Lightning Protection Systems (Part 1 of 3) - Air Termination by Kingsmill Earthing

By Chris Dodds on 18th December, 2014

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Part 1 – Risk Assessment & Air Termination System

Kingsmill Guest Blog for T&D by Jason Leatherland, UK Sales & Business Development Manager.

Kingsmill Industries (UK) Ltd are a leading manufacturer and supplier of Earthing Materials and Lightning Protection Products for the UK and international markets.

 

Is A Lightning Protection System Required?

 

Pictured: Lightning Protection System Requirements Flow Chart

Risk Assessment

Firstly a risk assessment must be carried out to ensure that the installation of a Lightning Protection System/LPS is applicable to the structure. The risk assessment takes into account many factors such as; the structure dimensions, wiring types to/in the structure, surrounding environment, combustible materials etc.

If the result of the risk assessment deems an Internal/External LPS to be unnecessary then no further action is required.

Structural Lightning Protection System (LPS)

The system is designed and installed to protect the structure from direct lightning strikes therefore preventing injury to living beings and physical damage to the structure and contents.

An External LPS is comprised of;

• Air Termination System
• Down Conductor System
• Earth Termination System 

Pictured Right: Lightning Protection System - Safe Route To Earth

The lightning protection system is designed and installed to protect the structure from direct lightning strikes therefore preventing injury to living beings and physical damage to the structure and contents.

Air Termination System

This is made up of vertical air terminals and / or a lattice of copper conductors on the roof and edges of the structure. Since no part of the roof should be more than 5m from the nearest horizontal earthing conductor.

Traditional taper-pointed air terminals are not as frequently used today but when they are they should be positioned near those points where a strike is most likely to hit the building.

Air Termination System - Air Rod Method Example 

 

Pictured: Air Rod Method Example Termination System

Air rods or finials may be free standing masts or to other conductors to form a protective mesh.

 

Kingsmill Air Terminal Rod Options

1. Air Terminal Base + Air Terminal
2. Air Terminal Base + Elevation Rod + Multi Point Air Terminal
3. Side Mounted Rod Brackets + Rod To Tape Coupler + Air Terminal

Air Termination System Mesh Method 

The mesh of lightning conductor may be in direct contact with the roof, or may be suspended directly above the roof. The mesh size is dictated by the risk assessment, as the risk assessment will inform you as to what level of protection is required. 

LPL	Mesh Size (m)
I (Maximum Risk)	5 x 5
II	10 x 10
III	15 x 15
IV (Minimum Risk)	20 x 20

 

Kingsmill via T&D can offer a wide range of copper earthing products including plain and tinned copper earth bars, earth tapes and flexible copper braid.

 

Kingsmill's Range Of Fixing Clips/Clamps

Kingsmill offer a range of clips and clamps including tape clips, DC tape clips and square clamps.

Air Termination System Important Remarks

• Copper is used as it is a good electrical and thermal conductor, and is highly resistant to corrosion.
• PVC covered copper tape is used for visual aesthetic reasons.
• Tinned copper tape is used in highly corrosive environments.
• Air Terminals can be supplied as a preference.
• Copper tape is advised to be fixed every one meter to resist any force that may occur as a result of the lightning current discharge. 

Further Reading : Lightning Protection Systems (Part 2 of 3) - Down Conductor System by Kingsmill Earthing

Lightning Protection Systems (Part 3 of 3) - Earth Termination System by Kingsmill Earthing

 

See also :  Lightning Protection & Earthing - A Brief Guide By Kingsmill Earthing 

Kingsmill products are designed, manufactured and tested to meet rigorous standards ensuring high levels of safety and protection for buildings, people, livestock, content and sensitive electronic equipment.

Video : It's All About The Bolt! 

Category:  Earthing & Lightning Protection

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