User guide

45 Mbps Backhaul User Guide
Issue 3, December 2004 Page 88 of 113
9 Lightning Protection
9.1 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. 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.
The installation of the ODU can be classified into two different lightning protection zones.
Zone A — In this zone a direct hit is possible.
Zone B — In this zone a direct hit is not possible, but the unattenuated electromagnetic field is still present.
The next diagrams (Figure 44 & Figure 45) show this zoning pictorially:
Equipment mounted in Zone A should 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
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. Failure to do so may put structures, equipment and life at risk.
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.
The 45 Mbps Backhaul ODU grounding point can be found on the bottom of the unit. The 45 Mbps Backhaul is
supplied with an appropriate grounding lug for attachment to the ODU.
9.2 Detailed Installation
The recommended components for an installation protected for nearby strikes are:
• 2 Grounding Kits — Andrew Type 223158 (www.andrew.com )
• Shielded Cat 5 Cable
• Line Protection Unit — Cyclix MTJ-POE 60V ( www.cylix.com )
• Grounding Stake
• 2 RJ45 connectors
• 10 AWG Grounding Cable
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Local regulations may also require the fitting of the 10AWG ground wire referred below.