Chopper Module Resistance Test Procedure - Lincoln Electric Cross Country 300 Service Manual

LINCOLN ELECTRIC
CHOPPER MODULE RESISTANCE TEST PROCEDURE
Service and repair should be performed by only Lincoln Electric factory trained personnel. Unauthorized
repairs performed on this equipment may result in danger to the technician or machine operator and will
invalidate your factory warranty. For your safety and to avoid electrical shock, please observe all safety
notes and precautions detailed throughout this manual. If for any reason you do not understand the test
procedures or are unable to perform the test/repairs safely, contact the Lincoln Electric Service Department
for electrical troubleshooting assistance before you proceed. Call 1-888-935-3877.
TEST DESCRIPTION
This test will determine if the Chopper Module is shorted. This test can only detect some problems in the
"Power" section of the module. Problems in some other PC board components may not be detected.
MATERIALS NEEDED
7/16"Nutdriver
Volt/Ohmmeter
Wiring Diagram
TEST PROCEDURE
1. Turn off the engine on the Cross Country 300 machine.
2. Perform the Case Cover Removal Procedure.
3. Perform the Capacitor Discharge Procedure.
4. Locate the chopper module PC board. See Figure F.21. See Wiring Diagram.
5. Using a 7/16" nutdriver, remove the six screws, lock washers and flat washers securing the heavy
leads to terminals B1, B2, B3, B4, B5 and B6 of the chopper module PC board. See Figure F.22. See
Wiring Diagram. Label leads for reassembly.
6. Using a volt/ohmmeter, perform the wide diode tests outlined in Table F.7. See Figures F.21 and
F.22. See Wiring Diagram.
7. If any of the tests fail, the chopper module pc board may be faulty.
8. If faulty, perform the Chopper Module PC Board Removal And Replacement Procedure.
9. Using a 7/16" nutdriver, attach the six screws, lock washers and flat washers securing the heavy
leads to terminals B1, B2, B3, B4, B5 and B6 of the chopper module PC board. See Wiring Diagram.
Torque to 50-60 inch/lbs.
10. Perform the Case Cover Replacement Procedure.
Cross Country™ 300 Service Manual
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