Precautions For Network Power Supply; Network Power Supply Unit Position - Mitsubishi Electric QJ71DN91 User Manual

5 SETUP AND PREPARATION

5.7 Precautions for Network Power Supply

5.7.1 Network power supply unit position

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This section describes the precautions for network power supply.
Follow the procedure below to determine the position to install the network power
supply unit.
1) Calculate the current consumption of each node on the network.
2) Measure the total length of the network.
3) Referring to Tables 5.4 and 5.5, find a maximum current value corresponding to
the network length and the cable type used.
4) If the current value calculated at step 1) is less than the one obtained at step 3),
any of the positions described on the next page can be used.
5) If the current value calculated at step 1) exceeds the one obtained at step 3),
install the network power supply unit near the center of the network referring to the
next page, and check if power can be supplied to all nodes.
6) As a result of step 5), if power cannot be supplied to all nodes, increase the
number of network power supply units.
Table 5.4 Maximum current capable of being supplied to master/slave
nodes, for each length of the network using thick cables
Network length (m) 0
Maximum current (A) 8.00
Table 5.5 Maximum current capable of being supplied to master/slave
nodes, for each length of the network using thin cables
Network length (m) 0
Maximum current (A) 3.00
POINT
Use a network power supply unit of which the current capacity is more than the
required total current consumption.
If the current capacity is insufficient, use of multiple power supplies is possible.
However, use power supply taps in such a case.
25 50 100 150
8.00 5.42 2.93 2.01
10 20 30 40
3.00 3.00 2.06 1.57
MELSEC-Q
200 250 300 350
1.53 1.23 1.03 0.89
50 60 70
1.26 1.06 0.91 0.80
400 450 500
0.78 0.69 0.63
80 90 100
0.71 0.64
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