Chapter 4 Installation and Debugging
Figure 27
shows the cabling of Ethernet switch in a four-floor
building with three units. Where, switch A in Unit 1 is the con-
vergence switch of the whole building, and switches B and C
are access switches. Switches A, B, and C are cascaded. That
is, the cascading cable of switch A is the uplink cable of switch
B, and the cascading cable of switch B is the uplink cable of
switch C. The rest subscriber lines are distributed inside the
building and connected to the subscriber terminals from bot-
tom to top in the corridor.
F
IGURE
27 CABLING OF THE ETHERNET SWITCH IN A BUILDING
In the above figure, 1 to 8 stands for subscribers. The cascad-
ing cable refers to the cable connecting two switches.
2. Reinforced lightning protection measures must be taken
and lightning protection bars must be added for the uplink,
downlink, and cascading Ethernet ports that are led outdoors.
In special case when the common subscriber lines must be
distributed outdoors, lightning protection bars must also be
added.
The lightning protection capability of the lightning
protection bar must reach 6 KV or above and the current
discharge capability must reach 5 KA. The grounding cable of
the lightning protection bar must have a diameter of 16mm
2
and a length less than 30 cm. It is recommended to use the
optical port as the uplink port of the convergence switch in
the building. If the electrical port is used, lightning protection
bars must be added.
Figure 28
shows the cabling of a convergence switch. Where,
the uplink port is the optical port and lightning protection bars
are added for the downlink or cascaded cables. The lightning
bars are connected to the earth through the shell. The rest
subscriber lines are distributed inside the building.
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