Hirschmann OZD Genius G12-1300, User Manual

Page: 37 / 72

Installation OZD Profi 12M ...
Release 01 07/2017
37
3.5 Laying cables outside of buildings
Figure 6: Laying cables outside of buildings
Requirements:

It is recommended to use fiber optic cables for bus installations which are
outside of buildings. In the case of bus cables between buildings which
are laid in the ground, you should use a special fiber optic cable type
which is suitable for this application.

Suitable copper cable types can be used if fiber optic cables cannot be
used.

Observe the admissible minimum and maximum temperature rating for
the type of cable used.
In principle, the same rules apply to laying cables outside of buildings as
within buildings. However, for outside installation, the cables should be
provided with additional protection by laying them inside a suitable plastic
pipe.
The transition from external to internal cables should always use an auxiliary
terminal block. It is used to interconnect the cable for burial in the ground with
the standard bus cable. Lightning arrestors should be installed directly where
the cable enters the building. In addition, the auxiliary terminal block should
contain appropriate circuits to protect against overvoltages (lightning
protection).
Lightning protection Lightning protection
Plastic pipe
Functional ground
Bus cable Bus cable
Potential equalization
Functional ground
Potential equalization