User guide

Additional Installation Tips
6.4 AmbientTemperature
The maximum ambient temperature for the operator panel is provided in the
specifications. The ambient temperature refers to the temperature in the device
cabinet which cools the panel’s electronics.
Operator
panel
Power
Power
Power
30 °C outside
Top
50 °C inside
Bottom
40 °C inside
Middle
45 °C inside
Airflow
Axial fan
120 x 120 mm
5354
Inmostcases,theambienttemperaturefortheoperatorpanelissignificantly
higher than the device cabinet’s ambient temperature.
If the cabinet is tall and there are a number of hea
t-generating devices, the
temperature at the top of the cabinet will be con
siderably higher than the
theoretical temperature increase th at would
be expected. All electronics are
sensitivetoheat. Thelifespanofanelectro
lytic capacitor is cut in half with an 8-10
° increase in temperature. A 15-20 ° tempera
ture increase results in a quarter of the
lifespan etc.
Rittal has a good program for estimating the anticipated average temperature in
the cabinet as well as a large program for controlling the temperature in the device
cabinet.
An enamel-coated steel cabinet has
a radiant heat value of 5.5 W/m
2
and degrees
C.
Installing a fan inside the cabinet will even out the temperature, while moving air
provides considerably better cooling than still air. A suitable fan is a 120 x 120 mm
axial fan, available in 24 V DC, 115 and 230 V AC.
Installthefansothatitsit
s in the cooler area and will blow cold air against the
operator panel. If the fan i
s mounted at the top and sucks air upwards, the fan’s
ambient temperature will
be higher = shorter lifespan.
Agoodfanwithaball-bearingmountinghasanexpectedlifespanofatleast
40,000 hours (not a guaranteed lifespan) at 40 °C. This corresponds to at least 4
years of continuous use. If a thermostat is installed, the fan only needs to come
on when needed.
Large graphic termi
nals draw only one fifth of the current when the background
lighting is off. Th
e loss effect drops from e.g. 25 W to only 5 W.
The operator panel’s loss effect = supply voltage x current. Virtually no power goes
to external users and no loss effects due to inputs.
BeijerElectronics, MAEN011A
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