Motorola MVME162P-242, Installation And Use Manual

Page: 111 / 134

Cooling Requirements
http://www.motorola.com/computer/literature A-3
A
Special Considerations for Elevated-Temperature Operation
The following information is for users whose applications for the
MVME162P2 may subject it to high temperatures.
The MVME162P2 uses commercial-grade devices. Therefore, it can
operate in an environment with ambient air temperatures ranging from 0°
C to 70° C. Several factors influence the ambient temperature seen by
components on the MVME162P2. Among them are inlet air temperature;
air flow characteristics; number, types, and locations of IP modules; power
dissipation of adjacent boards in the system, etc.
A temperature profile of a comparable board (the MVME172LX
embedded controller) was developed in an MVME954A six-slot VME
chassis. Two such boards, each loaded with two GreenSpring
IndustryPack modules, were placed in the chassis with one 36W load
board installed between them. The chassis was placed in a thermal
chamber that maintained an ambient temperature of 55° C. Measurements
showed that the fans in the chassis supplied an airflow of approximately 65
LFM over the MVME172LX boards. Under these conditions, a rise in
temperature of approximately 10° C between the inlet and exit air was
observed. The junction temperatures of selected high-power devices on the
MVME172LXs were calculated (from case temperature measurements)
and were found to be within manufacturers’ specified tolerances.
!
Caution
For elevated-temperature operation, perform similar measurements and
calculations to determine the actual operating margin for your specific
environment.
To facilitate elevated-temperature operation:
1. Position the MVME162P2 in the chassis to allow for maximum
airflow over the component side of the board.
2. Do not place boards with high power dissipation next to the
MVME162P2.
3. Use low-power IP modules only.