Lincoln Electric LN-23P Service Manual page 40

F-12
LN-23P
Control
Board
TEST PROCEDURE
1. Remove the weld wire from the drive rolls.
2. Disconnect the motor leads, 541 and 539, from the
Control Board and clamp an amp probe around one
of the leads.
NOTE: A DC ammeter may be connected in series
with a motor lead if a current probe is not
available.
3. Connnect a 12 VDC supply to the motor leads -
Positive to lead 541 and Negative to lead 539.
The drive rolls should turn and run smoothly and the
motor current should be less than 1amp. If so the
feed head is OK.
If the drive rolls do not turn, and the ammeter
shows no current, check the brushes for excessive
wear. Insure that they move freely in the brush
holders and are contacting the armature.
TROUBLESHOOTING AND REPAIR
All manuals and user guides at all-guides.com
FEED HEAD TEST (cont.)
FIGURE F.3
539
541
539
541
POS
12 Volt Supply
NEG
If drive rolls do not turn but the ammeter indicates
current flow. remove the motor from the gearbox
and repeat the test.
If the motor still does not run it is defective. If it
runs properly there is probably something
wrong in the gearbox.
If the drive rolls turn but not smoothly check the
motor and brushes as indicated. If OK replace the
gearbox.
LN-23P
F-12
DC
AMPS