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.

Surge Protection

When designing lightning protection it's important to consider adequate surge protection. On a smaller scale people protect their treasured home electrical devices with surge protection devices, on a larger scale devices are available to protect a wide range of items such as servers, communications, data storage, telephony etc.

There are a number of forms of protection needed against surges as there is more than one type of surge. One type of surge is transient over voltages which are short duration high magnitude voltage peaks with fast rising edges, often described as "spikes". The most common cause of these spikes is lightning strikes, but they can be caused by electrical switching when there is increased demand placed upon an electrical system it becomes overpowered. These surges can cause devastating damage to systems that are not protected. The most severe damage is to cable installation which in a worst case scenario can result in fatalities through either electric shocks or fire. Other damages can be to electrical and electronic equipment resulting in data loss, degradation and equipment failure. These aspects can cost a company a lot of revenue, in terms of a loss of productivity, product spoilage, staff overtime and delays to clients, not forgetting sales lost to competitors when your business is unable to run smoothly.

There are different types of surge protection devices dependent on the type of transient over-voltage. Direct lightning strikes are protected by lightning current or equipotential bonding SPDs. Indirect lightning strikes and switching transients are protected by transient over-voltage SPDs. The main purpose of lightning current and equipotential  bonding SPD's are to prevent sparking from cable damage by lightning strike, so the site does not become a fire hazard. Transient over-voltage SPD's are there to protect against secondary effects of indirect lightning and switching transients such as data loss and equipment failure.

There are certain areas that require surge protection in order for the protection to be adequate. You need to protect all cables which enter and leave a building including mains power supplies (including UPS), data communication and local are network cables, signal, control, instrumentation and alarm lines, CCTV, satellite, TV and antenna cables and telephone and telemetry lines. It is also important to protect the power supply local to important equipment, electronic equipment outside the main building.

Whatever the surge protection needed you can get both surge protection devices and advice from Churchill Specialist Contracting.

Lightning Protection Standards

The design of a suitable lightning protection system should always be undertaken by a suitably qualified BS EN 62305 2006 designer with certification to prove their competence, however unfortunately this is not always the case and unscrupulous designers have been known to deliberately under specify the design requirements ensuring they are then awarded the business.

At Churchill Specialist Contracting all Lightning protection designers are fully certificated and as part of very specialised and qualified team work under two renowned and highly beneficial quality systems: UKAS OHSAS 18001 and ISO 9001 both with LRQA. All directly employed site engineers are qualified to a minimum NVQ level 2 industry standard an achievement unparallel in the lightning protection sector.

Churchill Specialist Contracting offer two types of lightning protection the conventional Faraday cage type installation and the Pulsar ESE System of lightning protection that conforms to the European code NFC17-102 1995.

The BS EN 62305 2006 standard is split into 4 parts, Part 1 outlines the theory behind the protection methods that the other 3 parts require. Part 2 looks at risk management in installation and calculates the risk of loss of human life, loss of service to the public, loss of cultural heritage and loss of economic value. The third part details the protection measures required as a lightning protection system comprises of 3 main components, an air termination network to capture the lightning protection, down conductors to take the charge down to the ground and an earth termination system to disperse the lightning current safely to earth. Part 4 of the standard is the requirements to lightning protect electronic systems from a lightning electromagnetic impulse. Many modern systems need protection from the threat of lost and destroyed data, equipment damage, and repair work for remote and unmanned stations, loss of production and most importantly the reduction of a potential Health & Safety hazard.

Churchill Specialist Contractors offer onsite training via the OSAT route in the nationally recognised qualification NVQ. To qualify and work towards these qualification candidates must have 2 years Approved Prior Learning (APL) experience. As all Churchill’s directly employed engineers have this NVQ qualification you can be assured you are working with experienced and competent engineers.

So while lightning protection can be installed by contractors in closely related sectors such as electricians, alarm engineers etc if you don't want to take advantage of complete lightning protection installation services it is always worth having an inspection by a fully accredited company like Churchill Specialist Contracting to ensure lightning protection system will be effective and comply with all relevant standards.

Lightning Protection - Metal Theft

The theft of metal is continuously on the increase and whilst ever scrap prices remain high unfortunately it is a trend that will continue to blight so many including schools, hospitals, hotels, railways in fact any building or structure fitted with lightning protection.

Lightning protection systems commonly consist of copper or aluminium and why PVC sheathing can be fitted to take away the initial obvious presence of either copper or aluminum thieves very quickly get to know and become more aware of where and how lightning protection systems are installed.

Lightning protection systems are installed to almost every new commercial building constructed in the UK however where new modern constructions allow the use of structural steels to be incorporated reducing the opportunity for theft, existing structures do not always have this luxury. As a result external copper and aluminium down conductors are installed and unless they are adequately protected become a very soft target for thieves and vandals.

As a conductor we have recently witnessed a huge increase in the amount of enquiries from local councils, hospitals and businesses requiring stolen down conductors replacing, often security at schools and hospitals is in adequate so any additional precautionary measures need to be considered.

To prevent the theft of copper and aluminium down conductors Churchills supply and fit vandal/theft guards that are simply fitted over the down conductor secured with anti vandal fixing thus fully protecting the downtape conductor and preventing theft/damage.

The vandal/theft guards are economical and quick to install and offer a complete deterrent against theft or vandalism.

For more information on the supply and installation of this very simple but highly effective product please contact us on 0844 504 9998 or visit our web site where guards can be purchased for self installation.

Earthing Equipment

An essential requirement of all modern day structures and systems is an efficient and effective earthing system with a suitable earthing system being a key part of any lightning protection installation.

