Figure 157: Ac Pdm Three-Phase Wye Input Power; Table 62: Calculating Ac Thermal Output - Juniper MX2020 Hardware Manual

Copyright © 2013, Juniper Networks, Inc.
Appendix D: Power Guidelines, Requirements, and Specifications for the MX2020 Router

Figure 157: AC PDM Three-Phase Wye Input Power

AC PS_0
2800W
input
NE1
A1
B1
C1
AC PSM VIN=200-240 single phase:
Two AC PSMs are connected in parallel between two lines and neutral.
a.
Nominal value of input current for one AC PSM is 2800W/200V=14A.
b.
Nominal input current for two AC PSMs is 2*14A=28A.
c.
Nominal value of line current is 28A.
d.
So, input #1 rated current is 28A.
e.
Only one AC PSM is connected between two lines and neutral.
f.
Nominal value of input current for one AC PSM is 2800W/200V=14A.
g.
Nominal value of line current is 14A.
h.
Current rating for input #2 is 14A.
i.
Calculate thermal output (BTUs). Multiply the input power requirement (in watts) by
5.
3.41 as shown in Table 62 on page

Table 62: Calculating AC Thermal Output

Power Distribution Module
MX2020 Three-phase delta AC PDM
AC PS_1 AC PS_4
2800W 2800W
input input
AC PS_3 AC PS_2 AC PS_5 AC PS_6
2800W 2800W 2800W 2800W
input input input
379.
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.
AC PS_7
2800W
input
AC PS_8
2800W
input input
NE2
A2
B2
C2
379