T640 Four-Input 240-A Dc Power Supply Overview; Four-Input 240-A Dc Power Supply Description; Four-Input 240-A Dc Power Supply Inputs; Tolerance - Juniper T640 Hardware Manual

T640 Four-Input 240-A DC Power Supply Overview

Copyright © 2010, Juniper Networks, Inc.
Four-Input 240-A DC Power Supply Description on page 55
Four-Input 240-A DC Power Supply Inputs on page 55
Four-Input 240-A DC Power Supply Load Sharing and Fault Tolerance on page 55

Four-Input 240-A DC Power Supply Description

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 30 on page 55 shows the four-input 240-A DC power supply.

Figure 30: Four-Input 240-A DC Power Supply

LEDs Circuit breakers

Four-Input 240-A DC Power Supply Inputs

The four-input 240-A DC power supply inputs are labeled
and from top to bottom. Each input consists of –48 VDC and return, each with

INPUT 3

its own 60-A circuit breaker.
Table 22 on page 55 describes which components are powered by each input.
Table 22: Components Powered by Each Four-Input 240-A DC Power
Supply Input
Input
INPUT 0
INPUT 1
INPUT 2
INPUT 3
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.
Chapter 3: T640 Router Hardware Component Overview
Components
SIBs, control boards, Routing Engines, and half the system fan power
FPCs in slots FPC0 and FPC1 and half the system fan power
FPCs in slots FPC2 through FPC4
FPCs in slots FPC5 through FPC7
, , and
INPUT 0 INPUT 1 INPUT 2
,
55