Lincoln Electric Classic 300 MP Service Manual page 20

LINCOLN ELECTRIC
Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
The engine starts and runs at
correct speed, but there is no
or very low, welder output
voltage. There is no AC
auxiliary output voltage.
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)
OUTPUT PROBLEMS
1. Check the 15 amp fuse
located on the inside of the
front control panel.
2. If the welder output is zero
volts, the fields may need to be
flashed.
3. Check for loose or missing
brushes in the exciter
alternator and welding
generator.
Classic® 300 MP Service Manual
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. Perform the Exciter Flashing
Voltage Test Procedure.
2. Check the field diode bridge
and associated leads and
connections.
3. Perform the Exciter Rotor
Resistance And Ground Test
Procedure.
4. Perform the Exciter Brush
And Slip Ring Service
Procedure.
5. Perform the Exciter Rotor
Voltage Test Procedure.
6. Perform the Exciter Field
Diode Test Procedure.
7. Check for "opens" or
shorted turns in the alternator
stator windings. The coils must
NOT be grounded to the stator
lamination.
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