I have a question that deals with either the C8 A/C Relay, or a Hypertherm MAX20 built in the late 80's. I have my cnc plasma cutting table all wired up, torch switch wired up to the c8 relay. I checked that the relay is closing when the code says to fire the torch. All is good. I then hooked up the wires for the plasma torch to the C8 relay and ran it thu the code again and this is where I'm having a hard time figuring out what's going on.
When the code closes the relay to fire the torch, the plasma cutter will flow air and then for a split second it will fire the plasma, then cut out, but the air continues and i can hear rapit clicking in the plasma unit like the relay in the plasma unit wouldnt stay on. I've had this happen to me before when I would use it as a manual plasma cutter and all i had to do was change consumables and it would be fine. So I did just that, changed consumables but it will still flow air and fire the plasma for a split second, then cut out and the air would flow and I would head that same clicking coming from the plasma unit.
Now the next this I did was check that the plasma cutter would run fine without going through the C8 relay. All I did was take a short piece of wire and and touch the 2 torch wire terminals to bypass the relay and complete the circuit. I did that, the air flowed, the torch fired, all was fine.
So I'm stuck. I'm leaning toward the C8 relay as being the problem, but I know it's working because it the circuit closes and the plasma flows air, but the torch wont stay lit.
And I'm also leaning towards the plasma unit becuase I hear that rapid clicking like the relay in the plasma unit wont close.
Could my relay be to small for the load of closing the plasma switch? I didnt blow out the fuse on the C8 board. Im no electrical engineer but could there be enough voltage getting through the relay to open the soloniod to flow air, but not enough voltage geting through the C8 relay to close the plasma unit relay to fire the torch? (maybe the plasma unit realy is dirty & dusty?) When I measured the voltage running thourgh the torch switch, it read 24vac. Can the relay not handle 24vac.
Can someone help me out?
Chris