ESAB PCM-875A - Poor Cutting Performance; Air Does Not Shut off

SECTION 6 PCM-875A Plasmarc System Troubleshooting
6-7
6.2.6 High Frequency and Pilot Arc are on but Main Arc does not transfer.
· Make sure work clamp is connected to work
material.
· Check the torch. Replace consumables if necessary.
· Make sure the current setting potentiometer is set
above 10 amps. If it is, set below 10 amps, then HI
FREQUENCY will go on and off at 5 sec intervals.
6.2.7 Poor Cutting Performance.
· Check air supply regulator . It should be adjusted to
65-75 psig.
· The air supplied to the torch should be free of oil
and water.
· Make sure the consumables in the torch are
acceptable.
· Check open circuit voltage.
· Check the output. Use a calibrated current probe
capable of measuring 100 amps in the presence of
high frequency.
6.2.8 Air does not shut off.
· Check air test, the gas solenoid valve is energized
when the switch is in the “on” position.
· Does air flow stop when the torch switch is
unplugged? If yes, check and repair the torch. If not,
send unit to an Authorized Repair Station for repair.
· Check voltage to solenoid coil, if present when
torch switch is unplugged, replace PCB1. If voltage is
“0”, replace solenoid valve.