ENSURE PROPER LIGHTNING PROTECTION SYSTEM
THE warning by the Malaysian Meteorological Department recently is timely in view of the looming thunderstorm season. The public has been urged to avoid open spaces, where they are in danger of being struck by lightning, and to stay away from unstable structures, which can collapse during strong winds.
The department should also warn people to steer clear of outer walls of buildings as the materials could break and fall when struck by lightning.
Concrete and masonry debris can be knocked off the upper corners and edges of buildings by lightning bolts, which occur before the rain starts. While most of the debris is the size of bricks, some could be the size of perimeter walls, like the piece that fell off a highway under construction and landed on a car recently.
A lightning incident at Desa Mentari Apartment in Petaling Jaya in 2004 damaged a concrete wall and falling debris damaged a car and several motorcycles parked nearby. Fortunately, passers-by were not injured.
Most buildings that are installed with lightning protection (LP) systems do not fully comply with the LP standard recognised by the government, such as MS939 (Malaysia), BS6651 (Britain) and AS1768 (Australia).
Since 2007, the national LP standard is MS-IEC62305, which was adopted from the international IEC LP standard, the IEC62305.
This IEC LP standard incorporates safety features and has been adopted by the United Kingdom and European Union countries, hence our LP standard is on par with Western countries.
The IEC LP standard protects buildings during lightning bolts as it involves positioning lightning air terminals (LAT), such as lightning rods, in high-risk locations like rooftoops, where lightnings are most likely to strike.
This groundbreaking idea was mooted by Malaysian lightning researchers, who submitted the research to the IEC with the collaboration of lightning experts from Australia and Singapore a decade ago
Several European experts have analysed the Malaysian LAT positioning method, known as the Collection Surface Method (CSM), and found it to be 98 per cent effective in intercepting lightning bolts.
However, the CSM was rejected by local academics involved in lightning research when it was introduced 25 years ago. Their contention was that it was developed by two local engineers who were deemed not qualified to conduct research as they did not have a postgraduate degree.
They ignored the CSM even though it was endorsed as the IEC and national standards more than a decade later. As such, local engineering graduates were unaware of the CSM. This resulted in most buildings not having.their LAT positioned according to the IEC standard and damaged by lightning bolts.
To make matters worse, the academics supported LP systems that contravened the IEC standard, rendering buildings vulnerable to lightning bolts. Over the past 25 years, thousands of buildings have been installed with “non-standard” LP systems.
The manufacturers of non-standard LAT claimed that their devices can attract or repel lightning bolts, but it had never been proven scientifically by experts.
Hence, to ensure that buildings are well protected against lightning bolts, premises owners should make sure that their LP systems comply withtheMS-IEC62305standard,and the LAT is locally developed but positioned according to internationally recognised CSM.
Z.A. HARTONO