Connecting DC Power

Caution: If your J6350 Services Router includes an optional redundant DC power supply, connect each of the two power supplies to different input power sources. Failure to do so makes the router susceptible to total power failure if one of the power supplies fails.

The router must be connected to earth ground during normal operation. The protective earthing terminal on the rear of the chassis is provided to connect the router to ground.

For DC cable requirements, see DC Power, Connection, and Power Cable Specifications.

To connect DC power to the router:

1. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to the ESD point on the chassis. For more information about ESD, see Preventing Electrostatic Discharge Damage.
2. Use a grounding cable to connect the router to earth ground: (For cable requirements, see Chassis Grounding.)
   1. Verify that a licensed electrician has attached an appropriate grounding cable lug to the grounding cable.
   2. Connect one end of the grounding cable to a proper earth ground, such as the rack in which the router is installed.
   3. With a Phillips screwdriver, remove the screw and washer from the PEM nut at the grounding point on the rear of the chassis.
   4. Place the grounding lug at the other end of the cable over the grounding point, as shown in Figure 52 and Figure 53.
   5. Secure the cable lug to the grounding point, first with the washer, then with the screw. On J2320 and J2350 routers, use the screw containing a captive washer to secure the cable lug to the grounding point.

   Note: A DC power supply in a Services Router becomes grounded when you connect a grounding cable between the router and earth ground.

3. For each power supply:
   1. Ensure that the voltage across the DC power source cable leads is 0 V and that the cable leads cannot become active in any way 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. Verify that a licensed electrician has attached the appropriate power cable lugs to the negative and positive DC source power cables.
   3. Use a Phillips screwdriver to remove the clear plastic cover protecting the terminal block.
   4. Within the terminal block, remove the two center screws next to the labels –48 VDC and RTN.

      Each screw contains a captive washer to secure a DC source power cable lug to the terminal block.

   5. Using one of the removed screws, secure the positive (+) DC source power cable lug to the RTN terminal. Tighten the screw until snug. Do not overtighten. Apply between 8 lb-in. (0.9 Nm) and 9 lb-in. (1.02 Nm) of torque to the screw.
   6. Using the other removed screw, secure the negative (–) DC source power cable lug to the –48 VDC terminal. Tighten the screw until snug. Do not overtighten. Apply between 8 lb-in. (0.9 Nm) and 9 lb-in. (1.02 Nm) of torque to the screw.
   7. Dress the power cables appropriately.
   8. Replace the clear plastic cover over the terminal block.
4. Verify that the power cables do not block access to router components or drape where people can trip on them.
5. On J2320 and J2350 routers, use the power cable tie as follows to relieve strain on the cable (see Figure 52 ):
   1. Wrap the loose end of the tie around the cable, and insert it into the opening on the tie.
   2. Pull the end to tighten the tie.

   To release the tie from the cable, press down the tab on the tie and loosen it.

Figure 52: Connecting DC Power to the J2350 Services Router

Figure 53: Connecting DC Power to the J4350 or J6350 Services Router

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