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A closer look at Amendment 2 of the 18th Edition

18th Edition Amendment 2

Commenting on possibly some of the most significant revisions yet, Gary Parker, ECA technical manager, highlights some of the proposed changes to the 18th Edition of the Wiring Regulations.

The 18th Edition so far

The IET Wiring Regulations, the essential publication for all professionals in the electrotechnical and engineering services sector, underwent an overhaul when the 18th Edition (BS 7671:2018) came into full effect in 2019.

Amendment 1, which concerns electric vehicle charge points, came into effect on 1 February 2020. Now, BSI is seeking views on a new set of changes to the 18th Edition – Amendment 2 (AMD 2) – which could represent the biggest set of revisions to the Regulations yet.

Why now?

The rationale for Amendment 2 is similar to that behind the original 18th Edition: given the way our industry operates, the roles electrical engineers serve, and the increasing speed of technological change, the Regulations must reflect these changes to ensure installations are safe, efficient, useful, and able to meet evolving standards.

The key potential changes

Mandating of AFDDs on circuits with a rated current not exceeding 32 A

  • The proposal: Regulation 421.1.7 proposes that arc fault detection devices (AFDDs) be required on all single-phase final circuits supplying socket-outlets and fixed current-using equipment. Some exceptions to this are listed.
  • The impact: This proposal would effectively mandate the use of AFDDs across all small, single phase circuits, whether in a domestic, commercial or industrial installation, increasing the potential for safety but also the prospect of greatly increasing cost and complexity of installations.

Risk assessment for sockets

  • The proposal: Regulation 411.3.3 would be altered to remove the option for omitting RCDs on socket outlets not exceeding 32 A in installations other than dwellings.
  • The impact: This proposal would leave designers with no option but to install RCDs on all socket outlets – unless they raise a departure against BS 7671. However, this is something the client may not be content with.

Less paperwork for EICs

  • The proposal: To reduce the number of items on the schedule of inspections for an electrical installation certificate.
  • The impact: The number of boxes would be reduced to 13 items, greatly reducing the time needed to complete an EIC. A list of items that should be inspected (where relevant) is available, but this does not need to be completed.

New cut-off date for complying with the 18th Edition

  • The proposal: To state a date that, after which, all installations should be installed to the 18th Edition AMD 2 – regardless of when the design took place.
  • The impact: If an installation is undertaken after 28 March 2023 then this would need to conform to the requirements of the 18th Edition AMD 2 regardless of when it was designed. This could impact contractors working on contracts which take some years to come to fruition.

Energy efficiency and prosumers

  • The proposal: A new Part 8 would be added for ‘Prosumer’s’ low-voltage electrical installations.
  • The impact: This proposal highlights some of the additional requirements designers and installers should be aware of when working on newer installations that can generate their own energy supply.

SPD requirements

  • The proposal: To re-write the wording in section 443, Transient overvoltages due to the effects of indirect lightning strokes, to make this element easier to read.
  • The impact: Potentially reducing the number of mandatory SPDs required in installations, however the wording should be closely read to ensure compliance.

Foundation earthing

  • The proposal: Regulation 542.1.2.202 would require that for new premises, additional earthing, such as foundation earthing, shall be provided.
  • The impact: Every new build would need to be provided with a means of embedding electrodes to supplement the earthing system. This will require the use of electrodes or foundation earthing, in many cases at times when electrical contractors are not on site.

Protected areas

  • The proposal: The requirements of Section 422 would be dramatically re-written to introduce the phrase, ‘protected escape route’.
  • The impact: Removing the conditions BD2, BD3 and BD4 and using the term ‘protected escape route’ would introduce requirements for designers and installers to consider how they install circuits in areas of escape and what types of equipment can be installed.

Next steps

The 2nd Amendment to the 18th Edition of the Wiring Regulations (BS 7671:2018) was opened as a Draft for Public Comment (DPC) from 21 September to 11 December 2020. The DPC is now being reviewed before a final version is decided upon in the coming months.

In previous years, ECA Member comments have been directly responsible for improving the Regulations and ensuring that BS 7671 remains a practical and workable document, to the benefit of both customers and contractors.

This article originally appeared in Electrical Review January/February 2021.

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