Srx5400 Services Gateway Cabinet Airflow Requirements; Calculating Power Requirements For The Srx5400 Services Gateway - Juniper SRX5400 Hardware Manual

SRX5400 Services Gateway Cabinet Airflow Requirements

When you mount the device in a cabinet, you must ensure that ventilation through the cabinet is sufficient
to prevent overheating. Following is a list of requirements to consider when planning for chassis cooling:
Ensure that the cool air supply you provide through the cabinet can adequately dissipate the thermal
output of the device.
Ensure that the cabinet allows the chassis hot exhaust air to exit from the cabinet without recirculating
into the device. An open cabinet (without a top or doors) that employs hot air exhaust extraction from
the top allows the best airflow through the chassis. If the cabinet contains a top or doors, perforations
in these elements assist with removing the hot air exhaust.
Install the device as close as possible to the front of the cabinet so that the cable management system
just clears the inside of the front door. This maximizes the clearance in the rear of the cabinet for critical
airflow.
Route and dress all cables to minimize the blockage of airflow to and from the chassis.
Calculating Power Requirements for the SRX5400
Services Gateway
The information in this topic helps you determine which power supply configurations are suitable for
various services gateway configurations, as well as which configurations are not suitable because output
power is exceeded. You determine suitability by subtracting the total power draw from the maximum
output of the power supplies. Afterward, the required input current is calculated. Finally, you calculate
the thermal output.
We recommend that you provision power according to the maximum input current listed in the power
supply electrical specifications (see
page 46 and "SRX5400 Services Gateway DC Power Supply Specifications" on page
Use the following procedures to calculate the power requirement:
1. Calculate the power requirement.
2. Evaluate the power budget.
3. Calculate input power.
4. Calculate thermal output (BTUs) for cooling requirements.
"SRX5400 Services Gateway AC Power Supply Specifications" on
52).
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