Lincoln Electric IM939 RED-D-ARC LN-25 PRO EXTREME - Manual (Page 19)

B-4 OPERATION B-4
2. WIRE FEED SPEED KNOB
The large, calibrated wire feed speed knob makes
for easy and accurate adjustment of the wire feed
speed. The knob rotates 3/4 turn. Turn the knob
clockwise to increase the wire feed speed, and
counter clockwise to reduce the wire feed speed.
Models with analog voltmeters have a calibrated
scale printed around the wire feed speed knob
using "in/min" units. A separate decal with "m/min"
units is included with these models wire feeder.
Models with digital displays show the wire feed
speed on the display.
Wire Feed Speed, CV Operation
When Across the Arc models are operated with CV
power sources, the wire feed speed will remain a con-
stant value, independent of arc voltage changes, as
along as the arc voltage does not drop below the val-
ues per the following table.
CV Operation
Maximum WFS Minimum Arc Volts
280 15 V
340 17 V
440 21 V
520 24 V
600 27 V
Wire Feed Speed, CC Operation
When Across the Arc models are operated with CC
power sources, the wire feed speed changes as the
arc voltage changes. When the arc voltage increases,
the wire feed speed will increase; and when the arc
voltage decreases, the wire feed speed will decrease.
To preset the wire feed speed on CC power sources:
1. Set the Wire Feed Mode switch inside the LN25
PRO EXTREME to "CC".
2. Refer to the Figure B.1a graph for the setting for
the wire feed speed knob setting. Select the hori-
zontal line representing the Desired Wire Feed
Speed. (See Figure B.1a arrow for 375 in/min.)
3. Select the diagonal line representing the Arc
Volts. (See Figure B.1a for 29 volts.)
4. Determine the vertical line representing the CC
representing the CC Wire Feed Speed setting
where the above two lines cross. (See Figure
B.1a arrow line for 450.) Set the LN25 PRO
EXTREME wire feed speed knob to this value.
CC WFS dial setting = desired WFS x 35
Arc Volts
(See Figure B.1a)
LN-25 PRO EXTREME
50
100
150
200
250
300
350
400
450
500
550
600
650
700
50 100 150 200 250 300 350 400 450 500 550 650 700
35
31
29
27
25
23
21
19
17
15
33
600
V
CC
FIGURE B.1a