Lincoln Electric IM649 Wave Designer - Manual (Page 66)

B.5 PRIMARY STT WAVEFORM COMPONENTS
The following paragraphs describe how peak current, background current, and tailout effect weld
droplet transfer.
B.5.1 PEAK CURRENT
The peak current control acts similar to an “arc pinch” control. Peak current serves to establish
the arc length and promote good fusion. Higher peak current levels will cause the arc to broaden
momentarily while increasing the arc length. If set too high, long arc lengths will inhibit travel
speed. Setting this level too low will cause instability and wire stubbing. In practice, this current
level should be adjusted for minimum spatter and puddle agitation.
B-12 Appendix B STT WAVE SHAPING PRINCIPLES
WAVE DESIGNER
27850064
ADJUST ARC LENGTH WITH PEAK CURRENT
OPTIMUM LOW HIGH
NOTE: In 100% CO
2
shielding gas applications, the peak current level should be set greater
than in a similar application using a high percentage Argon blend. Longer initial arc
lengths with 100% CO
2
are required to reduce spatter.