Juniper JUNOS, Руководство по эксплуатации сети

Страница: 547 / 722

Understanding Redundant Power Supplies
! 511
Chapter 38: Monitoring Redundant Power Supplies
M20 Router Redundant Power Supplies
Two load-sharing, isolated power supplies are located at the bottom rear of the M20
router chassis.The router uses either AC or DC power. Figure 202 shows the M20
router power supplies and where they are installed in the chassis.
When the power supplies are installed and operational, they automatically share the
electrical load. If a power supply stops functioning for any reason, the remaining
power supplies instantly begin providing all the power the router needs for normal
functioning, and can provide full power indefinitely.
Figure 202: M20 Router Redundant Power Supplies
NOTE:
Mixing AC and DC power supplies is not supported. The two power supplies
must be either both AC or both DC.
When two power supplies are installed, at least one Routing Engine and one FPC
must also be installed for both power supplies to power on. In the absence of this
minimum load, only one power supply starts. (The router powers and on and
operates correctly with one power supply, but without the redundancy benefit of
having a second power supply installed.)
1695
Power supply B Power supply A
M20 router rear DC power supply
AC power supply