675
APPENDICES
A
Appendix 10 Calculating Heat Generation of Programmable Controller
(4) Average power consumption due to voltage drop in the output section of the
output module
(power consumption for simultaneous ON points)
WOUT = IOUT
× Vdrop
× Number of output points
× Simultaneous ON rate (W)
I
OUT : Output current (current in actual use) (A)
Vdrop : Voltage drop in each output module (V)
(5) Average power consumption of the input section of the input module
(power consumption for simultaneous ON points)
W
IN
= I
IN
× E
× Number of input points
× Simultaneous ON rate (W)
I
IN
: Input current (effective value for AC) (A)
E : Input voltage (voltage in actual use) (V)
(6) Power consumption of the external power supply section of the intelligent
function module
W
S
= I
+15V
× 15 + I
-15V
× 15 + I
24V
× 24 (W)
The total of the power consumption values calculated for each block is the power consumption of the entire
programmable controller system.
According to the calculated power consumption (W), calculate the heating value and a rise in ambient
temperature inside the panel.
The outline of the calculation formula for a rise in ambient temperature inside the panel is shown below.
If the temperature inside the control panel is expected to exceed the specified range, it is recommended to install a heat
exchanger to the panel to lower the temperature.
If a normal ventilating fan is used, dust will be sucked into the programmable controller together with the external air, and it
may affect the performance of the programmable controller.
W = W
PW
+ W
5V
+ W
24V
+ W
OUT
+ W
IN
+ W
S
(W)
W : Power consumption of the entire programmable controller system (value obtained above)
A
: Surface area inside the control panel [m
2
]
U : When the ambient temperature inside the panel is uniformed by a fan....................................6
When air inside the panel is not circulated................................................................................4
To Next Page
Loading...
