Cisco Nexus 7710 - Page 88

For example, if the power requirement for a switch is 2.8 kW, the switch uses two 110-V power sources,
and the switch has two 3-kW power supplies (each outputting 1.45 kW for 110-V power sources), consider
the following power planning scenarios:
• Scenario 1—no added power supplies
The available power is 1.45 kW (output from one 3-kW power supply using a 110-V power source)
and the reserve power is 1.45 kW (output from the other power supply). The available power does
not meet the switch requirements of 2.8 kW, so most of the modules will power up but one or more
I/O modules will not be able to power up.
• Scenario 2—adding two 3-kW power supplies
The available power is 2.9 kW (output from two 3-kW power supplies using a 110-V power source)
and the reserve power is 2.9 kW (output from the other two power supplies). The available power
(2.9 kW) exceeds the power requirement of the switch (2.8 kW), so the entire switch can power up.
The following table shows the results for each scenario.
ResultPower Source
Redundancy
Input Source
Redundancy
Output for Power SuppliesPower
Rqmnt
Scenario
Res.Avail.Res.Avail.4321
Available
power
for both
redundancies
does
not
meet
the
switch
requirements,
so some
of the
I/O
modules
cannot
power
up.
1.45
kW
1.45
kW
1.45
kW
1.45
kW
——1.45
kW
1.45
kW
2.8 kW1
Cisco Nexus 7710 Switch Site Preparation and Hardware Installation Guide
OL-30452-01.76
Managing the Switch
Guidelines for Configuring Power Redundancy Modes