Chapter 4 Installation and Debugging
Confidential and Proprietary Information of ZTE CORPORATION 33
distributed inside the building and connected to subscriber
terminals from bottom to top in the corridor.
Lightning protection bars must be added for the uplink,
downlink, and cascading Ethernet ports that are outdoors.
Lightning protection bar must reach 6 KV or above and the
current discharge capability must reach 5 KA. Grounding
cable of lightning protection bar must have a diameter of 16
mm2 and a length less than 30 cm. It is recommended to
use the optical port as uplink port for convergence switch in
the building. If the electrical port is used, lightning protection
bars must be added.
Cabling of a convergence switch is shown in
Figure 18.
Uplink port is optical port and lightning protection bars are
added for downlink or cascaded cables. Lightning bars are
connected to ground through shell. Rest of subscriber lines
are distributed inside building.
FIGURE 18 CABLING OF A CONVERGENCE SWITCH
。。。
Uplink cable
(optical interface)
Uplink cable or
cascading cable
Shell ground
Subscriber line
Less than 30 cm
Lightning
protection bar
Ethernet switch
Explanations are as follows:
Grounding system with good ground grid is preferred for
switch. Many residential buildings with proper grounding
have a grounding resistance of 1 ohm. If the test shows
that grounding system is not up to standard. It is
recommended to equip an independent grounding post and
the grounding cable must be of 16 mm2 in diameter and as
short as possible. What ever grounding method is used,
the grounding resistance must be less than 5 ohm and
cannot exceed 10 ohm.
It is prohibited that switch directly gets power from outdoor
overhead power cable. If switch gets direct power from
outdoor overhead power cables, special lightning protection
measures must be taken into account. Lightning protection
Convergence
switch cabling
Explanation
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