Tweco VS 212 PortaFeed - Manual (Page 35)

PORTAFEED VS 212
Manual No. 0-4994 4-3 OPERATION
4.05 Adjusting Burnback Time
Burnback time is set at the factory, but the motor
control printed circuit board contains a component
that permits adjustment of burnback time.
Burnback time relates to the amount of welding wire
remaining at the end of the welding gun after the
welding process ends. Increasing burnback time re-
sults in less wire remaining at the end of the welding
gun at the end of the weld. Decreasing burnback time
results in more wire remaining at the end of the weld-
ing gun after the welding process ends.
WARNING
ELECTRIC SHOCK CAN KILL. Make cer-
tain the power source and wire feeder are
both turned OFF before beginning the pro-
cedure.
1. Using a nut driver or socket, remove the wire spool
hub .
2. Remove the internal
cover (refer to Figure 4-3).
Remove the four screws
and Internal Cover
Artr # A-09406
R68 located on
this PCB
Figure 4-3: Accessing PCB for Burn
back
3. Locate component R68 (Burnback) on the motor
control printed circuit board (refer to Figure 4-3).
The best procedure is to make only slight adjust-
ments until the amount of burnback is acceptable.
Component R68 has a single turn (300°) range of
adjustment.
To increase burnback time, adjust component R68
clockwise.
To decrease burnback time, adjust component
R68 counterclockwise.
4. Replace the internal cover.
5. Replace the wire spool hub (refer to 3.03 Adjust-
ment Of Spool Tension in Section 3 of this manual).
4.06 Wire Feed Speed Ranges
The range of the wire feed speed adjustment knob on
the front panel can be set to either High or Low. The
High/Low switch is located on the inside panel next
to the CC/CV switch. Refer to figure 4-4.
High
Low
CC
CV
Art # A-07254
Figure 4-4: High/Low Switch Location