Flow Of Hot Air - Mitel Aastra 470 System Manual

4. 2. 4

Flow of hot air

The Aastra 470 communications server comes with a fan already pre-installed. The
housing is designed so the air flow is first guided at two levels over the processor
cards and the interface cards, then passes through cutouts in the backplane, ab-
sorbs the heat from the power supply unit, and exits the housing through the fan
aperture.
Fig. 18 Flow of hot air
The fan speed depends on the ambient temperature, the number of cards and
modules, and the communication server load, and continually adapts to the cur-
rent temperature inside the housing.
Note
Make sure all the housing openings on the communications server are
always closed and secured by screws during operation to ensure a con-
trolled flow of air. This applies in particular to the interface cards and pro-
cessor cards, but also to the dummy covers and housing covers.
Aastra 470 as of R3.2
syd-0337/1.6 – R3.2 – 09.2014
Installation
93