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    Installing an MX2010 DC Power Distribution Module

    Warning: Before performing DC power procedures, disconnect all power sources. To ensure that all power is off, locate the circuit breaker on the panel board that services the DC circuit, switch the circuit breaker to the off position, and tape the switch handle of the circuit breaker in the off position.

    To install a DC power distribution module (PDM) (see Figure 1):

    1. Ensure that the voltage across the DC power source cable leads is 0 V and that there is no chance that the cable leads might become active during installation.
    2. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
    3. Move the DC circuit breaker on the power input source to the off position.
    4. Move the power switch to the off O position on the DC power supply modules (PSMs) that will be powered by the DC PDMs you are installing.
    5. Remove the blank panel covering the PDM slot in the chassis.
    6. Open the locking levers on the PDM.
    7. While holding both handles, guide the PDM until the locking levers are inserted into the chassis. With both hands push the locking levers simultaneously until the PDM is fully seated into the chassis (see Figure 1).

      Figure 1: Installing a DC Power Distribution Module

      Installing a DC Power Distribution Module
    8. Tighten both captive screws on the PDM. 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.
    9. Remove the clear plastic cover protecting the terminal studs on the PDM faceplate.
    10. Remove the nut and washers from each of the terminal studs.
    11. Secure each power cable lug to the terminal studs, first with the flat washer, then with the split washer, and then with the nut. Apply between 23 lb-in. (2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut (see Figure 2). Do not overtighten the nut. (Use a 7/16-in. (11 mm) torque-controlled driver or socket wrench.)
      1. Attach the positive (+) DC source power cable lug to the RTN (return) terminal.
      2. Attach the negative (–) DC source power cable lug to the –48V (input) terminal.

      Caution: Ensure that each power cable lug seats flush against the surface of the terminal block as you tighten the nuts. Ensure that each nut is properly threaded onto the terminal stud. The nut must be able to spin freely with your fingers when it is first placed onto the terminal stud. Applying installation torque to the nut when it is improperly threaded might result in damage to the terminal stud.

      Caution: The maximum torque rating of the terminal studs on the DC PDM is 25 lb-in. (33.89 Nm). The terminal studs might be damaged if excessive torque is applied. Use only a torque-controlled driver or socket wrench to tighten nuts on the DC power supply terminal studs.

      Caution: You must ensure that power connections maintain the proper polarity. The power source cables might be labeled (+) and (-) to indicate their polarity. There is no standard color coding for DC power cables. The color coding used by the external DC power source at your site determines the color coding for the leads on the power cables that attach to the terminal studs on each power supply.

      Note: The DC PDMs in slots PDM0/Input0 and PDM1/Input1 can be powered by dedicated power feeds derived from feed A or feed B. This configuration provides the commonly deployed A/B feed redundancy for the system to balance the power draw. For information about connecting to DC power sources, see MX2010 DC Power System Electrical Specifications.

      Note: Make sure that the amperage switch is set to 60 A or 80 A to match the DC circuit input feed.

    12. Replace the clear plastic cable restraint cover over the terminal studs on the faceplate.
    13. Route the positive and negative DC power cables through the plastic cable restraint cover.
    14. Verify that the power cabling is correct, that the cables are not touching, and that they do not block access to router components or drape where people could trip on them.
    15. Switch on the dedicated customer-site circuit breaker.
    16. For each of the DC PDMs, switch the DC circuit breaker to the on position.

      Note: The circuit breaker might bounce back to the off position if you move the breaker too quickly.

    17. Verify that the –48V LED on the PDM is lit steadily green.
    18. Turn the power switch to the on (|) position for the PSMs that will be powered by the installed PDMs.

    Figure 2: Connecting DC Power to the MX2010 Router

    Connecting DC Power
to the MX2010 Router

    Modified: 2017-09-13