Lincoln Electric PIPEFAB Series Operator's Manual page 81

PIPEFAB™ WELDING SYSTEM
Example 2: 2-Step Trigger: Improved Arc Start and Arc End.
Tailoring the arc start and arc end is a common method for reducing spa�er and improving weld quality.
This can be accomplished with the Start and Burnback func�ons set to a desired values and Crater set to
OFF.
For this sequence,
PREFLOW: Shielding gas begins to flow immediately when the gun trigger is pulled.
RUN-IN: A�er preflow �me expires, the power source regulates to the start output and wire is
advanced towards the work piece at the Run-In WFS. If an arc is not established within
2.0 seconds, the power source output and wire feed speed skips to the weld se�ngs.
START: Once the wire touches the work and an arc is established, both the machine output and
the wire feed speed ramp to the weld se�ngs throughout the start �me. The �me
period of ramping from the start se�ngs to the weld se�ngs is called UPSLOPE.
WELD: A�er upslope, the power source output and the wire feed speed con�nue at the weld
se�ngs.
BURNBACK: As soon as the trigger is released, the wire feed speed is turned OFF and the machine
output con�nues for the burnback �me.
POSTFLOW: Next, the machine output is turned OFF and shielding gas con�nues un�l the post flow
�mer expires.
FIGURE B.25
B-30
OPERATION