We've talked a lot about lightning protection but not actually about the phenomenon of lightning itself to understand how protection works its worth having a look at why and how lightning strikes.
The lightning most frequently referred to in terms of lightning protection is cloud to ground lightning, other forms of lightning exist but cause less damage to buildings and people than this particular recognised form of lightning.
A lightning strike originates about 15,000 to 20,000 feet above sea level and works its way down to about 50 yards above ground, it’s about at this height that will determine the attachment point which is the point where lightning will strike. The currents in lightning range up to 400kA with average individual stroke of lightning ranging between 25kA to 40kA, the total current will be divided between the different paths of the lightning strikes.
When lightning strikes a stepped leader works its way towards the ground and is met by an upward leader that comes from the ground then a number of return strokes occur which are flashes from the point of contact to the cloud.
Lightning strikes cannot be prevented, they can only be intercepted or diverted onto a path that if well designed will not result in damage, injury or loss of life. Any designed path to earth should have a low impedance connection to earth; this means that the opposition to the flowing current should not be high. The measure is calculated using a complex formula but a protection system can be designed to have low impedance connection.
Lightning protection should always be installed by certificated ATLAS accredited lightning protection designer, if this is not possible measures should be taken to ensure that the installation is assessed by a suitably qualified ATLAS company and that the lightning protection installation will work and protect the building and its occupants against the effects of a lightning strike.
To discuss your lightning protection requirements email our design team at info@churchillsc.co.uk
Tuesday 31 January 2012
Tuesday 24 January 2012
Selecting Conductors For Your Lightning Protection System
One of the most important components of any lightning protection system is the actual lightning conductor. Conductors are available in two different materials, aluminium and copper and a range of different widths, the most common width used in the UK is 25x3mm.
Designers of lightning protection system will establish the correct width and length from the formulas needed to design the system to ensure the down conductors are capable of transferring the energy and forces of a lightning protection strike safely to earth.
To assist architects and designers of buildings conductors are also available in a wide selection of PVCs lightning protection is required for modern buildings there are a range of pvc covered colours for both aluminium and copper conductor tape. These colours such as black, green, grey, stone, white and brown have been selected to blend in with most modern buildings so the aesthetic impact of the conductor is reduced.
Conductors are also available in flat, solid circular and stranded versions. Flat tape lightning conductors are the most traditional and is also considered to be the easiest to install and where a degree of flexibility is required in a conductor there is also the option of fitting a copper braid.
Solid circular conductors are usually used in conditions where the aesthetic considerations are important, the solid circular conductors are still fairly easy to install but unlike the flat tape systems a straightening tool is required to achieve the desired finish, although it is rarely used in large applications there is also the option of using a stranded cable conductors.
If you require any assistance with the design of your lightning protection system or would like a sample of the products available please visit our ecommerce web site to request samples and assistance.
At Churchill’s we offer the complete solution from design to install however if you simply wish to purchase your lightning protection equipment and have it delivered anywhere in the UK within 3 working days this unique service is available via our on line store.
Designers of lightning protection system will establish the correct width and length from the formulas needed to design the system to ensure the down conductors are capable of transferring the energy and forces of a lightning protection strike safely to earth.
To assist architects and designers of buildings conductors are also available in a wide selection of PVCs lightning protection is required for modern buildings there are a range of pvc covered colours for both aluminium and copper conductor tape. These colours such as black, green, grey, stone, white and brown have been selected to blend in with most modern buildings so the aesthetic impact of the conductor is reduced.
Conductors are also available in flat, solid circular and stranded versions. Flat tape lightning conductors are the most traditional and is also considered to be the easiest to install and where a degree of flexibility is required in a conductor there is also the option of fitting a copper braid.
Solid circular conductors are usually used in conditions where the aesthetic considerations are important, the solid circular conductors are still fairly easy to install but unlike the flat tape systems a straightening tool is required to achieve the desired finish, although it is rarely used in large applications there is also the option of using a stranded cable conductors.
If you require any assistance with the design of your lightning protection system or would like a sample of the products available please visit our ecommerce web site to request samples and assistance.
At Churchill’s we offer the complete solution from design to install however if you simply wish to purchase your lightning protection equipment and have it delivered anywhere in the UK within 3 working days this unique service is available via our on line store.
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