Cv Box Test Procedure - Lincoln Electric Classic 300 MP Service Manual

LINCOLN ELECTRIC

CV BOX 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 CV Box Components are functioning normally.
MATERIALS NEEDED
9/16" Open-End Wrench
9/16" Nutdriver
5/16" Nutdriver
120 VDC Power Supply
12 VDC Power Supply
Volt/ohmmeter
Wiring Diagram
TEST PROCEDURE
1. Turn off the engine on the Classic 300 MP machine.
2. Perform the Case Cover Removal Procedure.
3. Locate the CV box assembly. See Figure F.10.
4. Using a 9/16" open-end wrench and a 9/16" nutdriver, remove the nut, bolt, lock washer and three
flat washers securing each side of the CV box to the fuel tank rail (two sets). See Figure F.10.
5. Using a 5/16" nutdriver, remove the thirteen screws securing the CV box support to the CV box
base. See Figure F.10.
Contactor CR2:
6. Using a volt/ohmmeter, measure the contacts resistance from terminal 631 to terminals 630 of the
contactor CR2. See Figure F.11. See Wiring Diagram. Normal resistance should be approximately
234 ohms.
7. Label and disconnect leads 631 and 630 from top terminals of contactor CR2. See Figure F.11. See
Wiring Diagram.
8. Using a 120 VDC power supply, apply 120 VDC to the top terminals of contactor CR2. There should
be an audible click as the contacts close. Using a volt/ohmmeter, measure the resistance from
terminal L1 to terminals T1, T2 or T3. Normal resistance should be less than 2 ohms (low
resistance). See Figure F.11. See Wiring Diagram.
9. When testing of contactor CR2 is complete, connect all previously disconnected leads.
10. If any of the tests fail, the contactor CR2 may be faulty.
Classic® 300 MP Service Manual
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