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18th Edition Wiring Regs

With the 18th Edition to the Wiring Regulations not too far off (it’s due to publish 1st July 2018), We have a look at what is being discussed at committee level now and what changes are likely to be included in what will be BS 7671:2018.

The BS 7671 Wiring Regulations written by the IET (The Institution of Engineering and Technology) set out the standards for electrical installations in the UK and many other countries. The IET plays a key role in electrical installation standards and safety, and is known for its independent and trusted voice. It manages the national committee JPEL/64 and publishes the IET Wiring Regulations BS 7671.

With the 18th Edition to the Wiring Regulations not too far off (it's due to publish 1st July 2018), we take a look at what is being discussed at committee level now and what changes are likely to be included in what will be BS 7671:2018. 

Significant Changes due in BS 7671:2018

Protection against overvoltages: Clause 443 is likely to be significantly revised based on the recently published IEC and CENELEC standard. However, the exact requirements will have to be agreed by the UK national committee. If the BS 7671 follows the IEC and CENELEC standard the AQ criteria for determining if protection against transient overvoltage is needed would no longer be included in BS 7671. Instead, protection against transient overvoltage would have to be provided where the consequence caused by overvoltage affects;

  1. human life, e.g. safety services, medical care facilities;

  2. public services and cultural heritage, e.g. loss of public services, IT centres, museums; and

  3. commercial or industrial activity, e.g. hotels, banks, industries, commercial markets, farms.

Fire Protection: 

Since electricity was introduced to buildings, fire protection has been of paramount importance. RCDs can reduce the chance of fires associated with earth faults. However, whilst RCDs can detect earth faults they aren't able to reduce the risk of electrical fire due to series or parallel arcing between live conductors because there is no leakage current to earth. Details will be included in BS 7671:2018 for the installation of arc fault detection devices (AFDDs) to mitigate the risk of fire in final circuits of a fixed installation due to the effect of arc fault currents.

Changes to Section 753: 

The scope of Section 753 has been extended to apply to embedded electric heating systems for surface heating. The designer will be required to provide appropriate information about approved substances in the surroundings of the heating units.

New section:

Energy efficiency: With global warming and reducing our consumption of energy becoming a big focus around the world, we have to consider how electrical installations can provide the required level of service and safety for the lowest electrical consumption. The draft proposals enable a client to specify the level of energy efficiency measures applied to an electrical installation. Installations can also be awarded points for energy efficiency performance levels, for example, transformer efficiency.


These points can be added together with points for efficiency measures to give an electrical installation an efficiency class, ranging from EIEC0 to EIEC4, depending on the number of points awarded.


Intersafe specialise in electrical testing, providing Fixed Wire Testing, Portable Appliance Testing and Thermal Imaging across the UK. 

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