The 18th Edition of the IET Wiring Regulations, also known as BS 7671, was issued on 1st July 2018: there will be a six month period before the new requirements come into effect on 1st January 2019. However, installations may be designed in accordance with the ‘new version’ before that date.
Why was change necessary?
The United Kingdom is obliged to take account of the technical intent of the CENELEC (CLC) HD 60364 series of standards relating to electrical installation work and associated technologies. These standards are published as separate parts. However, to date, the United Kingdom has chosen to amalgamate these into a single publication - BS 7671. The maintenance and publication cycles for the CLC documents vary and often do not align with those for BS 7671. To minimise the number of new editions or amendments that need to be published, the newest CLC version of a particular part or chapter is used as the basis for the corresponding Part or Chapter in the UK standard at the next occurring maintenance cycle, whether a new edition or an amendment.
Changes are also made occasionally to the terminology used in electrotechnical standards and these need to be adopted. For example, in this edition, the abbreviation for alternating current ‘a.c.’ is replaced by ‘AC’ and for direct current ‘d.c.’ is replaced by ‘DC’. Similarly, except for two brief explanatory notes, all references to the terms ‘protection against direct contact’ and ‘protection against indirect contact’ have been removed from the standard. These terms were replaced in the 2008 edition by ‘basic protection’ and ‘fault protection’ respectively but reference was made to them throughout the life of the 17th Edition as a transitional measure.
As new technologies and products emerge their use has to be recognised in BS 7671. For example this latest edition introduces recommendations relating to the use of arc fault detection devices (AFDDs).