Chapter 10 Installation and wiring MASTER-K
10-3
④ Average power consumption by voltage drop of output modules (with points
simultaneously switched ON)
• Wout = Iout × Vdrop × output points × the rate of points switched on simultaneously (W)
Iout : output current (actual operating current) (A)
Vdrop : voltage dropped across each output load (V)
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)