On-Site Guide (BS 7671:2018+A2:2022) (Electrical Regulations)

Product Information

The requirements for testing RCDs have been simplified, a single test is all that is required to show compliance with the minimum requirement laid out in BS 7671:2018+A2:2022. Regardless of RCD type, the test is carried out using an alternating test current, applied at the RCD’s rated residual operating current I Δn, the maximum disconnection time is expected to be less than 300ms for a general non-delay type RCD. For S type time-delayed RCDs, the operating time should be 130 - 500 ms. Other kinds of RCD testing may be useful for fault finding purposes. This is where knowledge of relevant product standards is essential, it would be reasonable to expect a 40 ms maximum disconnection time for a test at five times I Δn as would be the case with an AC test. However, this is not the case as the product standard BS EN 61008 requires a half wave pulsating residual current of 0.35 A (350 mA), see Table 4 extracted from BS EN 61008-1:2012+A2:23-1:2012+A11:2015. BS EN 61009-1:2012+A13:2021 Residual current operated circuit-breakers with integral overcurrent protection for household and similar uses (RCBOs). General rules. Dan Palmer, Associate Director of Committees at BSI said: “BS 7671 is one of the UK’s most important standards, providing authoritative requirements to promote electrical safety. The changes introduced in this new amendment will help electrical professionals keep up to date with new and innovative technologies, as well as ensuring they have current knowledge about designing safe installations.” Calling all those involved with electrical installations, we’ve made major amendments to the key national standard on electrical installations.

Updates to 18th Edition - BS7671- IET Wiring Regulations

BS 7671:2018+A2:2022 is the most widely accepted way to demonstrate compliance with the applicable legislation, and so if you are an electrical professional, you need to ensure that you are working to the new changes introduced in the latest version of this standard. What’s new about BS 7671:2018+A2:2022? With active energy management, the end-user should be able to permanently monitor and control his or her own electricity consumption and production. The concept of the PEI has also been developed to take advantage of renewable sources of energy (such as solar photovoltaic (PV) and wind turbines) and energy storage.

Similarly, for instruments with a setting for Type B RCDs a multiplier of two times I Δn is applied as required by the product standard, BS EN 62423:2012 Type F and type B residual current operated circuit-breakers with and without integral overcurrent protection for household and similar uses. Mark Coles, Head of Technical Regulations at the IET, said: “The IET is the authority for electrical installations in the UK and ensures that the National Wiring Regulations Committee carefully considers all necessary updates to the Regulations to ensure they best meet the needs of the industry. Regulation 443.4.2 requires protection against overvoltages to be considered in the case of equipment likely to produce switching overvoltages or disturbances and gives conditions.

On-Site Guide (BS 7671:2018+A2:2022) - Open Library On-Site Guide (BS 7671:2018+A2:2022) - Open Library

Each manufacturer’s instrument is different but changing the RCD Type is usually selected by pressing the relevant ‘function’ button on the instrument and the RCD Type symbol will change accordingly: see Figure 2. Most instruments will include a function to test general non-delayed and S Type time-delayed Type AC and Type A RCDs, some test instruments may also include a facility for testing other Types such as Type B RCDs. Shared PEIs are considered to be, for example, where a number of individual houses group their interests and agree to share their supply with their neighbours from their own renewable power sources. Each house-owner may have installed private renewable energy power sources, which can either supply the private electrical installation or the group of private electrical installations. The three operating modes considered for shared PEIs are as for individual and collective PEIs above. PEIs and EEMS The days of selecting an RCD according to current rating and rated residual current alone are gone, now the designer must select the RCD according to the nature of the residual fault currents, including pulsed or steady-state DC components expected to be present. Further information on RCD operating and non-operating times can be found in the relevant product standards. Type A and Type AC RCCBs and RCBOs are manufactured to BS EN 61008 and BS EN 61009 respectively, whereas Type F and Type B RCCBs and RCBOs are manufactured to BS EN 62423. a new requirement for Arc Fault Detection Devices (AFDDs) in some AC final circuits for installations in some types of higher risk residential buildings;

