UPS 1000S/ UPS 1200S Uninterruptible Power Supplys Caterpillar

The T7 Transformer is a multitap transformer that receives input power from the UPS protected output and provides AC power to the five fans in the middle of the Inverter Cabinet.

Illustration 1	g01281638
T7 Transformer Location (1) Transformer T7

The T7 Transformer is installed on the rear panel near the bottom of the cabinet. Refer to Illustration 1 for the transformer location.

Illustration 2	g01281674
T7 Transformer (Inverter Cabinet)

The thermistor (2) for T7 is located on the left side of the transformer, as installed. The thermistor (2) is connected to the H1 connector of the transformer. Refer to Illustration 2 for the location of the thermistor (2) .

The thermistor (2) limits the in-rush of current on power-up.

Table 1

Thermistor Specifications
	Size	Ohm
T7	35mm	10

Table 2

Transformer Specifications
	Input (V)	Output (V)	Wire Gauge (AWG)
T7	380, 400, 415, 440, 480	230	10-22

Removal

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

2. Loosen the two screws and pull the thermistor (2) free of the terminal block. Each thermistor is attached by two screws to the transformer terminal block. One to the H1 connector and one to the "COM", or unlabeled connector.

Thermistor Installation

1. Loosen the screw of the H1 connector and the "COM" or unlabeled connector next to the H1 connector.

2. Place one lead of the thermistor (2) into the H1 connector and place one lead into the "COM" connector next to the H1 connector.

3. Tighten the screws to attach the thermistor (2) firmly.

Transformer Removal

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

2. Remove the lower fan plenum.

3. Remove all four wires or wire pairs from the transformer by loosening the screws holding the wires in the terminal block.

4. Remove the 4 hex screws at the corners of the transformer that hold the transformer to the cabinet panel. Use a 76 mm (3/16 inch) hex key.

5. Remove the transformer from the cabinet.

Transformer Installation

1. Position the transformer on the lower rear panel at the bottom of the cabinet. The transformer is installed with the H connectors situated to the left.

2. Attach the transformer using 4 hex bolts to the rear panel. Use a 76 mm (3/16 inch) hex key.

3. Connect the four wires or wire pairs to the transformer. Each wire is labeled as to its location. Connect the yellow wire labeled "COM". to the left side of connector H1. Refer to Illustration 2.

4. Reinstall the lower fan plenum.