Tweco 38 CutMaster - Manual (Page 32)

OPERATION 4-8 Manual 0-2964
4.03 Sequence of Operation
The following is a typical sequence of operation for this power supply. Refer to Appendix 1 for block diagram.
1. Plug the input power cord into an active circuit.
a. AC power is available at the Power Supply.
2. Place the ON / OFF switch on the Power Supply to ON (up) position.
a. AC indicator turns on; fan turns on.
NOTES
If there is adequate gas supply pressure to the power supply, gas comes on if Torch Trigger is pressed.
If torch trigger is held while user turns on main AC power, system goes into 'protective interlock' mode. AC
indicator flashes; torch will not pilot. Release torch trigger, turn AC switch OFF then ON.
3. Put RUN / SET switch to SET (down position).
a. Gas flows to set pressure. Turn gas pressure adjustment knob to set pressure to 65 psi / 4.5 bar; Gas
indicator turns ON when there is sufficient gas pressure.
4. Put RUN / SET switch to RUN (up position). Gas flow stops.
5. Wear protective clothing and welding gloves. Protect eyes. Slide the trigger release to the rear; squeeze and
hold the trigger. Gas flows briefly, then shuts off momentarily. Then gas flow will resume. Pilot arc is estab-
lished. DC indicator
turns ON. Move Torch within transfer distance of workpiece.
a. Main arc transfers to workpiece.
6. Complete cutting operation.
NOTE
If the torch is lifted from the workpiece while the torch switch is activated, the main arc will stop and the pilot arc will
automatically restart.
7. Release the torch trigger.
a. Main arc stops; gas flows for approximately 10 seconds.
8. Set the power supply ON / OFF switch to OFF (down position).
a. AC indicator turns OFF; fan turns OFF.
9. Set the main power disconnect to OFF, or unplug input power cord.
a. Input power is removed from the system.