Connecting a dc power source

You might need to connect a dc power source to the rack. Use the procedure in this section to perform this task.

1. Remove the six mounting screws from the top cover of the dc power distribution panel and remove the top cover.
2. If installed, remove the four screws from the cable channel cover.
3. Remove the cable channel cover.
   

   1	Cable channel cover retaining screw	5	Shield
   2	Cable channel cover	6	Power distribution panel
   3	Power distribution panel top cover retaining screws	7	Front of rack
   4	Power distribution panel top cover

   Figure 1. Removing the cable channel cover.
4. Remove the -48 V dc bus bar shield from the power distribution panel.
   Attention: The bus bar shield must be correctly reinstalled over the -48 V dc return bus bars to protect against injury while servicing the power distribution panel.
5. Ensure that the following steps are performed when connecting the dc power source.
   1. At -48 V dc power source, turn off any -48 V dc power sources that will be connected to the power distribution panel.
   2. After the -48 V dc power sources are turned off, be sure there is a tag or label over the power source switches or fuses (lock-out/tag-out) to indicate that the power source is turned off intentionally.
      Note: Ensure that any oxidation on the copper bus bars is removed.
   3. If this is a raised-floor installation and you are working at the back of the rack, route the power cables up the rack's right side.
   4. Ensure that the external -48 V dc power cable is connected correctly to the -48 V dc bus bar.
   5. Ensure that the external -48 V dc return cable is routed correctly and installed on the return bus bar.
      

      1	-48 V dc power cable and return power cable
      2	Power distribution panel
      3	Front of rack
      4	-48 V dc power cable and return power cable

      Figure 2. Routing the power cables.
      

      1	Front of power distribution panel	6	(B) Return (-) power cable
      2	(A) -48 V dc (-) bus bar	7	(B) -48 V dc (-) power cable
      3	(A) -48 V dc (-) power cable	8	(B) Return (-) bus bar
      4	(A) Return (-) bus bar	9	(B) -48 V dc (-) bus bar
      5	(A) Return (-) power cable

      Figure 3. Return bus bar.
   6. If you want to install a power status alarm, connect the alarm cable to the terminal board on the back cover of the dc power distribution panel.
      Note: Ensure that the oxidation on the copper bus bars is removed.
   7. Ensure that the power-source ground cable is routed correctly and connects the power-source ground cable to the copper bar at the lower-back or upper-back center of the rack.
   8. If the rack is on a raised floor, attach the -48 V dc power source cables to the back of the rack with cable-restraint straps.
      

      1	Back view of rack (dc)
      2	Power cable, power return cable, and ground
      3	Ground cable (Install at either top or bottom of the rack)

      Figure 4. Cable locations.
6. Reinstall the -48 V dc bus bar shield.
7. Reinstall the top cover on the dc power distribution panel.
8. Reinstall the cable channel cover.
   

   1	Cable channel cover
   2	Terminal block (both sides)
   3	Power distribution panel
   4	Front of rack

   Figure 5. Reinstalling the cable channel cover.