UPSB220 Uninterruptible Power Supply Caterpillar

DC Capacitor Replacement Procedures

Overview

Use the following instructions to perform DC capacitor bank assembly replacement. The instructions involve the following:

• Removal of the rectifier/charger, inverter, and output static switch modules

• Removal the DC capacitor bank assembly

• Installation of the DC capacitor bank assembly

• Installation of the rectifier/charger, inverter, and output static switch modules

Illustration 1	g02545134
(1) Rectifier/charger module (2) Inverter modules (3) Output static bypass module (4) Module mounting bolts (5) Cables and connectors (6) DC bus insulation paper (7) DC capacitor bank assembly in UPS

Safety

Refer to the Operation and Maintenance Manual, SEBU8274, "General Hazard Information" section for safety-related information.

Personal protection equipment is required for safety:

• 11 cal arc flash suit

• 20 cal arc flash hood

• Electrical safety gloves

• Safety glasses

Tooling

The following list is tools that are needed:

• Fluke digital multimeter with extended leads

• DC source (a battery)

• 10 mm (0.394 inch) and 13 mm (0.512 inch) wrenches

• 22 mm (0.866 inch) open-end wrench

• Ratchet with 12 inch extension

• 7, 10, and 13 mm sockets

• Extension magnet

• Extension mirror

• Magnetic parts bowl

• Work table

Removal Procedure

Note: The following procedure provides instruction to remove the capacitor bank through the front side of the UPS.

1. The UPSB220 must be de-energized for the following procedure. Confirm that the Mains 1 and Mains 2 upstream breakers are tagged out and locked out.

2. The required PPE must be put on.

3. Use the Fluke meter to verify that no AC or DC voltage is present.

   1. Verify that the Fluke meter is working properly with a known AC source. Use the AC scale.

   2. Verify that the Fluke meter is working properly with a known DC source. Use the DC scale.

   3. Measure for AC voltage at Q1. Measure for voltage phase-to-neutral and phase-to-phase.

   4. Measure for DC voltage plus-to-minus at the DC capacitors.

4. After no voltage is confirmed, the PPE can be removed, except for safety glasses.

5. Ensue that all cables and components are appropriately labeled before removal.

6. Remove the cables and hardware from all five modules shown in Illustration 1.

7. Remove the output static switch module (3) .

8. Remove all three inverter modules (2) .

9. Remove the rectifier/charger module (1) .

10. Remove the DC bus insulation paper (6) .

11. Remove the DC capacitor bank assembly mounting bolts (10). There are six mounting bolts (10) to be removed.

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Illustration 2	g02545577
All mounting bolts are not shown. (10) DC capacitor bank assembly mounting bolts on rearward side of UPS

12. Slide the DC capacitor bank assembly forward to provide enough space to tilt the assembly. Tilt the top of the DC capacitor bank assembly towards the back of the unit. Refer to Illustration 3.

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Illustration 3	g02545796
(11) Support rails (12) DC capacitor bank assembly mounting plate

13. Remove the DC capacitor bank assembly.

DC Capacitor Bank Disassembly

Illustration 4	g02546746
(15) Mounting bolts for acrylic capacitor mounting brackets (16) Resistors (17) Capacitor mounting bolts for bus plates (18) Bus plate fasteners (19) Bus plates (20) Capacitor assembly mounting bracket (21) Capacitors (22) Acrylic capacitor mounting brackets

1. Ensure that all components are appropriately labeled before disassembly. Labeling the components will help avoid assembly problems.

2. Remove the resistors (16) that are on the front of the assembly.

3. Remove mounting fasteners (17) and (18) .

4. Remove the bus plates (19) .

5. Remove the 19 mm mounting bolts (15) for the acrylic capacitor mounting brackets (22) .

6. Remove the mounting bolts (25) that attach the acrylic capacitor mounting brackets (22) to the capacitors. Refer to Illustration 5.

   Note: All of the capacitors should be replaced at the same time with new capacitors.

Illustration 5	g02547266

DC Capacitor Bank Assembly

1. Secure the new capacitors (21) to the mounting brackets (22). The mounting bolts (25) must be torqued to 7 N·m (5.2 lb ft).

2. Assemble all of the capacitor components (15), (21), and (22) to the capacitor assembly mounting bracket (20). The torque for the mounting bolts (15) that attach the acrylic capacitor mounting brackets to the capacitor assembly mounting bracket (20) is 6 N·m (4.4 lb ft).

