UPS 1000S/ UPS 1200S Uninterruptible Power Supplys Caterpillar

Filter Fuses

Illustration 1	g01279343
(1) Filter Fuse Location

The Filter Fuses (1) are located between the AC filter capacitor banks in the middle of the Controls Cabinet. The Filter Fuses (1) protect the filter capacitors. Refer to Illustration 1 for the filter fuse location in the cabinet.

Illustration 2	g01279349
(2) AC Filter Fuses 1 F34-F36 (3) AC Filter Fuses 2 F37-F39

There are a total of six Filter Fuses (1) in the cabinet, three fuses for capacitor bank 1 (2) and three fuses for capacitor bank 2 (3). Each set of three fuses corresponds to Phase A, Phase B, and Phase C of the three-phase voltage.

Filter Fuse Status Indicators

The Filter Fuse Status Indicators are connected to the Filter Fuses (1) that are located between the AC Filter Capacitors in the middle of the Controls Cabinet. These indicators are connected to the General Purpose Interface Board which relays the indicators state through the Multidrop network to the APC2 Board.

If the fuse is blown, the indicator will trip and the status will be registered by the APC2.

Illustration 3	g01279352
AC Filter Fuse Status Indicator (4) Fuse Switch

Refer to Illustration 3 for Filter Fuse Status Indicator locations in the cabinet.

Filter Capacitor Resistors

Illustration 4	g01279462
(5) AC Filter Resistors

Illustration 5	g01279466

There are two filter capacitor resistors attached to the back side of each of the capacitor fuse banks, for a total of four capacitor resistors.

These resistors (R4 - R7) will discharge the AC capacitors after a shutdown of the system is performed.

Indicator Removal

1. Perform steps in the Systems Operation, Testing and Adjusting, "Internal Component Preremoval Steps (Controls Cabinet)" in order to de-energize the system and gain access to internal components.

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Illustration 6	g01279475

2. Remove the wires from the status indicator. The wires locations are labeled. Verify the labeling.

   AC Filter Fuse Status Indicator Wire Connections

3. Detach the indicator from the fuse.

Indicator Installation

1. Attach the indicator to the fuse with the three connectors facing the door of the cabinet.

2. Attach the wires to the indicator.

Fuse Removal

1. Perform steps in the Systems Operation, Testing and Adjusting, "Internal Component Preremoval Steps (Controls Cabinet)" in order to de-energize the system and gain access to internal components.

2. Remove the fuse status indicator from the fuse that is being replaced.

3. Remove the two nuts holding the fuse to the input and output contacts.

Fuse Installation

1. Position fuse across input and output connectors.

2. Fasten the fuse with two nuts.

3. Tighten the nuts firmly.

4. Attach the fuse switch to the fuse.