Field Bridge Rectifier Test Procedure - Lincoln Electric Cross Country 300 Service Manual

LINCOLN ELECTRIC
FIELD BRIDGE RECTIFIER 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 Input Rectifier is receiving AC input voltage and is converting it to the correct
DC output voltage.
MATERIALS NEEDED
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 field bridge rectifier. See Figure F.16. See Wiring Diagram.
5. Label and disconnect leads 200, 200A, 5H, 201A and 6A from the field bridge rectifier. See Figure
F.17. See Wiring Diagram.
6. Using a volt/ohmmeter, perform the forward voltage drop tests outlined in Table F.5. See Figure
F.17. See Wiring Diagram.
7. If any of the tests fail, the field bridge rectifier may be faulty.
8. If faulty, perform the Field Bridge Rectifier Removal And Replacement Procedure.
9. Connect the previously removed leads 200, 200A, 5H, 201A and 6A to the field bridge rectifier. See
Wiring Diagram.
10. Perform the Case Cover Replacement Procedure.
TEST POINT (POS)
TOP AC TERMINAL
BOTTOM AC TERMINAL
NEGATIVE TERMINAL
NEGATIVE TERMINAL
Table F. 5 – Field bridge rectifier forward voltage drop tests
POSITIVE TERMINAL
POSITIVE TERMINAL
BOTTOM AC TERMINAL
TEST POINT (NEG)
TOP AC TERMINAL
Cross Country™ 300 Service Manual
EXPECTED READING
0.2 VDC – 0.7 VDC
0.2 VDC – 0.7 VDC
0.2 VDC – 0.7 VDC
0.2 VDC – 0.7 VDC
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