Juniper MX2020 Hardware Manual page 44

AC power requirements—Table 6 on page 18
delta, three-phase wye, and single-phase power feeds.
Table 6: AC PDM Current Requirements
Three–Phase
Voltage Input Feed
200 V 1
(minimum–nominal)
(line-to-line) for 2
delta (per phase)
200 V 1
(minimum–nominal)
(line-to-neutral) for
2
wye (per phase)
200 V 1
(minimum–nominal)
NOTE: This is the minimum required to provide 2.5KW per PSM. Based on facilities guidelines,
you should over-provision the MX2020 router. The two numbers listed in the three-phase
delta and three-phase wye current columns reflect the distribution of phases from the feed
to the PSM. For example, from one feed, each phase goes to two PSMs, and from the other
feed, each phase goes to only one PSM.
Cooling system—The cooling system in a fully-configured MX2020 router has a total of four fan trays,
which are controlled by the host subsystem. If one of the fans fails, the host subsystem increases the
speed of the remaining fans to provide sufficient cooling for the router. See
Description" on page 45).The fan trays are powered by two power subsystems that are divided into
zones. The fan trays draw power from each zone depending upon whether you have a base DC power
subsystem (MX2020-BASE-DC) or an optimized DC power subsystem (MX2020-PREMIUM2-DC). In
the base DC power subsystem, two of the four fan trays draw power from both zones. In the optimized
DC power subsystem, two of the fan trays draw power from only one zone. See
Requirements for Your MX2020 Router" on page 209
distribution.
RELATED DOCUMENTATION
shows the MX2020 current requirements for the three-phase
Current Delta per
Three-Phase Current Wye per
PDM Three-Phase PDM
50 A –
25 A –
– 30 A
– 15 A
– –
for more information about MX 2020 power
Current per Single
Phase PDM
14 A
"MX2020 Cooling System
"Determining DC Power
18