UPS 250, UPS 300, UPS 500, UPS 600, UPS 750 and UPS 900 Uninterruptible Power Supply Caterpillar

Removal Procedure

Illustration 1	g00985643
(1) (1) Screw (2) Assembly (Rotor Position Sensor) (3) O-ring (4) Hex Bolt (5) Wheel (Rotor) (6) Spacer (7) Screw (8) Shipping Plug (9) Plug with an O-ring (10) O-ring (11) Assembly (Top Bearing) (12) Sensor (Vacuum) (13) Assembly (Bottom Bearing) (14) Spacer (15) Retaining Bolt (16) Mounting Hardware for the Drain (Charge) (17) Mounting Hardware for the Drain (Charge) (18) Drain (Charge) (19) Load Plate (20) Shims (Load Cell) (21) Load Cell and Base Plate Assembly (22) Hex Bolt (23) Spacer (24) Hex Bolt with Polished Head (25) Screw (26) O-ring (27) Assembly (Static Drain)

1. Shut down the System before attempting to remove the lower bearing. Refer to the Testing and Adjusting, "System Shutdown" for the proper shutdown procedure.

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Illustration 2	g00843202

2. Remove vacuum hose (30) from the system. This relieves the vacuum from the system.

3. Disconnect the following items from the bottom of the flywheel: the 19 pin instrument connector and the cable for the thermistor.

   Note: Skip forward to steps 13 through 12 if this system is equipped with an assembly (load cell). Refer to Illustration 1.

4. Disconnect the 19 pin instrument connector.

5. Disconnect the yellow connector for the thermistor.

6. . Remove four screws (25). Remove Assembly (Static Drain) (27) .

7. Remove polished rotor retainer bolt (24) .

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Illustration 3	g00852370

8. Use four feeler gauges. Measure the gap that is between the bearing cartridge and the end plate. Take measurements at four locations.

   The measurements will be used during the installation of the new bearing. Record the results in table 2.

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   Table 2

   Location	Measurement
   1
   2
   3
   4

9. Remove 6 bolts (22) that are holding the load cell.

10. Remove the load cell (21) .

11. Remove the Shims (Load Cell) (20) .

12. Remove the Plate (Load Cell) (19) .

13. Remove four plugs (9) from the lower end plate. Remove four O-rings from the four plugs.

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Illustration 4	g00712417
190-8386 Shim

14. Remove four plugs (9) from the bottom of the flywheel housing.

15. Install four 190-8386 Shims. Install one tool in each hole. The holes are located in the lower end plate.

    Note: Refer to illustration 4 for the correct placement of the 190-8386 Shims .

    The shims prevent the rotor from setting down on the hall effect sensors.

16. Loosen eight screws. Use quarter turns. Use a star pattern. Loosen the screws until the rotor rests on the 190-8386 Shim .

    When the rotor is setting on 190-8386 Shim, remove eight screws.

17. Install a 191-5217 Guide Pin in one of the eight bolt holes that are located in the bearing cartridge. This will prevent the bearing cartridge from turning.

Note: The location for the connector for the cable (thermistor) must be maintained when the bearing is reinstalled.

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Illustration 5	g00852427
190-8385 Bearing Puller Gp

18. Install the 190-8385 Bearing Puller Gp on the bearing cartridge.

    Reference: Refer to Illustration 5.

19. Turn the center bolt clockwise until the bolt contacts the bearing shaft.

Note: When the bearing is clear of the bearing shaft, the bearing cartridge may fall. Maintain one hand on the bearing cartridge.

20. Turn the center bolt in order to remove the bearing cartridge.

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Illustration 6	g00863802
(35) Bearing Cartridge (36) O-ring (37) Brass Shim

21. Remove O-ring (36) from the bearing cartridge.

22. Remove brass shim (37) from bearing cartridge (35).

23. Measure the old brass shim and record the measurement.

    Each bearing cartridge has a unique shoulder height. The height is stamped on the cartridge. The shims are added or removed in order to adjust the height of the shoulder. Record the height of the shoulder.

