I think that’s because it was going 300ipm vs the 60 ipm IHS.

Anyway, took the torch off, loosened and cleaned everything, still had the error. Oiled with the only thing I had in the garage, Outers tri care. Boom, back in business. The whole Z axis is as clean as the day it was assembled.

Checked live voltage and it was reading within the parameters. (For 1/8 inch mild steel). I suspect I was having IHS errors (was not touching the materials prior to piercing)but the torch was still able to fire and then IHS chose the wrong initial voltage? In reading the support page IHS picks the voltage based on the pierce right?

Anyway, next time I cut 1/4 inch I’ll watch the voltage. But for now, I think I got it.


It’s started happening again. Live voltage showing 40-50 while cutting 1/4 and 3/8 plate. Upon watching the torch, it’s touching correctly for the IHS cycle. Although I though I noticed it pierce early once or twice but I wasn’t sure. I cleaned the Z again real well, as well as the IHS contact screw.

I have a tiny bit of play in the Z lead nut as well.

Perhaps updating the firmware will help?

Are you on a laptop or a desktop?

The IHS firmware update wont fix your situation because when the torch pierces high you would get a higher than expected voltage.

I am guessing that you have ground interference somewhere.

Laptop. Now that you mention it, it started happening when I went back to my PC laptop vs my Mac. I’ll test again!

This would be the ground loop from working with the laptop plugged in and charging right?

I ran without it plugged in and voltages appeared correct, but I had switched to fine cut consumables.

Yes that is correct- the AC ground plane influences the THC measurement and must be isolated. Thats why desktop computers require the use of a 3 prong to 2 prong adapter (not really recommended for shock reasons) or a USB isolator. A UPS also works to isolate the ground.


@brownfox We have USB isolators in stock that will fix this issue if you are interested in purchasing one from us. Just mention this forum post and shoot an email over to !

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Dang. I had read about that, but I thought I was avoiding that problem by using a different power strip than the one my control box was on.

I’ll just charge it off the USB C port on it, should do the trick.