Replacement of the Capacitors and the Inverters on the UPS{4480, 7451} Caterpillar

Uninterruptible Power Supply:

UPS 1000S (S/N: CZS1-UP)

UPS 1200S (S/N: CZT1-UP)

Introduction

You must be a trained technician in order to perform the following procedure.

This Special Instruction contains important safety instructions that must be followed during the replacement of the capacitors and the inverters for the Series 1200 Uninterruptible Power Supply(UPS) in the inverter cabinet.

Read this Special Instruction thoroughly. Pay special attention to the section that applies to you before you begin working with the system. Only normal safety precautions are necessary when the module is under typical operation and all of the doors are closed.

Observe all of the safety precautions during the maintenance procedures.

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.

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Accidental engine starting can cause injury or death to personnel working on the equipment. To avoid accidental engine starting, disconnect the battery cable from the negative (−) battery terminal. Completely tape all metal surfaces of the disconnected battery cable end in order to prevent contact with other metal surfaces which could activate the engine electrical system. Place a Do Not Operate tag at the Start/Stop switch location to inform personnel that the equipment is being worked on.

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Personal injury or death can result from improper lifting or blocking. When a hoist or jack is used to lift any part or component, stand clear of the area. Be sure the hoist or jack has the correct capacity to lift a component. Install blocks or stands before performance of any work under a heavy component. Approximate weights of the components are shown. Clean all surfaces where parts are to be installed.

Illustration 1	g00740165

Illustration 2	g00740168

General Hazard Information

Attach a "Do Not Operate" warning tag or a similar warning tag to the keyswitch or to the controls before the system is serviced or before the system is repaired. These warning tags are available from your Caterpillar dealer. Attach the warning tags to the system and to each operator control station.

Illustration 3	g00104545

• Do not allow unauthorized personnel on the system, or around the system when the system is being serviced.

• Wear a hard hat, protective glasses, and other protective equipment, as required.

• Do not wear loose clothing or jewelry that can snag on controls or on other parts of the system.

• Report all necessary repairs.

Unless other instructions are provided, perform the maintenance under the following conditions:

• The system is stopped and the system is disconnected from power. Ensure that the system cannot be powered or ensure that power cannot be applied to the system.

• Do not attempt any repairs that are not understood. Use the proper tools. Replace any equipment that is damaged or repair the equipment.

• Remove all tools, electrical cords, and any other loose items from the system before starting the system.

Fire and Explosion Prevention

• Make sure that the room is ventilated properly.

• Keep the floor clean of debris.

• Store oily rags and other flammable material in protective containers.

• Do not smoke in areas that contain flammable material.

• Store all lubricants in properly marked containers. Store the protective containers in a safe place.

• Do not allow flammable materials to accumulate.

Wiring must be kept in good condition. Wires must be properly routed and securely attached. Routinely inspect the wiring for wear or for deterioration. Loose wiring, unattached wiring, or unnecessary wiring must be eliminated. All wires and all cables must be of the recommended gauge and the type. Do not use a wire or a cable that is physically smaller than the recommended gauge. The wires and cables must be connected to a fuse or to a circuit breaker, as required. Do not bypass fuses and/or circuit breakers. Arcing or sparking could cause a fire. The following practices will help prevent arcing and sparking:

• Use only recommended wiring.

• Secure all connections.

Acronyms

The following information is a list of the acronyms that may be used in this manual:

APC - Active Power Controller PWA

APM - Active Power Module

AWG - American Wire Gauge

CSHV - CleanSource High Voltage

CT - Current Transformer

IGBT - Insulated Gate Bipolar Transistor

NEC - National Electric Code

NEMA - National Electrical Manufacturers Association

SELV - Safety Extra Low Voltage

UPS - Uninterruptible Power Supply

Required Tools

The following tools will be required to install the capacitor and the inverter. The list below contains the recommended Caterpillar service tools.

Table 1

Quantity	Description
1	Ratchet Socket Driver Set
1	Torque Wrench
1	Assorted Standard Sockets
1	Phillips Head Screwdriver
1	Flat Head Screwdriver
1	Tie-wraps (Medium and Small) package
1	Tie-wrap mounts (Medium and Small) package
1	Drill with socket adapter
1	Notebook Computer with CSView installed
1	Appropriate interface cable

Removal and Installation Procedures

Overview of the Inverter Cabinet

Review Illustration 4 in order to become familiar with the internal components and assemblies that are located in the inverter cabinet. The steps that are defined in the following instructions are for maintenance of the electrical components with high electrical risk that are located behind the locked doors of the cabinets.

Illustration 4	g01757153
(1) Inverter assembly (2) Current Transformer (3) Upper left panel (4) DC bus (5) Heat sink (6) Lower plenum for the fan (7) Fan (8) Lower left panel

Prepare the Inverter Cabinet for Replacement of the Capacitor Bank and the Inverter

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Illustration 5	g01757155

1. Ensure each of the CSHV keyswitches are in the "Spindown/Offline" position. Refer to Illustration 5.

2. If it is necessary, use the brake on the flywheels.

3. Ensure that the input power is OFF to the UPS.

4. Ensure that the flywheel is at zero rpm.

5. Confirm that the voltages are at zero (0).

6. Allow the capacitors to bleed down for ten minutes.

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Risk of electric shock or energy hazard. Parts inside this UPS are energized by the flywheel even when the AC power is disconnected.

