Chapter 9 Installation and Wiring
9-
(5) Average power consumption of input parts (with points simultaneously ON)
•
W
in
= l
in
ለ
E
ለ
input points
ለ
the rate of points switched on simultaneously (W)
I
in
: input current (effective value for AC) (A)
E : input voltage (actual operating voltage) (V)
(6) Power consumption of the special module
•
W
S
= I
5V
X 5 + I
24V
X 24 (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 [m
2
]
U : if the control panel temperature is controlled by a fan, etc
6
if control panel air is not circulated 4
