Connect DC Power to the Router

Connect DC power to the router by attaching power cables from external DC power sources to the terminal studs on the power supplies. Power and grounding cables are not supplied with the router. For information about the required cable type, see DC Power and Grounding Cable Specifications. 

The router must be connected to two separate external DC power sources, one for each set of terminal studs on the circuit breaker box.

 

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 circuit breaker box. You must ensure that the connections at the circuit breaker box maintain the proper polarity. The power source DC cables might be labeled (+) and (-) to indicate their polarity.

 

To connect DC power to the router, follow this procedure:

1. Ensure that the voltage across the leads of the DC power source cables that you are connecting is 0 V and that there is no chance that the cable leads might become active during installation.
2. Verify that the power supplies are fully inserted in the chassis, that the thumbscrews and extractor/inserters on their faceplates are tightened, and that the power switches on both faceplates are in the OFF (0) position. See Figure 64.
3. Attach the grounding cable to a proper earth ground, if it is not already.
4. Slide the grounding cable lug onto the grounding studs at the lower right corner of the power supply faceplate. Secure the lug, first with locking washers, then with nuts. Using a 7/16-in. nut driver or wrench, tighten the nuts.  
   
   

   Do not substitute a metric nut driver or wrench. A tool that does not fit the nuts exactly can damage them. If a 7/16-in. tool is not available, use pliers or an adjustable wrench.

   
   

Figure 64: Power Switch on a DC Power Supply in the OFF Position

5. If the protective shield is installed over the power supply terminals, use a Phillips screwdriver to loosen and remove the screws that secure the shield to the power supply (see Figure 65).

Figure 65: Remove the Protective Shield from the Terminal Studs

6. Slide the power cable lugs onto the terminal studs on the power supply faceplate (see Figure 66):

• Connect the positive (+) source cable lug to the return terminal, which is labeled RTN.
• Connect the negative (-) source cable lug to the input terminal, which is labeled -48V.

Run the power cables to the left on the left power supply, and to the right on the right power supply. This arrangement enables you to replace a power supply without having to detach the cables from the other power supply. 

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 circuit breaker box. You must ensure that the connections at the circuit breaker box maintain the proper polarity. The power source DC cables might be labeled (+) and (-) to indicate their polarity.

Figure 66: Attach Cables to a DC Power Supply

7. Secure the cable lugs to the terminal studs, first with locking washers, then nuts.
8. Verify that the DC power source wiring from the source DC breaker to the power supply is correct.
9. Reinstall the protective shield covering the terminal studs.
10. Repeat Steps 4 through 9 for the other power supply.
11. Turn on the power to the management device that is connected to the Routing Engine through the craft interface port labeled CONSOLE, AUXILIARY, or MANAGEMENT ETHERNET. For more information on connecting management devices, see Connect the Router to Management and Alarm Devices.
12. Press the power switch on the power supply to the ON ( | ) position. Verify that the green LED labeled OK on the power supply faceplate eventually lights steadily.  
    
    

    After a power supply is turned on, it can take up to 60 seconds for status indicators—such as LEDs on the power supply, show chassis commands, and messages on the craft interface LCD—to indicate that the power supply is functioning normally. Ignore error indicators that appear during the first 60 seconds. The Routing Engine boots as the power supply completes its startup sequence. If the Routing Engine finishes booting and you need to power down the router again, first issue the CLI request system halt command. For complete instructions, see Disconnect DC Power from the Router. If after powering on the power supply you must power it off, wait at least 60 seconds. After powering off a power supply, wait 60 seconds before turning it back on.

    
    
13. Press the power switch on other power supply to the ON ( | ) position and confirm that the OK LED lights as described in Step 4. If the LED is not lit after 60 seconds, repeat the power supply installation procedures described in Install a DC Power Supply and the previous steps in this procedure.
14. On the management device, monitor the startup process to verify that the system has booted properly.