Motorola PTP 400 Series Manual De Usuario

 

 

142

11 Lightning 

Protection

 

 

 (

) damage is not covered under warranty  

 

11.1 Overview

 

 

The idea of lightning protection is to protect structures, equipment and people against 

lightning by conducting the lightning current to ground via a separate preferential solid path 

and by reducing the electromagnetic field.  

The following should be treated as a guide only, the actual degree of lightning protection 

required depends on local conditions and weather patterns and applicable local regulations. 

Full details of lightning protection methods and requirements can be found in the international 

standards IEC 61024-1 and IEC 61312-1, the U.S. National Electric Code ANSI/NFPA No. 

70-1984 or section 54 of the Canadian Electric Code.  

11.1.1  Lightning Protection Zones 

The installation of the ODU can be classified into two different lightning protection zones.  

Zone A — in this zone a direct lighting strike is possible.  

Zone B — in this zone a direct lightning strike is unusual, but the un-attenuated 

electromagnetic field is still present.  

The zones are determined using the ‘rolling sphere method’, an imaginary sphere, typically 50 

meters (164 feet) in radius is rolled over the structure. All structure points that contact the 

sphere, (Zone A) indicate the zone where a direct strike is possible. Similarly points that do 

not contact the sphere indicate a zone (zone B) where a direct strike is less likely. 

The following diagrams (Figure 76 and Figure 77) show this zoning pictorially: