Three-Input 240-A Dc Power Supply Load Sharing And Fault Tolerance; T640 Three-Input 240-A Dc Power Supply Leds; Table 55: Components Powered By Each Three-Input 240-A Dc Power Supply; Table 56: Fault Tolerance - Juniper T640 Hardware Manual

T640 Core Router Hardware Guide

Three-Input 240-A DC Power Supply Load Sharing and Fault Tolerance

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T640 Three-Input 240-A DC Power Supply LEDs

100
Table 55: Components Powered by Each Three-Input 240-A DC Power
Supply Input
Input Three-Input Mode
T640-SIBs, control boards, fan trays,
INPUT 0
Routing Engines, and FPCs in slots
and
FPC1
FPCs in slots
INPUT 1 FPC2
This input is not supported in
INPUT 2
mode.
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.
Table 56 on page 100 describes the behavior of the power supply if one of the inputs fails.

Table 56: Fault Tolerance

Redundancy
Nonredundant power supply
Redundant power supplies
T640 Power System Description on page 95
Powering On a DC-Powered T640 Router on page 239
Maintaining the T640 Power Supplies on page 456
LEDs on each power supply faceplate (see
the power supply. In addition, a power supply failure triggers the red alarm LED on the
craft interface. Table 57 on page 101
FPC0
through
FPC7
2–INPUT
Fault Tolerance When One Input Fails or is Disconnected
If this input fails, the router shuts down.
NOTE: We recommend that you install redundant power
supplies.
If an input on one power supply fails, the other power supply
assumes the electrical load for all inputs. If one input on the other
power supply is not functional, the router shuts down.
Figure 38 on page
describes the functions of the power supply LEDs.
Copyright © 2017, Juniper Networks, Inc.
101) indicate the status of