ENGINE AR- 3872670 - Caterpillar

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
Table 1
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)
Table 2
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.
Illustration 2 g01278195
Connect the four wires or wire pairs to the transformer.Each wire location is labeled. Refer to Illustration 2 for wire connections.