Lincoln Electric SP-250 Welding System User Manual


 
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F-4
TROUBLESHOOTING & REPAIR
F-4
IDEALARC SP-250
TROUBLESHOOTING GUIDE - Observe all Safety Guidelines detailed throughout this manual
OUTPUT PROBLEMS
PROBLEMS
(SYMPTOMS)
POSSIBLE AREAS OF
MISADJUSTMENTS(S)
RECOMMENDED
COURSE OF ACTION
No Open Circuit Voltage output and
no wire feed when gun trigger is
pulled. Display is functioning proper-
ly.
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.
1. Check thermostats and associ-
ated leads for loose or broken
connections. See Wiring
Diagram.
2. Perform The Main Transformer
Test.
3. The control board may be faulty.
Replace.
1. Check for loose or faulty con-
nections of the heavy current
carrying leads.
2. The output capacitor bank may
be faulty. Check for loose con-
nections at the capacitors. Also
check for leaky capacitors.
Replace if necessary. WARN-
ING: The liquid electrolyte in
these capacitors is toxic. Avoid
contact with any portion of your
body.
3. Perform the SCR Rectifier
Assembly Test.
4. Perform the Main Transformer
Test.
5. The control board may be faulty.
Replace.
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
ventilation. Make certain 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.
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, con-
tact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed call 216-
383-2531 or 1-800-833-9353
CAUTION