New Year, New Rules | 17th Edition - 3rd Amendment

01 January 2016


The 3rd amendment to the 17th Edition Wiring Regulations was released last January, bringing some major changes to the status-quo. Since July, all electrical Installations are required to be fully compliant with these changes.

On the 1st January 2016, the final regulation comes into play and, with this in mind; we thought it would be helpful to quickly recap the amendment in full.

Why change?

The primary reason for any changes to regulations is to keep safety levels up and to protect consumers from potential harm. In this case, loose connections have been found to be the root-cause of fires in a spate of recent instances.

What do you need to do?

All electrical contractors will need a copy of BS 7671:2008, incorporating amendment 3 and it is crucial that all engineers have a sound understanding of the mandatory requirements set out within the book, compliance is key.

Changes for 201617th_edition_amendment_3.png

Most amendments started being enforced in July 2015. Now, 6 months later, amendment 421.1.201 is ready to be implemented. Its main aim is the protection against fire caused by electrical equipment:

421.1.201 – Within domestic (household) premises, consumer units and similar switchgear assemblies shall comply with BS EN 61439-3 and shall:

i. have their enclosure manufactured form non-combustible material, or
ii. Be enclosed in a cabinet or enclosure constructed of non-combustible material and complying with Regulation 132.12.

The extra six months has been given to allow manufacturers to ensure an adequate supply of suitable cabinets and enclosures will be available.

Recap of all changes made last year:

  1. New numbering system - The regulations will be 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.
  2. Part 2 definitions - Definitions will be expanded and modified. The definition of competent persons will be removed and replaced with ‘instructed person (electrically)’ and ‘skilled person (electrically)’.
  3. Chapter 41 - Protection against electric shock -There will be a requirement for RCD protection for socket outlets up to 20A for all installations, with the exception of when a documented risk assessment determines that it’s not necessary.
  4. Chapter 52 - Selection and erection of wiring systems -New regulation 521.200 has been included giving requirements for the methods of support of wiring systems in escape routes, to help with the dangers to the fire forces. The regulations concerning selection and erection of wiring systems have been re-drafted. Tables for Maximum Zs values, (41.1-41.4) have been adjusted to allow for the new Cmin factor which takes into consideration the variations to supply voltages. In addition, notes have been changed in connection with maximum permitted operating temperatures. 
  5. 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.
  6. Chapter 42 - Protection against thermal effects - Regulation 421.1.200 has been added and requires switchgear assemblies including consumer units installed in domestic premises to have their enclosure manufactured from non-combustible material or otherwise suitably installed. The implication of this change will be that most consumer units in domestic premises will be metallic.
  7. Chapter 55 - Other equipment - A new section 557 Auxiliary Circuits is included. All auxiliary circuits are defined in Part 2.
  8. Chapter 550 - 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.
  9. Part 7 - Special installations or locations - Section 701 locations containing a bath or shower. There is a requirement for all low voltage circuits serving or passing through the location to be RCD protected.
  10. 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 verification (which must be appended to the Electrical Installation Certificate).

DTL has created a one-day 17th Edition Amendment 3 Workshop to help all concerned get up to date with the Amendment 3 changes. Find out more and book online here.

For those that are new to the profession, it is advised that they attend the full course, which also includes the changes covered in 17th Edition Amendment 3, click here for more information.