Feeding Problems - Lincoln Electric SP-100 Service Manual

Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
No wire feed when gun trigger is
pulled. Fan runs, gas flows and
machine has correct open circuit
voltage (28 vdc maximum) – weld
output.
Wire feed speed motor runs very
fast. Weld output, gas flow and fan
operate normally.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact the Lincoln
Electric Service Department for technical troubleshooting assistance before you proceed call 216-383-2531 or 1-800-833-9353.
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)

FEEDING PROBLEMS

1. If the wire drive motor is running
check to see if the correct wire
is in the machine.
2. If the wire drive motor is running
make sure that the correct drive
rolls are installed in the
machine.
3. Check for clogged cable liner or
feeding problems.
1. Make sure that the wire speed
control is not set at maximum.
CAUTION
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. Check for a DC voltage at wire
drive motor armature (leads
#539 to #541). The voltage
should be between 2 vdc and 10
vdc. This voltage will vary with
the wire speed control setting. If
the correct voltage is present,
the drive motor may be faulty.
Replace. See wiring diagram.
2. If the motor armature voltage is
not present, then check for OCV
at leads #203 (3J2) and #204
(4J2) on the control board. If
correct voltage is present, go to
Step 3. If OCV is not present at
leads #203 and #204, check
continuity (zero ohms) of leads.
3. If the motor armature voltage is
not present, then check the wire
speed control potentiometer and
associated wires #208, #209
and #203 for faulty connections.
4. The control board may be faulty.
Replace.
1. Remove main supply power to
machine. Disconnect plug J2
from the control board. Test the
resistance from lead #539 (2J2)
in the harness plug to the wire
feed motor case. If the resis-
tance is below 500,000 ohms,
replace the drive motor.
2. Check the wire speed control
potentiometer and associated
wires #208, #209 and #203 for
loose or broken connections.
3. The control board may be faulty.
Replace.
F-6
SP-100