The importance of annual Test Inspection and Maintenance

The importance of lightning protection has been recognised in the UK since 1985 when the British Standard was completely revised and built into the majority of electrical specifications for all UK new build projects, and for good reason.

It is essential for the protection of our structures, their contents and the lives of its occupants. As such, annual maintenance is a vital part of any systems longevity, efficiency, and our safety, even more so since the advent of BSEN 62305 which was first published in 2006, revised in 2011.

Danger exists not only from a direct strike to a structure from a lightning discharge of up to 200KA, but indirect strikes can cause havoc to our internal electrical equipment and cost us thousands in unnecessary and avoidable loss of production and  insurance claims. 

Annual test, inspection and maintenance is often overlooked when a new build project is handed over to its client, but at what cost? 

•    Lightning Protection is fundamentally installed to reduce the risk of “loss of human life” and “loss of service to the public”.
•    Maintenance of the Lightning Protection System is often a requirement of the building insurances.
•    The electricity at work regulations 1989 states that “all systems shall be maintained so as to prevent, so far as is reasonably practicable, danger”.
•    The effectiveness of the Lightning Protection System may be reduced over time due to physical damage, corrosion, adverse weather conditions, or as a result of additions or alterations to the building under protection.

Churchill Specialist Contracting Ltd are a driving force in leading our industry in the correct implementation of BSEN 62305 2011 and are dedicated and resourced to offer a technical and professional service to our current and future customer base. In addition to our range of extensive services, we are dedicated to providing a Test Inspection and Maintenance program which can be tailored to a customer’s particular needs for what is a crucial part of any structures ongoing maintenance.

As a recognised and well respected NVQ provider to our industry, Churchill’s are able to provide NVQ Level 3 qualification for Lightning Protection Test and Inspection Engineers, which has been developed in conjunction with ATLAS, the Training Group and the CITB National Training College.

The dangers of designing an incorrect level of protection.

Since September 2008 the lightning protection industry has been working to BSEN62305. The main difference between this and the previous British Standard (BS6651) was the introduction of a complex risk analysis calculation to establish which of four levels of protection should be applied to a particular structure.  Levels, or Classes of protection, range from 1 to 4 and are dependent on a number of factors, the major contributor being the actual physical size of the structure to be protected. Level 1 is the most stringent through to level  4 being the least  in terms of the amount of protection actually required. This inevitably gives rise to price differences between the various levels at quotation stage.

All Churchill’s lightning protection designers hold an ATLAS (The Association of Technical Lightning and Access Specialists) certificate of accreditation to demonstrate design competence, and are trained in the use of industry specific software to carry out these risk analysis and the subsequent design.

Until our sector is fully up to speed with how to complete the new risk assessments the very real risk is that companies may either through lack of training, or perhaps even in an attempt to achieve commercial gain choose to endorse Lightning Protection designs and installations which are non-compliant with BSEN62305 by using the incorrect level of protection.

For example, a group of structures physically linked together have to be classed as one complete structure and would therefore warrant a greater level of protection (possibly level 1 or 2) at a greater cost implication than if they were completely isolated, where they may only warrant a level 4 for instance.

“Loss of human life” is the primary reason for providing protection in the first instance. The final level of protection based on the information available to the designer is therefore of critical importance for obvious reasons. The responsibility for which, as well as the financial risk to rectify any non- compliance, may well fall on the original contractor or indeed the client.

Something to be avoided at all costs.

The Origins of Lightning Protection

Lightning protection science was first conceived by Benjamin Franklin in 1749 with his invention of the first pointed lightning rod conductor that became known as a “lightning attractor” and much later  as the “Franklin Rod.” Franklin spent many years in the lightning protection design process to include his famous kite experiment, which took place as he was waiting for permission to test his theories on the new Christ Church structure in Philadelphia, PA. Although Franklin did not patent any of his inventions, he published advice on lightning protection in Poor Richard's Almanac in 1753.

