Guidance Note 6: Protection Against Overcurrent is a key guide to this important area of BS 7671. It is intended for all involved with specifying, designing, installing or verifying electrical installations and has been fully updated to BS 7671:018+A4:2026, including bidirectional and unidirectional devices; selection of protective devices; back up protection.
Cooperating organizationsAcknowledgementsPrefaceIntroductionChapter 1: The regulations concerning protection against overcurrentChapter 2: Protection against overloadChapter 3: Protection against fault currentChapter 4: Determination of fault currentChapter 5: Equations for the calculation of short-circuit currentChapter 6: Equations for the calculation of earth fault currentChapter 7: Selection of conductor sizeChapter 8: Prosumer's electrical installations (PEIs)Appendix A: Calculation of reactanceAppendix B: Calculation of k for other temperaturesIndex