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MELSEC-Q
5 SETUP AND PREPARATION
(3) When the network power supply current capacity is insufficient
In the case where the network power supply unit is connected to the following
network that uses thick cables:
Master node
1.1A
Slave node
1.25A
0.5A
120m
Terminating
resistor
Terminating
resistor
0.25A
0.25A
0.85A
120m
Network power
supply unit
Slave node
Slave node
Slave node
Slave node
Power supply distance on the left side = Power supply distance on the right side
= 120m
Total current capacity of the left side = 1.1A + 1.25A + 0.5A = 2.85A
Total current capacity of the right side = 0.25A + 0.25A + 0.85A = 1.35A
Max. current capacity available for thick cable length of 120m (See Table 5.4.) =
approx. 2.56A
(Straight-line approximation between 100m and 150m)
In this configuration, the current capacity on the left side is insufficient.
In this case, move the network power supply unit in the direction of insufficient
current capacity (to the left in the figure above).
Master node
1.1A
Slave node
1.25A
0.5A
100m
Terminating
resistor
Terminating
resistor
0.25A
0.25A
0.85A
140m
Network power
supply unit
Slave node
Slave node
Slave node
Slave node
Total power supply distance on the left side = 100m
Total power supply distance on the right side = 140m
Total current capacity of the left side = 1.1A + 1.25A = 2.35A
Total current capacity of the left side = 0.5A + 0.25A + 0.25A + 0.85A = 1.85A
Max. current capacity available for thick cable length of 100m (See Table 5.4.) =
approx. 2.93A
Max. current capacity available for thick cable length of 140m (See Table 5.4.) =
approx. 2.19A
(Straight-line approximation between 100m and 150m)
As a result of shifting the network power supply unit, it is able to supply power to
all nodes.
Содержание QJ71DN91
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