Tweco 75XL Plus PAK Master - Manuel (Page 34)

OPERATION 4-4 Manual 0-2807
4.03 Sequence of Operation
The following is a typical sequence of operation for this
cutting system. Refer to Appendix II for a block diagram.
1. Close main power source disconnect.
a. AC power is available at the Power Supply.
2. Place RUN/SET/LATCH switch to RUN mode.
3. Place the ON/OFF power switch on the front
panel of the Power Supply to ON.
a. AC Power indicator blinks ON and OFF
for eight seconds then stays ON.
b. Fans turn on.
4. Place RUN/SET/LATCH switch to SET mode.
a. Gas solenoid opens and gas flows to set pres-
sure.
b. GAS indicator turns ON.
NOTE
GAS indicator will not come ON if the gas pres-
sure is set below 35 psi (2.4 bar) at the Regulator/
Filter Assembly.
5. Place RUN/SET/LATCH switch to RUN mode.
a. Gas flow stops.
b. GAS indicator turns OFF.
NOTE
Do Not use the LATCH position for automated
system applications.
6. Protect eyes and activate system (CNC start sig-
nal or press Remote Pendant switch)
a. Gas pre-flows starts.
b. GAS indicator turns ON.
7. After gas pre-flow (approximately 2 seconds)
a. Power supply enabled.
b. DC indicator turns ON.
c. Pilot relay closes.
8. Pilot arc is established
9. Torch moves to within transfer distance of work-
piece.
a. Main arc transfers to workpiece.
b. Pilot arc OFF.
10. Complete cutting operation.
NOTE
If the torch is lifted from the workpiece, while still
having torch is activated, the main arc will stop
and the pilot arc will automatically restart.
11. Stop system (CNC stop signal or release Remote
Hand Pendant switch)
a. Main arc stops.
b. Pilot arc stops (power supply enable signal re-
moved).
NOTE
If torch is activated during post-flow, pilot arc will
immediately restart.
If torch is within 3/8 in (9.5mm) transfer distance
of workpiece, main arc will transfer.
12. Gas will flow for 15 seconds (post-flow).
a. Gas solenoid closes
b. Gas flow stops.
c. GAS indicator turns OFF.
13. Place the ON/OFF power switch on the front
panel of the unit to OFF
a. AC Power indicator turns OFF.
b. Fans turn OFF.
14. Place the main power disconnect to open.
a. Main AC power is removed from the system.