Lincoln Electric IDEALARC SP-255 Service Manual page 57

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TROUBLESHOOTING GUIDE - Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
No Open Circuit Voltage output and
no wire feed when gun trigger is
pulled. Display is functioning prop-
erly.
Wire feeds but welding output is low
causing wire to "stub".
Welds are "cold". Machine cannot
obtain full rated output of 250 amps
at 26 volts.
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 1-888-935-3877.
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENTS(S)
OUTPUT PROBLEMS
1. The thermostats may be open
due to machine overheating. If
machine operates normally after
a cooling off period then check
for proper fan operation and ven-
tilation for both fans. Make cer-
tain that the machine's duty cycle
is not being exceeded.
2. Check the gun trigger circuit.
Leads #324 to #325 should have
continuity ( zero ohms) when the
gun trigger is pulled. If not then
the gun may be faulty - replace.
1. If an error message is displayed
on the display then proceed to
Explanation of Prompting and
Error Messages Section.
2. Make sure that the proper wire
and procedures are being used.
3. Check gun and work cable for
loose or faulty connections.
CAUTION
IDEALARC
COURSE OF ACTION
1. Check thermostats and associ-
ated leads for loose or broken
connections.
gram.
2. Perform The Main Transformer
Test.
3. The control board may be faulty.
Replace.
1. Check for loose or faulty connec-
tions of the heavy current carry-
ing leads.
2. The output capacitor bank may
be faulty. Check for loose con-
nections at the capacitors. Also
check for leaky capacitors. Re-
place if necessary.
WARNING:
trolyte in these capacitors is
toxic. Avoid contact with any
portion of your body.
3. Perform the SCR Rectifier As-
sembly Test.
4. Perform the Main Transformer
Test.
5. The control board may be faulty.
Replace.
SP-255
®
F-4
RECOMMENDED
See Wiring Dia-
The liquid elec-