- Uninterruptible Power Supply:
- UPS 120 (S/N: CNK1-UP)
- UPS 150 (S/N: CPC1-UP)
- UPS 250 (S/N: CNM1-UP; APZ1-UP)
- UPS 300 (S/N: CNJ1-UP; CPZ1-UP)
- UPS 301 (S/N: CSY1-UP)
- UPS 500 (S/N: CSE1-UP)
- UPS 600 (S/N: CTX1-UP)
- UPS 750 (S/N: CPM1-UP)
- UPS 900 (S/N: CRY1-UP)
- UPS 150 (S/N: CPC1-UP)
Introduction
The following Special Instruction will describe the procedure that is required in order to convert the Uninterruptible Power Supply (UPS) from a G3.0 load cell to a G3.5 load cell.
Important Safety Information
Work safely. Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs.
A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools in order to perform these functions properly.
Safety precautions and warnings are provided in this instruction and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons. Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard.
Therefore, the warnings in this publication and the warnings that are on the product are not all inclusive. If a tool, a procedure, a work method or operating technique that is not specifically recommended by Caterpillar is used, you must ensure that it is safe for you and for other people to use.
You should ensure that the product will not be damaged or the product will be made unsafe by the operation, lubrication, maintenance or the repair procedures that are used.
Parts Information
Part Number     | Description     | Qty     |
7M-7456     | Bearing Mount Compound     | 1     |
190-8380     | Shim Kit     | 1     |
6V-2055     | Grease     | 1     |
Required Tools
Part Number     | Description     | Qty     |
191-5217     | Guide Pin     | 2     |
190-8379     | Bearing Installer Gp     | 1     |
Retrofit Procedure
Illustration 1 | g01927518 |
(1) Screw for Rotor Position Sensor (2) Rotor Position Sensor (3) O-ring for Rotor Position Sensor (4) Retaining Bolt for Rotor (5) Serrated Rotor Wheel (6) Bearing Bolt (7) Upper Bearing Cartridge (8) Hex Plug (9) Shim Pack (10) O-ring (11) Flywheel Housing (12) Lower Bearing Cartridge (13) Rotor Retainer (14) Polished Retaining Bolt for Rotor (15) Load Cell (16) Screws for Load Cell |
The bearings should be replaced periodically. The recommended interval is estimated at 2 and 1/2 years. The bearings are contained in removable cartridges. The cartridges are replaced at the same time as the bearings. The cartridges must be accurately positioned for proper operation. Only trained personnel may perform the replacement.
Note: The lower bearing and upper bearing are always changed as a set. The lower bearing is changed first. Then, the upper bearing is changed. The flywheel must be de-energized and the flywheel must be at zero rpm.
Note: Shut down the system before attempting to remove the lower bearing. Refer to the Operation and Maintenance Manual,, "System Shutdown" for the proper shutdown procedure.
Firmware Requirements
All firmware must be at least version 3.56/3.59 or higher. Upgrade the firmware to this version before proceeding.
Refer to the appropriate Systems Operation, Testing and Adjusting manual in order to update the firmware.
Upper Bearing
Removal Procedure
Illustration 2 | g01927599 |
Upper Bearing Assembly (17) Screw for Position Sensor (18) Rotor Position Sensor (19) O-ring for Rotor Position Sensor (20) Retaining Bolt for Rotor (21) Rotor Wheel (22) Bearing Bolt (23) Upper Bearing Cartridge (24) Shim Pack (25) O-ring |
- Remove the three screws (17) for the rotor position sensor (RPS).
- Remove the RPS assembly (18) .
- Remove the O-ring (19) for the RPS.
- Remove the retainer bolt (20) for the rotor.
- Remove the rotor wheel (21) .
- Loosen the eight allen head screws (22) that are located around the perimeter of the bearing cartridge. Use quarter turns and loosen the screws in a star pattern.
- Install two 191-5217 Guide Pin in two of the eight bolt holes that are located in the bearing cartridge. Refer to Illustration 3.
Illustration 3 | g01927614 |
Location of Guide Pin |
- Install the 190-8385 Bearing Puller Gp on the upper bearing cartridge. Refer to Illustration 4.
Illustration 4 | g00852427 |
190-8385 Bearing Puller Gp |
- Turn the center bolt clockwise by hand until the bolt contacts the bearing shaft.
- Turn the center bolt with a wrench in order to remove the upper bearing cartridge.
