The National Environment Agency estimates that Singapore receives an average of 168 thunderstorm days per year, making the country one of the most lightning prone areas in the world. The prevalence of lightning poses an increased risk for weather related damages, and many housing residents have had their electronic devices ruined as a result of lightning strikes.

The public affairs department sat down with Thomas Rea, Navy Region Center Singapore Region Safety Manager, to learn more about how lightning can affect electronic devices and what steps can be taken to mitigate the damage.

Q: What are the different types of lightning strikes that can damage electronic equipment, and are there any safety measures already in place to mitigate the damages they can cause?

A: Lightning strikes fall into two categories: direct strikes to a building or the immediate surrounding area, and indirect service strikes that occur at a distance but send voltage down power lines and data lines into a residency. The Public Works Department has installed a series of lightning rods, cables and grounds on every installation residence as well as surge arrestors in the transformers that service the buildings, which ensure the safety of a building and its occupants by providing a safe path to the ground for the lightning to follow. These safety measures are inspected and certified on a monthly basis.

Q: How do these safety measures work in relation to direct lightning strikes to a residency?

A: The lightning protection systems maintained by Public Works are designed to provide a direct path to the ground in the event of a direct lightning strike to prevent fires or other damages from the intense heat and energy delivered in a lightning strike, but due to the physics involved with a direct strike, there are no preventative measures that can be taken to ensure the safety of electronic devices. When lightning comes down the lightning rods, it physically must take every single available path of travel to the ground, which includes the electrical lines, cable lines, phone lines and even the copper piping and metal framework inside a building. This why you can see some flashes at outlets or empty light fixtures when there is a direct lightning strike on your house. This is also why your television or your other favorite electronic gear gets taken out during a direct strike to your home, as there is no way to prevent the voltage from a direct strike from traveling down every available pathway.

Q: What about for indirect service strikes?

A: The electrical power that feeds the building comes from a transformer that is protected by a surge protection device (SPD). This SPD protects the transformer and what is down line from the transformer (like your house), from voltage surges. If lightning hits on or near the power line a good distant from your building the lightning will travel down the power lines, losing current as it travels. When the lightning hits the transformer's SPD, it will shut down the transformer when it detects the current overload. This will protect your building against lightning strikes on or near power lines a distance away from your house, depending on the relative distance and intensity of the lightning strike.

Q: Many people utilize surge protectors to add another layer of protection between their device and the electrical outlets in their home. How do these devices work, and what level of protection can they offer?

A: Personal surge protectors work by creating a gap in the line with the intention of stopping current from traveling down line when the device senses an overcurrent situation. This gap is a small pocket of air, sometimes as small as one inch across. Lightning, which already has travelled many miles from the sky to the ground, can easily jump the small gap created by the surge protector and continue into any device that is plugged into the surge protector if the strike occurs close enough to the residency or has enough current to overwhelm the device.

Q: What is the best safety measure that people can take in order to prevent lightning damage to their electric devices?

A: If you really value a piece of equipment, you should unplug both the power cable and any data lines connected to the device. Data lines such as cable cords, Ethernet cords, and phone lines are often overlooked, but all of these can carry an electrical current from a lightning strike directly into your device. All transformers within the housing area are protected from distant strikes by the SPDs maintained by Public Works, but the data lines are managed by private companies and may have no protections in place. So again, the best strategy to protecting your television, computer, etc., is to unplug both the power cable and all data lines connected to the device in the event of a lightning storm.

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