Layout Of Communication Power Supply - Hitachi HIDIC EH-150 Applications Manual

12.2 Layout of Communication Power Supply

Follow the procedure shown below when determining the position and number of communication power supplies
to be used.
1. Calculate the power consumption necessary for each device on the network.
2. Measure the total length of the network.
3. Calculate the maximum current capacity corresponding to the network distance and the cable type used.
See Figures 12.1 and 12.2 for how to calculate it.
4. If the power consumption calculated in step 1 above is lower than the maximum current capacity, any of the
positions to connect the power supply shown in Section 12.3 may be used.
5. If the power consumption calculated in step 1 above is greater than the maximum current capacity, it is
necessary to examine the position in greater detail in order to connect the power supply. For more
information, see Section 12.4.
Distance (m)
Maximum
current (A)
8
7
6
5
4
3
2
1
0
0 50
Distance (m)
Maximum
current (A)
3
2
1
0
0 10
0 25 50 100
8.00 8.00 5.42 2.93
100 150 200
Length of network (m)
Figure 12.1 Maximum current capacity (thick cable)
0 10 20 30
3.00 3.00 3.00 2.06
20 30 40
Length of network (m)
Figure 12.2 Maximum current capacity (thin cable)
Chapter 12 Communication Power Supply
150 200 250 300
2.01 1.53 1.23 1.03
250 300
40 50 60
1.57 1.26 1.06 0.91
50 60
12-2
350 400 450
0.89 0.78 0.69 0.63
350 400 450
70 80 90 100
0.80 0.71 0.64
70 80 90
500