Two of the transformers (T1 and T2) are connected to the UPS input and two transformers (T3 and T4) are connected to the UPS protected output.
Each transformer is connected to different phases on both input and output to prevent loss of power if a single phase is low or in operable.
The thermistors for T1 to T4 are located on the left side of the transformer, as installed. All thermistors are connected to the H1 and H2 connectors of the transformer. The thermistors limit the in-rush of current on power-up.
Illustration 1 | g01277295 |
Controls Cabinet Back Panel (318) Customer Contacts Interface Board #2 (Optional) (319) DC Bus Pre-charge Circuit Resistors (320) T1 - T4 Transformers (321) Power Supply Board (PWS) (322) Customer Contacts Interface Board #1 (323) Power Supply Board (PWS) (324) Thermistor (325) Fuse F69 (326) Fuses F88-F90 F70-F72 (327) Zig-Zag Transformer (328) K7 Pre-charge Contactor (329) K6 Pre-charge Contactor |
Thermistor Specifications     | ||
---|---|---|
    | Size     | Ohm     |
T1     | 35mm     | 10 (1)     |
T2     | 35mm     | 10 (1)     |
T3     | 35mm     | 10 (1)     |
T4     | 35mm     | 10 (1)     |
( 1 ) | 25 °C (77 °F) |
Transformer Specifications     | |||
---|---|---|---|
    | Input (V)     | Output (V)     | Wire Gauge (AWG)     |
T1     | 380, 400, 415, 480     | 21     | H=12-22 X=10-18     |
T2     | 380, 400, 415, 480     | 21     | H=12-22 X=10-18     |
T3     | 380, 400, 415, 480     | 21     | H=12-22 X=10-18     |
T4     | 380, 400, 415, 480     | 21     | H=12-22 X=10-18 !     |
Thermistor Removal
- 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.
- Loosen the two screws and pull the thermistor 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 H2 connector.
Thermistor Installation
- Loosen the screw of the H1 connector and the "COM" or unlabeled connector next to the connector.
- Place one lead of the thermistor into the H1 connector and place one lead into the "COM" or H2 connector.
- Tighten the screws to attach the thermistor firmly.
Transformer Removal
- 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.
Note: The transformers are heavy. Exercise caution when removing the last bolt so the transformer does not fall and damage components or personnel.
- Remove all four wires or wire pairs from the transformer by loosening the screws holding the wires in the terminal block.
- Remove the 4 hex screws at the corners of the transformer that hold the transformer to the rear panel. Use a 76 mm (3/16 inch) hex key.
Transformer Installation
- Situate the transformer in position on the rear panel.
- Attach the transformer using 4 hex bolts to the rear panel. Use a 76 mm (3/16 inch) hex key.
- Connect the four wires or wire pairs to the transformer.
Each wire location is labeled. Refer to Illustration 2 for wire connections.
Illustration 2 | g01278195 |