Lincoln Electric LN-25 SVM114-C - Manual (Page 62)

TROUBLESHOOTING AND REPAIR F-24 F-24
LN-25™
TEST PROCEDURE
1. Open the case door. Remove the wire reel by
removing the retaining collar. See Figure F.5.
2. Remove the screws holding the control box
cover in place and remove the control box
cover. See Figure F.5.
3. For codes 10148 and above, separate the in-
line connector (containing the drive motor
leads) located behind the mylar insulation. Be
sure to identify the correct in-line connector.
There is also an in-line connector for the hall
effect module behind the mylar insulation. See
Figure F.12.
For codes 9812 and below, remove the two
motor leads 539(white) and 541(black) from the
control PC board. See Figure F.10.
4. Apply a variable DC voltage to the drive motor
from lead 541(black)(+) to lead 539(white)(-).
5. When the supply voltage is varied from 2 to 23
VDC, the drive motor speed (RPM) should vary
accordingly. If the motor does not run or vary
in speed, the motor, gearbox or motor brushes
may be faulty. Check or replace.
6. Check the resistance between each of the
motor leads [541(black) and 539(white)] and the
motor case. The resistance should be very high
(at least 500,000 ohms). If the resistance is low,
the motor is grounded to the motor case and
should be replaced.
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DRIVE MOTOR
LEAD IN-LINE
CONNECTOR
HALL EFFECT MODULE
LEAD IN-LINE
CONNECTOR
FIGURE F.12 – HALL EFFECT MODULE AND DRIVE MOTOR LEADS IN-LINE CONNECTORS.