Juniper T640 - Four-Input 240-A DC Power Supply Load Sharing and Fault Tolerance; T640 Four-Input 240-A DC Power Supply Leds; Figure 40: Four-Input 240-A DC Power Supply Leds; Table 59: Four-Input 240-A DC Power Supply Leds

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.
Related
Documentation
T640 Four-Input 240-A DC Power Supply LEDs on page 103•
• Troubleshooting the T640 Power System on page 476
• Replacing a T640 Four-Input 240-A DC Power Supply on page 366
• T640 DC Power Supply Electrical Specifications on page 126
T640 Four-Input 240-A DC Power Supply LEDs
LEDs on each four-input 240-A DC power supply faceplate (see Table 59 on page 103)
indicate the status of the power supply. In addition, a power supply failure triggers the
red alarm LED on the craft interface. Figure 40 on page 103 displays the power supply
LEDs.
Figure 40: Four-Input 240-A DC Power Supply LEDs
CIRCUIT BREAKERS FOR MIN. 60
SEC. TO DE-ENERGIZE THE UNIT
COMPLETELY BEFORE TURN ON.
g004660
Power supply LEDs
60A
60A
60A
60A
INPUT 3
Table 59: Four-Input 240-A DC Power Supply LEDs
DescriptionStateColorLED
Input is receiving voltage.On steadilyGreenINPUT
PRESENT—One
per input
Input voltage is not present.Off
Circuit breaker is on.On steadilyGreenCB ON—One per
input
Circuit breaker is not turned on, or
host subsystem has detected a
failure and has turned the circuit
breaker off.
Off
103Copyright © 2017, Juniper Networks, Inc.
Chapter 7: Power System Components and Descriptions