In this Q&A video, we explain how to calculate Earth Fault Loop Impedance (Zs) for an electrical circuit step-by-step. Learn: ✅ What Earth Fault Loop Impedance is and why it matters. ✅ The components of the fault loop and how impedance affects circuit safety. ✅ How to apply BS7671 regulations and calculate Zs using Ze and (R1 R2). ✅ Real-world examples with a 50A Type B MCB and 10 mm² cable in a 9 kW boiler circuit. This video is part of our electrical design training series in collaboration wit

Total Earth Fault Loop Impedance Zs = Ze R1 R2 for TN-S and TN-C-S Earthing Arrangements How to calculate or measure total earth fault loop impedance for an installation connected to a TN-S and TN-C-S earthing arrangements. In this video I show drawings to aid with City and Guilds and EAL electrical exams at level 1, 2 and 3. The total earth fault loop impedance Zs of a circuit is made up for the impedance of the supply authorities cable Ze and the circuit impedance of the line conductor R1 and