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    Table 3

    Bearing Measurements
    Old Brass Shim Thickness
    Old Shoulder Height

    Save the brass shim. The shim may be used during the installation procedure.

Installation Procedure

Illustration 7	g00985643
(1) (1) Screw (2) Assembly (Rotor Position Sensor) (3) O-ring (4) Hex Bolt (5) Wheel (Rotor) (6) Spacer (7) Screw (8) Shipping Plug (9) Plug with an O-ring (10) O-ring (11) Assembly (Top Bearing) (12) Sensor (Vacuum) (13) Assembly (Bottom Bearing) (14) Spacer (15) Retaining Bolt (16) Mounting Hardware for the Drain (Charge) (17) Mounting Hardware for the Drain (Charge) (18) Drain (Charge) (19) Load Plate (20) Shims (Load Cell) (21) Load Cell and Base Plate Assembly (22) Hex Bolt (23) Spacer (24) Hex Bolt with Polished Head (25) Screw (26) O-ring (27) Assembly (Static Drain)

Each bearing cartridge has a unique shoulder height. The height is stamped on the cartridge. Shims are added or removed in order to adjust the height of the shoulder.

1. Compare the shoulder height of the old bearing cartridge and the shoulder height of the new bearing cartridge. When brass shims are needed, add brass shims or subtract brass shims. The tolerance of the measurement is ± 0.0508 mm (± 0.002 inch).
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   Table 5

   Bearing Measurements
   Old Brass Shim Thickness
   Old Shoulder Height (1)
   New Shoulder Height (1)
   New Brass Shim Thickness

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   ( 1 )

   The Shoulder Height is stamped on the shoulder.

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Illustration 8	g00863802
(35) Bearing Cartridge (36) O-ring (37) Brass Shim

2. Apply 6V-2055 High Vacuum Grease to O-ring (36).

3. Install O-ring (36) on bearing cartridge (35) .

4. Install a 191-5217 Guide Pin in one of the eight bolt holes that are located in the end plate. This pin should be installed 180° away from the first pin. This will locate the bearing cartridge during installation.

5. Align the bearing assembly for the cable (thermistor) so that the yellow cable will reach the connector.

6. Install the new bearing cartridge. Use your hand and seat the bearing cartridge.

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Illustration 9	g00863883
190-8379 Bearing Installer Gp (40) Nut (41) Center Bolt

7. Install 190-8379 Bearing Installer Gp on the bearing housing.

8. Turn center bolt (41) clockwise until bearing cartridge (35) is approximately 12.7 mm (0.5 inch) from the end plate.

9. Refer to "Removal Procedure" and then refer to illustration 4 for the position of the feeler gauges.

10. Position the 4 feeler gauges.

11. Turn nut (40). Seat the bearing cartridge.

12. Remove the two 191-5217 Guide Pins .

13. Install eight screws (18). Use quarter turns. Tighten the screws in a star pattern. Tighten the screws until the rotor does not rest on the Shim. Torque the screws to 27.1 N·m (20 lb ft).

14. Remove the four feeler gauges.

15. Remove the four 190-8386 Shims .

16. Apply 6V-2055 High Vacuum Grease to the O-rings that are located on four plugs (9) .

17. Install four plugs (9) .

18. Clean the threads on the polished rotor retainer bolt (24) with a wire brush or replace the bolt.

19. Place one drop of 7M-7456 Bearing Mount Compound on the threads of polished rotor retainer bolt (24) .

20. Install rotor retainer (23) so that the lip faces the flywheel.

21. Install polished rotor retainer bolt (24). Torque the bolt to 38 N·m (28 lb ft).

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Illustration 10	g00843202

22. Apply 6V-2055 High Vacuum Grease to the O-ring for vacuum hose (30). Connect vacuum hose (30) .

23. Connect the yellow connector for the thermistor and the nineteen pin instrument connector.