Grounding and lightning protection
Chapter 2 Planning considerations
phn-0896_012v000
2-22
Jul 2010
Protection requirements on a high rise building
If the ODU is to be mounted on a high rise building, it is likely that cable entry is at
roof level (
Figure 2-8
) and the equipment room is several floors below (
Figure 2-9
). In
addition to the general protection requirements (above), the following requirements
must be observed:
•
The ODU must be below the lightning terminals and finials.
•
A grounding conductor must be installed around the roof perimeter, to form the
main roof perimeter lightning protection ring.
•
Air terminals are typically installed along the length of the main roof perimeter
lightning protection ring typically every 6.1m (20ft).
•
The main roof perimeter lightning protection ring must contain at least two down
conductors connected to the grounding electrode system. The down conductors
should be physically separated from one another, as far as practical.
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