Juniper QFX5200 Hardware Manual page 45

Figure 21: Air Out Airflow Through QFX5200-48Y
Do Not Install Components with Different Airflow or Wattage in the Switch
Do not mix power supplies with different airflow. If the power supplies are color-coded, ensure they are
either all match. Likewise, ensure that all fan modules have the same airflow and match the airflow of
the power supplies. Fan modules are also color-coded that match the power supplies.
Mixing components with different airflows in the same chassis hampers the performance of the cooling
system of the switch and leads to overheating of the chassis.
CAUTION: The system raises an alarm if a fan module fails or if the ambient
temperature inside the chassis rises above the acceptable range. If the temperature
inside the chassis rises above the threshold temperature, the system shuts down
automatically.
Do not mix fan modules with different wattage. Only use the replacement fan modules that are designed
for use with your product number. See
QFX5200 device.
CAUTION: Do not mix AC and DC power supplies in the same QFX5200-32C or
QFX5200-32C-L chassis. You may mix AC and DC power supplies in the same
QFX5200-48Y chassis, but the fans and power supplies must have the same airflow
direction. Also note that load sharing is not the same for AC and DC power supplies.
However if you need to convert a QFX5200 device to have a different airflow, you can change the
airflow pattern. To convert an AIR IN product SKU to an AIR OUT product SKU or an AIR OUT product
Table 15 on page 32 for the correct part number for your
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