Output Rectifier Bridge Test Procedure - Lincoln Electric Fleet 650 Service Manual

LINCOLN ELECTRIC

OUTPUT RECTIFIER BRIDGE 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 Output Rectifier Bridge is grounded or if there are any failed Diode groups.
NOTE: This test will not be able to detect individual open Diodes within a group.
MATERIALS NEEDED
7/16" Socket
7/16" Open-End Wrench
1/2" Socket
1/2" Open-End Wrench
Volt/Ohmmeter
Wiring Diagram
TEST PROCEDURE
1. Turn off the engine on the Fleet 650 machine.
2. Perform the Case Cover Removal Procedure.
3. Perform the Chopper Module Capacitor Discharge Procedure.
Electrically isolate the three-phase input terminals of the output rectifier bridge as follows:
4. Using a 7/16" socket and a 7/16" open-end wrench, remove the bolt, nut, lock washer and two flat
washers securing each lead set (W1/W6, W2/W3 and W4/W5) to the AC terminals of the output
rectifier bridge. See Figure F.12. See Wiring Diagram.
5. Label and disconnect leads W1/W6, W2/W3 and W4/W5 and position them so they do not come in
contact with any part of the rectifier. See Figure F.12. See Wiring Diagram.
Electrically isolate the DC output terminals of the rectifier:
6. Using a 1/2" socket and a 1/2" open-end wrench, remove the bolt, nut, lock washer and two flat
washers securing leads B2/B5, B2/B5 and POS-SHUNT to the positive terminal of the output rectifier
bridge and leads B1/B4 and B1/B4 from the negative terminal of the output rectifier bridge. See
Figure F.12. See Wiring Diagram.
7. Label and disconnect leads B2/B5, B2/B5 and POS-SHUNT from the positive terminal of the rectifier
and leads B1/B4 and B1/B4 from the negative terminal of the rectifier. Position these leads so they
do not come to contact with any part of the output rectifier bridge. See Figure F.12. See Wiring
Diagram.
Fleet™ 650 Service Manual
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