Why are changes to the requirements for RCD testing necessary?

damage caused by any error or omission in the work, whether such an error or omission is the result Regulation 422.1 (Precautions where particular risks of fire exist. General) now introduces requirements for the fire safety design of the building(s) to be documented. Regulation 422.2 (Conditions for evacuation in an emergency) introduces separate requirements for escape routes and a new concept of ‘protected escape routes’. Reference to conditions BD2, BD3, and BD4 have been deleted. Chapter 44 Protection against voltage disturbances and electromagnetic disturbances Regulation 16 Regulations, BS 7671, must comply with all relevant statutory regulations, such as the

NICEIC | 18th Amendment

It was noted that those testing RCDs in the field would find it difficult to carry out the variety of tests permitted and may not know which of the available tests would be applicable to a given make or type of RCD. Many of the issues encountered when testing RCDs are down to user error as opposed to faulty RCDs. It may come as a surprise to some, but RCD testing should be carried out at the RCD with the outgoing wiring disconnected. However, this is not usually done. The usual live working procedures must be considered, and suitable precautions taken when carrying out work near live parts. The concept of the PEI has been developed to answer the needs of the end-user. For example, where a PEI has a storage capability, the user could take advantage of low demand to store energy when its price may be lower.Arcs can be caused by insulation defects in cables, damage to cables by impact and penetration of nails and screws, loose terminal connections, and so on. An AFDD is designed to operate (trip) when a dangerous arc is detected by analysing the signature of the arc. Switching arcs caused by fluorescent lighting, for example, should not cause an AFDD to operate. AFDDs can be installed in distribution boards and consumer units to protect final circuits and should be installed in accordance with the manufacturer’s instructions. When installing components from a different manufacturer to that of the existing equipment in a distribution board or consumer unit, it is important to seek advice from the manufacturer that the new equipment is suitable and compatible. A collective PEI could, for example, be a group of single private houses, a group of flats in a building, or a group of small shops in a shopping centre with a common electrical power supply from one separate unit (generator/energy storage) producing energy and from the grid/supply network. Three operating modes are considered for collective PEIs. These are: Post-Brexit, this Amendment sees the further adoption of CENELEC Harmonized Documents as the UK continues the inclusion of standards for new and developing technologies. As an accredited certification body, BSI Assurance cannot offer certification to clients where they have also received consultancy from another part of the BSI Group for the same management system. Likewise, we do not offer consultancy to clients when they also seek certification to the same management system.

The impact of Amendment 2 of the 18th edition (BS 7671:2018 The impact of Amendment 2 of the 18th edition (BS 7671:2018

Further information on RCD testing can be found in IET Guidance Note 3 Inspection and Testing and PD IEC TR 62350:2006 Guidance for the correct use of residual current-operated protective devices (RCDs) for household and similar use which states that ‘ The testing current should be applied between the upstream and downstream terminal of the RCD’, see Figure 4 extracted from IET Guidance Note 3 Inspection and Testing. This essential update to the IET Wiring Regulations will form the national standard to which all new electrical installations and additions, and alterations to existing electrical installations in the UK are to comply. The IET and BSI are now urging all electrical professionals to ensure they become familiar with the changes.The early style Residual Current Devices (RCDs) were highly effective protective devices but they have proven to be less reliable in modern buildings as a consequence of DC leakage and DC fault currents caused by electronic equipment. Subsequently, new types of RCD have been developed. Type AC RCDs are affected by residual DC components and can become desensitized or ‘blinded’ and may not operate within the required time or, in some instances, may not operate at all. Table 1 summarizes the various types of RCD referred in BS 7671:2018+A2:2022 and their resilience to DC components. The guidance is based on the requirements of BS 7671: 2018+A2:2022 Requirements for Electrical Installations, and references to Regulation numbers are to those contained in that Standard. Additional Details Author Amendment 2 is an essential update to provide for the safety of electrical installations in the UK and it is now imperative that the industry is ready to work to this amendment before BS 7671:2018+A1:2020 is withdrawn.” rights reserved. Apart from any fair dealing for the purposes of research or private study, or criticism