Replacing an M10i DC Power Supply

A DC-powered router has up to four load-sharing DC power supplies. The router must have at least two DC power supplies, and any two DC power supplies can provide full power to the router. Each redundant power supply is hot-removable and hot-insertable, as described in M10i Field-Replaceable Units (FRUs). For M10i routers with only two DC power supplies, you must power off the router before replacing a DC power supply.

1. Removing an M10i DC Power Supply
2. Installing an M10i DC Power Supply

Removing an M10i DC Power Supply

The DC power supplies are located at the bottom rear of the chassis, as shown in M10i Chassis Description. For information about power supply redundancy and replaceability, see M10i Power System Description.

Caution: Do not leave a power supply slot empty for more than a short time while the router is operational. The power supply must remain in the chassis for proper airflow.

To remove a DC power supply (see Figure 1):

1. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
2. Press the power switch for the power supply (located on the power supply faceplate) to the OFF (O) position.

   Note: If you are power cycling the power supply rather than shutting it off for a time, wait at least 60 seconds after turning it off before turning it back on. If you need to power it off again, wait for at least 60 seconds after powering it on.

3. Shut off the power flowing to the power supply from the external power source, so that the voltage across the leads of the DC power cables is 0 V. Ensure that there is no chance that the cable leads might become active during the procedure.
4. Using a number 1 Phillips screwdriver, turn the screw on each field-wiring terminal counter-clockwise to loosen the terminal connector from around the cable lug.
5. Remove the cables from the terminal connectors and from the hook located on the faceplate to the right of the field-wiring terminals.
6. Loosen the thumbscrew at each end of the power supply faceplate, using a Phillips screwdriver if necessary.
7. Grasp the handle on the power supply faceplate and pull firmly to slide the unit about halfway out of the chassis.
8. Place one hand under the power supply to support it, then slide it completely out of the chassis.

Figure 1: Removing a DC Power Supply

Installing an M10i DC Power Supply

To install a DC power supply (see Figure 2 and Figure 3):

1. Verify that there is no power flowing to the power supply from the external power source, so that the voltage across the leads of the DC power cables is 0 V. Ensure that there is no chance that the cable leads might become active during the procedure.
2. Verify that the power switch for the power supply (located on the power supply faceplate) is in the OFF (O) position.
3. Verify that the grounding cable is attached to the chassis and properly connected to an earth ground.
4. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to one of the ESD points on the chassis.
5. Grasp the handle on the power supply faceplate with one hand and place the other hand under the supply to support it.
6. Align the rear of the supply with the slide guides inside the chassis and slide the supply into the chassis until it contacts the midplane.
7. Tighten (but do not overtighten) the thumbscrews on the power supply faceplate.
8. Verify that a licensed electrician has attached a listed DC power cable lug to each power source cable.
9. Loop the DC power cables through the hook located on the faceplate to the right of the field-wiring terminals.
10. Depending on the type of DC power cable lugs used, loosen or remove the screws on the field-wiring terminals.
11. Insert the DC power cable lugs into the appropriate field-wiring terminals. Using a number 1 Phillips screwdriver, turn the screw on each field-wiring terminal clockwise to secure the DC power cable lug. Apply between 8 lb-in. (.9 Nm) and 9 lb-in. (1.02 Nm) of torque to each screw.
    1. Insert the positive (+) source cable into the return terminal, which is labeled RTN.
    2. Insert the negative (–) source cable into the input terminal, which is labeled –48V.

    Note: The DC power supplies in slots P/S 0 and P/S 1 must be powered by dedicated power feeds derived from feed A, and the DC power supplies in slots P/S 2 and P/S 3 must be powered by dedicated power feeds derived from feed B. This configuration provides the commonly deployed A/B feed redundancy for the system.

12. Verify that the DC source power cabling is correct, that the DC power cables are not touching or blocking access to router components, and that they do not drape where people could trip on them.
13. Turn on the DC power source so that voltage flows to the power supply.
14. Press the switch on the power supply faceplate to the ON ( | ) position. When the power supply has powered on successfully, the green OUTPUT OK LED lights steadily.

    Note: After powering off a power supply, wait at least 60 seconds before turning it back on. After powering on a power supply, wait at least 60 seconds before turning it off. If the router is completely powered off when you power on the power supply, the Routing Engine boots as the power supply completes its startup sequence. If the Routing Engine finishes booting and you need to power off the router again, see Powering Off an M10i Router . After a power supply is powered on, it can take up to 60 seconds for status indicators—such as the output status LED on the power supply, the command display output, and messages on the LED display on the craft interface—to indicate that the power supply is functioning normally. Ignore error indicators that appear during the first 60 seconds.

Figure 2: Installing a DC Power Supply

Figure 3: Connecting DC power cables to a DC Power Supply