3. General Specifications (Environment Conditions)
3.5 Heat Radiation Countermeasures
15
The following shows an example of calculation applied to heat radiation countermeasures for the operation
panel. Because heat will accumulate in the upper portions of the unit, install an agitating fan as required.
200
260 140
Display unit
(Agitating fan)
600
120
500
<Calculation example of heating value in operation panel>
(1) Calculation of unit heating value
Heating value (W)
Total heating value of units (W):
27W (= display unit + operation panel I/O unit)
Total heating value (W) by machine input (D1):
5.6W (= 24V;
total heating value when the 32 points are simultaneously turned ON
× 7.3mA × 32)
... 24V; current consumption per point of the operation panel I/O unit DI
÷
3.3k
Ω
≒
7.3mA
Total heating value W = 32.6W (27 + 5.6)