Juniper MX240 Hardware Manual page 196

NOTE: The power for the cooling system comes from a different tap on the power supply,
reserved for the cooling system only. The cooling system power requirement does not
need to be deducted from the output power budget of the power supply.
Table 84 on page 198
power deficit). See "DC Power Supply Electrical Specifications for the MX240 Router" on page 58
"AC Power Supply Electrical Specifications for the MX240 Router" on page 50
about the MX240 power supply electrical specifications.
Table 84: Calculating Power Budget
Power Supply
MX240 AC Normal-capacity (low-line)
MX240 AC Normal-capacity (high-line)
MX240 AC High-capacity (low-line)
MX240 AC High-capacity (high-line)
MX240 DC Normal-capacity
MX240 DC High-capacity (DIP=0)
MX240 DC High-capacity (DIP=1)
1
For this configuration, output power excluding the cooling system is 1400 W.
3. Calculate input power. In this step, the input power requirements for the example configuration are
calculated. To do this, divide the total output requirement by the efficiency of the power supply as
shown in Table 85 on page
Table 85: Calculating Input Power Examples
Power Supply
MX240 AC Normal-capacity (high-line)
MX240 AC High-capacity (high-line)
MX240 DC Normal-capacity
lists the power supplies, their maximum output power, and unused power (or a
198.
Maximum System Output
Power
2054 W
1590 W
2334 W
2050 W
1600 W
2400 W
2600 W
Power Supply Efficiency
85 %
89 %
~98 %
for more information
Unused Power
654 W
190 W
934 W
650 W
200 W
1000 W
1200 W
1
Input Power Requirement
1747 W
1669 W
1515 W
198
and
1
2