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Installing MX2020 AC Power Supply Modules

To install an MX2020 AC PSM:

  1. Verify that the power switch on the PSM is in the off (O) position.
  2. On the PSM, slide the plastic cover away from the input mode switch to expose the dual DIP switches. Move the input mode DIP switch 0 (left switch) to the ON position for the bottom feed INP0 (expected to be connected), and DIP switch 1 (right switch) to the ON position for the top feed INP1 (expected to be connected). If both DIP switches 0 and 1 are turned to the ON position, then both top and bottom feeds are expected to be connected (see Figure 1).

    In addition, a PSM failure triggers the alarm LED on the craft interface.


    The DIP switches are only used to indicate presence of a feed. If both feeds are present, power is always drawn from feed 0. Power will be drawn from feed 1 only if feed 0 fails.

    Figure 1: Selecting AC Power Subsystem Feed RedundancySelecting AC Power Subsystem Feed Redundancy
  3. Using both hands, grasp the handle and slide the PSM straight into the chassis until the PSM is fully seated in the chassis slot. Tighten the two captive screws (see Figure 2). Apply between 10 lb-in. (1.13 Nm) to 12 lb-in. (1.35 Nm) of torque to each screw. Do not overtighten the screws.
    Figure 2: MX2020 Router with AC Power Supply Modules InstalledMX2020 Router with AC Power Supply Modules Installed
  4. Verify that the INP0 and/or INP1 LEDs on the PSM are lit green steadily (see Figure 3).

    If you are connecting two feeds, INP0 and INP1, both LEDs on the PSM will be lit green steadily.

  5. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
  6. Move the switch to the on (|) position.
  7. Verify that the PWR OK LED is lit green steadily. See MX2020 AC Power Supply Module LEDs for information on MX2020 AC PSM LEDs.
  8. Repeat Steps 1 through 7 for installing PSMs in slots 0, 1, and 2, where required.
    Figure 3: MX2020 AC Power Supply Module Front ViewMX2020 AC Power Supply Module Front View

    Each PSM slot not occupied by a AC PSM must be covered by a PSM blank panel.