Switch User Manual

Table 49: Chassis Power Consumption for N+N Configurations Running

Junos OS Release 10.2 or Later

Redundant ConfigurationBase ConfigurationChassis Component

700 W700 WFan tray

200 W200 WSRE module

200 W—SRE module

100 W100 WSF module

1200 W1000 WTotal

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.

Complete Hardware Guide for EX8208 Ethernet Switches