Surge & Voltage Protection: Safeguarding Your Equipment from Power Fluctuations
Modern electrical systems are increasingly reliant on sensitive electronics — from smart home devices and computer systems to industrial control equipment and medical devices. All of these are vulnerable to power surges and voltage fluctuations. Installing the right surge and voltage protection is essential to prevent costly damage and unexpected downtime.
Understanding Power Surges and Voltage Fluctuations
A power surge is a sudden, brief increase in voltage that exceeds the normal operating level. Surges can be caused by lightning strikes, utility switching operations, or even the switching on and off of large electrical loads such as motors and air conditioning units. Voltage fluctuations, on the other hand, are more gradual variations in the supply voltage — too high or too low — that can also be damaging over time.
While a large surge can instantly destroy sensitive electronics, repeated exposure to smaller transient voltages can degrade components gradually, leading to premature failure and intermittent faults that are difficult to diagnose.
Surge Protective Devices (SPDs)
Surge Protective Devices (SPDs) are designed to clamp transient overvoltages and divert the excess energy safely to earth, preventing it from reaching connected equipment. Following Amendment 2 of the 18th Edition Wiring Regulations (BS 7671:2018), SPDs are now mandatory for most new domestic and commercial installations where a loss of supply would cause danger or loss of income.
SPDs are categorised by type. Type 1 SPDs are installed at the main service entrance and are designed to handle the very large surges that can result from direct or nearby lightning strikes. Type 2 SPDs are installed at sub-distribution boards to handle switching transients and residual surges that pass through the main protection. Type 3 SPDs provide fine protection close to sensitive equipment at the point of use.
For comprehensive protection, a combination of Type 1 and Type 2 devices is typically recommended in high-risk locations, with Type 3 devices added where particularly sensitive equipment requires the highest level of protection.
Voltage Optimisation and Stabilisation
In addition to surge protection, voltage optimisation technology is used to reduce and stabilise incoming supply voltage to an optimal level. The UK electricity supply is nominally 230V, but in practice it can often be higher. Voltage optimisation systems reduce this to the most efficient level for equipment operation, which can reduce energy consumption, extend equipment life, and lower electricity bills.
Why SPDs Are Now a Legal Requirement
The mandatory inclusion of SPDs in Amendment 2 of BS 7671 reflects recognition of the real damage that surges cause every year to UK homes and businesses. Electricians and contractors must now specify appropriate SPD protection as part of any new installation or significant rewire.
At Terelec Technologies, our range of surge protective devices covers Type 1, Type 2, and combined Type 1+2 products from leading manufacturers, all fully compliant with current UK wiring regulations. Whether you need basic protection for a domestic consumer unit or advanced protection for a commercial or industrial installation, we can help you find the right solution.
