Lincoln Electric Classic 300 MP Service Manual page 25

LINCOLN ELECTRIC
Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
The welding arc is loud and
spatters excessively.
The welding arc frequently
"pops out".
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, contact the
Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed. Call 1-888-935-3877.
POSSIBLE AREAS OF
MISADJUSTMENT(S)
WELDING PROBLEMS
1. The current setting may be
too high for the electrode and
process.
2. The polarity may be wrong
for the electrode and process.
1. The fine current control
rheostat may be set too low for
the process and electrode.
2. Check the welding cables for
loose or faulty connections.
Classic® 300 MP Service Manual
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. Check the engine speed.
High idle speed should be 1800
RPM.
2. Check the DC generator
brushes for good
communication and alignment.
Contact the Lincoln Electric
Service Department 1-888-935-
3877.
3. Perform the Welding
Generator Brush And
Commutator Inspection And
Service.
4. Perform the Rocker
Adjustment Procedure.
5. Perform the Output Choke
Test Procedure.
6. Check for shorted series
coils.
1. Check the engine speed.
High idle speed should be 1800
RPM.
2. Perform the Selector Switch
Test Procedure.
3. Check the DC generator
brushes for good commutation
and alignment. Contact the
Lincoln Electric Service
Department 1-888-935-3877.
4. Perform the Rocker
Adjustment Procedure.
20