Juniper PTX1000 Hardware Manual page 42

Figure 20: DC Power Supply in a PTX1000
1 Status LED
—
2 Ejector lever
—
Each of the four 1600-W power supplies has a single DC input. The power supply provides 12-VDC output
with a standby voltage of 12 VDC. A PTX1000 provides for twice the number of power supplies needed
to power all of the components in the router, which is known as 2N redundancy. When the PTX1000 has
all four power supplies installed and connected to power, the router has full power redundancy. If a power
supply fails or is removed, another power supply balances the electrical load without interruption.
The fan in the power supply provides port-to-FRU airflow, which is also known as airflow out (AFO). A
power supply with the label AFO or a gold-colored handle denotes port-to-FRU airflow.
CAUTION:
Power to the PTX1000" on page
page 103, and
NOTE: We recommend that the 48-VDC facility DC source be equipped with a circuit breaker
rated at 40 A (–48 VDC) minimum, or as required by local code.
NOTE: For more information about power system redundancy, see
Redundancy" on page
To avoid electrical injury, carefully follow instructions in
85,
"Removing a Power Supply from the PTX1000" on page
21.
3 Handle
—
"Installing a Power Supply in a PTX1000" on
"PTX1000 Component
"Connecting DC
101.
42