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7-16
Cisco Nexus 7000 Series Hardware Installation and Reference Guide
OL-23069-06
Chapter 7      Managing the Switch Hardware
Power Supply Configuration Modes
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Full redundancy mode—To activate this power mode, use the power redundancy-mode 
redundant command. The reserve power is the greater amount of reserve power for power 
supply redundancy and input source redundancy, and the available power is the lesser amount 
of available power for the same two redundancy modes.
For example, suppose your system has the following setup:
Grids A and B each provide 220 V.
Power supply units 1 and 2 each output 6.0 kW.
Switch usage requirement is 8.784 kW.
The following three scenarios explain what happens for different numbers of power supply units 
that you install:
Scenario 1: If you do not add a power supply unit, the reserve power is 6 kW and the available 
power is 6 kW. The available power does not meet the switch usage requirement, so you cannot 
power up the entire switch. 
Scenario 2: If you add a 3-kW power supply unit, the reserve power is 9 kW (3 kW for three 
power supply units on one grid), and the available power is 6 kW (3 kW for two power supply 
units on a second grid). The available power does not meet the switch usage requirement, so you 
cannot power up the entire switch.
Scenario 3: If you add a 6-kW power supply unit, the reserve power is 9 kW (3 kW for three 
power supply units on the same grid), and the available power is 9 kW (3 kW for three power 
supply units on a second grid). The available power meets the switch usage requirements, so 
you can power up the entire switch.
Table 7-6 shows the results for each scenario.
Table 7-5 Input Source Redundancy Mode Scenarios
Scenario
Power 
Supply 1 
(kW)
Power 
Supply 2 
(kW)
Power 
Supply 3 
(kW)
System 
Usage 
(kW)
Available 
Power 
(kW)
Reserve 
Power 
(kW) Result
1 6.0 6.0 - 8.784 6.0 6.0 Available power (the power supply output for either 
grid) does not meet the system usage requirement.
2 6.0 6.0 3.0 8.784 9.0 6.0 The power supply output for one grid meets the 
system usage requirement, but the power supply 
output for the other grid does not meet the system 
usage requirement.
3 6.0 6.0 7.5 8.784 9.75 9.75 The power supply output for both grids meet the 
meet the system usage requirement.