10 - 20 10 - 20
10 MOUNTING AND INSTALLATION
MELSEC-ST
(6) Power consumption of the power supply section of the intelligent
function module
W
S
= I
S5V
5 + I
S24V
24 (W)
I
S5V
:Current consumption of 5VDC circuit
I
S24V
: Current consumption of 24VDC circuit
The total of the power consumption values calculated for each block becomes
the power consumption of the overall MELSEC-ST system.
W = W
PW
+ W
5V
+ W
24V
+ W
OUT
+ W
IN
+ W
S
(W)
Based on 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
control panel is shown below.
T
W
UA C
W : Power consumption of overall MELSEC-ST system (value obtained
above)
A : Surface area inside the control panel
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
POINT
When a rise in ambient temperature inside the control panel exceeds the specified
limit, it is recommended to 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 the MELSEC-ST system
together with the external air, this may affect the performance of the MELSEC-ST
system.
(7) Example of calculating average power consumption
(a) System configuration example
ST1
H
-B
T
ST1
PSD
S
T
1X
2-DE
1
ST1
Y
2-
TPE3
S
T
1P
DD
ST1
A
D
2-
V
(b) 5VDC internal current consumption of slice modules and head module
ST1H-BT
: 0.410 (A)
ST1X2-DE1
: 0.085 (A)
ST1Y2-TPE3
: 0.095 (A)
ST1PDD
: 0.060 (A)
ST1AD2-V
: 0.110 (A)
(c) Power consumption of power supply module
W
PW
= 2/8 (0.410+0.085+0.095+0.060+0.110) 5 = 0.950 (W)
(d) Total 5VDC internal current consumption of slice modules and head module
W
5V
= (0.410+0.085+0.095+0.060+0.110) 5 = 3.80 (W)
Summary of Contents for MELESEC-ST
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Page 23: ...A 21 A 21 MEMO...
Page 114: ...10 22 10 22 10 MOUNTING AND INSTALLATION MELSEC ST MEMO...
Page 125: ...11 11 11 11 11 EMC AND LOW VOLTAGE DIRECTIVE MELSEC ST MEMO...
Page 163: ...Index 2 Index 2 MEMO Ind...
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