Tweco FP-55 - Manual (Page 25)

Manual 0-2846 4-3 OPERATION
B. Check Primary Input Power Source
1. Check the power source for proper input voltage.
Make sure the input power source meets the power
requirements for the unit per subsection 2.03-A,
Specifications/Design Features.
2. Connect the input power cable (or close the main
disconnect switch) to supply power to the system.
C. Gas Selection
Select desired single gas supply. Make sure gas source
meets requirements (refer to
subsection 3.06, Gas Con-
nections). Check connections and turn gas supply on.
D. Work Cable Connection
Check for a solid work cable connection to the
workpiece.
E. Torch Connection
Check that the torch is properly connected.
F. Power On
On the Power Supply place the ON/OFF switch to
the ON position.
G. Select Current Output Level
On the Control Panel, set the desired current output
level between 20-40 amps for cutting or gouging.
H. Set Operating Pressure
Place the RUN/SET switch to the SET position. Gas
will flow. Adjust gas pressure control to 70 psi (4.8
bar).
I. Prepare to Cut
Return the RUN/SET switch to RUN position. Gas
will not flow until the Torch Trigger is pressed.
The system is now ready for operation. Push the Torch
Trigger to start the pilot arc. There is a 2 second pre-
flow before the arc starts.
4.05 Sequence of Operation
The following is a typical sequence of operation for this
power supply. Refer to Appendix for block diagram.
1. Close main power source disconnect switch.
a. AC power is available at the Power Supply.
2. Place RUN/SET switch to RUN mode.
3. Place the ON/OFF power switch on the front panel
of the Power Supply to ON position.
a. AC Power Indicator blinks ON and OFF for
eight seconds then stays ON. Fan turns on.
NOTE
Gas comes on if Torch Trigger is pressed (although
unit will not pilot until switch is released and re-
closed after the light stops blinking).
4. Place RUN/SET switch to SET mode.
a. Gas solenoid opens and gas flows to set pres-
sure. Gas Pressure Regulator/Filter Assembly
should be set to 70 psi (4.8 bar). 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 Gas Pres-
sure Regulator/Filter Assembly.
5. Place RUN/SET switch to RUN mode.
a. Gas flow stops. GAS Indicator turns OFF.
6. Protect eyes and press or activate torch switch.
a. Gas pre-flow starts (approximately 2 seconds).
GAS Indicator turns ON.
7. After gas pre-flow:
a. Power Supply enabled. DC indicator turns ON.
Pilot Relay closes.
8. Pilot arc is established
9. Move Torch within transfer distance of workpiece.
a. Main arc transfer. Pilot arc OFF.
10. 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.
11. Release or deactivate the torch switch.
a. Main arc stops. Pilot arc stops (power supply
enable signal removed).
NOTES
If torch is activated during post-flow, the pilot arc
will immediately restart.
If torch is within 1/4 inch (6.4mm) transfer dis-
tance to workpiece, the main arc will transfer.