Juniper Networks EX8208 - Manual (Page 142)

Table 49: Chassis Power Consumption for N+N Configurations Running
Junos OS Release 10.2 or Later
Redundant Configuration Base Configuration Chassis Component
700 W 700 W Fan tray
200 W 200 W SRE module
200 W — SRE module
100 W 100 W SF module
1200 W 1000 W 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
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)
= (5200 W) / (0.90)
= 5778 W
Calculating System Thermal Output for Your EX8208 Switch Configuration
Use the following procedure to calculate the system thermal output in British thermal
units (BTU) per hour for your switch configuration.
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Complete Hardware Guide for EX8208 Ethernet Switches