Lincoln Electric SP-100 Service Manual page 41

Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
No weld output when gun trigger is
pulled. Fan runs, gas flows and
wire feeds normally.
BELOW CODE 9794 ONLY
No wire feed, weld output or gas
flow when gun trigger is pulled Fan
operates 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)
OUTPUT PROBLEMS
1. Arc voltage may be set too low.
2. Gun tip may be worn – Replace.
3. Check for correct input voltage
to machine.
4. Gun or work cable may be
faulty.
1. Check the circuit breaker locat-
ed in the machine's wire drive
compartment. Reset if tripped.
2. The thermostat may be tripped
due to overheating. Let machine
cool. Weld within the duty cycle
or remove any air obstruction to
machine.
3. Wire feed motor may be over-
loaded. Correct feeding prob-
lem.
4. Gun trigger may be faulty.
CAUTION
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. Check for open circuit voltage
(OCV) at the machine's output
terminals, located in wire drive
compartment. Normal OCV is
from 10 vdc to 28 vdc depending
on arc voltage control setting. If
correct OCV is present, check
gun and work cable.
2. If correct OCV is not present at
the output terminals, then check
for broken leads at the output
choke or at the positive output
terminal.
1. Remove main power supply to
SP-100. With gun trigger pulled,
check for continuity (zero ohms)
from 8J2 (lead #213) to 9J2 (lead
#211 ) at harness plug. If zero
ohms is indicated, then trigger
circuit is OK. See wiring diagram
and Figure F.1.
2. If an open circuit or high resis-
tance is indicated in Step 1, then
check leads #211,#212 and #213
for loose or broken connections.
Also check the normally closed
thermostat mounted on the diode
heat sink assembly. See wiring
diagram.
3. Check for 115 vac at lead #31A
to plug 3J1 on control board. If
115 vac is NOT present, remove
main supply power to machine.
Test continuity (zero ohms) of
leads #32 and #31A. See Figure
F.1.
4. If 115 vac is present at lead
#31A to plug 3J1 (lead #32), then
control board may be faulty –
Replace. See Figure F.1.
F-4
SP-100