2. DESIGN
2
−
21
(4) Average power consumption from voltage drop in output circuits of the output
modules (power consumption of simultaneously ON points)
W
OUT
=
I
OUT
Vdrop No. output points Simultaneously ON ratio (W)
I
OUT
: I
OUT
is the output current(actual operation current) (A)
Vdrop: Vdrop is the voltage drop of each output module (V)
(5) Average power consumption from voltage drop in input circuits of the input
modules (power consumption of simultaneously ON points)
W
IN
=
I
IN
E No. input points Simultaneously ON ratio (W)
I
IN
: I
IN
is the input current (effective value for AC) (A)
E : E is the input voltage (actual operation voltage) (V)
(6) Power consumption of special-function module power supply circuits
W
S
= I
5V
5 + I
24V
24 I
100
v 100(W)
The total power consumption of each block described above is the power
consumption of the entire PC system.
W = W
PW
+ W
5V
+ W
24V
+ W
OUT
+ W
IN
+ W
S
(W)
Use the overall calculated power consumption (W) to calculate the heat
generation and temperature rise inside the enclosure.
The following equation approximately calculates the temperature rise in the
enclosure:
T = ( C)
W
UA
W : W is the overall power consumption of the motion controller (calculated
above)
A : internal surface area of the enclosure (m
2
)
U : if a fan is used to make enclosure temperature uniform ............6
if air is not circulated inside the enclosure..................................4
CAUTION
If the enclosure temperature rises above the prescribed range, a heat exchanger should be
attached to the enclosure to lower the temperature.
Ventilation of the enclosure with a fan can result in dust problems with the motion controller
because of the dust which is introduced with the ambient air.