5 Lightning Protection
41
It may be possible to extend Zone B by installing a finial above the ODU ( Figure 13).
Figure 13 – Using a Finial to Extend Zone B
In Zone B, a direct lightning strike is unusual, but the un-attenuated electromagnetic field is
still present. Equipment mounted in Zone B should be grounded using grounding wire of at
least 10 AWG. This grounding wire should be connected to a grounding rod or the building
grounding system before entry in to building.
NOTE
Local regulations may also require the fitting of the 8 AWG grounding wire.
WARNING
Equipment mounted in Zone A must be capable of carrying the full lightning current.
Mounting of the ODU in Zone A is not recommended. Mounting in Zone A should only
be carried out observing the rules governing installations in Zone A. Failure to do so
may put structures, equipment and life at risk.
The PTP 300 Series bridge ODU grounding point can be found on the bottom of the unit. The
ODU is supplied with an appropriate grounding lug.
The following protection requirements are mandatory in both Zones A and B:
•
The ODU must be earthed
•
Screened CAT 5e cable must be used
•
Surge arrestors of type PTP-LPU must be installed at building entry
•
There must be an earth connection at building entry
The recommended standard components for protecting installations are listed in 5.5 “LPU
Installation Diagram”.
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