Motorola AltiVec MVME5100 Series Installation & Use Manual page 96

Cooling Requirements
A
The incoming air temperature is measured between the fan assembly and
the card cage, where the incoming airstream first encounters the module
under test. Test software is executed as the module is subjected to ambient
temperature variations. Case temperatures of critical, high power density
integrated circuits are monitored to ensure component vendors'
specifications are not exceeded.
While the exact amount of airflow required for cooling depends on the
ambient air temperature and the type, number, and location of boards and
other heat sources, adequate cooling can usually be achieved with 10 CFM
and 400 LFM flowing over the module. Less airflow is required to cool the
module in environments having lower maximum ambient temperature.
Under more favorable thermal conditions, it may be possible to operate the
module reliably at higher than 71° C with increased airflow. It is important
to note that there are several factors, in addition to the rated CFM of the air
mover, which determine the actual volume and speed of air flowing over a
module.
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