Juniper MX2020 Hardware Manual page 131

NOTE: The power backplane for a subsystem distributes regulated 52 VDC to all boards supplied
by that subsystem.
Each DC PDM has seven or nine DC inputs (–48 VDC) and return terminals for each input), (see
Figure 46 on page 108). You can select 60-A or 80-A input feed capacity on the DC PDM by setting the
DIP switch on the PDM to the rated amperage of the DC power input feeds.
NOTE: The selected input capacity applies to all inputs of this PDM. Selecting 60-A reduces the
available power output capacity of the PSMs supplied by this PDM.
Figure 46: MX2020 DC PDM
NOTE: The type of feed that you use on the DC PDM (60-A or 80-A) depends on the distribution
scheme and distribution equipment. With a 60-A feed, the maximum power supply output power
is limited to 2100 W while the maximum power supply input power is limited to 2400 W. With
an 80-A feed, the maximum power supply output is limited to 2500 W while maximum power
supply input power is limited to 2800 W. The system power management software calculates
the available and used power based on DIP switch positions in the PDM.
RELATED DOCUMENTATION
MX2020 DC Power Distribution Module (-48 V) LEDs | 110
MX2000 Router Grounding Specifications | 138
Calculating DC Power Requirements for MX2020 Routers
108