Power Supplies

The router can use either AC or DC power. In either case, there are two load-sharing power supplies that install into the bays located at the bottom rear of the chassis, as shown in Figure 2. As viewed from the rear of the chassis, the supply on the left is referred to as supply A and the supply on the right as supply B. The power supplies connect to the backplane, which distributes power to router components according to their individual voltage requirements. Each power supply has a system ground connector and an integrated fan to cool the power assembly.

The power supplies are fully redundant. When both power supplies are operational, they automatically share the electrical load. If one power supply stops functioning for any reason, the remaining power supply instantly begins providing all the power the router needs for normal functioning, and can provide full power indefinitely.

Power supplies are hot-removable and hot-insertable, as described in Field-Replaceable Units (FRUs). Each power supply has a safety interlock lever that prevents removal of the supply while it is on, but to avoid electrical injury, carefully follow the instructions in Replace an AC Power Supply and Replace a DC Power Supply.

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 After powering off a power supply, wait at least 60 seconds before turning it back on. After powering on a power supply, wait at least 60 seconds before turning it off.
 If the router is completely powered down when you power on a power supply, the Routing Engine boots as the power supply completes its startup sequence. If the Routing Engine finishes booting and you need to power down the router again, first issue the CLI request system halt command.
 After a power supply is powered on, it can take up to 60 seconds for status indicators—such as LEDs on the power supply, show chassis commands, and messages on the craft interface LCD—to indicate that the power supply is functioning normally. Ignore error indicators that appear during the first 60 seconds.

For information about the cables required for each type of power supply, see Power System Requirements and Specifications.

See the following sections for further information about the power supplies:

• AC Power Supply
• DC Power Supply
• Power Supply LEDs