Lightning Protection; Lightning Protection Zones - Motorola PTP 500 Series User Manual

5 Lightning Protection

This section provides instructions for protecting PTP 500 installations against lightning strike.
The purpose 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.
The following topics are described in this section:
•

5.1 Lightning Protection Zones

•
5.2 LPU Detailed Installation
•
5.3 LPU Kit
•
5.4 LPU Installation Wiring
•
5.5 LPU Installation Diagram
This section 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.
CAUTION
EMD (Lightning) damage is not covered under standard warranty. The
recommendations in this user manual, when implemented correctly, give the user the
best protection from the harmful effects of EMD. However 100% protection is neither
implied nor possible.
5.1 Lightning Protection Zones
When the ODU is installed on a mast, tower or wall, it may be in one of two possible lightning
protection zones :
•
Zone A: In this zone a direct lighting strike is possible. Do not mount the ODU in this
zone.
•
Zone B: In this zone, direct EMD (Lightning) effects are still possible, but mounting in this
zone significantly reduces the possibility of a direct strike. Mount the ODU in this zone.
The zones are determined using the 'rolling sphere method': an imaginary sphere, typically 50
meter in radius, is rolled over the structure. All structure points that contact the sphere
indicate the zone (A) where a direct strike is possible. Similarly points that do not contact the
sphere indicate a zone (B) where a direct strike is less likely.
39
5 Lightning Protection