Lincoln Electric IM10057 POWER WAVE STT MODULE (CE) - Manual (Page 27)

E-7 TROUBLESHOOTING E-7
POWER WAVE ® STT ® MODULE (CE)
Observe all Safety Guidelines detailed throughout this manual
If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your
Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.
CAUTION
PROBLEMS
(SYMPTOMS)
POSSIBLE CAUSE RECOMMENDED
COURSE OF ACTION
Thermal error indication on STT ®
Module (error 36).
General degradation of weld perfor-
mance.
1. Improper fan operation.
2. STT ® Switch PC board thermostat.
3. Open thermostat circuit.
1. Wire feed problem.
2. Cabling problems.
3. Loss of, or improper Shielding
Gas.
4. Verify weld mode is correct for
process.
5. Machine calibration.
6. STT ® Process ONLY: Excessive
cable inductance or STT ® snubber
malfunction.
1. Check for proper fan operation.
(Fans typically run whenever out-
put power is on.) Check for mater-
ial blocking intake or exhaust lou-
vers, or for excessive dirt clogging
cooling channels in machine.
2. After machine has cooled, reduce
load, duty cycle, or both. Check
for material blocking intake or
exhaust louvers and heat sink
fins.
3. Check for broken wires, open con-
nections or faulty thermostat in the
STT
® Module.
1. Check for feeding problems.
Check actual WFS vs. preset.
Verify proper wire drive and gear
ratio has been selected.
2. Check for bad connections,
excessive loops in cable, etc.
NOTE: The presence of heat in
the external welding circuit indi-
cates poor connections or under-
sized cables.
3. Verify gas flow and type are cor-
rect.
4. Select the correct weld mode for
the application.
5. Verify the calibration of the power
source output current and voltage.
6. Excessive cable inductance or
STT ® snubber malfunction can
cause the transient voltage to
exceed the safe operating thresh-
old on the STT
® Switch PC board.
Under these conditions the STT ®
switch turns ON to protect itself.
Follow recommended cable guide-
lines to minimize the inductance,
and inspect the snubber resistor
circuit for damage.
BASIC MACHINE PROBLEMS
WELD AND ARC QUALITY PROBLEMS