Panasonic KX-NS500 Installation Manual page 94

4.2.11 Surge Protector Installation
Outside Installation
Trunk
If you install an extension outside of the building, the following precautions are recommended:
a.
Install the extension wire underground.
b.
Use a conduit to protect the wire.
Note
The surge protector for an extension is different from that for trunks.
Installation of an Earth Rod
Surge Protector
Trunk
Earthing
Wire
(Underground)
94 Installation Manual
(Main Building)
Surge Protector
Trunk
Terminal
Board
Extn.
Extn.
Extn.
SLT
PBX
Earth Rod
PBX
Surge
Protector
Earth
Extn.: Extension Line
(Another Building)
Extn.
SLT