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T640 Two-Input 160-A DC Power Supply Description
Two-Input 160-A DC Power Supply
Each two-input 160-A DC power supply weighs approximately 23 lb (10.5 kg) and consists of two inputs, two 80-A (@ –48 VDC) circuit breakers, a fan, and LEDs to monitor the status of the power supply. Figure 1 shows the two-input 160-A DC power supply.
Figure 1: Two-Input 160-A DC Power Supply
Two-Input 160-A DC Power Supply Inputs
Each two-input 160-A DC power supply has two inputs—INPUT 1 and INPUT 0, from top to bottom—each with its own 80-A (@ –48 VDC) circuit breaker.
 | Note: All inputs on the two-input 160-A DC power supply in slot PEM0 must be powered by dedicated power feeds derived from feed A, and all inputs on the two-input 160-A DC power supply in slot PEM1 must be powered by dedicated power feeds derived from feed B. This configuration provides the commonly deployed A/B feed redundancy for the system. |
Table 1 describes which components are powered by each input.
Table 1: Components Powered by Each Input
| Input | Provides Power to These Components |
|---|---|
INPUT 0 | FPCs in slots FPC0 and FPC1, SIBs, control boards, Routing Engines, CIP, craft interface, and fan trays |
INPUT 1 | FPCs in slots FPC2 through FPC7 |
Two-Input 160-A DC Power Supply Load Sharing and Fault Tolerance
When the router is operating normally and both power supplies in a redundant power system 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 with both inputs active can provide full power for as long as the router is operational. Table 2 describes the behavior of the two-input 160-A DC power supply and router if one of the inputs fails.
Table 2: Fault Tolerance
| Redundancy | Fault Tolerance When One Input Fails or Is Disconnected |
|---|---|
Nonredundant power supplies | If either input fails, the router shuts down. Note: We recommend that you install redundant power supplies. |
Redundant power supplies | If either input on one power supply fails, the other power supply assumes the electrical load for both inputs. If one of the inputs on the other power supply is not functional, the router shuts down. |
