Replacing an MX2008 Three-Phase Delta AC Power Distribution Module

Removing an MX2008 Three-Phase Delta AC Power Distribution Module

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

1. Switch off the dedicated customer-site circuit breakers to the PDM being remove. 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 removal process.
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. Remove the ESD grounding strap from the ESD point on the chassis, and attach it to an approved site ESD grounding point. See instructions for your site.
4. Disconnect the AC power cord (see Figure 1) from the power source.

   Figure 1: Three-Phase Delta AC Power Cord

   

5. 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.
6. Using a number 2 Phillips (+) screwdriver, loosen the four screws on the cover of the metal wiring compartment that protects the AC terminal block.
7. Remove the cover of the metal AC wiring compartment.
8. Disconnect the wires from 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 remove each wire form the grounding point or input terminal.

   To remove wires from the terminal block that serves six PSMs:

   1. Remove the wire labeled L3 from the input terminal labeled C1.

   2. Remove the wire labeled L2 from the input terminal labeled B1.

   3. Remove the wire labeled L1 from the input terminal labeled A1.

   4. Remove the grounding wire from the grounding point labeled GND.

   Figure 2: Disconnecting the Power Cord from a Three-Phase Delta AC Power Distribution Module

   

   To remove wires from the terminal block that serves three PSMs:

   1. Remove the wire labeled L3 from the input terminal labeled C2.

   2. Remove the wire labeled L2 from the input terminal labeled B2.

   3. Remove the wire labeled L1 from the input terminal labeled A2.

   4. Remove the grounding wire from the grounding point labeled GND.

   Note

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

   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.

9. Loosen the plastic cable tie fastening the AC power cord to the PDM.
10. Loosen and remove the retaining nut from the AC power cord.
11. Pull the AC power cord out of the metal wiring compartment.
12. Carefully move the AC power cable out of the way.
13. Disconnect both of the AC power cords from the AC PDM.
14. Loosen the two captive screws on the locking levers of the PDM faceplate completely.
15. Pull the locking levers on either side of the faceplate up to unseat the PDM.
16. Grasp the levers on the PDM faceplate and pull firmly. Slide it halfway out of the chassis (see Figure 3).Caution

    Each three-phase delta AC PDM weighs approximately 12 lb (5.44 kg). Be prepared to support the full weight of the PDM as you remove it from the router.

17. Place one hand underneath the PDM to support it, and slide it completely out of the chassis.

Figure 3: Removing a Three-Phase Delta AC Power Distribution Module

Installing an MX2008 Three-Phase Delta AC Power Distribution Module

Before you install a three-phase delta AC power distribution module (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.
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. [Optional]—If you are switching from a DC PDM to an AC PDM, change the setting on the internal bar of the power distribution unit (PDU) cage to AC.

   To change the AC/DC setting:

   1. After removing all the PSMs and the PDMs, remove all the screws on the top and bottom bars of the PDU cage. See Figure 4.

   2. With the help of a screw driver, change the setting on the internal bar of the PDU cage to AC. See Figure 5.

   3. Replace the screws and tighten them. Apply between 7 lb-in (0.8 Nm) and 9 lb-in. (1.01 Nm) of torque to each screw.

   Note

   The MX2008, MX2010, and MX2020 routers support the same power modules (AC/DC PSMs and AC/DC PDMs).

   Note

   The AC/DC settings and the screw locations are same for MX2008, MX2010, and MX2020 routers.

   Figure 4: Removing the Screws on the PDU Cage

   Figure 5: Changing the AC/DC Setting

4. Pull the locking levers on either side of the faceplate away until they stop.
5. Using both hands, slide the PDM into the chassis until you feel resistance (see Figure 6).
6. Push the lock levers until they make contact with the PDM faceplate.
7. 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.
8. 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 6: Installing a Three-Phase Delta AC Power Distribution Module (MX2008)

   

9. Remove the cover of the metal AC wiring compartment.
10. Unscrew the retaining nut from the AC power cord.
11. Place the retaining nut inside the metal wiring compartment.
12. Insert the wires of the AC power cord through the hole of the retaining nut and rubber grommet.
13. Insert the wires of the AC power cord through the hole of the metal wiring compartment.
14. Connect the wires to the AC terminal block on the three-phase delta AC PDM (see Figure 7). 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 7: 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 might vary. The MX2008 chassis is not sensitive to phase rotation sequence—either clockwise or counterclockwise will operate correctly.

    Caution

    Wire label configuration is for Juniper Networks supplied cable only. If you are 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 might be caused by mis-wired PDMs, before reinstalling the metal cover to the wiring compartment, apply AC voltage to the PDM (with the PSM power switch turned off). Verify that the 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 three-phase delta PDM is not more than 264 VAC when measured with a digital voltage meter (DVM). Then turn off the AC breaker to remove power from 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.

15. Verify that the power cord wire connections are correct.
16. Screw the retaining nut onto the AC power cord to secure it to the metal wiring compartment.
17. Using a number 2 Phillips (+) screwdriver, tighten the four captive screws on the metal AC wiring compartment.
18. Verify that the AC power cord does not touch or block access to router components, and that it does not drape where people could trip on it.
19. 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.
20. Connect the AC power cord plug to the power source.
21. Switch on the customer-site circuit breakers to provide voltage on the AC power cord.
22. 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.
23. Verify that the LED on the PDM faceplate is lit steadily, indicating that the AC terminal block is receiving power.