Chapter 10. INSTALLATION AND WIRING
10 - 3
(5) Average power consumption of input circuits if input modules (with points simultaneously switched ON)
•
Win = Iin
×
E
×
input points
×
the rate of points switched on simultaneously (W)
Iin : input current (effective value for AC) (A)
E: input voltage (actual operating voltage) (V)
(6) Power consumption of the special module power supply
•
Ws = I
5V
×
5
+
I
24V
×
24
+
I
100V
×
100 (W)
The sum of the above values is the power consumption of the entire PLC system.
•
W = W
PW
+
W
5V
+
W
24V
+
W
OUT
+
W
IN
+
W
S
(W)
Check the temperature rise within the control panel with calculation of that total power consumption(W).
The temperature rise in the control panel is expressed as:
T = W/UA [
°
C]
W : Power consumption of the entire PLC system (obtained as shown above)
A : Control panel inside surface area (m2)
U : 6 (if the control panel temperature is controlled by a fan, etc.)
4 (if control panel air is not circulated)