The information below gives you a summary of the changes following the implementation of the Third Amendment to BS 7671: 2008, The IET Wiring Regulations. 

For more information about the changes, download our 3rd Amendment Factsheet.

More information about our products and services can be found at www.3rdamendment.co.uk or call 0333 015 6626.

Implementation Dates:

1st January 2015 - The Third amendment to BS 7671:2008, The IET Wiring Regulations, became effective on this date. Following this, contractors have a six month transition period to get up to speed with the changes and can design, install and certify to either the new or previous standard.

1st July 2015 – From this date it is a requirement that all electrical installations designed and periodically inspected comply with the updated regulations. Contractors will be expected to hold a copy of BS 7671:2008, incorporating Amendment 3, for any assessment visit taking place after this date.

1st January 2016 – Regulation 421.1.201 (PROTECTION AGAINST FIRE CAUSED BY ELECTRICAL EQUIPMENT) comes into full effect. 

A summary of the key changes:

New numbering system

The Third amendment recognises UK only regulations and these are now identified by a new numbering system. Regulations with a .100 number are CENELEC requirements and those with a .200 number are specific to the UK.

Part 2 Definitions

Definitions have been expanded and modified, including the introduction of some new symbols. A list of abbreviations used in the Regulations has been added. The definition of ‘competent person’ has been removed and it has been replaced with ‘instructed person (electrically)’ and ‘skilled person (electrically)’. These changes have been reflected throughout the wiring regulations. 

Chapter 41 – Protection against electric shock

There is now a requirement for RCD protection for socket-outlets up to 20A for all installations, however exceptions are permitted for:
• a specific labelled or otherwise suitably identified socket-outlet provided for connection of a particular item of equipment, or 
• where, other than for an installation in a dwelling, a documented risk assessment determines that the RCD protection is not necessary

Maximum earth fault loop impedances given in tables 41.2, 41.3, 41.4 and 41.6 have been revised to take account of the Cmin factor. Cmin is the minimum voltage factor to take account of voltage variations depending on a number of considerations.

Chapter 42 - Protection against thermal effects

Due to the number of consumer unit fires reported within domestic premises, Regulation 421.1.201 (UK only) has been added and requires  consumer units and similar switchgear to have their enclosure manufactured from non-combustible material or be enclosed in a cabinet or enclosure constructed of non-combustible material and complying with Regulation 132.12. 
Please note: This regulation will be implemented on 1st January 2016 to allow for manufacturers to ensure an adequate supply of suitable cabinets or enclosures is available.

Chapter 51 – Common rules

Section 551 concerning compliance with standards requires all equipment to be suitable for the nominal voltage and also requires certain information to be noted on the Electrical Installation Certificate.

Chapter 52 – Selection and erection of wiring systems

A new regulation 521.11.201 (UK only) has been included giving requirements for the methods of support of wiring systems in escape routes. 

The regulations concerning selection and erection of wiring systems have been re-drafted. Reference to “under the supervision of a skilled or instructed person” has been removed.

Chapter 55 - Other Equipment

A new section 557 Auxiliary Circuits is included. All auxiliary circuits are defined in Part 2.

Section 559 - Luminaires and lighting installation

Requirements for outdoor lighting installations and extra low voltage lighting installations have been moved to new Sections 714 and 715 respectively.

Part 7 Special Installations or Locations Section 701 locations containing a bath or shower 

There is now a requirement for RCD protection to be provided for: 
• low voltage circuits serving the location
• low voltage circuits passing through zones 1 and 2 not serving the location. 

Appendix 3 Time/current characteristics of overcurrent protective devices and RCDs

This includes changes in connection with maximum earth fault loop impedance to take account of the Cmin factor given in CLC/TR50480:2011.

Appendix 6 – Model forms for certification and reporting

The schedule of inspections (for new work only) has been replaced by examples of items requiring inspection during initial verifications (which must be appended to the Electrical Installation Certificate). 

A small number of changes to the Electrical Installation Condition Report and associated notes have been made, including a requirement to carry out an inspection within an accessible roof space where electrical equipment is present in that roof space.

This summary is not a definitive guide to all the changes introduced by Amendment 3 and contractors will be required to demonstrate a full and comprehensive understanding of Amendment 3 at their assessment visit.

For more information about Amendment 3 or to purchase the updated BS 7671 17th Edition Wiring Regulations and 3rd Amendment Training, please visit www.3rdamendment.co.uk or call 0333 015 6626.