Connecting Power to a DC-Powered Router

Connect DC power to the router by inserting power cables into the field-wiring terminals on the faceplate of each power supply. DC Power cables are not supplied with the router. For information about the required cable type, see DC Power, Connection, and Cable Specifications.

1. Verify that there is no power flowing from either external power source, so that the voltage across the leads of the power cables is 0 V. Ensure that there is no chance that the cable leads might become active during the procedure.
2. Verify that a licensed electrician has attached a listed power cable lug to each power source cable.
3. For each power supply, verify that the power switch on the power supply faceplate is in the OFF (O) position.
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. For more information about ESD, see Preventing Electrostatic Discharge Damage.
5. Loop the power cables through the hook located on the faceplate to the right of the field-wiring terminals.
6. Depending on the type of power cable lugs used, loosen or remove the screws on the field-wiring terminals.
7. Insert the 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 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.

   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 the power supply faceplate.

   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. For information about connecting to DC power sources, see DC Power, Connection, and Cable Specifications.

8. Verify that the DC source power cabling is correct, that the DC cables are not touching or blocking access to router components, and that they do not drape where people could trip on them.

Figure 47: Connecting DC Power and Grounding Cables