• Supported Platforms
• T320 Routers

• Related Topics
• T320 Power System Description
• Maintaining the T320 Power Supplies
• T320 Power System Electrical Specifications
• Site Electrical Wiring Guidelines for M Series and T Series Routers

Installing a T320 DC Power Supply

Caution: Each power supply must be connected to a dedicated DC power source.

To install a power supply (see Figure 1):

1. 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 installation.

   Caution: You must ensure that power connections maintain the proper polarity. The power source cables might be labeled (+) and (–) to indicate their polarity. There is no standard color coding for DC power cables. The color coding used by the external DC power source at your site determines the color coding for the leads on the power cables that attach to the terminal studs on each power supply.

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. For more information about ESD, see Preventing Electrostatic Discharge Damage to an M Series, MX Series, or T Series Router.
3. Switch the circuit breaker on the power supply faceplate to the off position (O).
4. Using both hands, slide the power supply into the chassis until you feel resistance.
5. Twist the ejector handles at the upper corners of the power supply faceplate clockwise until they stop.
6. Tighten the captive screws at the lower corners of the power supply faceplate to secure the power supply in the chassis.
7. Remove the clear plastic cover protecting the terminal studs on the faceplate.
8. Remove the nuts and washers from the terminal studs.
9. Attach the lugs on the DC source power cables to the terminal studs.
   1. Attach the positive (+) DC source power cable lugs to the RETURN (return) terminals.
   2. Attach the negative (–) DC source power cable lugs to the –48V (input) terminals.

   Secure the cable lugs to the terminal studs, first with the washers, then with the nuts. Apply between 23 lb-in. (2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut.

10. Verify that the power cables are not touching or in the way of any other components.
11. Loosen the captive screws on the cable restraint on the right edge of the power supply faceplate.
12. Route the positive and negative DC power cables through the top and bottom of each cable restraint.
13. Tighten the cable restraint captive screws to hold the power cables in place.
14. Verify that the ground and power cabling are correct, that they are not touching or blocking access to router components, and that they do not drape where people could trip on them.
15. Replace the clear plastic cover over the terminal studs on the faceplate.
16. Switch on the external circuit breakers to provide voltage to the DC power source cable leads.
17. Switch the circuit breaker on the power supply to the on position (|) and observe the LEDs on the power supply faceplate. If the power supply is correctly installed and is functioning properly, the DC OK LED lights steadily, and the CB ON LED blinks momentarily, then 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 system 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 system again, see . After a power supply is powered on, it can take up to 60 seconds for status indicators—such as the output status LEDs on the power supply, the command display output, and messages on the LCD on the craft interface—to indicate that the power supply is functioning normally. Ignore error indicators that appear during the first 60 seconds.