Lincoln Electric INVERTEC SVM129-B - Manual (Page 42)

TROUBLESHOOTING & REPAIR
F-4 F-4
INVERTEC® STT® & STT® II
Observe Safety Guidelines TROUBLESHOOTING GUIDE
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
Major physical or electrical damage
is evident. 1. Contact your local Lincoln
Authorized Field Service
Facility.
1. Contact the Lincoln Electric
Service Department, 1-888-935-
3877.
Machine has no open circuit volt-
age. Wire feeds OK. 1. Check the control cable
between the feeder and the
STT unit. Make sure the #2 and
#4 leads are intact.
2. Put a jumper wire between Pins
"C" and "D" on the 14 pin
amphenol. If normal open cir-
cuit
voltage (85VDC) is
restored, the problem is in the
feeder control cable or the wire
feeder.
3. Make sure the reconnect switch
S7 is in the correct position for
the three-phase input voltage
being applied.
Do not switch reconnect switch
with input power applied to
machine.
1. Perform the T1 Auxiliary
Transformer Test.
2. Perform the T4 Auxiliary
Transformer Test.
3. Perform the Power Board Test.
4. Perform the Trigger Circuit
Test.
5. Perform Capacitor Balance
Test.
6. Perform the Protection Board
Test.
7. Perform the Switch Board
Test.
8. Check for loose or broken con-
nections on the heavy current
carrying conductors (i.e., main
transformer,
choke, output
diodes, IGBT module and out-
put terminals).
9. The control PC board may be
faulty. Replace.
CAUTION
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