Lincoln Electric SVM138-A Service Manual page 111

F-47
WIRE SPEED ACCURACY TEST (continued)
TEST PROCEDURE
Perform the following checks with the LN-9 GMA
wire feeder connected to a Lincoln CV welding
power source according to the proper connection
diagram. (See the Installation section of this
manual.)
A. Check for the proper wire feed inches per
revolution of the drive roll.
1. Set the LN-9 GMA wire speed control for
between 50 and 120 IPM (1.27 to 3.17
M/MIN).
2. Measure the precise length of wire fed by
exactly 10 revolutions of the drive rolls.
This measured length should be 53.0 ± .8
inches (1.35 ± .02 meters). If not, there
may be a problem with the wire or the wire
feed path.
Guide (Feeding Problems) in this sec-
tion of the manual. Also check for correct
drive roll tension adjustment.
MODEL
MODEL
LN-9 GMA
or
LN-9F GMA
TROUBLESHOOTING & REPAIR
See the Troubleshooting
ACTUAL SPEED METER
READING
IN/MIN M/MIN
161 4.1
322 8.2
LN-9 GMA Wire Feeder
B. Check for the proper drive roll revolutions
per minute.
1. Adjust the LN-9 GMA wire speed control
for the LN-9 GMA ACTUAL speed meter
readings given in the table below.
2. Compare the corresponding LN-9 GMA
drive roll RPM (counted revolutions in 60
seconds) and LN-9 GMA SET speed
meter readings with the table below. The
numbers should match. If not, perform
the Meter Circuit Accuracy Test.
MEASURED SET SPEED METER
DRIVE ROLL
SPEED
RPM IN/MIN
30 ± 1/2 161 ± 3
60 ± 1 322 ± 3
F-47
READING
M/MIN
04.1 ± .1
08.2 ± .1