GEAR 4824508 - Caterpillar

Description
Illustration 1 g01278148
Location of the Assembly for the Utility Inverter
(1) Utility Inverter ModulesThe assembly for the Utility Inverter is located in the upper part of the cabinet for the flywheel in the middle.There are two inverters in the system, the flywheel inverter and the utility inverter. The inverters are used for the following reasons:
developing the current that is necessary to rotate the flywheel
developing the voltage that is used during a discharge
charging and maintaining the DC bus voltagePower is provided by one inverter at a time to the DC bus. The Utility Inverter maintains the voltages for the DC bus. The Utility Inverter regulates output voltage.The Utility Inverter contains a three-phase insulated gate bipolar transistor (IGBT). The IGBTs perform the following functions:
rectifying the AC voltage from the filter node
converting the DC voltage back to AC voltage during dischargeRemoval Procedure
Refer to Systems Operation, Testing and Adjusting, UENR3954, "Internal Component Preremoval Steps (Flywheel Cabinet)" in order to shut down the system and gain access to internal components.
Remove the two screws that attach the interface board to the front of the utility inverter assembly. Place the interface board in an anti-static bag.
Disconnect the input cable from the right side of the module (1).
Cut the tie-wrap that attaches the ribbon cable and the toroid to the assembly.
Disconnect the "18 AWG Red/Black" wires from the module (1).
Remove the ribbon cable from the module (1).
Remove the two mounting bolts from the positive connection of the DC bus.
Remove the two mounting bolts from the negative connection of the DC bus.
Loosen the two mounting bolts at the top of the assembly for the heat sink.
The module for the Flywheel inverter is heavy. Exercise caution upon removing the last bolt of the assembly in order to not damage components.
Remove the module (1) from the assembly.Installation Procedure
Remove the hardware for mounting the cables and capacitors from the old module (1). Attach the hardware to the new module (1).
Install the new assembly in the cabinet.
Install the two mounting bolts for the negative connection of the DC bus. Tighten the bolts to 11.3 N m (100 lb in).
Install the two mounting bolts for the positive connection of the DC bus. Tighten the bolts to 11.3 N m (100 lb in).
Install the two mounting bolts at the top of the assembly for the heat sink. Tighten the bolts to 4.5 N m (40 lb in).
Connect the ribbon cable to the module (1).
Connect the input cable to the right side of the module (1). Tighten the bolt to 9 N m (80 lb in).
Attach the SKiip Interface board to the bottom of the module (1) with the two screws.
Connect the "18 AWG Reb/Black" wires to the module (1).
Energize the system.
Illustration 2 g03374044
(2) Mounting bolt
(3) Heat sink and shroud
(4) Capacitors
(6) DC bus
(7) Fuses for DC bus
(8) DC capacitors