Appendix Ii: Sequence Of Operation (Block Diagram) - Firepower FP-78 Operating Manual

APPENDIX II: SEQUENCE OF OPERATION
ACTION
Protect eyes and
activate torch
RESULT
Gas flows (2 seconds).
After gas pre-flow:
DC indicator on.
Pilot relay closes.
Pilot arc established
Torch deactivated (by torch switch
release or by remote device).
Main arc stops. Pilot stops.
(Power supply enable signal removed.)
Gas flows (15 seconds)
NOTE - If torch is activated during
post-flow, pilot arc will immediately restart.
If torch is within transfer distance (3/8 in) of
workpiece, main arc will transfer.
After post-flow:
Gas solenoid closes, gas flow stops.
APPENDIX
(BLOCK DIAGRAM)
ACTION
Close external
disconnect switch.
RESULT
Power to system.
ACTION
RESULT
ACTION
ON/OFF switch to ON.
RESULT
AC indicator blinks for 8 seconds then steady on.
Fans on.
Gas solenoid open, gas flows to set pressure.
Gas flow stops after pre-flow (purge).
Power circuit ready.
PILOT ARC
ACTION
ON/OFF switch
to OFF
RESULT
All indicators off.
Power supply fans off.
32
ACTION
Torch moved away
from work (while
still activated).
RESULT
Main arc stops.
Pilot arc automatically
restarts.
ACTION
Torch moved within
transfer distance of workpiece.
RESULT
Main arc transfer.
Pilot arc off.
ACTION
Open external
disconnect.
RESULT
No power to system.
A-01654
Manual 0-2700