Lincoln Electric IM716 POWER WAVE 455STT - Manual (Page 29)

B-9 OPERATION B-9
STT WELDING
The pictures illustrate the waveshape of current for
the process. They are not drawn to scale, and are
intended only for the purpose of showing how the vari-
ables effect the waveform.
Trim in the STT mode adjusts the tailout and back-
ground portion of the waveform. For open root
processes, the tailout is fixed, and the trim affects only
the background level. Trim values greater than 1.0
add more energy to the weld and make the weld pud-
dle hotter; trim values less than 1.0 reduce energy to
weld A nominal value of 1.0 will work for most applica-
tions. (See Figure A.7)
For most programs, peak current is adjusted by arc
control, also referred to as wave control. A wave con-
trol value of +10.0 maximizes the peak current, while
a wave control of -10.0 minimizes peak current. In
general, the peak current is proportional to the arc
length. (See Figure A.8)
POWER WAVE 455
Wave Control 0.0
Wave Control +10.0
Wave Control -10.0
Trim 1.00
Trim 1.50
Trim 0.50
Current
Time
Time
Current
FIGURE A.7
FIGURE A.8