Electrical devices are designed to handle specific voltages. Unfortunately, in cases where devices are subject to higher voltages than they are designed for, damage can occur. Generally speaking the greater these voltages are, and the longer the period over which they are experienced, the greater the damage will likely be.

Sudden, severe voltage surges like those experienced as a result of lightning can cause almost immediate and total failure of electronic devices, requiring expensive repair work or replacement. However even small voltage surges are capable of causing damage over an extended period of time.

One common example of the damage that can be caused by excessive voltage involves the rapid heating – and subsequent cooling – of electrical wiring. Over time this repeated overheating can lead to “electronic rust” and eventual failure of devices.

It is also important to note that minor voltage surges can frequently go unnoticed; where these do not cause immediate failure, the owner may not be aware that their computer or other electronic device is being degraded on a consistent basis. As a result, power surges can be seen as one of the “silent killers” of electronic devices.

The damage caused by voltage surges can be serious enough in the home; however when the effects are felt in a wider industrial scale they can even more disastrous, affecting expensive machinery and even whole sections of the power grid. Unsurprisingly, for such a disastrous process, it is wise to use some form of surge protection, so as to mitigate the risks that power surges can cause.

Voltage Surges vs Voltage Spikes

 

In terms of short-term increases in voltage being supplied to a system we can think of both “voltage surges” and “voltage spikes”. While these may at first value sound like identical phenomena they are in fact considered rather different, on account of their longevity.

A sudden rise in voltage lasting three nanoseconds or more is generally classed as a “voltage surge” while a spike more typically refers to shorter-lived increases in power.

As a result while both phenomena can be disruptive in a system and cause considerable damage, generally speaking voltage surges are considered more damaging. This is due to the longer period of time in which the electric circuit must deal with the excessive power.

What Causes Voltage Surges

 

Engineers generally recognize two causes of voltage surges. These are classified as “internal” sources as they derive from changes within the system itself or “external” causes which come from outside the system currently being affected by the surge.

Internal Sources – Voltage Surges

 

Many electrical systems operate by either turning on and off power or by increasing and decreasing the flow of power. Think of thermostats or dimmer switches as examples of circuits designed to increase/decrease electrical load. Alternatively, think of the fan in your computer or the compressor on your fridge repeatedly turning on and off, consequently affecting the power available in your home.

However this is far from the only internal source of power surges. A second source of power surges involves “magnetic coupling”. When electricity flows through a circuit, a magnetic field is created. In some circumstances this field can affect nearby wires, inducing a voltage in them and so leading to an unexpected power surge.

Lastly static electricity can build up within a system over time which, when discharged, causes a significant short term voltage surge.

External Sources – Voltage Surges

 

The different external sources of voltage surges can differ by region. In developing countries a common source of power surges arises from differences in how power in the national grid is used. In the evening, for example, as the nation returns home and switches on their TVs, air conditioning and so on can drain power from the grid. As these are turned off en masse in readiness for bed power surges can result.

Elsewhere in the world arguably the most common external cause of voltage surges come from lightning. While lightning may actually strike the circuit itself causing a power surge, a far more common cause of voltage surges is lightning hitting circuits nearby. In such situations overhead power cables may find themselves in the receiving end of a lightning strike – leading to a short-term spike in electrical activity for the surrounding properties.

Voltage Surge Protectors

 

There can be few engineers or electricians have not seen the devastating impact that voltage surges can cause. It should therefore come as no surprise that protecting systems from voltage surges should be considered of primary importance. This is especially so in situations where voltage surges are highly likely, or where the effects of an uncontrolled voltage surge could cause widespread, or expensive, damage.

To this end a range of voltage surge protectors are now available. In essence these devices are designed as “gate keepers” for a system, helping to monitor the electrical charge entering the system. In cases where surges or spikes are experienced the excess voltage is then removed from the system, such as through earthed lead.

Clearly when choosing a surge suppressor there are a number of factors that should be considered. On the one hand, surge protectors are manufactured to deal with a range of voltages around the anticipated mean. The broader this range is, the more protection will be offered to the system. Consequently selecting protection devices with a wide functional range is highly recommended.

A second consideration is the speed of operation; how quickly can a voltage surge protector eliminate unwanted excess current, and as a result how long will the system experience a sub-optimal load? The greater speed at which your protector can respond will minimize the risk of damage such as burnout occurring.

Lastly consider whether the device you are considering includes moving parts. While many of the newer models on the market are electronic-only designs, some manufacturers still produce surge protectors with moving parts which can, as a result, lead to mechanical failure.

Generally speaking electronic-only surge suppressors suffer far fewer mechanical problems and so offer higher levels of reliability. This eliminates the need (and cost) of regular maintenance and ensures fewer complications from negative environmental conditions such a dusty or humid atmospheres.

View our full range of voltage surge protectors here.