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18th Edition: A greener era for electrical safety

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Ushering in a new ‘green’ era for electrical safety, the 18th Edition of the IET Wiring Regulations came into force in January 2019. Almost a year after its implementation, Michael Kenyon, technical manager at Bureau Veritas, explains why the new framework is helping to raise safety standards in surge protection, electric vehicle infrastructure and energy efficiency.

With the rising adoption of ever-more smart technologies in UK homes and workplaces, electrical safety and best practice is increasingly at the top of the agenda across many sectors and industries. This is particularly evident since the introduction of the 18th edition of BS 7671 – IET Wiring Regulations in January 2019, applying to all new and rewired installations. For the modern electrician and the wider industry, the escalating impact of climate change has seen an increased focus on sustainability in the regulations – in the form of recommendations on installation of electric vehicle charging points and considering energy efficiency.

Indeed, these were introduced against the growing attractiveness of electricity as a clean power source in today’s society. For the first time since the Industrial Revolution, Britain is obtaining more electric power from zero-carbon sources than from fossil fuels, spurring the switch to electric technology in everything from transport, heating and other industries.

And what this means is a wholesale shift in the use of electricity not only in lighting, heating and ventilating commercial buildings but also in terms of transitioning energy-intensive commercial processes to cleaner power. In fact, in July, the UK government launched an £80m fund to help businesses create the supply chains required to enable wider electrification in the automotive, aerospace, energy, industrial, marine, off highway and rail sectors.

A large driver is the government’s ambitious carbon targets. While we have been one of the most successful countries when it comes to cutting our carbon reductions, earlier this year the UK became the first nation to enshrine into law the net zero target, committing to reducing greenhouse gas emissions by “at least” 100% below 1990 levels in 2050.

To meet these obligations, drastic action will be needed in the way our buildings use energy. In particular, non-domestic buildings in the UK account for 17% of our energy consumption and 12% of greenhouse gas (GHG) emissions.

As such, greater use of electricity as a power source will be the cornerstone of meeting the UK’s environmental obligations, presenting the electrical industry with ample opportunity to grow and diversify their income stream. However, in order to do so, electrical contractors must first and foremost understand the 18th edition standard and the direction of travel its evolution is likely to take.

Powering the EV revolution

Nowhere is this more evident than in the rapidly evolving rules on electric vehicle charging, which are facing a major update since the 18th Edition of the IET Wiring Regulations were published in July 2018.

As part of its Road to Zero strategy, the UK government has ambitious targets in place for half of all new cars sold to be ‘ultra-low emission’ by 2030 – and with sales of electric cars at their highest level to date, creating a world-class charging infrastructure is critical to achieving this.

The installation of electric charging points represent a massive growth opportunity for the electrical contracting industry, especially as the government recently announced a £400 million fund to help develop rapid charging infrastructure points. Despite being a fledgling industry, the technology in this area is developing at such a fast pace and the wiring regulations are being amended to adequately reflect this.

For instance, the initial guidance focused on the earthing requirements and the use of RCDs in such installations. Subsequently, this led to the Code of Practice for Electric Vehicle Charging Equipment Installations moving on to its 3rd Edition being released earlier this year. As such, there’s a greater onus for installers of EV charging points to be accredited by the Office for Low Emission Vehicles (OLEV), as well as clearer guidance on different types and classifications of RCDs and how to test them. What’s more, being accredited by OLEV will also allow installers and their clients to access vital government grants such as the Electric Vehicle Homecharge Grant (EVHS) or Workplace Charging Grant (WCS).

Most recently, the Institution of Engineering and Technology (IET) announced it will publish a standalone update to Section 722 in early 2020, as part of a new amendment to BS 7671:2018. The amendment, which will be implemented immediately and free to view on the IET website, follows advances in technology such as integrated EV charging devices that satisfy the restrictions around PME earthing by disconnecting the supply including the protective conductor upon detecting an open circuit in the neutral (PEN conductor).

This latest update is expected to make installing charging points quicker and easier, and cheaper for both installers and consumers and will look to keep up to speed with European regulations, taking into account harmonised standards in the CENELEC Harmonised Document (HD). It will also most likely provide further changes to the earthing requirements for EV charging points. It may also provide additional guidance on how RCDs are used in EV chargers.

