Lincoln Electric IM761 POWER FEED 15M - Manual (Page 19)

B-5 OPERATION B-5
CONSTANT VOLTAGE (CV) WELDING
(See figure B.1)
• Synergic CV:
Synergic welding allows for easy procedure setting. The
WFS and Voltage change together to maintain optimal arc
length.
When synergic welding and the WFS (right) knob is rotated,
the WFS is adjusted accordingly to control deposition rate.
The voltage changes too, to maintain a similar arc length.
Change WFS to change deposition rate.
When the Voltage (left) knob is rotated, the voltage is adjust-
ed accordingly to control the arc length.
Change Voltage to change Arc length.
• Non Synergic CV:
This type of CV mode behaves more like a conventional CV
power source. WFS and Voltage are independent adjust-
ments. Therefore to maintain the arc characteristics, the oper-
ator must adjust the voltage to compensate for any changes
made to the WFS.
• All CV Modes:
Arc Control adjusts the inductance of the waveshape. (This
adjustment is often referred to as "pinch". Inductance is
inversely proportional pinch.) Increasing Arc Control greater
than 0.0 results in a crisper, colder arc while decreasing the
Arc Control to less than 0.0 provides a softer, hotter arc.
CURRENT WAVE FORM (CV)
FIGURE B.1
POWER FEED 15M
Arc
Arc Control 0.00
Control +10.0
Wave Control -10.0
Current
C
u
r
r
e
n
t
Amps
A
m
p
s
T
T
ime
ime
PULSE WELDING
(See figure B..2)
Pulse welding procedures are set by controlling an over-
all "arc length" variable. When pulse welding, the arc
voltage is highly dependent upon the waveform. The
peak current, back ground current, rise time, fall time
and pulse frequency all affect the voltage. The exact
voltage for a given wire feed speed can only be predict-
ed when all the pulsing waveform parameters are
known. Using a preset voltage becomes impractical, and
instead the arc length is set by adjusting "trim".
Trim adjusts the arc length and ranges from 0.50 to
1.50, with a nominal value of 1.00. Higher trim values
increase the arc length, while lower trim values
decrease the arc length.
Most pulse welding programs are synergic. As the wire
feed speed is adjusted, the power source will automati-
cally recalculate the waveform parameters to maintain
similar arc properties.
Power Wave power sources utilize "adaptive control" to
compensate for changes in electrical stick-out while
welding. (Electrical stick-out is the distance from the
contact tip to the work piece.) Power Wave waveforms
are optimized for a 0.75" (19mm) stick-out. The adaptive
behavior supports a range of stickouts from 0.50"
(13mm) to 1.25" (32mm). At very low or high wire feed
speeds, the adaptive range may be less due to reaching
physical limitations of the welding process.
Arc Control in pulse programs usually adjusts the focus
or shape of the arc. Arc Control values greater than 0.0
increase the pulse frequency while decreasing the back-
ground current, resulting in a tight, stiff arc best for high
speed sheet metal welding. Arc Control values less than
0.0 decrease the pulse frequency while increasing the
background current, for a soft arc good for out-of-posi-
tion welding.
CURRENT WAVE FORM
FIGURE B.2
C C Arc ontrol 0.0
C Arc ontrol +10.0
C Arc ontrol +10.0
Arc Control -10.0
Arc Control -10.0
Current
C
u
r
r
e
n
t
Amps
A
m
p
s
T
T
ime
ime