Removing an MX960 DC Power Supply

Before you remove a power supply, be aware of the following:

Note: The minimum number of power supplies must be present in the router at all times.

Warning: Before performing DC power procedures, ensure that power is removed from the DC circuit. 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.

Caution: To maintain proper cooling and prevent thermal shutdown of the operating power supply unit, each power supply slot must contain either a power supply or a blank panel. If you remove a power supply, you must install a replacement power supply or a blank panel shortly after the removal.

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

1. Switch off the dedicated customer site circuit breaker for the power supply being removed. Follow your site's procedures for ESD.
2. Make sure that the voltage across the DC power source cable leads is 0 V and that there is no chance that the cables might become active during the removal process.
3. Verify that the INPUT OK LEDs on the power supply to be removed are not lit.
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. Move the DC circuit breaker on the power supply faceplate to the off (O) position.
6. Remove the clear plastic cover protecting the terminal studs on the faceplate.
7. Remove the nut and washer from each of the terminal studs. (Use a 7/16-in. [11 mm] nut driver or socket wrench.)
8. Remove the cable lugs from the terminal studs.
9. Loosen the captive screw on the cable restraint on the lower edge of the power supply faceplate.
10. Carefully move the power cables out of the way.
11. While grasping the handle on the power supply faceplate with one hand, use your other hand to pull the spring-loaded locking pin in the release lever away from the chassis and turn the release lever counterclockwise until it stops.
12. Let go of the locking pin in the release lever. Ensure that the pin is seated inside the corresponding hole in the chassis.
13. Pull the power supply straight out of the chassis.

    Warning: Do not touch the power connector on the top of the power supply (see Figure 2). It can contain dangerous voltages.

Figure 1: Removing a DC Power Supply from the MX960 Router

Figure 2: Top of the Power Supply Showing Midplane Connector