Toshiba 2000 V Series Manual page 61

(4) Single Power Unit Central Connection
Shown below is an example of configuration where a network power unit is installed
at the center of a trunk line (thick cable) 240 meters in overall length. The current
consumption of each node is shown in the figure below.
The central location of the network power unit permits supply of the maximum current
in all directions of the network.
Node 3
0.1A
(a) Total current consumption of section 1 = 0.1A+0.25A+0.2A=0.55A
(a') Total current consumption of section 2 = 0.15A+0.25A+0.15A=0.55A
(b) Overall power cable length of section 1 = Overall power cable length of section 2
= 120 m
(c) Maximum current that can be supplied to the cables based on Figure 3-10 =
About 2.56 A (Obtained by linear approximation of 100 to 150 m)
(d) Since the total current consumption is smaller than the maximum current, power
can be supplied to all the nodes by single power unit central connection.
(e) Install a network power unit with a rated current capacity of 0.65 A or more.
(Select one with an adequate capacity, considering the conditions of use.)
If the current consumption of a section exceeds the maximum current in a configuration
of single power unit central connection, take steps as shown in the table below. Figure 3-
14 shows an example of overloaded single power unit central connection.
Section exceeding the maximum current to
Only one of the two section
Both sections
6F8C0845
セクション 1 Section 1
120 m
Node 2 Node 1
0.25A 0.2A
Figure 3-12 Example of Single Power Unit Central Connection
cables
3.5 Network Power/Grounding
Section 2
セクション 2
120 m
V +−
電源
Power
Node 4
タップ
tap
V −
0.15A
ネットワーク
Network power
電源供給装置 unit
Step
Move a node from the overloaded section to the
other section.
Move the power tap closer to the section
overloaded.
Use two power taps.
Node 5 Node 6
0.25A 0.15A
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