Power Mode Configuration Guidelines
The amounts of available and reserve power depend on the power redundancy mode that you specify. The
amounts of available and reserve power also depends on and the number of power supplies that are installed
in the switch. For each redundancy mode, consider the following:
Combined mode
The available power equals the combined output of all installed power supplies. There is no reserve
power. You activate this mode by using the
power redundancy-mode combined
command. If the power
requirement for a switch is 5.2 kW and the switch has one 3-kW power supply with 220-V input and
3.0-kW output, consider the following power planning scenarios:
• Scenario 1—No added power supplies
If you do not add a power supply unit, the available power (3.0 kW) is insufficient for the switch
power requirement of 5.2 kW. The switch powers the supervisor modules, system controllers, fan
trays, and at least one fabric module before powering as many of the fabric and line cards as the
remaining available power can support (one or more fabric or line cards might not be powered).
• Scenario 2—Install an extra 3-kW power supply
If you install an extra 3-kW power supply unit that can output 3.0 kW, the available power becomes
6.0 kW. The increased amount of available power exceeds the switch power requirement of 5.2 kW,
so all the modules and fan trays in the switch can power up.
The following table shows the results for each scenario.
Result
Reserve
Power
Available
Power
Power
Supply 2
Output
Power
Supply 1
Output
Power
Requirement
Scenario
Available
power is less
than the
power
requirement
for the
switch. You
cannot power
the entire
switch (some
of the line
cards will not
be able to
power up).
—
3.0 kW
—
3.0 kW
5.2 kW
1
Cisco Nexus 9516 NX-OS Mode Switch Hardware Installation Guide
54
Managing the Switch
Power Mode Configuration Guidelines
