We enjoy a reliable and uninterrupted supply of electricity pretty much all the time, but power surges are one type of interruption to the process of electricity supply. They can cause damage to appliances and circuits and can potentially cause fires, and here we will learn about what they are, how we experience them and what causes them.
What is a power surge?
A power surge is a sudden rush of electrical power that is higher than normal. In the UK, the standard voltage for households is 230 volts, and when more voltage comes through wires and devices this is known as a power surge. A power surge can vary in size. Technically we experience a power surge of 5-10 volts when we turn on a household appliance, such as a hairdryer, while at the other extreme, a lighting bolt striking a transformer can cause a power surge of thousands of volts. Most power surges experienced in UK homes are somewhere in between and will result in reduced performance of some circuits, or damaged devices, ie. anything that is plugged in at the time is susceptible to possible damage caused by a power surge.
We will experience a power surge through an interruption in the flow of electricity, followed by a short. Or there could be a sudden increase in the voltage sent through a power system from internal or external sources, which damages a circuit.
What causes a power surge?
Being struck by lighting is an extreme example of a power surge, more typically there are three common causes:
- Electrical overload – When there is too much power drawn from a single circuit. An example of this is when we plug too many devices into an extension socket. In this case a single circuit is overwhelmed and is not designed to draw so much power.
- Faulty wires – Damaged or exposed wires are not easy to spot as they could be within your walls, however, you may spot burn marks around power outlets or you can smell burning wires. You may also hear a buzzing sound around your outlets or may experience circuit breakers frequently tripping.
- After a power outage – A power outage is usually a large scale failure in the national grid which causes the electricity supply to shut down locally. There are no safety issues when the power is off, but when power is restored, the sudden jump in current can damage anything plugged in, or which hasn’t got surge protection.
What can I do to prevent damage through power surges?
As well as signs of burning wires, you may also spot lights flickering or dimming, and if a power surge has already happened you may experience devices suddenly shutting off or not working. To avoid power surges you can try not to overcrowd circuits, such as plugging too many devices into one socket. You should also avoid plugging large devices and small devices into the same socket, such as an air conditioning system and a lamp. It is also advisable to unplug items that are not in use.
However, the main protection against everyday power surges is ensuring that your electrical wiring is safe and compliant. Many older houses, such as those built in the 1980s or before, have wiring systems designed to cope with appliances very different to what we have today. Now we have bigger fridges, TVs and have many more appliances such as laptops and PCs at home. It is possible that the wiring systems in older homes can’t cope with the power demands of these devices, so power surges could be common in this scenario.
Please note that this section is for information purposes only. Anyone using equipment referred to in this section must be suitably qualified and/or experienced within the respective field. If in doubt before use, please consult a qualified electrician or engineer & thoroughly read all instruction booklets.