Mitsubishi Electric C70 Connection Manual page 84

(6) Power consumption of the external power supply section of the intelligent function module
= I × 5 + I × 24 + I
W
S 5V 24V
The total of the power consumption values calculated in (1) to (6) becomes the C70 overall power
consumption.
W = W
+ W + W
PW 5V
From this overall power consumption [W], calculate the heating value and a rise in ambient
temperature inside the control panel.
The outline of the calculation formula for a rise in ambient temperature inside the control panel is
shown below.
W
T =
[°C]
UA
W : C70 overall power consumption (value obtained above)
A : Surface area inside the control panel[m2]
U : When the ambient temperature inside the control panel is uniformed by a fan......6
When air inside the control panel is not circulated .................................................4
When a rise in ambient temperature inside the control panel exceeds the specified limit, it is
recommended that you install a heat exchanger in the control panel to lower the ambient
temperature inside the control panel. If a normal ventilating fan is used, dust will be sucked into C70
together with the external air, and it may affect the performance of C70.
(7) Example of average power consumption calculation (Q173NCCPU use)
(a) System configuration
Q64PN
(b) 5VDC/24VDC current consumption of each module
Unit
Q04UDHCPU (Note)
Q173NCCPU
Q173SXY
QX80 (Note)
QY80P (Note)
QJ71FL71-T-F01 (Note)
Q38DB (Note)
5VDC current consumption of the MELSEC standard module may be changed.
(Note)
It must be always confirmed in the latest manual.
× 100 [W]
100V
+ W + W + W
24V OUT IN S
Q04UDH Q173NC Q173
CPU CPU SXY
5VDC current consumption
0.20[A]
0.08[A]
3.3 Calculating Heat Generation by C70
[W]
QX80 QY80
24VDC current consumption
0.39[A]
1.25[A]
0.02[A]
0.05[A]
4.00[A]
0.50[A]
0.23[A]
C70 Connection Manual
QJ71
FL71- Q38DB
T-F01
65