Airflow Requirements - Cisco Nexus 9396PX Hardware Installation Manual

Airflow Requirements

• Two 930-W DC power supplies
• One 650-W AC power supply and one 930-W DC power supply
Note For power-supply redundancy, you must provide power to both power supplies. For grid redundancy, you
must provide power to both power supplies and each power supply must be connected to a different power
source.
The AC power supply is rated to output up to 650 W to the switch and the DC power supply is rated to output
up to 930 W to the switch, but the switch requires less than those amounts of power from the power supply.
To operate the switch you must provision enough power from the power source to cover the requirements of
both the switch and a power supply. Typically, this switch and a power supply require about 232 W of power
input from the power source, but you must provision as much as 455 W power input from the power source
to cover peak demand.
To minimize the possibility of circuit failure, make sure that each power-source circuit used by the switch is
dedicated to the switch.
For the AC power cables that you can use with this switch, see
Note
For DC power cables, the recommended wire gauge is 8 AWG and the minimum wire gauge is 10 AWG.
Airflow Requirements
The switch is designed to be positioned with its ports in either the front or the rear of the rack depending on
your cabling and maintenance requirements. Depending on which side of the switch faces the cold aisle, you
must have fan and power supply modules that move the coolant air from the cold aisle to the hot aisle in one
of the following ways:
• Port-side exhaust airflow—Coolant air enters the chassis through the fan and power supply modules in
• Port-side intake airflow—Coolant air enters the chassis through the port end in the cold aisle and exhausts
You can identify the airflow direction of each fan and power supply module as follows:
• Fan and AC power supply modules:
• DC power supply modules have port-side intake airflow and green colored release levers
Note To prevent the switch from overheating and shutting down, you must position the air intake for the switch
in a cold aisle, and all of the fan and power supply modules must have the same direction of airflow.
Cisco Nexus 9396PX NX-OS-Mode Switch Hardware Installation Guide
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the cold aisle and exhausts through the port end of the chassis in the hot aisle.
through the fan and power supply modules in the hot aisle.
◦ Blue coloring for port-side exhaust airflow
◦ Burgundy coloring for port-side intake airflow
Preparing the Site
Power Cord Specifications, on page 47.