3. Install the insulator, that may have been removed, from between the bus plates. Install the bus plates (19). Install, but do not yet tighten the mounting bolts (17). Install the bus plate fasteners (18) .

4. Tighten the mounting fasteners (17) and (18). The mounting bolts (17) are to be torqued to 6 N·m (4.4 lb ft). Torque the bus plate fasteners (18) to 14 N·m (10.3 lb ft).

5. Install the resistors (16) that were removed.

DC Capacitor Bank Installation

1. Place capacitor assembly mounting bracket (12) flat on the mounting rails (11). Slide the capacitor assembly toward the back of the UPS cabinet.

2. Rotate the top of the capacitor assembly toward the front of the UPS cabinet. Ensure that the capacitor assembly will have the clearance needed to avoid hitting the cooling ducts (26) .

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Illustration 6	g02547679

3. Install all six of the capacitor assembly mounting fasteners. Tighten all six of the mounting fasteners.

4. Install the modules that were removed.

5. Connect all power cables and ribbon cables that were removed.

DC Capacitor Forming

The DC capacitor forming procedure will expose personnel to live electrical components. Any individual within 5 feet of live equipment must use all of the appropriate PPE listed below.

Refer to the Operation and Maintenance Manual, SEBU8274, "General Hazard Information" section for safety-related information.

The process for forming capacitors, allows the capacitors to work more efficiently and last longer if the capacitors are charged slowly with an initial charge.

Personal protection equipment is required for safety:

• 11 cal arc flash suit

• 20 cal arc flash hood

• Electrical safety gloves

• Safety glasses

Equipment Needs

The following items are needed for the process to occur:

• Fluke digital multimeter with gator clips

• Soft Tuner software

• Null modem cable

DC Capacitor Forming Procedure

Refer to the Test and Adjust Manual, UENR1798, "Component Location" for component location within the UPS.

1. Connect the null modem cable to COSI board.

   Note: The COSI board is also referred to as the Media 11 Contact board.

2. Connect the null modem cable to a laptop computer that has UPS Soft Tuner installed.

3. The appropriate personnel must put on the required PPE.

4. Clip the meter leads to the DC bus or the DC connections on the rectifier/charger module.

   Note: The meter leads can also be attached to the DC bus in battery cabinet before the UPS has power applied.

5. Apply power to the unit.

6. Close Q4S.

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Illustration 7	g02549536

7. The UPS should power up and the cooling fans should all start running.

8. The LED status lights on the control panel must be documented.

9. Open the Soft Tuner program.

10. At the first soft tuner screen. click the "Refresh all" button (28) .

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Illustration 8	g02549537

11. Click the diagnostic tab on the menu bar. Highlight "Manual drive" from the drop-down menu. After the sub menu opens, click "Rectifier open loop".

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Illustration 9	g02549540

12. Follow the instructions on the starting conditions screen to configure the UPSB220.

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Illustration 10	g02549744

13. After the configuration instructions have been met, select ok (30) on the Soft Tuner window.

14. Close Q1 to start the charger.

15. Press the UPSB220 control panel fault push-button as needed to clear faults. Clear the faults as needed throughout the procedure.

16. Click on the down arrow (35) in the "Commands" field of the "Manual drive" dialog. Select the "Charger on" command. Click the green button (36) that is in the "Commands" field.

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Illustration 11	g02549819

17. A confirmation dialog will appear warning of the risk of power interruption. Select yes in the confirmation dialog.

18. On the "Manual drive" dialog, use the slider (37) to set the increment value to 125.

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Illustration 12	g02549821

19. Select "Apply" in the "Manual drive" dialog.

20. Slowly increase the DC bus voltage in 10 V increments. Increase the voltage by clicking "Apply" until 100 VDC is shown on the Fluke meter.

21. Wait several minutes to verify that the DC bus is stable. If the DC bus is stable, then continue the forming process until 545 VDC is reached. Verify on the UPS display that voltage and current are correct. If abnormal readings occur, abort the DC forming process. Verify that all of the connections are correct. Verify that the DC capacitor assembly was installed correctly.

22. Wait for several minutes after 545 VDC has been reached. Exit the manual mode. The DC capacitor forming process has been completed.

23. On the "Manual drive" screen, select "Quit" (39) .

24. On the main Soft Tuner dialog, select "Disconnect" (40) .

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Illustration 13	g02550577

25. Open the Q1 breaker.

26. Open the Q4S breaker.

27. Verify that the DC voltage is under 50 V before removing the meter leads.