Category Archives: 18th Edition Regulations

Key changes to BS 5839-1:2025 – Part 2

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This was first posted in IET Magazine November 2025.

Main Changes Covered

1. False Alarm Reduction

  • The standard now explicitly highlights the user’s responsibility to investigate and respond to false alarms every time they occur — those commissioning or handing over systems must inform users of this duty.

2. Commissioning and Handover Improvements

  • Before handover, the client or their representative must verify that manual call points have the correct replaceable parts and tools.
  • A cause-and-effect matrix (or equivalent text) explaining how system inputs affect outputs must be provided.

3. Maintenance Changes

  • Routine servicing intervals remain every six months but now allow flexibility of 5–7 months without losing compliance.
  • Control and indicating equipment clocks must be checked/adjusted to ensure accurate event logs.
  • In England & Wales, zone plans must be verified annually to reflect building changes.
  • New cybersecurity clauses require appropriate security measures and authentication to protect systems.

4. Extensions & Modifications

  • A new dedicated section covers how to extend or modify existing fire alarm systems.
  • Extensions must comply with the current standard, even if the original system does not.
  • Redundant devices (e.g., obsolete call points) should be removed or clearly labelled to avoid confusion during emergencies.

5. User Responsibilities

  • If the installation deviates from the standard (e.g., due to compromises in device placement), these variations must now be documented in the logbook, with provided model formats.

Relationship Between BS 5839-1:2025 and BS 7671

The article also clarifies how this fire alarm standard interacts with the UK electrical wiring rules:

  • BS 7671 (IET Wiring Regulations) often references BS 5839 for fire alarm systems under certain regulations.
  • Where differences occur between the two standards regarding fire alarm systems, BS 5839-1:2025 takes precedence.
  • The guidelines emphasise the need for safe isolation — BS 5839 no longer mandates a double-pole isolator, but safe isolation per UK electrical safety regulations remains essential.

Inspection & Testing Notes

  • Although functional testing of fire alarm systems should follow BS 5839-1:2025, electrical inspection and testing (e.g., for certification purposes) remains under BS 7671.
  • Inspectors must clearly agree with clients on what parts of the fire alarm system are included in any electrical inspection report to avoid misunderstandings about coverage.

Overall Message

Staying current with standard changes helps professionals and building duty holders manage fire safety, meet legal obligations, and reduce risk. Specialists should clearly communicate responsibilities, documentation, and limitations of inspections.

Further details – https://electrical.theiet.org/wiring-matters/years/2025/108-november-2025/key-changes-to-bs-5839-12025-part-2/

IET and BSI urges electrical industry to have its say on IET Wiring Regulations

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The Institution of Engineering and Technology (IET) and BSI are calling on the electrical industry to have its say on an amendment to the current BS 7671:2018 Amendment 2 (2022) + Amendment 3 (2024), which will go to DPC (Draft for Public Consultation) on 7 August 2024. BS 7671 is the Requirements for Electrical Installations: IET Wiring Regulations.

  • Draft for Public Consultation open from 7 August 2024 to 3 November 2024.
  • Latest amendment expected to be published in 2026

The amendment, known as Amendment 4, has been long-scheduled and will incorporate changes to harmonised standards at European level which the UK has to adopt within a certain time period.

The DPC for Amendment 4 is hot on the heels of Amendment 3 which has just been published and is available as a free-to-download PDF ‘bolt-on’ to Amendment 2 from the IET and BSI websites.

Amendment 4 is expected to be published in 2026, until that time electrical installers need to have a copy of Amendment 2 (2022) – the ‘brown book’ and Amendment 3 (2024) free PDF bolt-on to be up to date. Join the IET for a live webinar at midday on Wednesday 7 August 2024 as we announce the proposed changes and how they may affect you.

Comments on the DPC for Amendment 4 can be submitted through BSI’s Standards Development portal between 7 August 2024 to 3 November 2024.

IET’s Mark Coles, Head of Technical Regulations, said: “The days of the ‘evergreen electrician’ are gone. Changes in technology, installation practices and developments in standardisation are happening so quickly. It’s therefore so important that installers and designers stay well-informed of what’s happening in the industry. The IET is the authority for electrical installations in the UK and ensures that the wiring regulations committee, JPEL/64, carefully considers all necessary updates to the Regulations to ensure they best meet the needs of industry.

“It is intended that this Amendment will include requirements for Stationary Secondary Batteries, low voltage generating sets, power over ethernet, energy efficiency and functional earthing and functional-equipotential-bonding for Information and Communication Technology Equipment and Systems (ICT). Each area of change is a response to fast evolving technologies.”

