JLG 460SJ Service Manual - Manual (Page 140)

SECTION 3 - CHASSIS & TURNTABLE
3-88 – JLG Lift – 3120895
Replacement of Weld Rectifier Bridge
1. Remove top cover ad control panel.
2. Disconnect three six gauge wires from rectifier
bridge.
3. Un-bolt rectifier Bridge upward from base.
4. One elastic stop nut on each end.
5. Lift defective Rectifier Bridge upward out of slots.
6. Re-install new bridge.
7. Insert two elastic stop nuts.
NOTE: Be sure two mounting studs are all the way on bot-
tom of slots.
AS YOU TIGHTEN, THE TWO NUT RECTIFIER BRIDGES MUST BE
PERFECTLY HORIZONTAL. IF IT TILT FORWARD OR BACKWARD,
IT WILL SHORT OUT AGAINST THE CASE.
8. Reconnect the three wires.
9. Remount the panels and top covers.
Replace Brushes on Sky Welder
1. Remove receptacle panel.
2. Cut tie raps holding brush holder wires, red & black.
3. Unplug red & black from rectifier bridges.
4. Install wires in same way with new brush holder - red
to red and black to black.
5. Remove old brush holder by removing one screw
holding brush holder.
6. Do not lose plastic insulator located behind the
brush holder.
7. Check slip rings.
8. Clean and polish with very fine sandpaper.
9. Check resistance of rotor (armature) on slip rings.
10. Reading should be a 22 ohms ± 3 ohms.
11. Install new brush holder with brushes.
NOTE: Make sure brush holder is seated (dimple in casting).
12. Check brushes to be on slip rings.
13. Install tie rap’s to hold wires.
14. Check resistance of rotor (armature) on slip rings.
15. Reading should be a 22 ohms ± 3 ohms.
Replacing Range Switch
1. Remove top cover held with four screws.
2. Remove nut holding range switch to front panel.
3. Install range switch in front panel.
NOTE: Be sure key on threaded bushing is pointing the
same way.
4. Move wires from old switch to new switch.
5. Re-install top cover.
Replacing Selector Switch
1. Remove top cover held with four screws.
2. Remove phillips screw from selector knob.
3. Remove two phillips screws from selector switch
front panel.
4. Transfer all wires to new selector switch.
NOTE: Be careful not to mix up any of the wires.All wires
have wire markers on them.
5. Mount new selector switch to front panel with two
phillips screws.
6. Re-install knob, be sure knob pointer aligns with all
markings on front panel.
7. Re-install top cover.