IET Guidance Note 6: Protection Against Overcurrent (BS 7671:2018+A4:2026)

IET Guidance Note 6: Protection Against Overcurrent (BS 7671:2018+A4:2026)

IET Guidance Note 6: Protection Against Overcurrent (BS 7671:2018+A4:2026) is a practical guide to one of the most important areas of the Wiring Regulations: selecting and applying overcurrent protection correctly. It supports safer, more reliable electrical installations by helping users interpret BS 7671 requirements for protection against overload and fault current in a clear, consistent way.

Intended for everyone in specifying, designing, installing or verifying electrical installations, this guidance not has been fully updated to align with BS 7671:2018+A4:2026. It’s designed to assist with real world decisions around protective device choice, coordination and compliance verification, particularly where modern systems introduce new installation conditions and multiple sources.

Updates include guidance covering bidirectional and unidirectional devices, improved direction on the selection of protective devices, and guidance on back-up protection to help ensure protective measures remain effective under a wider range of fault conditions.

Key Features

• Overcurrent protection guidance aligned with BS 7671:2018+A4:2026
• For specifiers, designers, installers and those verifying electrical installations
• Clear guidance on applying BS 7671 requirements for overload and fault current protection
• Includes guidance on bidirectional and unidirectional devices
• Guidance on the selection of protective devices for compliant protection
• Includes guidance on back-up protection and protective device coordination