BSI’s Dan Palmer, Associate Director, Committees, said: “BSI is proud to have been partners with the IET for over 30 years.  As electrification increases in the UK, we can all benefit from supporting high standards of safety. Keeping this critical standard on electrical installations updated is vital to ensure continued safety. We urge people with an interest to look at the suggested changes made in the draft and provide your comments.”

The Chair of JPEL/64, Graham Kenyon, said: “The members and officers of JPEL/64 invite anyone involved in the industry to contribute to the standard by providing comments on the Draft. We will initially focus on addressing comments related to the intent of technical changes put forward. Comments made on other parts of the standard will be considered in future work of JPEL/64, both for BS 7671 and international work. I extend personal thanks to all the organisations and individuals that have contributed to this Draft so far, both at National and International level.” 

The IET and BSI jointly manage JPEL/64, the committee responsible for BS 7671.

Can I install a metal consumer unit with a TT earthing system?

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High earth fault loop impedance values associated with TT earthing systems mean the earth fault current level is unlikely to be sufficient to operate the distributor’s protective device within the permitted time of 1 second, as required in Regulation 411.2.4, or at all in some cases, depending on Earth resistance values.

There is nothing to prevent a metal consumer unit being installed with a TT earthing system, but it’s important to ensure that an earth fault cannot develop between the meter tails and the metallic enclosure before the RCD.

Methods of reducing an earth faults include keeping the meter tails as short as possible, the installation of proprietary clamps and glands to secure the cables and prevent strain on the terminations, minimising the risk of damage to the meter tails and a subsequent earth fault.

Amendment number 1 to BS 7671:2018+A1

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Amendment 1 of BS 7671:2018 was published at the beginning of February this year and may be implemented immediately. The amendment concerns Section 722 of BS 7671:2018 (electric vehicle charging installations). In this article, we give a brief overview of some of the main changes to Section 722.

Protection against electric shock

Regulation 722.411.4.1 concerning the use of protective multiple earthing (PME) supply has been redrafted. Indent (iii) has been fully revised. In addition, Regulation 722.411.4.1 now includes an additional indent (iv) to cover single-phase installations and a further additional indent (v) has been added. Regulation 722.411.4.1 does not allow PME to be used to supply an electric vehicle (EV) charging point located outdoors (or that might be used to charge a vehicle located outdoors) unless you meet (i) or (ii) or (iii) or (iv) or (v) of 722.411.4.1.

A summary of the requirements of the indents to Regulation 722.411.4.1 is as follows.

Regulation 722.411.4.1(i) refers to a situation where a connecting point is supplied from a three-phase installation used to supply loads other than charging points and where the load is sufficiently well balanced.

Regulation 722.411.4.1(ii) requires a very low resistance earth electrode to mitigate the effects of an open-circuit (PEN) conductor fault on the supply.

Regulation 722.411.4.1 (iii) has been revised and refers to a voltage monitoring device (or functionality within the charging equipment) that detects PEN conductor failure. The informative Annex to Section 722 describes that suitable arrangements include measurement of the voltage between either:

   a. the circuit protective conductor (CPC) and a suitable measurement earth electrode, or
   b. the CPC and a reference point derived from the line conductors of a three-phase system provided that suitable precautions are also taken to disconnect the device when the supply to one or more of the line conductors is interrupted.

Regulation 722.411.4.1 now includes an additional new indent (iv) to cover protection by a device (or functionality within the charging equipment) for a single-phase installation.

Finally, Regulation 722.411.4.1 includes an additional new indent (v), which allows protection against electric shock to be provided by the use of an alternative device to those in (iii) or (iv), providing that it does not result in a lesser degree of safety than using (iii) or (iv). The indent states that equivalent means of functionality could be included within the charging equipment.

The touch voltage threshold of 70 V mentioned in Regulation 722.411.4.1 is on the basis that Table 2c (ventricular fibrillation for alternating current 50/60 Hz) of IEC 60479-5{ed1.0} gives a value of 71 V for both-hands-to-feet, in water-wet conditions with medium contact area (12.5 cm2).

Regulation 722.411.4.1 includes some important notes. Note 5 explains that BS 7671 does not deal with the safety requirements for the construction of electrical equipment. Where equipment to be used is not covered by a British or Harmonized Standard, the electrical installation designer should establish that the manufacturer of the equipment has ensured that the equipment satisfies the safety objectives of the relevant directive(s).

Note 6 states that creating a TT earthing system for charging equipment or for the whole installation, as an alternative to using a PME earthing facility with one of methods (i) to (v) above, may not be an appropriate solution, due to the inability to provide sufficient separation from buried metalwork connected to the supply PEN conductor.

