Replacing a T320 DC Power Supply Cable

1. Removing a T320 DC Power Supply Cable
2. Installing a T320 DC Power Supply Cable

Removing a T320 DC Power Supply Cable

1. Locate a replacement power cable that meets the specifications defined in T320 DC Power Cable Specifications.

   Caution: A licensed electrician must attach a cable lug to the power cable that you supply. A cable with an incorrectly attached lug can damage the router (for example, by causing a short circuit).

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.

   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.

3. 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 a T320 Router.
4. Switch the circuit breaker on the power supply faceplate to the off position (O).
5. Remove the power cable from the DC power source.
6. Remove the clear plastic cover protecting the terminal studs on the faceplate.
7. Remove the nuts and washers from the terminal studs (see Disconnecting Power Cables From the DC Power Supply). (Use a 7/16–in. nut driver or pliers.)
8. Remove the cable lug from the terminal studs.
9. Loosen the captive screw on the cable restraint on the right edge of the power supply faceplate.
10. Carefully move the power cable out of the way.

Installing a T320 DC Power Supply Cable

1. Attach the lug on the replacement power cable to the terminal studs, making sure the cable is not touching or in the way of any router components.
2. Secure the cable lug to the terminal studs, first with the washers, then with the nuts (see Connect Power Cables to the T320 Power Supply). Apply between 23 lb-in. (2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut.
3. Route the power cable through the cable restraint.
4. Tighten the cable restraint captive screw to hold the power cable in place.
5. Replace the clear plastic cover over the terminal studs on the faceplate.
6. Attach the power cable to the DC power source.
7. Verify that the DC source power cabling and grounding 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.
8. 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 Powering Off the T320 Router. 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.

Figure 1: Connecting Power Cables to the T320 Power Supply