Skip to Navigation Skip to Content
Back to blog

IET Wiring Regulations

March 17, 2017 featured image

With the 18th Edition to the IET Wiring Regulations due to be published on 1st July 2018, we take a look at some of the likely changes, as well as revisiting the last amendment (the 17th Edition of BS 7671) which highlighted the importance of using RCDs in non-domestic environments.

18th Edition – BS 7671: 2018

According to Nicole Whitton from the IET, the new regulations will likely include:

  • Protection against overvoltages – significant revision of Clause 443
  • Protection against fire – 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 – scope extended
  • New section on energy efficiency – covering several energy efficient areas, such as electric vehicles, lighting, metering, cable losses, transformer losses, power-factor correction, and harmonics.

To read the full article, visit:

17th Edition – BS 7671: 2008

The current amendment to the IET’s Wiring Regulations came into force in July 2015.  It reinforced the requirement for using residual current devices (RCDs) in non-domestic environments, making it harder for designers to omit the use of RCDs from installations. The 17th Edition Wiring Regulations brought in the requirement for a documented risk assessment to be undertaken in order for non-domestic socket outlets with a rated current below 20A to be installed without an RCD to protect it (in most cases).

At the time of the new regulations, Steve Marr, an expert in power distribution at Legrand UK, said he welcomed the amendment, which would improve safety in the workplace:

“Under the new legislation RCDs will become a much more regular fixture across non-domestic power distribution systems, making the workplace much safer. They can only be omitted if a documented risk assessment determines that RCD protection is not necessary.

“Amendment 3 placed the responsibility for the omission of RCD protection clearly on the installation’s designer. The designer must produce a risk assessment which determines that RCD protection was not necessary and justify their reasoning, possibly in a court of law, if someone is killed or injured as a result of RCD protection being omitted.

“In short, RCDs are there to save lives. Whilst some RCDs may trip on occasion, the potential consequences for not using them far outweigh the initial one-off cost of including them in an installation. The new amendment removes ambiguity and reinforces the requirement for inclusion of RCD protection. This will undoubtedly make the workplace a safer place.”

You can read more about the 3rd Amendment to the 17th Edition to the IET Wiring Regulations on the Voltimum website.

Want to keep up to speed with the latest Wiring Regulations?

We now deliver 18th Edition training.

Newsletter Sign Up

For industry news, special offers and the latest from our centres, sign up to our mailing list

    Sign me up for the newsletter!