All earthing systems require specific key components in order for them to be beneficial, with lightning protection the designer planning the earthing system must decide on the conductor type to be used of which there are three commonly used types of conductor:

- Flat tape

- Solid Circular

- Stranded Cable

Above ground there is a choice of conductor materials that can be used, albeit the choice is often between copper or aluminum, however below ground the most appropriate conductor material is copper, this is mainly because copper possesses greater anti corrosion properties.

Earth rods and earth plates are commonly used as Earth installations, the primary function of earth rods is to take advantage of lower resistivity soils at greater depths than standard excavation will allow. Earth plates are used to attain an effective earth in shallow soil where ground conditions are not conductive for installing earth rods.

All effective earthing systems also rely on connections and joints that provide good electrical conductivity with high mechanical strength. Joints and connections that are poorly chosen and incorrectly installed will potentially damage and compromise the performance of the earthing system.

A high quality electrical connection is required, exothermic welding is a straight forward method that uses no external power or heat source. Connections are created using the high temperature reaction between powdered copper oxide and aluminium. Correct connections will never loosen and are highly conductive and have exceptional corrosion resistance.

Compression connections may be used in circumstances where exothermic welding is not suitable for creating long-lasting connections. Very sturdy joints can be provided by compression connectors, they can be buried in the ground or in concrete.

When permanent connections are not appropriate, the ideal method is mechanical clamps. Mechanical clamps are more often used on smaller scale installations where periodic disconnection for testing is required. Top quality mechanical clamps are manufactured from high copper content alloy and will as a minimum posses mechanical strength, outstanding corrosion resistance and conductivity.

It's crucial that all earthing systems receive frequent inspection and testing, installation inspection pits enable easy access to earth electrodes and conductors. A reliable and convenient way of providing a common earth point is via the use of earth bars, integral disconnection links mean the earth bars can be isolated for testing purposes.

In areas where necessary resistance levels are difficult to obtain, Earth electrode backfills can be used, these products such as Marconite or Bentonite effectively enhance the electrodes surface area thus reducing its resistance to earth.

The Importance of Lightning Protection

Lightning strikes are one of the most common occurrences on Earth and they happen everywhere on the planet and often are sudden and severe.

Lightning Protection is a consideration for all business owners, but it is something that often gets overlooked. Insurance is often the first place many business owners turn, but it may not be the best option instead the best option is to try and prevent damage/loss from occurring in the first place and lightning strikes are one of the most preventable disasters. Lightning can destroy entire neighborhoods, one strike can quickly turn a building into an inferno if the conditions are right, beyond fire damage lightning can cause electrical problems which can be very expensive to repair and cost businesses lost production time.

One of the easiest ways to remove the destructive force of a lightning strike is to channel the energy somewhere safe, if the lightning is directed into the earth without passing through non-conducting materials, like wood, brick, or concrete, damage will often be minimal or completely avoided. When this path is created, it is called earthing, Earthing is easily the most effective way to protect a building but it can't completely protect the electrical systems contained within a building.

Electrical components in a lightning struck building are vulnerable to damage even when a building is well grounded. If electrical items such as computers are damaged it can have a significant cost to a business. One way to prevent damage to electrical systems is via the installation of a Faraday Cage, a network/grid system that is designed to protect every part of a building and direct any strike through to earth. A second way to prevent damage to electrical systems during a lightning strike is to fit surge protection. Surge protectors are useful for dealing with extra electricity that can occur after a lightning strike. Surge protectors divert excess electricity before it can damage occurs within an electrical system contained within a building, surge protection is reliable and very cost-effective.

With lightning being one of the most common natural occurrences on the planet, it could be considered foolish to allow your business to remain unprotected.

The Advantages Of Earthing Systems

In the United Kingdom, an earthing system identifies the electrical potential of the conductors relative to the conductive surface of the Earth. The world is a conductor rated at reference (zero) potential, referred to as earth in the UK. People are in direct contact with earth, so when something within a person’s reach becomes charged to a different voltage from earth a shock hazard occurs. The earthing process connects all parts which could become charged to the mass of earth to provide a path for fault currents which are a shock hazard. Earthing prevents a potential difference between earth and earthed parts, while allowing the flow of a fault current which will cause the operation of the protective system in place designed specifically to simply reduce the incidence of a shock hazard and provide protection in the case of lightning strike.

In the past, earthing was considered a black art, a practice with no scientific value, but regarded as necessary due to lore or tradition. Currently proper earthing processes are established through scientific methods to best predict electrical current dissipation under fault conditions and the consequent voltages possible. To design adequate earthing system specific information is gathered and evaluated: 1) expected fault current and its characteristics, 2) fault current duration, and 3) soil resistivity. The analysis of this information, best practice engineering, and utilization of industry standards create a dependable solution to reduce the hazard of electrical shock.

In the UK, the following technical standards are utilized to create earthing systems:
1. BS 7430: 1999 – British Standard Code of Practice for “Earthing”
2. IEEE 80 – Guide for Safety in AC Substation Grounding
3. Electricity Association Technical Specification (EA TS) 41-24
4. Electricity at Work Regulations 1989
5. Electricity Supply Regulations 1988

The services of a reputable lightning protection and earthing systems contractor should provide services including design, supply, installation, commissioning, test and inspection, plus maintenance of the systems after installation. Such specialists devoted to providing a comprehensive service for lightning protection and earthing systems in the UK can be found at Churchill Specialist Contracting Ltd. These specialists include engineers and installation teams with vast knowledge and experience and the sectors most comprehensively qualified and certificated operatives both on site and managerial level. All projects undertaken by CSC Ltd are completed in accordance with UK Codes of Practice and the new European standard BS EN 62305: 2006 “Protection Against Lightning and BS 7430 “Earthing.”