Lincoln Electric VANTAGE 400 Service Manual page 56

F-8
Observe Safety Guidelines detailed in the beginning of this manual.
PROBLEMS
(SYMPTOMS)
The machine will weld but the
welding arc is "COLD". The
engine runs normally and the aux-
iliary power is normal.
(continued)
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 tests/repairs safely,
contact the Lincoln Electric Service Department for technical troubleshooting assistance before you proceed.
Call 1-888-935-3877.
TROUBLESHOOTING & REPAIR
POSSIBLE AREAS OF
MISADJUSTMENT(S)
FUNCTION PROBLEMS
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.
Check that the electrode is of
good quality, dry and free from
contamination. Try using some
Lincoln Electrode, and setting the
machine per Lincoln recommenda-
tion.
If shielding gas is used, check that
the gas and gas flow are correct.
Check for damaged, pinched or
leaking gas lines.
Check for proper work, and elec-
trode leads and connections (size,
length, coils, or bad connections).
The machine may not be maintain-
ing the correct RPM.
CAUTION
VANTAGE® 400
RECOMMENDED
COURSE OF ACTION
If the maximum weld output can-
not be obtained even though the
front panel displays are reading
accurately, check for damaged
conductors and lose or damaged
connections the large current car-
rying conductor connect the stator,
output rectifier, chopper modules,
choke, shunt, and output termi-
nals. See the Wiring Diagram.
If all these connections are good
perform the ROTOR VOLTAGE
TEST, the STATOR VOLTAGE
TEST, the OUTPUT RECTIFIER
TEST, and the CHOPPER MOD-
ULE RESISTANCE TEST.
Perform the CONTROL POTEN-
TIOMETER AND MODE RESIS-
TANCE TEST.
Perform the REMOTE RECEPTA-
CLE RESISTANCE TEST.
Replace the Control P.C. Board.
Perform the THROTTLE
ADJUSTMENT TEST.
If the engine will not maintain the
correct load RPM, the engine may
be servicing fuel, air, and fuel fil-
ters should be checked.
Check internal cables and leads
that connect the weld winding of
the stator, chopper module and the
shunt, choke and output terminals.
See the wiring diagram. Look for
damaged conductors or faulty con-
nections.
F-8