- Remove the O-ring (25) from the bearing cartridge.
- Remove the brass shims (24) from the upper bearing housing.
- Measure the old brass shims and record the measurement. Refer to Illustration 5.
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 that is stamped on the face of the bearing cartridge.
Show/hide tableTable 3 Bearing Measurements     Old brass shim thickness         Old shoulder height         Save the brass shims (24). The shims may be used during the installation procedure.
Illustration 5 | g01810454 |
Installation Procedure
Illustration 6 | g01927599 |
Upper Bearing Assembly (17) Screw for Rotor Position Sensor (18) Rotor Position Sensor (19) O-ring for Rotor Position Sensor (20) Retaining Bolt for Rotor (21) Rotor Wheel (22) Bearing Bolt (23) Upper Bearing Cartridge (24) Shim Pack (25) O-ring |
Part Number     | Description     | Qty     |
191-5217     | Guide Pin     | 2     |
190-8379     | Bearing Installer Gp     | 1     |
7M-7456     | Bearing Mount Compound     | 1     |
190-8380     | Shim Kit     | 1     |
6V-2055     | Grease     | 1     |
The kit contains the following brass shims:
- Eight 190-8381 Shim Kit (0.05 mm)
- Four 190-8382 Shim Kit (0.13 mm)
- Two 190-8383 Shim Kit (0.25 mm)
- One 190-8384 Shim Kit (0.50 mm)
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.
- 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).
Show/hide table
Table 5 Bearing Measurements     Old brass shim thickness         Old shoulder height         New shoulder height         New brass shim thickness         Note: The shoulder height is stamped on the surface of the bearing cartridge.
- Install a 191-5217 Guide Pin in one of the six bolt holes that are located in the bearing cartridge (23) .
- Install another 191-5217 Guide Pin in one of the six bolt holes that are located in the bearing cartridge (23). This pin should be installed 180 degrees away from the first pin. This will locate the bearing cartridge during installation.
Illustration 7 | g01933736 |
(23) Upper Bearing Cartridge (24) Shim Pack (25) O-ring |
- Align the 6 pin Amphenol connector in order to enable the connector to reach the connecting harness from the Printed Wire Assembly (PWA) for the Flywheel Interface (FWI).
- Apply 6V-2055 Grease to the new O-ring (25).
- Install the new O-ring (25) on the upper bearing cartridge (23) .
- Install the new bearing cartridge with the required number of shims. Use your hand in order to seat the bearing cartridge.
- Install the 190-8379 Bearing Installer Gp on the bearing housing.
Illustration 8 | g01933854 |
190-8379 Bearing Installer Gp (26) Nut (27) Center Bolt |
- Hand tighten the nut (26). Use a wrench in order to tighten the nut until the bearing is completely seated.
- Remove the 190-8379 Bearing Installer Gp .
- Remove the two 191-5217 Guide Pins .
- Install the six screws around the perimeter. Use quarter turns in order to install the bolts. 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).
- Clean the threads on the polished retainer bolt (4) with a wire brush or replace the bolt.
- Place one drop of 7M-7456 Bearing Mount Compound on the threads of the polished retainer bolt (4) .
- Install the rotor wheel (21) and the retaining bolt (4) for the rotor wheel. Torque the bolt to 38 N·m (28 lb ft).
Note: Do not install the RPS at this time. The RPS should be installed after the lower bearing cartridge and the load cell have been installed.
Lower Bearing
Removal Procedure
Illustration 9 | g01933974 |
(24) Shim Pack (25) O-ring (28) Lower Bearing Cartridge (29) Bolt for Lower Bearing (30) Rotor Retainer (31) Retaining Bolt for Rotor (32) Mounting Bolt for Load Plate (33) Mounting Bolt for Static Drain (34) Mounting Washer for Static Drain (35) Static Drain (36) Load Plate (37) Load Cell (38) Bolt for Load Cell |
- Remove the three, one inch hex plugs.
- Insert the three 190-8386 Shims into the three openings on the bottom of the flywheel case.
Refer to Illustration 10.
Note: The short tabs of the three 190-8386 Shims must face outward from the center of the flywheel when the shims are inserted in the rotor casing. Ensure that the tabs rest on the pole ring that is located on the inside of the flywheel case.
