Cisco Nexus 7000 Hardware Installation And Reference Manual page 212

Power Supply Configuration Modes
Table 8-3 Input Source Redundancy Mode Scenarios
Power Power
Supply 1 Supply 2
Scenario (kW) (kW)
1 6.0 6.0
2 6.0 6.0
3 6.0 6.0
Cisco Nexus 7000 Series Hardware Installation and Reference Guide
8-14
Scenario 2: If you add a power supply that outputs 3 kW, the reserve power is 9 kW (3 kW for
three power supply units), and the available power is 6 kW (3 kW for each of two power supply
units). The available power does not meet the system usage requirement, so you cannot power
the entire switch.
Scenario 3: If you add a power supply unit that outputs 7.5 kW, the reserve power is 9.75 kW
(3 kW for two power supply units and 3.75 kW for the new power supply unit), and the available
power is 9.75 kW (3 kW for two power supply units and 3.75 kW for the new power supply
unit). The available power exceeds the switch usage requirement, so you can power up all of the
modules and fan trays in the switch.
Table 8-3 shows the results for each scenario.
Power System Available
Supply 3 Usage Power
(kW) (kW) (kW)
- 8.784 6.0
3.0 8.784 9.0
7.5 8.784 9.75
– 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 8-4 shows the results for each scenario.
Appendix 8
Reserve
Power
(kW) Result
6.0 Available power (the power supply output for either
grid) does not meet the system usage requirement.
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.
9.75 The power supply output for both grids meet the
meet the system usage requirement.
Managing the Switch Hardware
OL-23069-06