Troubleshooting & repair, Caution – Lincoln Electric INVERTEC SVM129-B User Manual
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TROUBLESHOOTING & REPAIR
F-7
F-7
INVERTEC® STT® & STT® II
TROUBLESHOOTING GUIDE
Observe Safety Guidelines
detailed in the beginning of this manual.
CAUTION
If for any reason you do not understand the test procedures or are unable to perform the test/repairs safely, con-
tact the Lincoln Electric Service Department for electrical troubleshooting assistance before you proceed.
Call 1-888-935-3877.
PROBLEMS
(SYMPTOMS)
POSSIBLE AREAS OF
MISADJUSTMENT(S)
RECOMMENDED
COURSE OF ACTION
OUTPUT PROBLEMS
No output. Main fuses are open,
indicating excessive current draw.
1. With the input power removed,
inspect input leads for possible
shorts or grounds or miscon-
nections.
2. Install new fuses and reapply
power. If fuses open again,
contact your local Lincoln
Authorized
Field
Service
Facility.
1. Check the input power switch
(S1) and the reconnect switch
for "shorted" or "grounded"
wires or connections.
2. Perform the Input Rectifier
3. Perform the Switch Board
Machine loses output when gun
trigger is pulled or arc is struck.
Machine output returns after a few
seconds and trigger is pulled again.
The thermal indicator light is lit.
1. The overcurrent sensor is acti-
vated, indicating that too much
output current is being drawn
from the machine. Reduce
welding current demands or
remove the "fault" in welding
cables.
2. Make sure that the gun tip is not
"shorted" to the work surface
and that the proper welding pro-
cedures are being used.
1. The current sensor may be
faulty.
2. The control PC board may be
faulty.