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Consumer units / fuse boards

Consumer unit or fuse board changes are the the start of your installation and how the cables and accessories are protected. As of the 1st January 2019 the 18th edition of BS7671 came into effect. 

This builds on the 3rd amendment of the 17th edition with the major changes that effect domestic installations being the inclusion of an SPD (surge protection device), below is a brief description of what it does. 

"SPDs are designed to limit transient overvoltages due to lightning or switching and divert the associated surge currents to earth, so as to limit these overvoltages to levels that are unlikely to damage the electrical installation or equipment."

In laymen's terms, if the voltage spikes for whatever reason the SPD will function protection all of the delicate electrical items in your household. For the relatively small cost of an SPD all your phones, computers, TV's etc will be protected and not fried.

The 18th edition of BS7671 states;

“Protection against transient over voltages shall be provided where the consequence caused by overvoltage effects:

(a)        results in serious injury to, or loss of, human life, or

(b)        results in interruption of public services and/or damage to cultural heritage,

(c)        results in interruption of commercial or industrial activity, or

(d)        affects a large number of collocated individuals”.

Full article on SPD's can be found on the IET website.

Another change is the limitation of earth leakage per RCD protective device. This will push consumer units to be installed using RCBO's rather than a mix of RCD's and MCB's. This has a definite advantage from the consumers point of view, in the event of a fault on a circuit, you will only lose that circuit, you will not lose half of your house. This reduces the inconvienience of a fault, if fixing it is not immediate. 

If you have any questions, or to discuss any future or existing projects please contact us


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