BASE AS 1270291 - Caterpillar

Illustration 1 g01277009
STSW Fan Transformer Location (1) Fan (x3) (2) T5 TransformerThe T5 transformer is a 480V/230V transformer that feeds the three fans in the middle of the STSW cabinet.The fan transformer is installed on the back panel at the bottom of the cabinet. Refer to Illustration 1 for the transformer location.
Illustration 2 g01277016
T5 Transformer Wire ConnectionsThe thermistor for T5 is located on the upper side of the transformer, as installed. The thermistor is connected to the "H1" connector of the transformer. Refer to Illustration 2 for the thermistor location.The thermistor limits the in-rush of current on power-up.
Table 1
Thermistor Specifications    
   Size    Ohm    
T5     35mm     10    
Table 2
Transformer Specifications    
   Input (V)    Output (V)    Wire Gauge (AWG)    
T5     380, 400, 415, 440, 480     230     10    Thermistor Removal
Perform steps in the Systems Operation, Testing and Adjusting, "Internal Component Preremoval Steps (Static Switch 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" connector.Thermistor Installation
Loosen the screw of the "H1" connector and the "COM" or unlabeled connector next to it.
Place one lead of the thermistor into the "H1" connector and place one lead into the "COM" connector next to the "H1" connector.
Tighten the screws in order to attach the thermistor firmly.Transformer Removal
Perform steps in the Systems Operation, Testing and Adjusting, "Internal Component Preremoval Steps (Static Switch Cabinet)" in order to de-energize the system and gain access to internal components.Note: The transformer is 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 cabinet panel. Use a 76 mm (3/16 inch) hex key.
Remove the transformer from the cabinet.Transformer Installation
Position the transformer on the back panel at the bottom of the cabinet as indicated in Illustration 2.
Attach the transformer using 4 hex bolts to the back panel. Use a 76 mm (3/16 inch) hex key.
Connect the four wires or wire pairs to the transformer. Each wires location is labeled. Connect the orange wire that is labeled "COM" to the underside of the unlabeled connector next to "H1".Refer to Illustration 2.