Green light for energy efficiency

As the first edition of wiring regulations to have a dedicated focus on energy efficiency, although part 8 of the 18th Edition was later relegated to appendix 17, it’s expected to become a fundamental part of the next major amendment to BS 7671 in 2022.

Appendix 17 offers expert guidance on the lessening environmental impact of electrical installations, through measures such as replacing traditional standard filament, halogen and fluorescent lights with super-efficient LEDs as one of the easiest ways to cut energy costs.

Power factor correction is also covered as an increasingly sought-out energy-efficient measure which employs the use of high quality, reliable capacitors that compensate for any wasted reactive power demand; restoring power factor as close to unity as possible. In this way, power factor correction (PFC) units can achieve significantly reduced power consumption and CO2 emissions, along with lower electricity bills – another great revenue stream for the electrical contractor to enter into.

It’s likely that as appendix 17 develops into part eight there will be greater guidance on where electronic equipment creates an unclean distorted electrical supply and can damage equipment by creating heat/overload. As a complex area that many contractors struggle to get to grips with, now would be the time for many in the industry to refresh their knowledge on existing guidelines.

A step up for fire safety

As expected, BS 7671 – IET Wiring Regulations has also pushed the standards of electrical safety a step further, in particular addressing the risks of fire safety. For instance, one of the most significant recommendations in the 18th edition regulations is that all new installations should now be fitted with arc fault detection devices (AFDDs) to mitigate the risk of fire in final circuits from arc fault currents.

Indeed, since the 18th Edition went live, the electrical industry has transitioned well to the new standard, with wholesalers now stocking Arc Fault Detection Devices (AFDDs), surge protection devices (SPDs), as well as a wide range of fire resistant cable supports.

Another recommended measure to thwart fires and protect people from getting fatal electric shocks is the greater emphasis on the use of residual current devices (RCDs). However implementation of such measures has come with its own challenges.

The widespread adoption of such devices has gradually increased over the years, with AC Type RCDs often promoted as the first choice, particularly since 2001 where the 17th edition (amendment 1) directly stated AC Type RCDs should be used for sockets that might supply outdoor equipment.

However, as more and more homes, commercial and industrial sites are now using electronic equipment and installing renewables such as solar PV, many of these RCDs may well be not fit for purpose – putting an increasing number of people at risk.

Essentially, what’s happening is that devices such as Solar PV and electric vehicle chargers could be leaking (direct current) back into the electrical system and saturating the iron core of the AC type RCDs which are not designed to handle it.

As an independent electrical safety specialist, we suggest the industry, instead, looks at using A or B type RCDs that are specifically designed to offer protection against alternating and pulsating direct currents- as stated in the recent rewrite of 531.3 of BS7671.

A surge in surge protection

The 18th Edition section 443.4 also sets out changes and guidance on protection against overvoltage, advising the use of surge protection devices (SPDs) in public sector buildings such as hospitals, where they could potentially save lives. And that’s not all, SPDs are increasingly being used to preserve the cultural heritage of historic buildings by reducing the risk of fire from overvoltages as well as minimising disruption to commercial activities in a number of industries.

Although not a new technology, SPDs have not been used as widely until the 18th Edition, with section 443.5 introducing a new more complex risk assessment for electricians using such devices and leading to accreditation bodies such as NAPIT and NICEIC now offering seminars on the practical application of this assessment. What’s more, the market has also responded, with manufacturers now selling 18th Edition-compliant distribution boards readily-installed with SPDs.

It’s worth noting that although the regulations don’t specifically state that you need SPDs in ‘single dwellings’, such devices should still be considered by those that work on domestic premises.


As electrical safety faces its biggest shakeup in decades and amid the very real threat presented by climate change, there’s no doubt energy efficiency and greater use of electricity as an energy source will continue to dominate the electrical contracting industry for years to come. The knock-on effect is a rapidly changing business landscape for contractors, which presents a number of opportunities to branch out into new business areas including smart solutions and EV charging installations. To truly realise the business opportunities this presents will require a best practice approach – one that will entail the industry to invest the time and resources needed to ensure compliance with the 18th Edition and its anticipated updates.

Bureau Veritas offers a range of testing and certification services to support customers in managing compliance around electrical safety in general for new and existing installations or for specific areas, such as electric vehicle charging point.


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