Replacing a Side Air Filter on a T640 AC Power Supply

1. Removing a Side Air Filter on a T640 AC Power Supply
2. Installing a Side Air Filter on a T640 AC Power Supply

Removing a Side Air Filter on a T640 AC Power Supply

To remove an AC power supply side air filter:

Note: The router has either one nonredundant power supply or two redundant, load-sharing power supplies. If you have only one power supply, you must power off the system before removing the side air filter on an AC power supply. Each redundant power supply is hot-removable and hot-insertable. When a redundant power supply is powered down or removed, the other power supply automatically assumes the entire electrical load for the router.

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. Switch the power switch on the power supply faceplate to the standby position.

   Note: After powering off a power supply, wait at least 60 seconds before turning it back on.

3. Detach the ESD grounding strap from the ESD points on the chassis. Reattach the strap to an approved site ESD grounding point. Follow the instructions for your site.
4. Switch off the customer site circuit breakers to the power supply. Make sure that the voltage across the AC power source cable leads is 0 V and that there is no chance that the cables might become active during the replacement.
5. Disconnect the AC power cord from the AC power source.
6. Reattach the ESD grounding strap to one of the ESD points on the chassis.
7. Grasp the front filter cover on the power supply faceplate and pull it straight off the power supply.
8. Remove the front filter element.
9. Loosen the screws (using a Phillips (+) screwdriver, number 2) on the bracket located on the side of the power supply.
10. Pull the side filter, located on the left side of the AC power supply, out of the power supply.

Figure 1: Removing the AC Power Supply Side Air Filter

Installing a Side Air Filter on a T640 AC Power Supply

1. Verify that the customer site circuit breakers to the power supply is off, that that the voltage across the AC power source cord is 0 V, and that there is no chance that the AC power cord might become active during the replacement.
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. Install the replacement side filter.
4. Using a Phillips (+) screwdriver, number 2, tighten the screws on the bracket located on the side of the power supply.
5. Reinstall the front filter element.
6. Press the front filter cover straight onto the power supply faceplate until all four sides click into place.
7. Detach the ESD grounding strap from the ESD points on the chassis. Attach the ESD to an approved site ESD grounding point. Follow the instructions for your site.
8. Connect the AC power cord to the power source.
9. Switch on the customer site circuit breakers to the power supply.
10. Detach the ESD grounding strap from the approved site ESD grounding point. Follow the instructions for your site. Reattach the ESD grounding strap to one of the ESD points on the chassis.
11. Verify that the AC OK LED on the power supply faceplate is lit steadily, indicating that the inputs are receiving power.
12. Switch the power switch on the power supply to the ON position (|).
13. Verify that the DC OK LED on the power supply faceplate is lit steadily, indicating that the power supply is correctly installed and is functioning properly. The DC OK LED blinks momentarily, then lights steadily.

    Note: After a power supply is powered on, it can take up to 60 seconds for status indicators—such as the LEDs on the power supply, the command output displays, 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 the Side Power Supply Filter