Figure 27: Dc Power Supply Module - Juniper MX2020 Hardware Manual

MX2020 3D Universal Edge Router Hardware Guide
52
NOTE: The MX2020 systems configured for DC input power must use only
DC PDMs and DC PSMs. AC and DC PSMs or PDMs must not be mixed within
a single system.
Up to nine PSMs may be connected in parallel to increase available system power across
MPCs as needed and provide redundancy.

Figure 27: DC Power Supply Module

The DC power subsystem is feed redundant. Each DC PSM can be connected to two
separate feeds from different sources that are used to provide feed redundancy. If two
feeds are connected, PSM input power will be drawn from the feed with the higher voltage
present. There are two PDMs per power subsystem capable of carrying nine feeds each.
Connect feeds from one source to one PDM and feeds from the other source to the second
PDM of the power subsystem. The primary input of the PSM is a dual redundant feed,
and . Both feeds are active during operation, but both feeds may or may not
INP0 INP1
be providing current. Move the input mode DIP switch
position), for the bottom feed
switch) to the (top position), for the top feed
ON
both DIP switches and
0 1
are expected to be connected, (see
triggers the alarm LED on the craft interface. Each PDM has an LED per feed indicating
whether the feed is active or not, or whether the feed is connected properly, see
DC Power Subsystem Electrical Specifications" on page
Figure 27 on page
INP0 (expected to be connected), and DIP switch
INP1
are turned to the position, then both top and bottom feeds
ON
Figure 28 on page
52) shows the DC PSM.
(left switch) to the (top
0 ON
(expected to be connected). If
53). In addition, a PSM failure
"MX2020
357.
Copyright © 2013, Juniper Networks, Inc.
1 (right