Amendment 3 to BS7671 Wiring Regulations Explained


Announced on May 1, 2024, the Institution of Engineering and Technology (IET) has launched a new consultation to revise the BS7671:2018 (18th Edition) Wiring Regulations for the third time. This initiative, starting on May 8, 2024, was prompted by a technical bulletin from BEAMA1. It aims to clarify guidelines for properly connecting unidirectional and bidirectional residual current devices (RCDs) and miniature circuit breakers (MCBs). For a brief breakdown, watch our video from Darren, the senior quality and testing engineer at One Way Group.

Understanding Amendment 3 to BS7671

Engineering & Managing Director, Wayne Bennett, considers this new amendment a significant and positive progression for the industry. He highlights the need for electricians to stay informed about frequently updated regulations to guarantee the utmost safety for end-users.

Focus on RCD and MCB Connections

This new focus on connecting unidirectional and bidirectional RCDs and MCBs comes at a relevant time. The industry is seeing a marked rise in demand, installation, and use of renewable energy solutions. Introducing renewable technology such as solar PV, Electric Vehicle charging, or battery storage systems requires considering safety implications and parallel supplies within a single installation.

Understanding RCDs

An RCD is a safety device designed to reduce the risk of electrocution and fire caused by earth faults. It identifies a fault in an electrical system and switches it off. A unidirectional RCD will only identify a fault when electricity flows in the designed direction. Newer technologies like solar, EV, and battery storage may require bidirectional devices. Designers and installers must refer to manufacturers’ advice on where to connect these within the distribution board.

Technological Advances and Safety Implications

The regulations are being updated to keep pace with advances in technology and relevant manufacturers’ guidance. The demand and scope for renewable energy sources continue to grow and develop. This proposed emergency amendment to the IET 18th Edition Wiring Regulations marks the third review in six years. The BEAMA report accelerates this evolution of the regulations.

Frequency of Regulation Updates

We don’t expect a slow-down in regulatory changes. Technology will continue to evolve in the race to Net Zero. We learn new things about the technological advancements aiding us to achieve this. This is just the start. For example, EV charging guidance is changing quickly. The Code of Practice for Electric Vehicle Charging Equipment Installation moved to edition 5 in 2023, after only 11 years in publication.

Importance of Compliance with Updated Guidelines

As outlined in the BEAMA report, electrical installation designers must decide on the method to use for new installations. They must ensure they utilize the correct connections for unidirectional and bidirectional RCDs and MCBs.

Time will tell what this third amendment of the 18th Edition will bring. Industry leaders have the opportunity to comment on the proposed changes until June 5. The final amendment is due to be published in summer 2024.

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