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Cisco Nexus 7000 Series Hardware Installation and Reference Guide
OL-23069-07
Chapter 6 Installing Power Supplies
Connecting a DC Power Supply to DC Power Sources
Note The power cables required for a 6-kW DC power supply are shipped with the power supply. If you did
not receive the correct cables for a 6-kW DC power supply, contact Cisco TAC. You must supply the
power cables for a 3-kW DC power supply.
Warning
Read the installation instructions before connecting the system to the power source.
Statement 1004
Connecting a 3-kW DC Power Supply Directly to DC Power Sources
If the DC power supply is within one cable length of the DC power sources, you can connect them
directly to one another. Otherwise, if you need additional cables, you can connect the cables using a
power interface unit (PIU) as explained in the “Connecting a Power Supply to DC Power Sources
through a Power Interface Unit” section on page 6-18.
To connect the 3-kW DC power supply directly to one or two DC power sources, follow these steps:
Step 1 Turn the power switch to standby (labelled 0 on the power switch).
Step 2 Turn off the power at the circuit breakers for the portions of the DC grid power that you are connecting
to and verify that all of the LEDs on the power supplies are off.
Warning
Before performing any of the following procedures, ensure that power is removed from the DC circuit.
Statement 1003
Step 3 Size the power cables to the distance between the power supply and the DC power grid. If you need to
cut the cable, cut it at the end that connects to the DC power grid, remove 0.75 inch (19 mm) of insulation
from the cut ends, and attach them to the DC power system. Be sure to connect the negative cables to
negative lines and positive cables to positive lines.
Note For all your power connections, if you are using cables with two different colors, use one color
cable for all positive circuits and the other color for all negative circuits.
Warning
Hazardous voltage or energy may be present on DC power terminals. Always replace cover when
terminals are not in service. Be sure uninsulated conductors are not accessible when cover is in
place.
Statement 1075
Step 4 Remove the three screws that hold down the safety cover for the terminal box on the front of the DC
power supply and remove the cover (see Figure 6-7).
Note The terminal box has four slots for four power terminals (ordered as negative [-], positive [+], positive
[+], and negative [-]). Each terminal has two nuts that you use to fasten a power cable to the terminal.