Environment - GE Mark VIe System Manual

5.4 Environment

5.4.1 Temperature Considerations
Mark VIe and Mark VIeS control electronics can be packaged in a variety of different configurations and designed for
different environmental conditions. Proper thermal considerations for active electronics with heat sensitive components must
be considered for electronics packaging.
Note Refer to the table,
Mark VIe and Mark VIeS Equipment with Restrictive Ambient
For internal enclose design considerations, components have an ambient temperature rating. The allowable temperature
change without condensation is ±15°C (59 °F) per hour. It is recommended that the environment be maintained at levels less
than the maximum rating of the equipment to maximize life expectancy. Packaging the equipment and selecting an
appropriate enclosure to maintain the desired temperature is a function of the following:
• Internal heat dissipation from the assemblies
• Outside ambient temperature
• Cooling system (if used)
5.4.2 Enclosures
It is recommended that enclosures not be placed in direct sunlight, and locations near heat generating equipment need to be
evaluated. Since the internal temperature increases from the bottom to the top of the enclosure, limiting the temperature at the
top is a key design objective.
When selecting an enclosure system for Mark VIe hardware, it is the responsibility of the system designer to select an
enclosure which will ensure reliable operation of the enclosed equipment. The designer must ensure that the local
temperatures inside the enclosure do not exceed the rating of the equipment. For solid door and vented free convection
cooling designs, enclosure level analyses which predict overall temperature rises are typically insufficient. It is instead
necessary to consider the localized hot spots generated by the distributed heat sources inside the enclosure and verify that
those heated zones do not exceed the temperature rating of equipment located in the hot spot.
Technical Regulations, Standards, and Environment
Temperature Considerations in Packaging Electronics
Public Information
Ratings.
GEH-6721_Vol_I_BP System Guide 121