I am having an intermittent problem with my brand new Hypertherm Powermax 1000. I'm cutting 18 gauge steel on my table at 40 amps using fine cut consumables, and most of the time it works great, but sometimes the torch will not fire. When the torch does not fire, the plasma cutter's fault light comes on, but no other light comes on with the fault light (i.e., the torch light and the low air pressure light remain off) so this would seem to indicate that whatever the problem is, its not low air pressure and its not whatever the torch light checks for (the only time I have seen it come on is if I unscrew the consumables when the power switch is still on).
When this happens, the air does not come on and the torch does not appear to try to fire. The fault light turns off by itself after several seconds. If I retry the cut right away, sometimes it will work fine, other times I can try it a few times and it will not cut. If I shut the plasma cutter off, remove the consumables, clean them up a bit, and reinstall them, it always seems to cut again, but the problem re-occurs, sometimes after several cuts, sometimes on the very next cut.
I thought maybe there was a problem with the consumables, I think there is something that needs to move in there to start the arc, but I don't know how to check for that...
Initially, I had a 2 second delay after each cut, during which time the air continues to flow, then the gantry moves to the next position which takes another couple of seconds before the next cut begins. It doesn't seem like this would be exceeding the duty cycle with 40 amp 18 gauge, but just to test it, I increased the delay between cuts to 6-8 seconds. This had no effect on the problem, it still occured just as frequently.
Something that is very strange is that my gantry moves along the cut path, even though the torch does not fire. My software is set up to not move the gantry until it gets the "ok to move" signal, which comes from the plasma cutter. I admit that I have not yet stuck a multimeter on these contacts to verify this for certain, but this feature has been working fine all along, so I can only assume that for some reason, the plasma cutter is signalling "ok to move", even though no arc has been established.
My air goes through a standard air dryer as it comes out of the compressor, and I have a dedicated Motor Guard air filter at the plasma cutter itself, so although the air quality isn't as nice as if I had an A/C dryer, it should be fairly decent.
My ground clamp has a nice clean connection to the metal itself, and there is no dirt or rust on this metal. (If it were a ground path type problem, the torch should still spit out a pilot arc, right? Its not even doing that when it fails to fire. Plus, like I mentioned, its closing the "ok to move" circuit, which is weird if no arc has been established. This makes me wonder if this is some sort of problem in the plasma cutter itself.)
Does anyone have any ideas, or things that I should try?