Hypertherm Powermax900 Service Manual - Manual (Page 34)

3-7
M
AINTENANCE
Service Manual
SEQUENCE OF OPERATION
Shaded boxes represent operator action. Clear boxes represent results from operator action.
2-00
• Connect torch and lead assembly
• Connect gas supply to filter-regulator on power unit
• Apply power at line voltage disconnect box.
• Set power circuit breaker S1 to ON (1).
Within five seconds, TEMP LED turns off indicating the
transformer temperature is within operating limits.
Fan M1 operates and POWER, LINE VOLTAGE, and GAS
PRESSURE LEDs illuminate indicating system is ready for
operation.
• Push and hold GAS TEST switch to
check air pressure.
Gas solenoid valve V1 opens to
purge system and to allow setting
of pressure.
• Select cutting current with AMPS knob.
Power circuits ready.
• Connect work cable to workpiece and
position torch on workpiece.
• Depress plasma start switch on hand
torch or remote start switch for machine
torch.
Pilot arc relay CR2 closes and pilot arc
current starts.
.
• Move torch to make cut. Workpiece
falls away after cut.
Arc extinguishes when trigger
is released. Post flow
continues for 6-10 seconds.
System off
• Release GAS TEST switch.
Gas solenoid valve V1
closes. Gas flow stops.
Current flows to nozzle.
Gas solenoid valve V1 opens and gas flows.
Pilot arc is sensed.
Cutting arc transfers to workpiece.
Pilot arc relay CR2 opens and pilot arc stops.
Gas solenoid V1 closes - gas
flow stops