Juniper MX2020 Hardware Manual page 236

Table 78: MX2020 PSM DC Output Power Budget
Power Supply Module
MX2020 DC PSM 60 A (feed to each
input)
MX2020 DC PSM 80 A or DC PSM
(240 V China) (feed to each input)
3. Calculate input power. Divide the total output requirement by the efficiency of the PSM. Refer to
Table 79 on page 214.
Table 79: Calculating DC Input Power
Power Supply Module
MX2020 DC PSM 60 A
MX2020 DC PSM 80 A or DC
PSM (240 V China)
4. Calculate thermal output (BTUs) for cooling requirements. Multiply the input power requirement (in
watts) by 3.41. Refer to
Table 80: Calculating DC Thermal Output (BTUs)
Power Distribution Module
MX2020 DC PDM
Maximum Output Power of
Power Supply Module (Watt)
2100
2500
Power Supply
Module Efficiency
91%
91%
Table 80 on page 214.
Thermal Output (BTUs per hour)
34.5 KW divided by 0.91 * 3.41 = 129,280 BTU/hr (Zone 0
output. The calculation method for Zone 1 is the same as
for Zone 0).
34.5 KW of output power consumed by the chassis. This is
the maximum output the chassis can consume in a redundant
configuration. The input power is 34.5 divided by 0.91 =
37.9 KW.
Maximum Output Power for
System (Watt)—including
redundant capacity
37,800
45,000
Output Power
Requirement Input Power Requirement
(Watt)—per PSM (Watt)—per PSM
2100 2307
2500 2747
214