BUREAU VERITAS WELCOMES 3RD AMENDMENT TO 18TH EDITION, BUT SAYS IT ‘SPARKS’ A RENEWED FOCUS FOR DUTY HOLDERS

BS 7671:2018+A3:2024 Requirements for Electrical Installations aims to address the requirements for the correct connections of unidirectional and bidirectional residual current devices (RCDs) and miniature circuit breakers (MCBs). According to the amendment:

• A bidirectional protective device is a protective device where it is intended by the manufacturer that a source of supply is connected to either or both sets of connection terminals.
• A unidirectional protective device is a protective device where it is intended by the manufacturer that a source of supply is only connected to one defined set of connection terminals.

This new focus on connection of unidirectional and bidirectional RCD & MCBs comes at a relevant time for the industry, as we’re seeing a marked rise in the demand, installation and use of renewable energy solutions. Introduction of renewable technology such as solar PV, Electric Vehicle charging or battery storage systems means that we must now consider the safety implications and likelihood of parallel supplies within a single installation.

An RCD is a safety device designed to reduce the risk of electrocution and fire, caused by earth faults; it essentially identifies a fault in an electrical system and switches it off. A unidirectional RCD will therefore only identify a fault when electricity is flowing in the one direction it was designed for. Newer technologies such solar, EV and battery storage may require bidirectional devices. The designer and installer must refer to manufacturer’s advice on where to connect these within the distribution board.

The regulations are being updated to keep pace with the advances in technology and the relevant manufacturers guidance.

However, also important to note is the significance of yet another amendment to the wiring regulations. As the demand and scope for renewable energy sources continues to grow and develop, so too will the regulation that sits alongside it. This latest amendment to the IET 18th Edition Wiring Regulations marks the third review of the document in six years - a notable increase in frequency compared to previous versions.

There won’t be a slow-down in regulatory change either. Despite the third amendment having only just been released, Amendment 4 is already being talked about which may bring about requirements for stationary secondary batteries, low voltage generating sets, power over ethernet (POE), and much more. All of which is in response to ever-evolving technologies being developed on the race to Net Zero.

There are other fast-changes too. For example, EV charging guidance is changing quickly with the Code of Practice for Electric Vehicle Charging Equipment Installation, moving onto edition 5 in 2023 after only 11 years in publication.

The difficulty for duty holders is its often not feasible or realistic to be across these ever-changing regulations for which they may not be a specialist. However, the onus and responsibility are firmly on them to ensure electrical installations under their responsibility, remain safe for users.

As outlined in the BEAMA report which triggered this latest review of the 18th Edition regulations, electrical installation inspectors must remain up to date with the latest testing, inspection and certification advice, so they can support duty holders on the risks of this issue for existing electrical installations, and the correct route forwards.