Rockwell Automation 141A Mounting System Temperature Rise Calculation Software Tutorial - Manual (Page 9)

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Now enter the data in the “Environmental conditions” tab as shown below.
Note: Calculations in accordance with IEC 60890 assume that the enclosures are not aff ected by any
sources of radiation (ovens, sun).
Maximum ambient temperature
Th
e maximum ambient temperature is required for the calculation of the inside temperature,
which is the product of the ambient temperature and the temperature rise caused by the power
dissipation of the installed devices, conductors and busbars.
Altitude of the location
If the altitude of the location it is more than 1000 m above sea level, it needs to be considered for
fi lter fan sizing.
Th e effi ciency of a fi lter fan is inversely proportional to the air density. Assuming a heat
dissipation in excess of 60 W (as in our tutorial project), the required air fl ow changes,
depending on the altitude as follows:
Enclosure stands outside
If the enclosure is installed outside, the radiation’s eff ect is higher, because of increased air
movement on the surface. Approximately, a factor of 2 is used for calculations.
2.1
“Environmental
Conditions” Tab
(continued)
Altitude Required Air fl ow
Sea Level 7.9 m 3
1,500 m 8.9 m 3
3,000 m 10.0 m 3