Electricity + Control January 2018

EARTHING + LIGHTNING PROTECTION

the course of 2018. This is a cause very dear to our hearts. We plan to carry the costs of the equipment and its installation, and will consolidate the physical protection we install in the schools by offering training and education to both learners and teachers. These are some practical yet child-friendly lightning safety tips, which can be understood by both children and their families. Safety tips to pass on to schools, families and chil- dren • Lightning is a great threat to anyone outdoors. Try to go to a safe place indoors if there is thunder and lightning around • The best place to be during a thunderstorm is inside a build- ing. Stay away from windows and metal appliances, and do not use electronic equipment, telephones (even cell phones) and appliances, especially if the home or other building is not fitted with a surge protection device. Switch off your ap- pliances and electronics before the storm hits. Such devices as your computer, television and air conditioner all provide potential pathways between the lightning and you. As an added precaution, don’t bath or shower during a thunder- storm • If you cannot get inside a building, your next best option is to get inside a car, which acts like a Faraday cage. Close the windows • If you can hear thunder, you are close enough to the storm to be struck! Thunderstorms extend approximately eight to 15 kilometres into the atmosphere, and high winds can blow the upper portion of the storm many miles downstream. Lightning can come out of the side or top part of the storm, striking the ground approximately 15 to 30 kilometres away from the rain portion of the cloud • Count the seconds between seeing lightning and hearing thunder. If this time is less than 30 seconds, lightning is still a potential threat, so seek shelter immediately. After the last lightning flash, wait 30 minutes before leaving the shelter - stay in a safe area until you are sure the threat has passed • If you can’t get inside to a building that would offer shelter (with a metal roof), or a car, and you have to wait out the storm in the open, then do the following: firstly, stay away from trees and other tall structures, and get off the high part of a mountain or hill if you can. Instead, get into the open and then crouch: put your feet closely together, wrap your arms around your legs and keep your head down. Don’t lie flat – the current from a nearby strike will spread out along the ground, and through you, so offer as little body contact with the ground as possible. It’s important, in such a vulner- able situation, to put at least three metres of space between you and other people, as well as anything you’re carrying. Similarly, try to make sure you are at least three metres from bicycles, trees, poles, masts, fence posts and metal fences • Water is a conductor. Try to get off a water surface as fast as possible if you are on a boat

28 Electricity + Control

JANUARY 2018