What is a Minor Works Certificate? MEIWC explained
What is a Minor Works Certificate? When you can use a Minor Electrical Installation Works Certificate, what tests it needs and when an EIC is required instead.
What is a multifunction tester (MFT)? Explained
What is a multifunction tester (MFT)? What it measures, which BS 7671 tests it performs, calibration requirements and the mistakes that produce bad readings.
What is a schedule of test results? Explained
What is a schedule of test results? The BS 7671 schedule explained column by column: circuit details, continuity, insulation, Zs, RCD times and common errors.
What is an AFDD? Arc fault detection devices explained
What is an AFDD? How arc fault detection devices work, where BS 7671 Regulation 421.1.7 requires them, how they are tested, and the mistakes to avoid.
What is an EIC? Electrical Installation Certificate
What is an EIC? The Electrical Installation Certificate explained: when BS 7671 requires one, what it contains, who signs it and how it differs from an EICR.
What is an EICR? Electrical Installation Condition Report
What is an EICR? A plain definition of the Electrical Installation Condition Report, when it's needed, what it contains and the C1–FI codes explained.
What is an RCD? Types AC, A, F, B and RCBOs explained
What is an RCD? How residual current devices work, the difference between Type AC, A, F and B, what an RCBO is, BS 7671 requirements and RCD test times.
What is BS 7671? The IET Wiring Regulations explained
What is BS 7671? The IET Wiring Regulations explained: the 18th Edition, Amendments 1 to 4, what changed in A4:2026, legal status and how it relates to Part P.
What is main protective bonding? Explained
What is main protective bonding? What it does, which services need it, conductor sizes under BS 7671 Section 544, how to test it and why it is coded C2.
What is prospective fault current (PFC)? Explained
What is prospective fault current (PFC)? PSCC and PEFC explained, how to measure PFC at the origin, device breaking capacity and the common errors to avoid.
What is Ze? External earth fault loop impedance
What is Ze (external earth fault loop impedance)? Maximum values for TN-S, TN-C-S and TT, how to measure Ze safely at the origin and what a high reading means.
What is Zs? Earth fault loop impedance explained
What is Zs (earth fault loop impedance)? What it means, how it is measured, the 80% rule against BS 7671 maximum values and the errors that fail circuits.