At that time, common belief was that lightning was a creation of God and therefore should not be interfered with in anyway. Franklin was finally able to convince the church deacons that they should take precautions against lightning damage by installing the lightning protection he designed, citing that rain was also a creation of God but roofs were still used on buildings to protect people and contents of buildings.

During the 19th century, lightning protection became an architectural addition to many public and private structures. The overall pointed rod design was complimented with ornamental solid glass balls, which were not only decorative but were believed to be an integral element in the effectiveness of the lightning protection of the structure. The theory behind this addition was that since glass is a non-conductor of electricity that they would repel the charge and for a time, because of the erratic behaviour of lightning it was believed this was scientifically proven.

Both the pointed design and the addition of the solid glass balls were soon proven by Nicola Tesla to be a flawed lightning protection design. Tesla's patented design was a great improvement over Franklin's original lightning protection of the pointed rod. In 1919, years after receiving his patent, Tesla publish an article, “Famous Scientific Illusions” in The Electrical Experimenter explaining the logic he used to dispel the science of Franklin's pointed lightning rod and scientific knowledge he used to design his lightning protection device. In his article, Tesla proved that the pointed tip of the iron rod actually ionised the air around it, which rendered it air conductive and raised the probability of a lightning strike.

Over the decades, since Franklin and Tesla, there has been much progress in lightning protection systems. Great innovations in design and methodology have advanced the protection of mission critical systems for military and government operations and commercial applications. From transportation system control centres to mobile phone transmission towers, the instances of catastrophic damage to these and other services we had all come to take for granted has been greatly reduced.

10 Interesting Facts about Lightning

With lightning being a specialty here, we have decided to share with you 10 interesting facts about lightning!

1. A single bolt of lightning is around 50,000f or 5 times hotter than the surface of the sun.
2. The irrational fear of lightning is known as keraunophobia.
3. There are two types of lightning, negative strikes and positive strikes. Positive strikes are 5 times more powerful than negative strikes.
4. The odds of being struck by lightning in your lifetime is 1 in 3,000.
5. Most lightning strikes average at 2-3 miles long and carry a current of 10000 Amps at 100million volts.
6. Each second there are 50 to 100 Cloud-to-ground lightning strikes to the earth worldwide.
7. The Empire State Building in New York is struck 24 times a year and was once struck eight times in 24 minutes.
8. An average instance of lightning lasts about a quarter of a second and consists of 3-4 strikes
9. The energy contained from a single lightning strike can power a 100 watt light bulb for 90 days.
10. "Lightning never strikes twice" is just a myth, lightning can strike the same location many times.

How Lightning Damages Buildings

Lightning is both amazing to watch, and also highly destructive. The amount of energy a lightning strikes imparts on an object means damage to people and buildings can be significant. It isn't just the strike itself though that causes the problems, there are in fact three ways in which a lightning strike on a building can be devastating.


Physical
Unsurprisingly, most lightning damage is on the rood of a building although this isn't always the case. Roofing titles, chimneys and other roof furniture like satellite dishes and air conditioning unites are often most at risk. However it isn't just this immediate physical damage that is the biggest problem, the risk of fire that can follow a strike is recognised as the biggest potential threat to any building. Tall buildings are especially vulnerable therefore it is rare to see prominent buildings without some form of lightning protection.

Conduction
Of course, anything metal both attracts the strike and then conducts the electricity, this can often be carried deep inside a building causing irreparable damage to electronic equipment. It's not just electronics that spread the damage around though; plumbing is just as likely to create problems. In fact, the conductive nature of metal can be so attractive to lightning that even hidden pipe work underground can often be in the direct firing line.




Electromagnetic
Finally, it doesn't even have to be a direct strike to cause problems, electromagnetic fields caused by a strike can create havoc with computer equipment and other sensitive electronics. Many choose to protect themselves by fitting surge protection devices in addition to physical protection. Whilst physical damage can often be repaired, the loss of data which is possible with the Electromagnetic fields has the potential to be extremely costly and disruptive to businesses heavily reliant on data communications.

The Basics of Lightning

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

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 - 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.