IET Guidance Note 8: Earthing and Bonding (BS 7671:2018+A4:2026)

IET Guidance Note 8: Earthing and Bonding (BS 7671:2018+A4:2026)

IET Guidance Note 8: Earthing and Bonding (BS 7671:2018+A4:2026) is a practical reference for applying earthing and bonding requirements correctly across electrical installations. It supports the generally applied methods of protection against electric shock set out in BS 7671, and also includes key information drawn from BS 7430 Code of Practice for Earthing, helping users align installation practice with recognised earthing guidance.

Designed for everyone involved in specifying, designing, installing or verifying electrical installations, this updated edition aligns fully with BS 7671:2018+A4:2026. It helps users select the appropriate earthing arrangements, understand the impact of supply characteristics, and apply bonding measures consistently to support safety and compliance.

Updates include guidance on system types, plus clearer direction on functional bonding and protective bonding, including sizing requirements. It also includes updated coverage relating to highway power supplied and street furniture, supporting modern infrastructure and public realm installations where earthing and bonding decisions are critical.

Key Features

• Earthing and bonding guidance aligned with BS 7671:2018+A4:2026
• Supports generally applied methods of protection against electric shock in BS 7671
• Includes key information from BS 7430 Code of Practice for Earthing
• For specifiers, designers, installers and those verifying electrical installations
• Covers earthing system types and selection considerations
• Guidance on functional bonding and protective bonding
• Includes bonding sizing requirements to support compliant installation
• Updated guidance for highway power supplies and street furniture