Installing an MX2020 Three-Phase Delta AC Power Distribution Module

Before you install a three-phase delta AC PDM, be aware of the following:

1. Make sure that the voltage across the AC power source cord is 0 V and that there is no chance that the cord might become active during the installation process.Note

   After powering off a PDM, wait at least 60 seconds before turning it back on.

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. Pull the locking levers on either side of the faceplate away until they stop.
4. Using both hands, slide the PDM into the chassis until you feel resistance (see Figure 1).
5. Push the lock levers completely in until they make contact with the PDM faceplate.
6. Tighten the two captive screws on the locking levers of the PDM faceplate to secure the PDM in the chassis. 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.
7. Using a number 2 Phillips (+) screwdriver, loosen the four screws on the cover of the metal wiring compartment that protects the AC terminal block.

   Figure 1: Installing a Three-Phase Delta AC Power Distribution Module

   

8. Remove the cover of the metal AC wiring compartment.
9. Unscrew the retaining nut from the AC power cord.
10. Place the retaining nut inside the metal wiring compartment.
11. Put the wires of the AC power cord through the hole of the retaining nut and rubber grommet.
12. Put the wires of the AC power cord through the hole of the metal wiring compartment.
13. Connect the wires to the AC terminal block on the three-phase delta AC PDM (see Figure 2). Loosen each of the input terminals or grounding point screws, and insert the wire into the grounding point or input terminal, and tighten the screw (see Table 1 for approved AC wire gauge).

    To insert wires into the terminal block that serves six PSMs:

    1. Insert the grounding wire into the grounding point labeled GND.

    2. Insert the wire labeled L1 into the input terminal labeled A1.

    3. Insert the wire labeled L2 into the input terminal labeled B1.

    4. Insert the wire labeled L3 into the input terminal labeled C1.

    Figure 2: Connecting Power to a Three-Phase Delta AC Power Distribution Module

    

    Note

    The three-phase delta AC PDM terminal blocks will be flipped depending on which slot the PDM gets plugged into.

    Note

    The color of each AC power wire may vary. The MX2020 chassis is not sensitive to phase rotation sequence—either CW or CCW will operate correctly.

    Caution

    Wire label configuration is for Juniper Networks supplied cable only. If using your own cable, make sure you use the proper connections.

    To insert wires into the terminal block that serves three PSMs:

    1. Insert the grounding wire into the grounding point labeled GND.

    2. Insert the wire labeled L1 into the input terminal labeled A2.

    3. Insert the wire labeled L2 into the input terminal labeled B2.

    4. Insert the wire labeled L3 into the input terminal labeled C2.

    Note

    The terminal connections have either slotted screws or hex screws. Use a 1/4-in. slotted screwdriver for the slotted screws. Use a 5/32-in. (4 mm) Allen wrench for the 5/16-in. hex screws.

    Warning

    To protect power supplies from input voltage that may be caused by miswired PDMs, before reinstalling the metal cover to the wiring compartment apply AC voltage to the PDM to make sure that two LEDs on the PDM are lit green and that the AC voltage between AC terminal blocks A1-B1, B1-C1, C1-A1, A2-B2, B2-C2, and C2-A2 for the three-phase delta PDM is not more than 264VAC when measured with a DVM. Then turn off the AC breaker de-energizing the PDM and install the metal cover.

    Note

    Three-phase delta AC wire assembly kits can be purchased from Juniper Networks.

    Table 1: Supported Three-Phase Delta AC Wire Gauge

    Wire Gauge	Description
    4 x 6-AWG or equivalent	4 conductor wires, each wire is 6-AWG

    Note

    We recommend that you use the proper gauge wire in order for the cable clamps to hold the AC cables. Using smaller gauge wiring will result in the cable clamps not tightening properly.

    Warning

    Power connections must be performed by a licensed electrician only.

14. Verify that the power cord wire connections are correct.
15. Screw the retaining nut onto the AC power cord to secure it to the metal wiring compartment.
16. Using a number 2 Phillips (+) screwdriver, tighten the four captive screws on the metal AC wiring compartment.
17. Verify that the AC power cord is not touching or blocking access to router components, and that it does not drape where people could trip on it.
18. Remove the ESD grounding strap from the ESD points on the chassis. Connect the strap to an approved site ESD grounding point. See the instructions for your site.
19. Connect the AC power cord plug to the power source.
20. Switch on the customer site circuit breakers to provide voltage on the AC power cord.
21. Remove the ESD grounding strap from the approved site ESD grounding point. See the instructions for your site. Reconnect the strap to one of the ESD points on the chassis.
22. Verify that the LED on the PDM faceplate is lit steadily, indicating that the AC terminal block is receiving power.