Meter Tails Over 3m? Here’s How to Protect Them Safely

If you need to install a consumer unit over 3 meters away from the origin of an installation you'll need to protect the tails. This can usually be done by means of providing a fuse for overload and fault protection. However in doing this an interesting question arises: What about selectivity? How do you make sure that you stay compliant with the regs on all fronts? Is it even possible? Joe Robinson answers these and other questions to do with protecting meter tails and selectivity and some of the answers may surprise you. Take the free Circuit Protection Myth-busting training module here 👉 https://training.efixx.co.uk/course/c... ========================================== 🕐 Chapters 🕕 00:00 Are you calculating maximum demand properly? 00:15 Full free CPD Module on Circuit Protection: 👉 https://training.efixx.co.uk/course/c... 00:24 Can you really omit circuit protective devices? 00:50 Regulation 434.3 explains more. 01:32 Where does the DNO get a value of 3 meters for meter tails from? 01:50 Regulation 434.2.1 contains a clue... 02:30 But what happens when we go over 3 metres away? 02:45 Now selectivity (formerly known as discrimination) rears its officious head. 02:50 What does selectivity actually mean? 03:19 What size fuse should we use to provide protection and selectivity? 03:36 Regulation 536.4.1.2.1 tells us what we need to do selectivity. 04:17 The Regulations' Rule of Thumb on selectivity A53.4 05:04 A worked example of using the 1.6:1 ratio for selectivity. 05:25 The challenge of complying with the requirements for selectivity. 05:59 Understanding the principles of the regulation. ========================================== #electricaldesign #electricians #electricalinstallation