Wire Drive Motor Test Procedure - Lincoln Electric LN-25x Service Manual

LINCOLN ELECTRIC

WIRE DRIVE MOTOR 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 procedure will help determine if the Wire Drive Motor and Tachometer are functioning properly.
MATERIALS NEEDED
DC Ammeter
Volt/Ohmmeter
Variable DC Voltage External Supply
Wiring Diagram
DRIVE MOTOR TEST PROCEDURE
1. Remove the input power to the LN-25x wire feeder.
2. Perform the Wire Drive Assembly And Control Box Cover Removal Procedure.
3. Locate the wire drive motor, on the rear of the wire drive panel, and plug P53. See Figure F.5. See
Wiring Diagram.
4. Label and disconnect plug P53 from the harness. See Wiring Diagram.
5. Using a volt/ohmmeter, measure the resistance of the motor armature at plug P53 pin 7 (black lead
#551) to pin 8 (white lead #550). The resistance should be approximately 1.5 ohms. Also make sure
there is at least 500,000 ohms of resistance between the armature leads and the motor case. See
Figure F.6. See Wiring Diagram.
6. Carefully connect a variable DC voltage external supply to the armature leads (positive to lead #550
white and negative to #551 black). See Wiring Diagram. The motor should run and the speed
should increase as the armature voltage is varied from 2.6 VDC to 27 VDC.
7. If any of the tests fail, the wire drive motor may be faulty.
8. Perform the Wire Drive Motor Removal And Replacement Procedure.
9. When testing is complete, perform the Wire Drive Assembly And Control Box Cover Replacement
Procedure.
DRIVE MOTOR OVERLOAD TEST PROCEDURE
1. Remove the input power to the LN-25x wire feeder.
2. Perform the Wire Drive Assembly And Control Box Cover Removal Procedure.
LN-25x™ Service Manual
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