Voltage Drops to Zero

[KineticArc]

So, I have a ArcLight 12000 that is not quite 2 years old. It has been a great table! I cut a lot of of 14 ga. mild steel with 45 amp Fine Cut and a Hypertherm 65. I use the book settings, and usually have pretty good luck, with minimal dross.
However, recently it has developed an issue, where it starts out cutting just fine on the first few files. The pre-set voltage is set for 78 volts and the THC tracks right along. Then after a few cuts (files), my voltage starts dropping off to "0", and the torch climbs to about .250 and stays there. I have tried moving the ground around with no change. I have shut off the thc, and then just let it run. Obviously this isn't the way it was intended to be operated, but it works. Of course, the consumable life starts suffering. I have shut down the computer, and rebooted with limited success, and the issue seems to return after a few cuts.

Anybody, got any ideas of what is going on? All the lights on all the controllers are lit, and appear to be as they should be.

Also,
The table is grounded with two cables, one from the slat frame, and one from the table frame, both to a grounding rod driven into the ground about 6-8 feet. The HyperTherm ground is run across the floor with no coils.
The THC cable leaves the console, and goes straight up to the ceiling, and the across and down the wall to the Hypertherm, following the airline, and not crossing any of the power cables.
The water in the table is down about an inch from the bottom of the plate, but I don't think that makes any difference, and I seem to get less dross this way.
I vent my air system frequently. I use this system right before the air enters the plasma unit (http://www.tptools.com/Filter-Regulator ... l?b=d*8088) I've never even seen a "Damp" filter, and I get very little water in the separator.

Thanks,
Blaine

[drossmaker]

KineticArc,
I would suggest giving us a call so we can trouble shoot in real time. There are many possible scenarios that may result in the THC rising and we would like to mete those out. We definitely want to get your table dialed!!! 866-222-2154.

~drossmaker

[KineticArc]

KineticArc,
I would suggest giving us a call so we can trouble shoot in real time. There are many possible scenarios that may result in the THC rising and we would like to mete those out. We definitely want to get your table dialed!!! 866-222-2154.

~drossmaker

Thanks Scott, I just figured maybe there was something obvious that I was missing. So, I decided to give the forum a try.

I'm kind of limited to Fridays, as my real job gets in the way. So, this Friday is the earliest time I will be able to call, and have the table in front of me. I will try and call your shop then, and see if we can figure out what is going on with the table.

Thanks,
Blaine

[tcaudle]

when it drops again pull the stereo plug out of the small module at the plasma. Clean it real good and reseat it and see if the voltage returns. If not pull it again and with a DVM on 20V scale meter between the tip(+) and the next ring (-) on the stereo plug. fire the torch in the air and you should see about 3.2V DC. If it is a lot lower then something is wrong with either the CPC cable or the divider circuit in the Hypertherm.

If it is close to the 3,2V (simply take the reading you get and multiply by 50 and that is the voltage that should be on the screen) then the problem is in the PWM Module itself. Cables are always suspect and if you can wiggle the CAT5 cable or the CPC cable and the votls comes back or goes away it time to change that cable

[drossmaker]

KineticArc,
We will be here in Friday. We open up at 7:30am PST. I think trouble shooting over the phone will be the most efficient use of our time. We look forward to your call.

~drossmaker

[KineticArc]

Sorry, I haven't followed up on this. I will try to call the shop this next Friday morning.

I will also give Tom's suggestions a go.

Thanks,
Blaine