Potential Damage Caused by Direct Lightning Strikes

Did you know that lightning is the single biggest cause of damage to and destruction of electrical and electronic equipment in industrial facilities, commercial buildings, and homes. Due to the ever changing climate and rising temperatures lightning strikes are becoming more and more frequent.

This is the remanence of 2 distribution boards that have been struck by a lightning strike. The bolt of lightning found its way down the mains cable and destroyed / burnt out what were a distribution boards within a school where we carry out regular work.
While the exact cause of lightning is still uncertain, scientists know it happens when clouds filled with water and ice rise rapidly. It is thought the heat causes the clouds to soar creating a lightning strike.

Interesting Facts about thunderstorms

A bolt of lightning lasts on average for about one 10,000th of a second but could light a 100 Watt light bulb for three months
Lightning travels through the air at around 270,000 mph – that’s around 75 miles every second
Lightning is hotter than the surface of the sun reaching temperatures of around 30,000 °C
The island of Java is the most thundery place on earth with 220 days of thunderstorms every year.
Thunderstorms can trigger asthma.

Lightning is produced in thunderstorms when liquid and ice particles above the freezing level collide, and build up large electrical fields in the clouds. Once these electric fields become large enough, a giant “spark” occurs between them (or between them and the ground) like static electricity, reducing the charge separation. The lightning spark can occur between clouds, between the cloud and air, or between the cloud and ground.
Experts say that for every 1C rise in global temperatures, there will be an increase of 12 per cent in the frequency of lightning strikes. With that said we can expect to see a 50 per cent rise in the next 100 years. For every two lightning strikes in 2000, there will be three lightning strikes in 2100.
Due to the nature of probability, the increased number of lightning strikes happening means that the likeliness of one of us being affected is also increased.

Lightning strikes the ground in the UK over 300,000 times a year and poses a significant hazard to buildings and individuals, both from the initial strike and the current surge so we should all understand the consequences.

A lightning protection system designed and installed to the latest British standard (BS EN 62305) reduces the risk of damage to a structure and the systems and people within it.

Full lightning protection systems for buildings and other structures, together with surge protection for their contents, can be designed and installed so as to divert high levels of electrical current generated by lightning strikes. Their purpose is to carry the current safely to earth and ensure the continued functioning of equipment, the protection of the building or structure, and the safety of the people inside.

What should you do to protect your home / business?

1. Install Lightning Protection Systems
A lightning protection system is designed to protect a structure from damage due to lightning strikes by intercepting such strikes and safely passing their extremely high currents to ground. A lightning protection system includes a network of air terminals, bonding conductors, and ground electrodes designed to provide a low impedance path to ground for potential strikes.
The air terminals are typically arranged at or along the upper points of a roof structure, and are electrically bonded together by bonding conductors called down conductors or down leads, which are connected by the most direct route to one or more grounding or earthing terminals.
A basic lightning protection system would provide a conductive path between an air terminal and earth, so that most of the lightning’s current will follow the path of the lightning protection system.
2. Install Surge Protection Devices

A surge protector (or surge suppressor) is an appliance designed to protect electrical devices from voltage spikes. A surge protector attempts to limit the voltage supplied to an electric device by either blocking or by shorting to ground any unwanted voltages above a safe threshold.
The terms surge protection device (SPD), or transient voltage surge suppressor (TVSS), are used to describe electrical devices typically installed in power distribution panels, process control systems, communications systems, and other heavy-duty industrial systems, for the purpose of protecting against electrical surges and spikes, including those caused by lightning. Scaled-down versions of these devices are sometimes installed in residential service entrance electrical panels, to protect equipment in a household from similar hazards.

Credit to: John McGovern at Powercor