Ht 2000

[Plasman]

Working on a HT 2000 on a Whitney. Going through alot of consumables,like 6 cuts per set, The electrode shows very little wear but the nozzle is showing excessive wear.
When cutting at 200 amps there is a green flash at the end of the cut (copper burning at ramp down). When cutting at 100 amps, at the end of the cut I get a extended arc flash during ramp down, almost like cap discharge. This flash seems to end the same time the contactor opens after ramp down. Went through the gas system completely, spent alot of time on the gas sys. have good flow with no leaks. Cutting with oxy/air for my gasses. I am starting to lean towards a failing chopper. DC leaking through the power mod in the chopper until the contactor opens up and removes AC from the rectifier in the chopper. Has anybody seen this or can anybody give me any other ideas.

[ccawgc]

Check out the pilot arc system first, there may be a stuck contactor.
If the pilot arc contactor does not open then cut current hits the nozzle and they don't last long. Feel free to contact hypertherm tech support after you have the covers off and they will direct you.
You also need clean dry oil free air at the correct pressure. worked on one the had a loose air connection in the arc starter box.

[jimcolt]

Agree with CCAWG......it is almost positively a Pilot Arc Relay with the constacts welded shut. This keeps the nozzle at positive potential all during the cut and will show as excess heat and rapid nozzle orifice erosion. The pilot arc relay is a part that should be kept in stock for high use industrial plasma systems....


Jim Colt Hypertherm



Working on a HT 2000 on a Whitney. Going through alot of consumables,like 6 cuts per set, The electrode shows very little wear but the nozzle is showing excessive wear.
When cutting at 200 amps there is a green flash at the end of the cut (copper burning at ramp down). When cutting at 100 amps, at the end of the cut I get a extended arc flash during ramp down, almost like cap discharge. This flash seems to end the same time the contactor opens after ramp down. Went through the gas system completely, spent alot of time on the gas sys. have good flow with no leaks. Cutting with oxy/air for my gasses. I am starting to lean towards a failing chopper. DC leaking through the power mod in the chopper until the contactor opens up and removes AC from the rectifier in the chopper. Has anybody seen this or can anybody give me any other ideas.