Juniper PTX10008 Hardware Manual page 168

Table 57: Total Power Available (continued)
Power Supply Module
Models
JNP10K-PWR-DC2 single
feed, low power (60-A)
setting
NOTE: The HVAC/HVDC power supply, JNP10K-PWR-AC2, has a set of dip switches on the
faceplate that allows you to configure the power supply for either high power (30 A) or low
power (20 A) input mode. If any JNP10K-PWR-AC2.power supply is set to 20 A, then the power
budget for all power supplies installed in the system becomes 20 A, regardless if other power
supplies are set at 30 A. This design is to prevent overloading of the power supply that is set
to 20 A. See Table 12 on page 65
2. Determine the total power required for your configuration with line cards installed. The total power
available to the chassis is calculated by dividing the wattage needed by the power rating, then rounding
up.
In the previous examples, we calculated that a PTX10008 AC system would require 9300 W with five
PTX10K-LC1102 and three PTX10K-LC1101 line cards. In this example, we calculate the total power
available for this configuration:
= (9300 W) / (2700 W)
= 3.444
Round up the result to 4 AC power supplies to determine the minimum power level.
CAUTION:
power alarm. Add an additional power supply for redundancy (n+1) to ensure you
have covered the maximum power budget for your specific configuration.
In our example, a basic configuration (3 power supplies, standard) would require two additional power
supplies, one for the minimum power level and second as the redundant power supply. In a redundant
AC system (6 power supplies, standard), the system would have sufficient power supplies for both
minimum and n+1 redundancy.
With Three Power
Supplies
—
for details on setting the dip switches.
The minimum power level does not prevent the system from raising a
With Four Power
Supplies
—
With Five Power
Supplies
11,000 W
170