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MX2020 Power Subsystem Description

 

The MX2000 routers are available in -48 V and 240 V China DC power configurations, three-phase (delta and wye) AC power configurations, and a single-phase power configuration. You can add additional power to the rack as needed. The MX2020 router is configurable with up to four AC or DC power distribution modules (PDMs) (two per subsystem), and up to eighteen AC or DC power supply modules (PSMs). The PSMs connect to the top and bottom power backplanes that distribute the output voltages produced by the PSMs to the router components.

Table 1 describes the MX2020 DC power components and Table 2 describes the MX2020 AC power components.

Caution

Do not mix AC and DC PSMs or different PDM types within a single system. The systems configured for DC (-48 V) input power must use DC (-48 V) PDMS and PSMs. The systems configured for DC (240 V China) input power must use DC (240 V China) PDMs and PSMs. The MX2010 systems configured for three-phase wye AC input power must use only three-phase wye AC PDMs and AC PSMs. The systems configured for three-phase delta AC input power must use three-phase delta AC PDMs and AC PSMs. The systems configured for single-phase AC input power must use single phase AC PDMS and AC PSMs.

Table 1: MX2020 DC Power Components

Component

Description

DC power subsystem

The MX2020 DC power system comprises two subsystems. Each power subsystem provides power to 10 line-card slots, three fan trays, two CB-REs, and eight SFBs. There are nine DC PSMs and two DC PDMs in each subsystem. This means, if one power subsystem stops functioning for any reason, only the MPCs will stop functioning; the router will continue to function.

There are two types of DC power subsystems available for the MX2020: a “base” DC power subsystem (MX2020-BASE-DC) and an “optimized” or premium DC power subsystem (MX2020-PREMIUM2-DC). SeeDetermining DC Power Requirements for Your MX2020 Router for more information.

DC Power Distribution Modules (-48 V)

In the DC PDM (-48 V) configuration, each subsystem provides N+1 PSM redundancy along with N+N feed redundancy. The power feeds from different sources need to be connected to different PDMs. If feeds that connect to one PDM fail in a redundant configuration, the other feed will provide full power. You can install a total of four PDMs into a router. Each DC PDM operates with seven feeds or nine feeds of either a 60-A or 80-A current limit. You can select the input feed capacity (60-A or 80-A) by setting the DIP switch on the PDM to the rated amperage of the DC power input feeds. Each DC PDM has seven or nine DC inputs (–48 VDC) and return terminals for each input).

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.

In a redundant configuration, the 7-feed DC PDMs support a total of fourteen 60-A or 80-A feeds, and the 9-feed DC PDMs support a total of eighteen 60-A or 80-A feeds.

DC Power Distribution Modules (240 V China)

In the DC PDM (240 V China) configuration, each subsystem provides N+1 PSM redundancy along with N+N feed redundancy. The power feeds from different sources need to be connected to different PDMs. If feeds that connect to one PDM fail in a redundant configuration, the other feed will provide full power. You can install a total of four PDMs into a router. Each DC PDM (240 V China) operates with nine feeds.

DC Power Supply Modules (PSMs)

The MX2020 DC PSMs (-48 V and 240 V China) are hot-removable and hot-insertable. The DC PSMs are a dual redundant feed (INP0 and INP1). To provide feed redundancy, you can connect each DC PSM to two separate feeds from different sources. When both input feeds are present, power is drawn from the feed supplying higher DC voltage. You can set these feeds by using the input mode DIP switch located on the DC PSM (see MX2020DC Power Supply Module (-48 V) Description). There are two PDMs per power subsystem capable of carrying seven feeds or nine feeds each. The 240 V China PDM has nine feeds. Each DC PSM is capable of delivering 2500 W of power if -48 V/80 A is applied to the -48 V PSM, and 240 V/16 A is applied to the China 240 VDC PSM.

Table 2: MX2020 AC Power Components

Component

Description

AC power subsystem

The MX2020 supports connection of a single-phase or three-phase (delta or wye) AC power system. In the three-phase power systems, the AC power going to the PSMs is split into three individual phases (wye) or a pair of phases (delta). Each PSM works on a single phase; therefore, the power system works independent of the type of AC feed connected. You can connect one or two AC feeds, depending on the power system configuration (number of PSMs, redundancy, and so on). Each phase from each of the two feeds is distributed among one or two PSMs. One feed has each phase going to two PSMs, and the other feed has each phase going to a single PSM.

The single-phase AC PDM provides an AC input connection from the single-phase AC power source, and also provides an input power interface to the PSM through a system power midplane.

AC Power Distribution Modules (PDMs)

The MX2020 supports connection of a single-phase or three-phase (delta or wye) AC PDM. Four AC PDM models are available: three-phase delta, three-phase wye, seven-feed single-phase, and nine-feed single-phase.

  • Each three-phase AC PDM requires two three-phase feeds to be connected. Each phase from each of the two feeds is distributed among one or two PSMs. One feed has each phase going to two PSMs, and the other feed has each phase going to a single PSM.

    • The single-phase AC PDM provides an AC input connection from the single-phase AC power source, and also provides an input power interface to the PSM through a system power midplane. The single-phase AC PDMs accept seven or nine AC power cords from a single-phase AC source.

    • Each AC input is independent and feeds one PSM. Up to nine PSMs can be connected through the AC PDM.

AC Power Supply Modules (PSMs)

The MX2020 AC PSMs are hot-removable and hot-insertable. The AC PSMs have a dual redundant feed (INP0 and INP1). One input feed is active during operation. These feeds are set by the input mode DIP switch located on the AC PSM (see MX2020 AC Power Supply Module Description). Each AC PSM works with a single phase derived from either three-phase delta 200-240 VAC (line-to-line) or three-phase wye 200-240 VAC (line-to-neutral). Each AC PSM is capable of delivering 2500 W of power.

The MX2020 router supports the power system models and Junos OS releases in Table 3.

Table 3: Supported MX2020 Power System Components

Name

Model Number

Junos Release

DC PSM (-48 V)

MX2000-PSM-DC

12.3R2 and later

DC PSM (240-V China)

MX2K-PSM-DC-240V

18.2R1 and later

Nine-feed DC PDM (240-V China)

MX2K-PDM-DC-240V

18.2R1 and later

Nine-feed DC PDM (-48 V)

MX2000-PDM-DC

12.3R2 and later

Seven-feed DC PDM (-48 V)

MX2K-PDM-OP-DC

15.1R1 and later

AC PSM

MX2000-PSM-AC

12.3R2 and later

Three-phase delta AC PDM

MX2000-PDM-AC-DELTA

12.3R2 and later

Three-phase wye AC PDM

MX2000-PDM-AC-WYE

12.3R2 and later

Nine-feed single-phase AC PDM

MX2K-PDM-AC-1PH

15.1R1 and later

Seven-feed single-phase AC PDM

MX2K-PDM-OP-AC

15.1R1 and later

Note

Routers configured with AC or DC PDMs and PSMs are shipped with blank panels installed.

Note

To avoid triggering any PSM-related or power-related alarms for the PSMs that are not used but still plugged into the MX2020 router, make sure that you:

  • Do not connect external power feeds to the PSM through the PDM.

  • Move the DIP switch on the PSMs to the off position.

  • Turn off the PSM by using its ON/OFF switch.