Lincoln Electric INVERTEC POWER WAVE 450 SVM112-B Service Manual page 114

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OUTPUT SHUNT/WELDING FEEDBACK TEST (continued)
WARNING
ELECTRIC SHOCK
can kill.
Proceed with caution.
careful not to touch any inter-
nal machine components during the remainder
of the test procedure.
9. Check for +15 VDC between plug J50 -
pin 3+ and J50 - pin 1-.
10. Carefully move the probes, placing the
negative probe (-) at plug J50 - pin 6 and
the positive (+) probe at
Check for -15 VDC.
11. If the voltage readings are NOT correct,
check the associated wiring to the control
board. If the wiring is okay, the control
board may be faulty. Replace the control
board. Refer to the Printed Circuit Board
Removal and Replacement Procedure
in this section of the manual.
TROUBLESHOOTING & REPAIR
Be
J50 - pin 1.
12. If the supply voltage readings are correct,
load the machine to 400 amps.
CAUTION
Do not run the machine under load for more
than 15 sec. with case removed.
13. Use a current probe to check for 5 ma of
current through lead #218 (plug J50 - pin
4). This also reads approximately 1 VDC if
you use a voltmeter.
14. If the current reading is NOT correct, the
shunt amplifier board may be faulty.
Replace the shunt amplifier assembly and
perform current calibration.
15. If the current reading IS correct, the con-
trol board may be faulty. Replace the con-
trol board. Refer to the Printed Circuit
Board Removal and Replacement proce-
dure in this section of the manual.
16. After the test is completed and the prob-
lem successfully repaired, install the
machine case sides and top.
17. Install the handle and the lift bail rubber
gasket.
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