Juniper MX2010 Hardware Manual page 141

NOTE: The MX2020 systems configured for DC (240 V China) input power must use only DC
(240 V China) 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 49: DC Power Supply Module (240 V China)
The DC power system 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, INP0 and INP1. Both feeds are active during operation, but both feeds may or may not be providing
current. Move the input mode DIP switch to the on or off position to determine the power supply feeds
(see Table 38 on page 117
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 MX2000 Router DC Power Subsystem Electrical Specifications.
Table 39: DIP Switch Positions on the DC PSM
Left Switch Position
Off
On
Figure 47 on page 117) shows the DC PSM.
and Figure 48 on page 118). In addition, a PSM failure triggers the alarm LED on
Right Switch Position
Off
Off
Input Source
None
Input 0 (INP0)
119