What is protective multiple earthing (PME)?

The Electricity Safety, Quality and Continuity Regulations 2002 (ESQCR) (as amended) permit the distributor to combine neutral and protective functions in a single conductor, provided that (in addition to the neutral to Earth connection at the supply transformer) there are one or more other connections with Earth. The supply neutral may then be used to connect the CPCs of the customer’s installation with Earth if the customer’s installation meets the requirements of BS 7671.

PME has been almost universally adopted by distributors in the UK as an effective and reliable method of providing their customers with an earth connection. Such a supply system is described in BS 7671 as TN-C-S. However, whilst a PME terminal provides an effective and reliable facility for the majority of installations, under certain supply system fault conditions (external to the installation), a potential can develop between the conductive parts connected to the PME earth terminal and the general mass of Earth.

The potential difference between true Earth and the PME earth terminal is of importance when:

   a. body contact resistance is low (little clothing, damp/wet conditions), and/or
   b. there is relatively good contact with true Earth. 

Contact with Earth is always possible outside a building and, if exposed-conductive-parts and/or extraneous-conductive-parts connected to the PME earth terminal are accessible outside the building, people may be subjected to a voltage difference appearing between these parts and Earth.

Residual current device (RCD) protection

The requirements for RCD protection have been redrafted. The Regulation now contains further requirements for Type B and Type A or Type F RCDs, to take account of DC fault current, as follows (extract below):

“Except where provided by the EV charging equipment, protection against DC fault currents shall be provided by:

(i) an RCD Type B, or

(ii) an RCD Type A or Type F in conjunction with a residual direct current detecting device (RDC-DD) complying with BS IEC 62955 as appropriate to the nature of the residual and superimposed currents and recommendation of the manufacturer of the charging equipment.”

ANNEX A722 (Informative)

Annex A722 has been redrafted. This Annex now includes guidance on the voltage monitoring device described in Regulation 722.411.4.1 (iii). In addition, the Annex now includes an example arrangement of a separated system as described in Regulation 722.413. 

Conclusion

It is important to note that this article gives only a very brief overview of some of the changes in the Amendment to BS 7671:2018. For more information, please refer to BS 7671:2018, Amendment 1:2020.

By: Geoff Cronshaw – IET Wiring Matters – Issue 79

New amendment to BS 7671 (IET Wiring Regulations) Amendment 1

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The IET has announced a new amendment to BS 7671:2018 (IET Wiring Regulations 18th Edition). The national Wiring Regulations committee, JPEL/64, agreed the publication of Amendment 1, which will consist of a stand-alone update to Section 722: Electric Vehicle Charging Installations.

The amendment, which is due to publish in early 2020, will be free to view on the IET website, and only form part of a consolidated new Regulations following the next major amendment to BS 7671, expected in 2022.

The amendment follows advances in technology that were not available when BS 7671:2018 published, enabling a more practical solution for the installation of charging points. Functionality built directly into charging equipment uses existing technology, but employed in a new way, allowing charging points to be deployed more widely than ever before.

The updated Section 722 will make installing charging points quicker and easier, and will reduce the cost of installations for both installers and consumers.

The UK government is investing £400 million to accelerate the roll-out of charging infrastructure to help meet its target of at least 50% of new car sales to be ultra-low emission by 2030*.

Mark Coles, Head of Technical Regulations at the IET, is proud of the way that JPEL/64 has been able to respond to the changes in technology. He explains: “JPEL/64 has been able to address a new opportunity for electric vehicle charging equipment that provides a practical, cost-saving solution benefiting industry, consumers and government alike, to help the UK lead the way in the roll-out of infrastructure to support the electric vehicle revolution.

“This update to the IET Wiring Regulations puts the electrical industry at the forefront of driving technological innovation to ensure the installation of practical, safe charging points that are accessible to all.

“By producing Amendment 1 to BS 7671:2018 as a stand-alone, free-to-view document, this updated Section 722 will reach industry much quicker than a full, consolidated amendment would allow, enabling installers to take advantage of BS 7671:2018+A1:2020 as soon as possible.”

Keep an eye on theiet.org/updates to for information on the Draft for Public Comment and publication information.

Proposed timeline

  • 04 September 2019: Amendment 1 approved by JPEL/64
  • October 2019: The Draft for Public Comment for Amendment 1 will be available for 60 days to allow industry to respond to the proposed changes (see theiet.org/updates for details)
  • January 2020: Amendment 1 will publish as a free-to-view document on the IET website and come immediately into effect, eschewing the usual 6-month adjustment period to ensure industry can immediately take advantage of the changes