Mitsubishi A1SJH - Page 89

8. LOADING AND INSTALLATION
8 - 5
MELSEC-
A
(1) Power consumption of a power supply module
Approximately 70 % of the power supply module current is converted into
power and 30 % of that 70 % is dissipated as heat, i.e., 3/7 of the output
power is actually used.
Wpw = {(I
5V
×
5) + (I
24V
×
24)} (W)
Where, I
5V
= V DC logic circuit current consumption of each module.
I
24V
= current consumption of the output modules
(with an average number of points switched ON)
...(Not for 24 V DC input power supply modules)
(2) Total 5 V DC power consumption
5 V DC is supplied to each module via the base plate, which powers the logic
circuitry.
W
5V
= I
5V
×
5 (W)
(3) Total 24 V DC output module power consumption (with an average number of
points switched ON)
24 V DC is supplied to drive output devices.
W
24V
= I
24V
×
24 (W)
(4) Power consumption of output circuits (with an average number of points
switched ON)
W
OUT
= I
OUT
×
Vdrop
×
average number of outputs on at one time (W)
Where, I
OUT
= output current (actual operating current) (A)
Vdrop = voltage dropped across each output load (V)
(5) Power consumption of input circuits (with an average number of points
switched ON)
W
IN
= I
IN
×
E
×
average number of inputs on at one time (W)
Where, I
IN
= input current (effective value for AC) (A)
E = input voltage (actual operating voltage) (V)
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