Figure 5: PSU
To facilitate different data center cooling configurations of hot or cold aisles and racks, there are two models
of PSUs. The first type has airflow with port-side intake and exhaust at the rear of the chassis. The second
type has airflow in the opposite direction, that is, rear-chassis intake and port-side exhaust. The airflow direction
is denoted on each PSU as follows:
• Red—Port-side intake airflow
• Blue—Port-side exhaust airflow
The switch supports PSUs of only one airflow type at a time. Both PSUs have to be either port-side exhaust,
or port-side intake PSUs.
The direction of PSU airflow must match the direction of the fan module airflow.
Note
For more information on installing and removing PSUs, see
Installing and Removing Power Supply Units
.
Cisco MDS 9124V-K9 Switch Hardware Installation Guide
10
Overview of Cisco MDS 9124V-K9 Switch
Power Supplies
