The revised edition of BS 7430 – Protective Earthing of Electrical Installations – Code of Practice has been published.

The updated British standard came into effect on 31 May, replacing BS 7430:2011+A1:2015, which has now been formally withdrawn.

The main updates include:

• Updated recommendations for earthing of High-Voltage (HV)-derived Low Voltage (LV) supplies, including:

1. Public and private transformers
2. Combined HV/LV earthing systems
3. HV/LV and LV/LV separation

• Updated recommendations for generators, including:

1. TN‑S systems
2. IT systems

• Application of Protective Neutral Bonding (PNB) system earthing
• Updated recommendations for installations having particular considerations for earthing, addressing more complex or higher-risk environments
• Updated recommendations for earth electrode systems, reflecting current best practice and performance expectations
• Removal of recommendations for special installations, streamlining the document and aligning with other applicable standards and guidance.

Protective earthing is fundamental to electrical safety, particularly as installations become more sophisticated and incorporate technologies such as EV charging, energy storage, and distributed generation.

The revised BS 7430 will support Members by providing:

• Enhanced guidance for modern installation design and construction
• Improved clarity for complex earthing arrangements
• Better alignment with current industry standards and safety expectations
• Continued support for compliance with BS 7671 Wiring Regulations and Electricity at Work Regulations.

The revised code of practice is available via the ECA BSI Online Standards Library — a unique benefit providing access to more than 80 British Standards for ECA Members.

The ECA Technical team is also on hand to support Members with this update.