A LETTER published in another paper recently by “University Student” shows that misconceptions about lightning protection are a growing problem in this country since they affect the general public and Malaysian engineering professionals.
Some of these misconceptions are so serious that public safety is adversely affected when buildings have been repeatedly struck by lightning even after modern lightning protection systems (LPS) have been installed.
The student claimed that his house suffered a direct lightning strike, which left cracks in the outer wall and toasted the TNB fuse, meter, electrical wiring and home appliances.
However, his description of the event suggested that the lightning might have struck the TNB cable near his house and the current had entered the residential wiring via the TNB fuse.
Part of the lightning current might have flashed into the masonry and this caused cracks in the wall.
Had the lightning directly struck the house, it should have left a large hole in the roof and might even have started a fire at the wooden rafters and ceiling-mounted electrical wiring.
The student also blamed large trees in his neighbourhood for lightning incidents that occurred to his house and those of his neighbours.
This is another misconception since large trees do not attract lightning at all. In fact, the tall trees may even have spared houses from direct lightning strikes since they partially shield nearby lower objects (houses) from lightning strikes if the latter is within the tree’s conical protection zone.
Misconceptions about lightning held by the general public are an old problem since this situation resulted from popular folklore and from inaccurate information given by non-experts.
For example, the misconception that metal can attract lightning was again raised in a safety guide issued by the Malaysian Meteorological Department when it discouraged the public from handling metal objects and tools during a thunderstorm.
Scientifically speaking, lightning is not attracted to any metal or non-metal object, not even a lightning rod.
The purpose of a lightning rod is to act as a low resistance conductor when it intercepts a lightning flash so that the large current does not damage the building fabric.
However, the existence of misconceptions about lightning found in books and journals published by Malaysian universities is something that the government should be very concerned about since public safety is adversely affected.
This misconception has made it easier for Malaysian engineers and the public to believe that lightning rods can attract lightning and that some lightning rods can attract lightning better than others.
Hence, for the past 25 years, the country has become a dumping ground for non-conventional (non-standard) LPS that do not comply with the national and international lightning protection standards.
These non-conventional LPS, which go by fanciful names, have already been studied in detail and rejected by western lightning protection experts and standards since 1995.
Since 2001, SIRIM has adopted the international (IEC) lightning protection standard as the new Malaysian standard. This standard firmly rejected all types of non-conventional LPS.
The latest version of the standard, MS-IEC62305, was endorsed by the Science, Technology and Information Ministry in 2007 and it contains a simple Malaysian-made lightning rod placement method that can intercept more than 95% of lightning strikes if applied in full.
On the other hand, studies conducted by Czech and German lightning experts suggested that the ESE lightning rods can only intercept up to 65% of lightning strikes at the most.
This explains why most highrise buildings in Malaysia have been repeatedly struck and damaged by lightning if they have been installed with ESE lightning rods.
ZA Hartono
Kuala Lumpur