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Personal injury or death can result from high voltage. When power generation equipment must be in operation to make tests and/or adjustments, high voltage and current are present. Improper test equipment can fail and present a high voltage shock hazard to its user. Make sure the testing equipment is designed for and correctly operated for high voltage and current tests being made.

7. Unlock the inverter cabinet. Use a hex "5/16" key on the upper and lower latches. Open the inverter cabinet.

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Illustration 6	g01757174
(4) DC bus (6) Lower plenum for the fan (10) Lower metal protective shield (11) Upper metal protective shield

8. Remove the hardware that secures the protective shields that are inside of the cabinet. Refer to Illustration 6.

9. Measure the DC voltage in order to confirm that the bus has bled down.

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Illustration 7	g01757177

10. Remove the vertical plenum for the fan. Use a "7/16" socket in order to remove the twelve bolts.

    Note: Use care when you handle the sheet metal components. Sharp edges may exist. Refer to Illustration 7.

    Note: The system may have the original bus bars ("PN 17313 Positive" and "PN 17312 Negative"). The bus bars and the original hardware must be removed. Replace the existing bus bars with new bus bars ("PN 1820833 Positive" for the left and the right and "PN 1820824 Negative" for the left and the right) and the associated hardware. The style of the bus bars differs in appearance. The mounting connections of the components is very similar. The exception is in the noted sections in these instructions.

Current Transformer (CT) Removal

Remove the CTs by performing the steps that are contained in the latest revision of the Series 1200 maintenance manual ("AP PN 60098-1". Call Active Power in order to verify that you have the correct version.

DC Bus Bar Removal

1. Remove all of the DC cables that are connected to the positive DC bus bar fuses and negative DC bus bar fuses.

2. Remove all of the spacers and the bolts that are used in order to secure the bus bar in place.

   Note: Hold the DC bus bar in place while you remove the hardware. Holding the DC bus bar will prevent damage to the components that are inside of the cabinet.

3. Remove the bus bars.

AC Fuse Assembly Removal

1. Remove the Inverter Module Assembly.

2. Remove the AC Fuse Assembly.

3. Remove the two clear plastic shields that cover the DC Capacitors.

4. Remove the white neutral bus wires from the resistors. The wires are labelled to the respective locations. Verify and record the labeling.

5. Remove the red and black wires from the resistors. The wires are labelled to the respective locations. Verify and record the labeling.

6. Remove all of the DC cables from the positive DC bus bars and the negative DC bus bars.

7. Loosen the front four bolts that hold the DC Capacitor Assembly to the frame of the cabinet.

8. Remove the rear two bolts that hold the DC Capacitor Assembly to the frame of the cabinet.

9. Slide the DC Capacitor Assembly straight out of the front of the cabinet.

Inverter Module Removal

1. Remove the clear plastic cover that is over the Digital Gate Logic (DGL) PWA of the inverter assembly. Three phillips head screws need to be removed in order to remove the cover.

2. Remove the connectors from the DGL PWA. The wires are labelled to the respective locations. Verify the labels.

3. Cut the tie-wraps in order to move the cables out of the way.

4. Remove the toroid wire assembly that is bolted to the bottom of the DGL bracket.

   Note: Toroids are very fragile. Use extreme caution when you handle the toroids. Use extreme caution when you use tools near the toroids.

5. Remove the bolt from the bracket of the Inverter Module Assembly that holds the assembly to frame of the cabinet.

6. Remove the four bolts that connect the Inverter Module Assembly to the DC Capacitor Assembly fuse bus. Use a deep "9/16" socket in order to remove the bolts.

7. Slide the inverter module forward out of the frame of the cabinet.

DC Capacitor Assembly Installation

1. Slide the DC Capacitor Assembly straight to the front of the cabinet. The loosened bolts should slide into the corresponding slots in the frame of the cabinet.

2. Install the rear two bolts that hold the DC capacitor assembly to the frame of the cabinet.

3. Tighten all six of the bolts that hold the DC capacitor assembly to the frame of the cabinet.

4. Attach the red and black wires from the resistors. The wires are labelled for the connecting locations.

5. Attach the white and neutral bus bar wires to the two large resistors that are connected to the frame at the back of the cabinet.

6. Attach the two clear plastic shields that cover the DC Capacitors.

   Note: One of the plastic shields is new.

7. Install the AC Fuse Assembly.

8. Install the Inverter Module Assembly.

AC Fuse Assembly Installation

1. Slide the AC Fuse Assembly forward onto the two bolts that have were loosened in the frame of the cabinet.

2. Tighten the two bolts that hold the top and the bottom of the AC Fuse Assembly to the frame of the cabinet.

3. Attach the bolt from the bracket that connects the AC Fuse Assembly to the Inverter Module Assembly. Use a "9/16" socket in order to tighten the bolt.

