Replace Fan Modules

You can replace fan modules as needed while the switch is operating ("hot swapping").

All installed fan modules must blow air in the same direction and must match the airflow direction of the installed power supplies.

If the switch's fan tray has a red tab, the airflow is front-to-back. Use a fan module labeled Air Out.
If the switch's fan tray has a blue tab, the airflow is back-to-front. Use a fan module labeled Air In.

Note

The operating-system software cannot display the airflow direction.

There are sensors inside the chassis that monitor the temperature. These sensors send information to a controller that automatically regulates the fan speed to maintain the proper temperature.

If any sensor exceeds its threshold, an alarm is triggered and the log is generated in the format:
```
Temperature Sensor [sensor] is ([sensortemp] C) has exceeded the alarm
threshold temperature ([thresholdtemp] C)
```
where sensor is one of the temperature sensors, sensortemp is the temperature reading of one of the sensors, and thresholdtemp is the threshold temperature.
When the temperature cools by 2° below the threshold, the alarm clears and the log is generated in the format:
```
Temperature Sensor [sensor] overheat temperature alarm cleared
```

There are ten sensors in VSP 7400-48Y-8C. The following table shows the types of sensors, temperatures, and the corresponding threshold values:


Sensor Name	Temperature (C)	Warning Threshold	Critical Threshold
INTERNAL MAC	41	100	103
SODIMM	15	80	85
CPU	27	65	70
MAC	28	65	70
PHY1	29	65	70
PHY2	25	65	70
PRESS_FIT_CONNECTOR	29	65	70
MGMT_BRD	25	65	70
MB	24	65	70
CPU CORE	37	100	110

There are ten sensors in VSP 7400-32C. The following table shows the types of sensors, temperatures, and the corresponding threshold values:


Sensor Name	Temperature (C)	Warning Threshold	Critical Threshold
CPU	24	70	75
MAC	39	80	85
PHY1	26	70	75
PHY2	34	70	75
PRESS_FIT_CONNECTOR	24	70	75
MGMT_BRD	27	65	70
MB	25	70	75
CPU CORE	29	100	110
INTERNAL MAC	44	100	103
SODIMM	15	80	85

Before you begin, have the replacement fan module on hand so that you can complete the replacement promptly. The switch can overheat if left without adequate cooling for an extended time.

To replace the fan module in a switch, do the following.

Gently pull the tab (labeled Air Out or Air In) on the end of the fan module.

The fan module is held in place by spring clips. As you pull, the clips will disenagage and the fan will stop.
Slide the fan module out of the switch and set it aside.
Verify that the airflow direction on the replacement fan module matches that of the installed fan modules.

Fans with front-to-back airflow have red tabs and are labeled Air Out.

Fans with back-to-front airflow have blue tabs and are labeled Air In.
Carefully slide the replacement fan module into the switch.

Push until the fan module snaps into place. The fan will automatically start to operate.