Technical Documentation

T640 Three-Input 240-A DC Power Supply Inputs

The three-input 240-A DC power supply inputs are labeled INPUT 0, INPUT 1, and INPUT 2, from top to bottom. Each input consists of –48 VDC and return, each with its own 80-A circuit breaker. The input mode switch on the faceplate allows you to set the DC power supply to either 2–INPUT or 3–INPUT mode. 3–INPUT mode is required for the T640 router.

Table 1 describes which components are powered by each input.

Table 1: Components Powered by Each Three-Input 240-A DC Power Supply Input

InputThree-Input Mode


T640-SIBs, T-CBs, fan trays, and Routing Engines


FPCs in slots FPC4 through FPC7


FPCs in slots FPC0 through FPC3

Published: 2009-11-11