Inverter Module Assembly and Installation

1. Slide the Inverter Module Assembly straight forward into the cabinet.

2. Attach the bolt that connects the Inverter Module assembly to the AC Fuse assembly. Use a "9/16" socket in order to tighten the bolt.

3. Attach the four bolts that connect the inverter Module Assembly to the DC Capacitor Assembly fuse bus. Use a deep "9/16" socket in order to tighten the bolts.

4. Torque the bolts to 61 N·m (45 lb ft).

5. Attach the bolt from the bracket of the Inverter Module Assembly that holds the assembly to the frame of the cabinet.

6. Attach the toroid wire assembly that is bolted to the bottom of the DGL bracket.

7. Use a tie-wrap in order to secure the cables out of the way.

8. Attach the connectors to the DGL PWA. The wires are labelled for the connecting locations.

9. Attach the clear plastic cover over the DGL PWA of the inverter module using the three phillips head screws.

Install the New DC Bus Bars

1. Start at the far right bus bar in the inverter cabinet.

2. Insert the hex "2.5 x 3/8 in." bolt through the IGBT bus bar.

3. Slide the spacer "PN 1820822-1" onto the bolt that is going through the IGBT bus bar.

4. Position the left DC bus bar "PN 1820824" in the inverter cabinet by sliding bus bar onto the bolt that is going through the spacer.

5. Position the nomex sheet "PN 1820835" on the DC bus bar.

6. Place the right DC bus bar "PN 1820824" against the nomex sheet so that the right DC bus bar is in line with the left DC bus bar.

7. Hand tighten the bolt in order to hold the assemblies in alignment.

8. Attach the fuse assemblies. Use the "1.75 inch x 3/8 inch" hex head bolts and the "1.5 inch x 3/8 inch" hex head bolts.

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Illustration 8	g01757585
(15) Bus bar (16) Nomex (17) Fuse (18) Spacer

9. Add the spacers and bolts that are remaining in order to complete the bus assembly.

   Note: Do not put the full weight of the DC bus bar assembly on one of the IGBT bus bars. Hold the DC bus bar assembly in place while you assemble the remaining spacers, fuses, and bolts. Refer to Illustration 8.

   The bus bar setup should resemble the one in Illustration 9.

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Illustration 9	g01757588
(A) 1 in. spacer (B) 1/2 in. spacer (C) 3/8 in. nut (D) 3/8 in. split washer (E) 3/8 in. flat washer (F) 2 1/4 in. bolt (G) 3/8 in. washer (H) 1 in. spacer

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Illustration 10	g01757597
(J) Fuse (K) DC bus cable mounting plate

10. Attach all of the DC cables to the positive and the negative fuses for the DC bus bar. Refer to Illustration 10.

11. Torque the bolts that are going through the spacers and the bus bars to 61 N·m (45 lb ft).

12. Torque the bolts that are going into the fuses to 26 N·m (19 lb ft).

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Illustration 11	g01757613
(16) Nomex (J) Fuse (L) Cable lugs

13. Torque the cable lugs that go to the DC bus mounting plates to 54 N·m (40 lb ft). Refer to Illustration 11.

Install the Current Transformers

Install the CTs by performing the steps that are contained in the lastest revision of the Series 1200 maintenance manual ("AP PN 60098-1". Call Active Power in order to verify that you have the correct version.

Inverter Post-Installation Steps

1. Attach the vertical plenum for the fan over the inverter heat sinks. Use a "7/16" socket in order to secure the twelve bolts.

2. Attach the protective shield. Use the hardware that was retained in a previous step.

3. Use the following instructions in order to bring the UPS on-line after all of the work is complete.

Bring the System On-line

Note: All of the alarms and the notices must be acknowledged before the UPS/SMS or MMU can be placed on-line.

1. Apply facility power to the Main Input of the UPS.

2. Close the DC Disconnect in each of the CSHV cabinets. Make sure that the green light is ON before you operate the DC Disconnect Switch.

3. Press the "Transfer from Maintenance Bypass" push button in the Maintenance Bypass cabinet. The button must be illuminated green before operating.

4. Touch the "Log On" tab on the GUI or login by using CSView.

5. Enter a valid service level user name and a password. The GUI displays the one line page.

6. If the UPS is in Shutdown Mode, touch the "Enable Bypass Command" button.

7. Touch the "Bypass" button. The UPS transfers to the "Bypass Mode".

8. Pre-charge the DC bus by performing an "Autostart to Pre-Charge" command. Use the GUI or CSView by pressing "Alt-P".

9. Manually check the balance by using the telemetry files in CSView. Manually check the voltages of the DC bus on CSHV and the UPS.

10. Put the system in "Bypass" by pressing "Ctrl-B".

11. Verify all of the inverters by performing an "Autostart to Inverters" command. Use the GUI or CSView by pressing "Ctrl-I".

12. Verify that the filter voltages are balanced by using the CSView telemetry.

13. Touch the "Enable Bypass" button.

14. Touch the "Bypass" button.

15. Wait for the vacuum to come down to an operable level on all of the flywheels.

16. Turn all of the CSHV keyswitches to the "Online" position.

17. Command the UPS to go on-line by using the GUI or CSView.