UPS 750 Uninterruptible Power Supply Caterpillar

Illustration 1	g06058602
Snubber Capacitor (1.5 μF, 1200 VDC) (1) Tinned copper terminals

This capacitor is a snubber-type capacitor between the inverter and the DC bus. Refer to the following steps to remove and replace the snubber capacitor.

Note: Always practice Electrostatic Discharge (ESD) prevention.

1. Ensure that all preremoval steps are performed for the Extended Runtime Cabinet (EXRC) before gaining access to the internal components. Refer to Operation & Maintenance Manual, UENR4695, "Internal Component Preremoval Steps (FPU Cabinet)" for the preremoval procedure.

   Note: The system must be shut down before removal steps can be performed.

2. Remove two M8 x 1.25 (metric) nuts from the center threaded studs.

3. Remove snubber capacitor from the DC capacitor booster.

4. Install the snubber capacitor.

5. Secure the hardware removed in Step 2.

6. Return the system to service.

DC Bus Capacitor - Removal and Installation

Illustration 2	g06063209
(2) Positive terminal (3) Vent plug (4) Negative terminal (5) Mounting nut location

The DC bus capacitor stores energy for the DC bus. Refer to the following steps for the proper removal and installation procedure.

Note: Always practice Electrostatic Discharge (ESD) prevention.

1. Ensure that all preremoval steps are performed for the Extended Runtime Cabinet (EXRC) before gaining access to the internal components. Refer to Operation & Maintenance Manual, UENR4695, "Internal Component Preremoval Steps (FPU Cabinet)" for the preremoval procedure.

2. Remove the DC booster neutral bus insulator, fasteners, and capacitor wiring.

   Note: Shut down the system before performing the removal steps.

3. Identify and remove the M12 nylon insulated nut securing the capacitor in place.

4. Remove the capacitor from the DC capacitor booster.

5. Install the replacement capacitor.

6. Secure the capacitor with the nylon insulated nut previously removed.