OPERATION |
Return to Section TOC
TOC
EXAMPLE 2 - 2 STEP TRIGGER: Improved Arc Start and Arc End. Tailoring the arc start and arc end is a common method for reducing spatter and improving weld quality. This can be accomplished with the Start and Burnback functions set to a desired values and Crater set to OFF. (See Figure B.20)
For this sequence,
PREFLOW:
Shielding gas begins to flow immediately when the gun trigger is pulled.
STRIKE:
After preflow time expires, the power source regulates to the start output and wire is advanced towards the work piece at the Strike WFS. If an arc is not estab- lished within 1.5 seconds, the power source output and wire feed speed skips to the weld settings.
UPSLOPE:
Once the wire touches the work and an arc is estab- lished, both the machine output and the wire feed speed ramp to the weld settings throughout the start time. The time period of ramping from the start settings to the weld settings is called UPSLOPE.
WELD:
After upslope, the power source output and the wire feed speed continue at the weld settings.
BURNBACK:
As soon as the trigger is released, the wire feed speed is turned OFF and the machine output continues for the burnback time.
POSTFLOW:
Next, the machine output is turned OFF and shielding gas continues until the post flow timer expires.
Return to Section
Return to Master TOC
Return to Master TOC
Trigger Pulled
Idle Preflow
Shielding On
FIGURE B.20
|
| 2 Step Trigger | |
|
| Start = ON |
|
|
| Crater = OFF |
|
| ArcEstablished | Burnback = ON | |
|
| Weld | |
Strike Upslope | |||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Trigger Released
Burnback Postflow Idle
TOC
TOC
Gas
Off
Return to Section
Return to Master
| Weld | Start tim e |
Power |
| |
1.5 sec max. | Burnback Time | |
Source | Start |
|
Output |
| |
| Off |
|
Return to Section TOC
Return to Master TOC
WFS
Weld
Off
