Instruction manual

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3 DESIGN
3.3.3 Calculating heat generation by Motion controller
The ambient temperature inside the control panel storing the Motion controller must be
suppressed to a Motion controller operating ambient temperature of 55°C(131°F).
For the design of radiation from the storing panel, it is necessary to know the average
power consumption (heating value) of the devices and instruments stored in the control
panel. Here the method of obtaining the average power consumption of Q173HCPU/
Q172HCPU system is described. From the power consumption, calculate a rise in
ambient temperature inside the control panel.
Calculating average power consumption
The power consuming parts of the Motion controller are roughly classified into six
blocks as shown below.
(1) Power consumption of the power supply module
The power conversion efficiency of the power module is approx. 70 [%], i.e., 30
[%] of the output power is consumed by heating. As a result, 3/7 of the output
power becomes the power consumption.
Therefore the calculation formula is as follows.
3
7
Wpw= (I
5V
5)[W]
I
5V: Current consumption of logic 5 VDC circuit of each module
(2) Power consumption of a total of 5 VDC logic section of each
module
The power consumption of the 5 VDC output circuit section of the power module
is the power consumption of each module (including the current consumption of
the base unit).
W
5V = I5V 5 [W]
(3) A total of 24 VDC average power consumption of the output module
(power consumption for simultaneous ON points)
The average power of the external 24 VDC power is the total power consumption
of each module.
W
24V = I24V 24 [W]
I
24V
: Current consumption of the output module
(4) Average power consumption due to voltage drop in the output
section of the output module
(Power consumption for simultaneous ON points)
W
OUT = IOUT Vdrop Number of output points Simultaneous ON rate [W]
I
OUT : Output current (Current in actual use) [A]
Vdrop : Voltage drop in each output module [V]