The IEE/BSI Requirements for electrical installations has been updated as BS 7671:2008 Requirements for electrical installations. IEE wiring regulations. 17th Edition. This creates a new revised edition of the wiring regulations, which came into effect on 1 July 2008. This article looks briefly at the changes incorporated into the new edition.
New sections have been introduced to align BS 7671:2001 much closer to IEC 60364, which is the basis of the electrical rules for international adoption. Up to July 2008, engineers could use either the 16th or 17th Editions but after 1 July all installations must be designed and installed to
BS 7671, the national standard for all electrical installation work in the UK, was first published in 1992 when the BSI adopted the IEE wiring regulations, 16th Edition and made it a national standard. However, the wiring regulations have been around for much longer; the first edition was compiled in 1882.
BS 7671 has been amended six times since its initial publication, as harmonised documents have been added or revised. This new edition of the IEE wiring regulations is the result of a complete review of its predecessor and adopts all of the harmonised documents published to date.
The 17th Edition will be produced with a red cover and will adopt the IEC numbering system. Some of the layout and certain parts have been heavily revised, with some chapters completely rewritten. BS 7671:2008 includes additional sections on special locations not currently included; the existing special locations have been revised to align with changes in CENELEC harmonisation documents. For example the current Part 6 (special locations) has become Part 7 to align with IEC.
There are now added requirements to protect against voltage disturbances and implement measures against electromagnetic influences. There are also requirements for safety services, such as emergency escape lighting. There is also now a requirement that an assessment shall be made for each circuit of any need for continuity of service considered necessary during the intended life of the installation. Also, socket outlets for use by ordinary persons now require RCD protection, though certain exceptions are permitted.
BS 7671:2008 also introduces new concepts of protection: protection against direct contact becomes 'basic protection', and protection against indirect contact is now 'fault protection'.
The standard also introduces new additional requirements for the connection of low-voltage, small-scale embedded generators (SSEGs), such as turbines and photovoltaics, in Chapter 55. Furthermore, Section 559 on luminaires and lighting installations now becomes a new series of regulations concerning lighting installations. This includes highway power supplies and street furniture, previously in Part 6.
The current special locations contained in the IEE wiring regulations are revised to align with the latest IEC and CENELEC standards. Providing a revised list of existing and new part 7s, which are:
- 701 - Locations containing a bath or shower - there is no Zone 3, and zones have now been simplified
- 702 - Swimming pools and other basins
- 703 - Rooms and cabins containing sauna heaters - This covers all saunas; zones are now 1, 2 and 3
- 704 - Construction and demolition site installations
- 705 - Agricultural and horticultural premises
- 706 - Conducting locations with restricted movement
- 708 - Electrical installations in caravan/camping parks and similar locations.
The new part 7s are:
- 709 - Marinas and similar locations
- 711 - Exhibitions, shows and stands
- 712 - Solar photovoltaic (pv) power supply systems
- 717 - Mobile or transportable units
- 721 - Electrical installations in caravans and motor caravans - relates specifically to caravans in caravan/camping parks
- 740 - Temporary electrical installations for structures, amusement devices and booths at fairgrounds, amusement parks and circuses
- 753 - Floor and ceiling heating systems.
Appropriate changes have been made to the existing appendices 1 to 7. In addition, several new appendices have now been included.
Finally, chapter 41 has a new structure and includes the two new definitions, 'Basic protection' and 'Fault protection'; the former is protection against electric shock under fault-free conditions, and the latter is protection against electric shock under single fault conditions.
BS 7671:2008 (Incorporating Amendment No 1: 2011)
The 17th Edition of the wiring regulations is available from RIBA Bookshops, priced at £80.