Lincoln Electric PIPEFAB Series Operator's Manual page 82

PIPEFAB™ WELDING SYSTEM
Example 3: 2-Step Trigger: Customized Arc Start, Crater and Arc End.
Aluminum is an example of where start, crater and burnback are commonly used to improve welding
performance.
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 & UPSLOPE: 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.
CRATER & DOWNSLOPE: As soon as the trigger is released, the wire feed speed and power source
output ramp to the crater se�ngs throughout the crater �me. The �me period of
ramping from the weld se�ngs to the crater se�ngs is called DOWNSLOPE.
BURNBACK: A�er the crater �me expires, 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.26
B-31
OPERATION