Справочник Пользователя для Mitsubishi Electronics Q25HCPU
9 - 7 9 - 7
MELSEC-Q
9 LOADING AND INSTALLATION
(6) Power consumption of the power supply section of the intelligent
function module
W
S
= I
5V
5 + I
24V
24 + I
100V
100 (W)
The total of the power consumption values calculated for each block becomes
the power consumption of the overall sequencer system.
W = W
PW
+ W
5V
+ W
24V
+ W
OUT
+ W
IN
+ W
S
(W)
From this overall power consumption (W), calculate the heating value and a rise
in ambient temperature inside the board.
The outline of the calculation formula for a rise in ambient temperature inside the
board is shown below.
T =
W
UA
(°C)
W : Power consumption of overall sequencer system (value obtained above)
A : Surface area inside the board
U : When the ambient temperature inside the board is uniformed by a fan......... 6
A : Surface area inside the board
U : When the ambient temperature inside the board is uniformed by a fan......... 6
When air inside the board is not circulated .............................................. 4
POINT
When a rise in ambient temperature inside the board exceeds the specified limit, it
is recommended that you install a heat exchanger in the board to lower the ambient
temperature inside the board.
If a normal ventilating fan is used, dust will be sucked into the PLC together with
the external air, and it may affect the performance of the PLC.
(7) Example of calculation of average power consumption
(a) System configuration
Q35B
Q6
1P
-A
1
Q0
2H
C
P
U
QX
4
0
QX
4
0
QY
1
0
Q
J
71LP
21-25
Va
ca
n
t
(b) 5 VDC current consumption of each module
Q02HCPU
: 0.64 (A)
QX40
: 0.05 (A)
QY10
: 0.43 (A)
QJ71LP21-25 : 0.55 (A)
Q35B
Q35B
: 0.074 (A)
(c) Power consumption of power supply module
W
PW
= 3/7 (0.64+0.05+0.05+0.43+0.55+0.074) 5) = 3.84 (W)
(d) Power consumption of a total of 5 VDC logic section of each module
W
5V
= (0.64+0.05+0.05+0.43+0.55+0.074) 5) = 8.97 (W)
(e) A total of 24 VDC average power consumption of the output module
W
24V
= 0 (W)