Troubleshooting and repair, Repair procedure, Potentiometer replacement – Lincoln Electric LN-8 SVM132-A User Manual
Page 75
F-25
TROUBLESHOOTING AND REPAIR
F-25
REPAIR PROCEDURE
1. Remove input power to the LN-8
2. Using the 5/16 in. nutdriver,
remove the screws from the left
side cover assembly.
3. Using a 5/64 in. Allen wrench or
slothead screwdriver, loosen the
setscrew on the potentiometer knob
and remove the knob from the
potentiometer. Refer to Figure F.7.
4. Remove the nut and lockwasher
holding the potentiometer to the
left side cover assembly.
5. Remove the potentiometer and
insulation sheet from the inside of
the left side cover assembly.
6. Tag the three wires on the poten-
tiometer so that they can be reat-
tached in the same location from
where they were removed.
Unsolder the three wires from the
potentiometer.
7. Solder the three wires to the new
potentiometer on the correspond-
ing terminals from where they were
removed.
8. Place the new potentiometer and
insulation sheet through the cover
assembly from the inside. Ensure
that the index pin in the poten-
tiometer fits in the locating hole on
the cover assembly. Install the
lockwasher and nut on the poten-
tiometer. Tighten the nut until it is
snug.
9. Install the knob onto the poten-
tiometer so the set screw aligns
with the flat on the potentiometer.
Tighten the set screw.
10. Install the screws that secure the
left side cover assembly.
POTENTIOMETER REPLACEMENT
(continued)
FIGURE F.7 – POTENTIOMETER REMOVAL
LN-8
POTENTIOMETER
NUT
KNOB
LOCKWASHER
SET
SCREW
INSULATION