Selector Switch Removal And Replacement Procedure - Lincoln Electric Classic 300 MP Service Manual

LINCOLN ELECTRIC

SELECTOR SWITCH REMOVAL AND REPLACEMENT 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 procedure will aid the technician in the removal and replacement of the Selector Switch.
MATERIALS NEEDED
1/2" Open-End Wrench
1/2" Nutdriver
Slotted Screwdriver
3/8" Nutdriver
Wiring Diagram
REMOVAL PROCEDURE
1. Turn off the engine on the Classic 300 MP machine.
2. Perform the Case Cover Removal Procedure.
3. Using a 1/2" open-end wrench and 1/2" nutdriver, remove the five nuts securing the heavy leads to
terminals 1-5 of the selector switch. See Figure F.46. See Wiring Diagram.
4. Using a 1/2" open-end wrench and 1/2" nutdriver, remove the nut securing the two leads to the
negative terminal of the selector switch. See Figure F.46. See Wiring Diagram.
5. Using a slotted screwdriver, remove the screw securing the control knob to the upper control panel
assembly. See Figure F.47.
6. Using a 3/8" nutdriver and a slotted screwdriver, remove the two screws, nuts, lock washers and flat
washers securing the selector switch to the upper control panel. See Figure F.46.
7. The selector switch can now be removed and replaced.
REPLACEMENT PROCEDURE
1. Carefully position new selector switch into the machine.
2. Using a 3/8" nutdriver and a slotted screwdriver, attach the screw, nut, lock washer and flat washer
securing the selector switch to the upper control panel.
3. Using a slotted screwdriver, attach the screw securing the control knob to the upper control panel
assembly.
4. Using a 1/2" open-end wrench and 1/2" nutdriver, attach the nut securing the two leads to the
negative terminal of the selector switch. See Wiring Diagram.
Classic® 300 MP Service Manual
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