MX2020 DC Power Supply Module (-48 V) Description
The MX2020 supports a two zone DC power system. Each zone (upper
and lower) is provided power by one half of the power subsystem. In
the DC power configuration, the router contains up to eighteen DC
PSMs located at the rear of the chassis in slots PSM0 through PSM8 (bottom), and slots PSM9 through PSM17 (top) (left to
right). The DC PSMs in slots PSM0 through PSM8 provide power to the lower half of the router components,
MPCs in slot 0 through 9, CB-REs in slot 0 and 1, SFBs in slot 0 through 7, and Fan Trays 0, 1, and 2. The DC PSMs in slots PSM9 through PSM17 provide power to the upper half of the router components,
MPCs in slot 10 through 19, CB_REs in slot 0, and 1, SFBs in slot 0 through 7, and Fan Trays 0, 2, and 3.
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 1) shows the DC PSM.
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, 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 1 and Figure 2). In addition, a PSM failure
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 MX2000 Router DC (-48 V) Power Subsystem Electrical Specifications.
Table 1: DIP Switch Positions on the DC (-48 V) PSM
Left Switch Position | Right Switch Position | Input Source |
|---|---|---|
Off | Off | None |
On | Off | Input 0 ( |
Off | On | Input 1 ( |
On | On | Both Input 0 and Input 1 |
