Lightning: Are you protected?

Lightning is a deadly “by-product” of thunderstorms. According to the New Vision, lightning struck 40 people dead and left about 120 injured.

By Agnes Kyotalengerire

Lightning is a deadly “by-product” of thunderstorms. According to the New Vision, lightning struck 40 people dead and left about 120 injured.

Joseph Ssempasa, a civil engineer, blames the increasing deaths by lightning countrywide on ignorance and failure to take precautionary measures during construction.

“People have been reluctant to install lightning protection systems on their buildings because they have not been experiencing fatal lightning cases in the past,” Ssempasa says. He adds that cultural beliefs and installation costs have also made it difficult to implement the safety precautions.

“When engineers advise people to install lightning conductors on their houses after construction, they compromise and regard it as an expensive venture and prefer to spend the money on other things,” notes Ssempasa.

Joseph Kawombe, a rural energy specialist, says installation of the lightning conductors is a requirement for every building, regardless of whether it is commercial or residential.

Kawombe adds that according to the Ministry of Housing regulations, the owner of the building is given a certificate of occupancy after inspection to enforce safety measures.

With the majority of the buildings having electrical installations, inspection is done by UMEME to ensure proper earthing is done before power is installed.

Kawombe notes that the new UMEME technology provides protection by earthing electricity poles. Tapping power from an already earthed electricity pole in addition to the earthing done in the meter box is enough to protect the whole structure.

Areas prone to lightningThe concept of lightning works by affecting wide flat areas, a characteristic that is more common in rural areas. Moreover, electrical installations done on most houses in urban areas offer more protection compared to buildings in rural areas that are not installed with power.

Nevertheless, Kawombe insists that all buildings can be struck by lightning, whether they are storeyed or not and should be installed with lightning protection systems.

He adds that people who steal power or who do not follow the proper power installation procedures risk having their houses struck by lightning.

Installing a lightning protection system. Ssempasa says the lightning safety mechanism contains a lightning arrester, copper strip or tape, copper rode, charcoal dust and salt. The installation is done after the house is roofed. The most important requirement is the lightning arrestor. It has got pointed, finger-like features and is placed at the highest point of the building. It is attached to a copper strip which runs from the top on the outside of the building into the ground.

It is at this point that the earthing procedure is done, by connecting a copper rod or preferably a copper mat of about one-and-a-half to two metres to the copper strip. The copper rode is then pushed into a bag of charcoal dust mixed with about 15kgs of rock salt, placed in a pit three to four feet deep and then covered.

Godfrey Roma, an engineer with Busia Municipal Council, says the cost of installing a lightning conductor is about sh650,000, depending on the number of copper strips used. He explains that a lightning arrester costs about sh300,000 a metre of copper strip goes for sh30,000 and a metre of copper clips to hold them firm on the wall costs sh7,000. The copper rod costs sh230,000 and a kilogramme of rock salt costs about sh1,000.

Roma explains that you can use more than one lightning arrester if the building has different points. He affirms that earthing helps to increase the conductivity of the charge coming from the clouds.

Although any metal strip can work, for effective protection, Roma advises using a cooper rod because it is a good conductor.

When lightning strikes, it is diverted through the rod and the charcoal and salt absorb the high voltage generated.