Technical Documentation
T640 Four-Input 240-A DC Power Supply Description
Four-Input 240-A DC Power Supply
Each four-input 240-A DC power supply weighs approximately 26.6 lb (12.0 kg) and consists of four inputs, four 60-A circuit breakers, a fan, and LEDs to monitor the status of the power supply. Figure 1 shows the four-input 240-A DC power supply.
Figure 1: Four-Input 240-A DC Power Supply
Four-Input 240-A DC Power Supply Inputs
The four-input 240-A DC power supply inputs are labeled INPUT 0, INPUT 1, and INPUT 2, and INPUT 3 from top to bottom. Each input consists of –48 VDC and return, each with its own 60-A circuit breaker.
Table 1 describes which components are powered by each input.
Table 1: Components Powered by Each Four-Input 240-A DC Power Supply Input
| Input | Components |
|---|---|
INPUT 0 | SIBs, control boards, Routing Engines, and half the system fan power |
INPUT 1 | FPCs in slots FPC0 and FPC1 and half the system fan power |
INPUT 2 | FPCs in slots FPC2 through FPC4 |
INPUT 3 | FPCs in slots FPC5 through FPC7 |
Four-Input 240-A DC Power Supply Load Sharing and Fault Tolerance
When the router is operating normally and both power supplies are switched on, load sharing between them occurs automatically. When one power supply fails or is turned off, the other power supply immediately assumes the entire electrical load for the system. A single power supply can provide full power for as long as the router is operational. If any of the four inputs fails, the router shuts down, and the other power supply assumes the electrical load for all four inputs.