Illustration 10 | g00712417 |
190-8386 Shims in place (cutaway view) |
- Disconnect the following items from the bottom of the flywheel: the 19-pin connector, the cable for the thermistor and the vacuum hose.
- Bearing Thermistor
- Load Cell Connector
- Flywheel Connector
- Vacuum Cable
- Bearing Thermistor
- Remove the six bolts (38) that connect the load cell to the bottom bearing. Use the 1/4 inch allen wrench in order to remove the bolts.
Note: Do not remove the two recessed bolts on the opposing sides of the load cell.
Note: Remove the bolts evenly. Use a star pattern when you remove the bolts. Removing the bolts by using a star pattern ensures that the movement of the load cell stays vertical and the load cell will not bind in the housing.
- Remove the load cell from the bottom bearing.
- Remove the polished retainer bolt (31) and the rotor retainer (30) .
- Remove the two remaining 5/16 inch bolts from the bearing cartridge. Use a 1/4 inch allen wrench.
- Install the 190-8385 Bearing Puller Gp on the lower bearing cartridge (35) .
- Install the two 191-5217 Guide Pins in two opposite holes of the eight bolt holes that are located in the lower bearing cartridge. This will prevent the lower bearing cartridge from turning.
- Carefully turn the center bolt by hand until the center bolt makes contact with the journal for the rotor.
- Turn the center bolt in order to extract the lower bearing cartridge.
Note: When the bearing is clear of the shaft, the bearing cartridge may fall. Maintain one hand on the bearing cartridge.
- Remove the brass shims from the bearing.
Note: Ensure that no brass shims remain in the flywheel housing.
- Measure the old brass shims and record the measurement. Refer to Illustration 11.
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 that is stamped on the face of the bearing cartridge.
Show/hide tableTable 6 Bearing Measurements     Old brass shim thickness         Old shoulder height        
Illustration 11 | g01810454 |
- Remove the bearing puller from the bearing cartridge.
- Compare this height to the height that is stamped on the face of the new lower bearing.
- If the new height is less than the original height, subtract the difference from the original shim pack.
- If the new height is greater than the original height, then add the difference to the original shim pack.
Note: The result indicates the thickness that the shims need to be adjusted in order to ensure that the rotors rest in the correct position. Refer to the following examples.
Show/hide tableTable 7 Example 1     New Bearing Height:     1.997     Old Bearing Height:     1.995     Difference:     .002
Add .002 to the shim pack.    Show/hide tableTable 8 Example 2     New Bearing Height:     2.029     Old Bearing Height:     2.032     Difference:     .003
Subtract .003 from the shim pack.    
Installation Procedure
Illustration 12 | g01933974 |
(24) Shim Pack (25) O-ring (28) Lower Bearing Cartridge (29) Bolt for Lower Bearing (30) Rotor Retainer (31) Retaining Bolt for Rotor (32) Mounting Bolt for Load Plate (33) Mounting Bolt for Static Drain (34) Mounting Washer for Static Drain (35) Static Drain (36) Load Plate (37) Load Cell (38) Bolt for Load Cell |
Part Number     | Description     | Qty     |
191-5217     | Guide Pin     | 2     |
190-8379     | Bearing Installer Gp     | 1     |
7M-7456     | Bearing Mount Compound     | 1     |
190-8380     | Shim Kit     | 1     |
6V-2055     | Grease     | 1     |
The kit contains the following brass shims:
- Eight 190-8380 Shim Kit (0.05 mm)
- Four 190-8382 Shim Kit (0.13 mm)
- Two 190-8383 Shim Kit (0.25 mm)
- One 190-8384 Shim Kit (0.50 mm)
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.
- 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).
Show/hide table
Table 10 Bearing Measurements     Old brass shim thickness         Old shoulder height         New shoulder height         New brass shim thickness         Gap between bearing and retainer         Note: The shoulder height is stamped on the surface of the bearing cartridge.
- Install a 191-5217 Guide Pin in one of the eight bolt holes that are located in the bearing cartridge (28) .
- Install another 191-5217 Guide Pin in one of the eight bolt holes that are located in the bearing cartridge (28). This pin should be installed 180 degrees away from the first pin. This will locate the bearing cartridge during installation.
Illustration 13 | g01935044 |
(38) Bolt for Load Cell |
- Align the Amphenol connector for the thermistor so that the harness cable will reach the connector of the Printed Wire Assembly (PWA) for the Flywheel Interface (FWI).
