IET Wiring Regulations – corrigendum May 2023 explained

May 18, 2023 Editor

Following the announcement from the Institution of Engineering and Technology (IET) and BSI that a corrigendum to BS 7671:2018+A2:2022 would come into effect from 15 May, Jake Green, Head of Technical Engagement at Scolmore Group, provides some more detail on the changes.

Under the auspices of the IET/BSI, JPEL64, the committee responsible for BS 7671, has issued a corrigendum to address issues raised after the publication of Amendment 2 of BS 7671: 2018. These issues fall into three specific areas:

Protected escape routes – amendment to Regulation 422.2 to clarify the scope of the provision in general installations, and a new provision for medical locations (710.422.2).
Birthing pools – amendment to Regulation 701.1 removing the reference to birthing pools.
Provision of protection against overvoltage for safety services.

Protected escape routes

Regulation 422.2 has been amended to provide clarification on its application. The regulation now states:

‘Cables or other electrical equipment shall not be installed in a firefighting lobby, shaft or staircase of a protected escape route…’

The text in bold italics is the amended detail. This change enables designers to better understand the scope of application of this requirement. Note 2 to Regulations 422.2 has been similarly amended, however, there are no changes to the guidance given in Appendix 13.

Further to this change to Regulation 422.2, a new regulation (710.422.2.201) has been added to Section 710 covering medical locations. This new text takes account of the specific concerns of the health sector and points towards the guidance issued under HTMs (England), SHTMs (Scotland) and WHTMs (Wales).

Birthing pools

Regulation 701.1 in Section 701 (Locations containing a bath or shower) has been amended to remove the reference to birthing pools. This change supports the work of designers in the health sector.

Protection against transient overvoltages of atmospheric origin

Regulation 443.4.1 now limits the requirement for transient overvoltage protection to two conditions, (serious injury to, or loss of human life, and significant financial or data loss) by removing the reference to ‘safety services’.

However, the rest of the regulation remains the same, and protection against transient overvoltages (typically using SPD) should still ‘…be provided unless the owner of the installation declares it is not required due to any loss or damage being tolerable…’

As a consequence of this change, Table 443.2 has been amended by deleting the references to alarm panels, computers and home electronics. Furthermore, the note attached to Regulation 534.4.1.1 has been amended to remove the example of ‘fire/security alarm systems’.

All of these changes became ‘live’ on 15 May 2023.