[dmiller47591]

We have two HPR260s Auto gas running on a large C&G systems Crossfire cnc gantry. Both torches are controlled by Innova (kaliburn) thc. The controller is a burny 10 LCD +.

The problem is with torch 2. With the thc set exactly as torch 1, torch 2 dives to the plate. Arc volts never really stabilize at the setpoint.

5/8" MS
THC settings: 131 Arc Volts, .320" Pierce Height, .160" Cut Height, 0.6 sec pierce delay set in Burny controller.

The dive occurs on straight runs when the machine is NOT cornering. Only get about 1.5" of cut before crash. Pierce delay is turned off when we restart IN the kerf (cut).

We were finally able to get good stable arc volts and no crash at about 140-145 arc volts. The cut profile of the part suggested the torch was actually a little too low. "Positive" cut angle I think is the term. With the large dimension being at the top of the part. This angle was more noticeable after the first corner.

So my questions are:
How much torch height difference SHOULD one expect out of a difference of 15V?

Should I be looking at the voltage divider? I think I found it in the ignition console, not the power supply as some setups have. Theres a line for the CTP from the torch cap, P+, P-,S+,S-. Our THC takes a 1/40 division, so I think I can test this as S+ and S- should be 1/40th of P+ and P-, right?

Or Maybe cut gas problems? The torch leads on this torch are at least 6 years old. The other torch leads have been replaced after cut gas and coolant leaks at the torch body end.

I haven't called Hypertherm or Kaliburn because I have yet to isolate either of their systems as the cause. Any help would be appreciated.
Or is my positioner/encoder to blame?

[dmiller47591]

Okay, an update after scouring the manuals and doing a bit of troubleshooting. The torch leads were good, no gas leaks. The voltage divider was good. P+ and P- showed about what was on the THC remote screen within 2 volts. S+ and S- were 1/40 of arc voltage. Good news, I suppose.

We found that it ran fine cutting 3/4" MS at 260A with all recommended settings, but didn't when we switched to 5/8" MS at 200A. So I amp clamped the lead once we raised the arc volts enough to stabilize and not crash. 263 Amps DC.---Not right---We tried resending the cut chart, then 130A, then 80A, then "marking" which is 15-18A with a Nitrogen shield. Didn't work. It cut at 260A every time. The #2 used to work fine, although its been awhile since we've used it for anything other than 260A.

These cut parameters are sent serial via RS422, with both units daisy chained together. This problem is happening with the #2 unit in line. The #1 unit switches parameters fine. That means the main serial TX and RX lines from the controller are good, right? The manual says that the controller must send a "sleep" command to all units and then a "wake" command to the unit it is going to communicate with. I get no errors on the controller, so I wonder if the power supply even knows its talking to it?
I know I should probably just speak with hypertherm support. Problem is I work night shift, yet its my baby. I'll open the power supply tomorrow and take a look at the cnc interface components and cable. Maybe the boards will have LEDs that indicate during serial transmission. Any help or advice would be much appreciated.