- Apply 6V-2055 Grease to the new O-ring (25).
- Install the new O-ring (25) on the upper bearing cartridge (23) .
- Install the new bearing cartridge with the required number of shims. Use your hand in order to seat the bearing cartridge.
- Install the 190-8379 Bearing Installer Gp on the bearing housing.
Illustration 14 | g01933854 |
190-8379 Bearing Installer Gp (26) Nut (27) Center Bolt |
- Hand tighten the nut (26). Use a wrench in order to tighten the nut until the bearing is completely seated.
- Remove the two 191-5217 Guide Pins .
- Remove the 190-8379 Bearing Installer Gp .
- Install the six screws around the perimeter. Use quarter turns in order to install the bolts. 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).
Note: If the bolt head shows wear, replace the bolt. A smooth surface is very important for proper operation.
- Place a drop of 7M-7456 Bearing Mount Compound onto the bottom of the threads of the retainer bolt.
- Clean the threads on the retainer bolt (31) with a wire brush or replace the bolt.
- Place one drop of 7M-7456 Bearing Mount Compound on the threads of the retainer bolt (31). Torque the bolt to 38 N·m (28 lb ft).
- Verify the angle for the static discharge drain by using the angle block. If the angle does not match the block, adjust the angle of the static drain. Refer to the Systems Operation, Testing and Adjusting manual for your unit in order to measure and adjust the static drain.
- Remove, lubricate, and install the O-ring for the new load cell.
- Insert the six 5/16 inch hex head bolts (38) into the load cell.
- Tighten the bolts to 27.1 N·m (20 lb ft) with a 1/2 inch socket wrench.
Note: Use a star pattern when you tighten the bolts.
Installation of the load cell is not complete. Proceed to the ""Continuity Check" " section of this document.
Continuity Check
After the charge drain and the load cell is installed, check for continuity using the following procedure:
- The commutation sensor should still be disassembled from the flywheel. If the commutation sensor is not removed, remove the commutation sensor.
- With a standard ohmmeter, check continuity between the retaining bolt of the upper rotor and any unpainted, bare metal surface on the flywheel housing.
If there is no continuity, the charge drain has not been installed and adjusted properly.
- If continuity does not exist:
- Remove the load cell from the lower bearing cartridge.
- Check the installation of the charge drain and the height adjustment.
- Verify that the contact surfaces are clean.
- Check continuity between the upper retaining bolts for the rotor and the lower retaining bolts for the rotor.
- Reinstall the load cell.
- Repeat the check for continuity.
- Remove the load cell from the lower bearing cartridge.
- Once continuity is verified, reinstall the commutation sensor onto the upper bearing cartridge.
- Apply a light coat of vacuum grease to the O-ring for the commutation sensor. Reinstall the commutation sensor onto the assembly in the O-ring groove.
- Reinstall the commutation sensor with the three mounting screws.
- Remove the support shims for the rotor.
If the support shims for the rotor are still bound between the rotor and the surface of the pole ring, remove the "load cell" and add a "2 mil" shim to the shim package for the load cell. Reinstall the "load cell".
Note: If the shim package for the bearing cartridge is measured correctly, then no more than one shim should be required in this adjustment. If the gap between the retainer and bearing is less than "6 mils", the cartridge must be removed and an additional "2 mil" shim must be added to the brass shim package:
- If the gap is "7 mils", one "2 mil" shim may be added to the shim package for the load cell.
- If the gap is "9 mils", two "2 mil" shims may be added to the "Load Cell" shim package.
If the load plate is stuck, try to wiggle the load plate by hand. Do not use a screwdriver or any other tool because of the risk of damaging the charge drain.
- If the gap is "7 mils", one "2 mil" shim may be added to the shim package for the load cell.
- Apply Dow-Corning high vacuum grease to the O-rings that are located on four plugs.
- Install the three plugs.
- Connect the lower harness from the Printed Wire Assembly (PWA) for the Flywheel Interface (FWI) to the load cell connector.
- Connect the lower harness from the Printed Wire Assembly (PWA) for the Flywheel Interface (FWI) to the lower flywheel housing connector.
- Connect the upper harness from the Printed Wire Assembly (PWA) for the Flywheel Interface (FWI) to the upper bearing cartridge connector.
- Connect the upper harness from the Printed Wire Assembly (PWA) for the Flywheel Interface (FWI) to the upper flywheel housing.
- The conversion is complete.