Lightning protection zones
Use the rolling sphere method to determine where it is safe to mount equipment. An imaginary sphere, typically 50 meters in radius, is rolled over the structure. Where the sphere rests against the ground and a strike termination device (such as a finial or ground bar), all the space under the sphere is considered to be in the zone of protection (Zone B). Similarly, where the sphere rests on two finials, the space under the sphere is considered to be in the zone of protection.
Figure 6 Rolling sphere method to determine the lightning protection zones
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Assess locations on masts, towers and buildings to determine if the location is in Zone A or Zone B:
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Warning Do not mount equipment in Zone A which can put the equipment, structures and life at risk. |