Lightning Protection FAQs
Why surge protection?
Because the electronic equipment you use within your building is at risk of damage caused by lightning LEMP (Lightning Electro Magnetic pulse). In short, anything including data systems, computer networks, phone networks and anything connected to the mains, is at risk of damage by LEMP.
How can lightning damage your equipment, and how likely is it to happen?
Lightning damage can be caused in 2 ways: direct and indirect strikes. A direct strike, as the name suggests, occurs when a bolt of lightning discharges its energy directly into a piece of equipment, the enormous amount of energy released will destroy any equipment which is not surge protected. Whilst the damage caused by direct strikes is usually catastrophic, direct strikes account for only 20% of damage to electronic equipment. The majority of damage is caused by the indirect effects of lightning. In fact, a lightning strike up to a quarter of a mile away from your building can seriously damage electronic equipment, computers and telecommunication equipment. The destructive energy from these indirect strikes is transferred into your premises by inductive coupling of the powerful magnetic field generated, or by capacitive or galvanic coupling. As a result when ever an electrical storm occurs in your locality, all of your electrical equipment is potentially at risk. Lightning damage is far more prevalent than you might think. Due to climate change and global warming, both the frequency and severity of lightning storms are increasing in the UK.
Contrary to popular belief, lightning does strike twice. It is the local geographic and topological factors (e.g. height, proximity to tall structures or trees etc.) which predominantly cause the original strike. Since these features rarely change, the chances of a repeat lightning strike are high. It is also not generally realised that when a building is fitted with a lightning conductor system to protect the building structure, that can make the transient problem within the building worse. As the heavy lightning current flows through the down conductor, a powerful fluctuating magnetic field (LEMP) can be generated. This induces damaging transients within computer, electrical, electronic and telecommunications equipment within the building.
How does surge protection equipment work?
Surge protection equipment works in two basic ways. Firstly through the use of a combination of extremely fast acting electronic components, the transient is detected almost instantly, before it has a chance to damage the equipment. The damaging energy is then immediately diverted safely to earth where it is dissipated harmlessly.
How much does it cost?
The simple answer is, not as much as the replacement cost of the equipment that could be destroyed without adequate surge protection. Insurance policies, service agreements and maintenance contracts typically treat lightning induced damage as an "Act of God" and exclude this type of damage from their cover. Under these circumstances the cost of installing surge protection equipment, is a fraction of the potential cost of not doing so.
