Lincoln Electric Fleet 650 Service Manual page 15

LINCOLN ELECTRIC
Observe Safety Guidelines
detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
The machine welds but it will
not maintain a steady output.
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. This condition may be
normal in the Downhill Pipe
Mode. The downhill pipe mode
allows the arc current to
increase and decrease slightly
as the arc length changes.
2. Check that the electrode is
of good quality, dry and free
from contamination. Try using
Lincoln Electrode and setting
the machine per Lincoln's
recommendation.
3. Check for proper work and
electrode leads and
connections (size, length, coils
or bad connections).
Fleet™ 650 Service Manual
TROUBLESHOOTING GUIDE
RECOMMENDED
COURSE OF ACTION
1. If the engine will not
maintain the correct load RPM,
the engine may be in need of
service. Air and fuel filters
should be checked.
2. Check large current carrying
leads that connect to the
stator, chopper module boards,
shunt, chokes and output
terminals. See Wiring Diagram.
Look for damaged conductors
or faulty connections.
3. Check the connections at the
weld control board and the
chopper module boards.
4. The output control or the
arc control potentiometer may
be defective or grounded. The
mode switch may also be
faulty. Perform the Output
Control And Arc Control
Potentiometer Test Procedure.
5. Perform the Pipe/Gouge
Range Switch And Weld Mode
Switch Test Procedure.
6. Replace the weld control
board.
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