Help us improve your experience.

Let us know what you think.

Do you have time for a two-minute survey?

 
 

Cooling System and Airflow for QFX3600 and QFX3600-I Devices

The cooling system in QFX3600 and QFX3600-I devices consist of three field-replaceable unit (FRU) fan trays with two fan modules each (see Figure 1). In addition, the power supplies have internal fans to cool themselves.

Figure 1: Fan Tray for QFX3600 and QFX3600-I DevicesFan Tray for QFX3600 and QFX3600-I Devices

The fan tray provides FRU-to-port or port-to-FRU airflow depending on the SKU you purchase. Table 1 lists the different QFX3600 and QFX3600-I SKUs and their direction of airflow.

Note:

In QFX Series device model names, AFI, or airflow in, describes FRU--to-port airflow. AFO, or airflow out, describes port-to-FRU airflow.

Note:

The rear panel of the device where the power supplies and fan trays are located is the FRU side of the device.

Table 1: Airflow Direction in QFX3600 and QFX3600-I Device Models

Model

Direction of Airflow

QFX3600-16Q-AFI

FRU-to-port

QFX3600-16Q-AFO

Port-to-FRU

QFX3600-I-16Q-AFI

FRU-to-port

QFX3600-I-16Q-AFO

Port-to-FRU

In QFX3600 and QFX3600-I device models that have FRU--to-port airflow, the air intake to cool the chassis is located on the rear panel of the chassis, where the FRUs are installed. Air is pulled into the chassis and pushed away from the fan trays. Hot air exhausts from the rear of the chassis, where the ports are located. See Figure 2.

Figure 2: FRU-Side-to-Port-Side Airflow Through the QFX3600 and QFX3600-I ChassisFRU-Side-to-Port-Side Airflow Through the QFX3600 and QFX3600-I Chassis

In QFX3600 and QFX3600-I device models that have port-to-FRU airflow, the air intake to cool the chassis is located on the front panel of the chassis, the side with access and uplink ports. Air is pulled into the chassis and pulled through the fan trays. Hot air exhausts from the front of the chassis, where the FRUs are installed. See Figure 3.

Figure 3: Port-to-FRU Airflow Through the QFX3600 and QFX3600-I Chassis Port-to-FRU Airflow Through the QFX3600 and QFX3600-I Chassis

Each airflow type requires specific power supplies and fan trays that have fan modules oriented in the proper direction. The fan trays are designed so that they can only be inserted into the device model that supports the same airflow type. The power supplies have labels and arrows on the handles that depict the direction of airflow (see Figure 4). The label AFI denotes FRU-to-port airflow. AFO denotes port-to-FRU airflow.

CAUTION:

Verify that the direction of the arrow on the power supply handle matches the direction of airflow in the chassis. See Table 1 to determine your model’s airflow direction.

Figure 4: Label Identifying Airflow Direction on Power Supply HandleLabel Identifying Airflow Direction on Power Supply Handle

Table 2 lists QFX3600 and QFX3600-I device FRUs and their direction of airflow.

Table 2: Airflow Direction in QFX3600 and QFX3600-I SKUs

FRU

Part Number

Direction of Airflow

Fan tray

QFXC01-FANBI

FRU-side-to-port-side

QFXC01-FANBO

Port-side-to-FRU-side

AC power supply

  • JPSU-650W-AC-AFI

  • QFXC01-PWRACI-650A

FRU-side-to-port-side

JPSU-650W-AC-AFO

Port-side-to-FRU-side

DC power supply

JPSU-650W-DC-AFI

FRU-side-to-port-side

JPSU-650W-DC-AFO

Port-side-to-FRU-side

The chassis includes a fan speed-control system. Under normal operating conditions, fans operate at reduced speed to reduce noise and power consumption.

Temperature sensors in the chassis monitor the temperature within the chassis. The system raises an alarm if a fan fails or if the temperature inside the chassis rises above permitted levels. If the temperature inside the chassis rises above the threshold, the device shuts down automatically. You can see the status of fans and the temperature remotely through the CLI by issuing the operational mode command show chassis environment.

You cannot replace a single fan module. If one or more fan modules fail, you must replace the entire fan tray.