Juniper EX8208 Hardware Manual page 123

Table 59: Chassis Power Consumption for N+N Configurations Running Junos OS Release 10.2 or
Later
Chassis Component
Fan tray
SRE module
SRE module
SF module
Total
2. Calculate the maximum internal power consumption of the entire switch by adding in the power
requirements of each line card.
For example, for a switch fully loaded with 8-port SFP+ line cards and using N+1 power redundancy,
the maximum internal power consumption:
= (chassis watts) + 8 (8-port SFP+ line card watts)
= (1600 W + 8 (450 W))
= (1600 W + 3600 W)
= 5200 W
For switches with PoE line cards, be sure to include the configured PoE power budget for each line
card.
3. Calculate the maximum system power consumption by dividing the maximum internal power consumption
by the efficiency of the power supply. This accounts for the loss of energy within the power supply.
NOTE: The efficiency of a 2000 W AC power supply is approximately 90 percent when input
is high-voltage line (200–240 VAC).
The efficiency of a 2000 W AC power supply is approximately 87 percent when input is
low-voltage line (100–120 VAC).
For example, for a switch fully loaded with 8-port SFP+ line cards and using N+1 power redundancy
with high-voltage line input, the maximum system power consumption:
= (maximum internal power consumption) / (power supply efficiency)
Base Configuration
700 W
200 W
—
100 W
1000 W
Redundant Configuration
700 W
200 W
200 W
100 W
1200 W
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