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Surge Protection

What is a Surge Protective Device or SPD?

A surge protection device will protect your installation and equipment from overvoltages caused by lightning strikes or power surges on the mains supply from faulty power network conditions.

Over voltages are spikes in the mains supply voltage. These are sometimes refered to as transient voltages.

Contactum T2C4011 SPD surge protection

What are the risks of electrical surges?

An electrical power surge is likely to shorten the lifespan of your electronic equipment and can even damage the wiring itself in an electrical installation.

In the modern home or office, more and more electronic technology is used in appliances, lighting controllers, heating systems, alarm systems and fire detection equipment, power surges can lead to costly electronics repair bills and the untimely replacement cost of electrical and electronic equipment.

A Contactum T2C4011 type 2 surge protection device

How does a surge protection device work?

A surge protection device will prevent transient voltage spikes from damaging and shortening the life of your electronic equipment. An SPD will do this by absorbing and diverting the surges or spikes to earth using an electrical component called a metal oxide varistor or MOV.

How do you know a surge protector is working?

Commonly surge protective devices have an indicator flag at the front, which may turn red when replacement is required.

Fusebox F2010MX SPD consumer unit installed in Nottingham

A Fusebox F2010MX Surge protection RCBO consumer unit installed in Nottingham

How long does a surge protection device last?

Typically the longer the transient voltage duration the more likely the surge protection device will overheat, thus cutting short the lifespan of the SPD when the internal thermal fuse element blows.

Higher rating surge protection devices are available which can withstand higher transient peaks although come at a much higher price.

How would I know if I have surge protection already?

The devices at your mains supply and consumer unit should have been labelled.

You may see a device like the ones shown on this page.

If you are not sure you could email a photo to and we could confirm.

If you have any concerns about the safety of your electrical installation, an EICR test is recommended every five years 

 Do I need to have Surge Protection?

If you want to protect your sensitive electrical equipment from damage from the effects of transient over voltages then the answer is YES.

Is Surge Protection expensive to fit?

As demand for Surge Protection has increased the price has fallen in recent times. Compared to the cost of electronic equipment its practically a must have.

What are the different types of surge protection devices?

T1, T2 and T3 SPDs (Surge Protective Devices) are used to protect electrical equipment and systems from power surges. T1 SPDs are designed to protect systems from surges up to 1,500 volts, while T2 SPDs can protect against surges up to 2,500 volts. T3 SPDs can protect against surges up to 5,000 volts. T1 and T2 SPDs can be used in both residential and commercial settings, while T3 SPDs are only suitable for commercial applications. All three types of SPDs provide safety and protection to electrical systems and equipment from power surges.

Do I need a new consumer unit with a SPD?

Surge protection can be retrofitted to almost any electrical installation, a new consumer unit is not required to benefit from having a surge protective device installed although the opportunity to fully check and improve the safety of an electrical installation is one that should be taken.

How can I get surge protection installed?

Contact us at Niman Electrical,

we are always happy to help.

 What causes power surges?

Power surges and voltage spikes can come from all different sources from failiures in the electrical supply, lightning, motors stopping and starting and faulty equipment. These can really only be detected by the home owner by appliances or sensitive electronic devices failing to operate.

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