Lincoln Electric IDEALARC SP-250 Service Manual page 56

F-9
TROUBLESHOOTING GUIDE - Observe all Safety Guidelines detailed throughout this manual
PROBLEMS
(SYMPTOMS)
The arc is unstable and or "hunting".
Weld bead is narrow or ropey. May
have porosity with electrode stub-
bing into plate.
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
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENTS(S)
WELDING PROBLEMS
1. Check for worn or melted con-
tact tip.
2. Check for loose or faulty con-
nections on the work and elec-
trode cables.
3. Make sure electrode polarity is
correct or welding process being
used.
4. Check for rusty or dirty wire.
5. Make sure machine settings and
gas are correct for process
being used.
1. Make sure the weld procedure
and electrode polarity is correct
for the process being used.
2. Make sure shielding gas is cor-
rect and flow is proper.
3. Make sure the weld joint is not
"contaminated".
CAUTION
IDEALARC SP-250
RECOMMENDED
COURSE OF ACTION
1. Check for loose connections at
the output terminals, the choke,
the capacitor bank and all heavy
current carrying leads.
2. Make sure that the transformer
secondary leads are securely
connected to the SCR Rectifier
Assembly.
3. The output capacitor bank may
be faulty. Check for loose con-
nections at the capacitors. Also
check for leaky capacitors.
Replace if necessary.
WARNING: The liquid elec-
trolyte in these capacitors is
toxic. Avoid contact with any
portion of your body.
4. The control board may be faulty.
Replace.
1. The output capacitor bank may
be faulty. Check for loose con-
nections at the capacitors. Also
check for leaky capacitors.
Replace if necessary.
WARNING: The liquid elec-
trolyte in these capacitors is
toxic. Avoid contact with any
portion of your body.
2. Perform the SCR
Assembly Test.
3. The control board may be faulty.
Replace.
F-9
Rectifier