Connecting DC Power Cables

Procedure

1. Turn off the power source to which the power cables need to be connected.
2. Measure the distance that the power cables will go through, and cut the DC power cables into an appropriate length based on the measured distance.
3. Identify positive and negative power cables, attach temporary labels to both ends of each power cable, and write numbers on the labels. For details on how to number the cables, see Engineering Labels for DC Power Cables.

   By default, DC power cables delivered with a DC power module include a blue negative cable and a black positive cable. Connect the negative cable to the NEG (-) terminal and the positive cable to the RTN (+) terminal. Different DC power cables may be delivered in compliance with local regulations or customer requirements.

4. (Only for power cables outside the cabinet) Route the power cables along the planned paths. Arrange the power cables from the power distribution frame (PDF) into a bundle and route them to the cabinet along the cable tray. Lead the power cables into the cabinet from the left side.

   • To connect cables in the cabinet more conveniently, you can remove the side panels of the cabinet before connecting cables.

   • Use appropriate force on the cables. Dragging cables with too much force may damage them.

5. Wear an ESD wrist strap or a pair of ESD gloves. When wearing an ESD wrist strap, insert the other end to the ESD jack of a device and ensure that the device is reliably grounded.
6. Connect power cables to power modules (OT terminals).
   1. Place the required power cables near the switch.
   2. Use a Phillips screwdriver to loosen the screw on the power terminal cover, take off the screw and power terminal cover, and save them for later use. See callout 1 in Figure 9-3.
   3. (Optional) Cut the cables to the required length, and then crimp OT terminals on the cable ends.
   4. Use a Phillips screwdriver to loosen the screws on the power terminals, take off the screws and washers, and save them for later use. See callout 2 in Figure 9-3.
   5. Connect the positive and negative power cables to the positive and negative power terminals on the power module. Put the screws through the washers and OT terminals on the power cables, and then tighten the screws. See callout 3 in Figure 9-3.
   6. Install the power terminal cover and secure it with the screw. See callout 4 in Figure 9-3.

      The methods for connecting OT and JG bare crimp terminals are similar. The OT bare crimp terminal is used as an example here.

      Figure 9-3 Connecting power cables to a power module
      

7. Connect power cables to power modules (quick-connect terminals). Connect the power cable connector to the power socket on the power module. Ensure that the positive and negative power cables are connected to the positive and negative receptacles respectively. See Figure 9-4.
   Figure 9-4 Connecting power cables to a DC power module
   

8. Connect power cables to the power distribution box or PDF.
   • If a power distribution box is used, connect power cables to the power distribution box and then to the PDF.
   • If no power distribution box is used, connect power cables directly to the PDF.

   Generally, power terminals on the power distribution box and PDF are cord end terminals or OT terminals.

   • If OT terminals are used:
     1. Place the required power cables near the power distribution box or PDF.
     2. (Optional) Cut the cables to the required length, and then crimp OT terminals on the cable ends.
     3. Use a Phillips screwdriver to loosen the screws on the power terminals, take off the screws and washers, and save them for later use. See Figure 9-5.
        Figure 9-5 Removing screws from power terminals
        
     4. Connect the positive and negative power cables to the positive and negative power terminals. Put the screws through the washers and OT terminals on the power cables, and then tighten the screws. See Figure 9-6.
        Figure 9-6 Securing power cables with screws
        
   • If cord end terminals are used:
     1. (Optional) Cut the cables to the required length, and then crimp cord end terminals on the cable ends.
     2. Loosen the screws on the power terminals to which the power cables will be connected. See Figure 9-7.
        Figure 9-7 Loosening screws on power terminals
        
     3. Insert the cord end terminals of the positive and negative cables to the positive and negative power terminals, respectively, and then tighten the screws. See Figure 9-8.
        Figure 9-8 Securing power cables with screws
        

9. Arrange and bundle the power cables on the left side of the cabinet. See Figure 9-9.
   Figure 9-9 Bundling power cables
   

   • Ensure that power cables do not block power switches or indicators or hinder installation of other power modules. See callout 1 in Figure 9-9.

   • Route power cables from the left side of the cabinet and bundle them with cable ties at 200-mm intervals. Do not bundle power cables at the bent part.

   • Bundle power cables with appropriate stress. Ensure that power cables are not crossed or twisted.