Distribution Boards, Consumer Units or Fuseboxes

Distribution Boards, Consumer Units or Fuseboxes

Distribution Boards, Consumer Units or Fuseboxes
The New Rules

It doesn’t matter what you call it, the box is now subject to British Standard BS EN 61439-3. Distribution boards intended to be operated by ordinary persons (DBO) and The third amendment to BS 7671:2008 (IET Wiring Regulations Seventeenth Edition). This came into effect on 1 July 2015 and requires consumer units and similar switchgear assemblies in domestic premises to have a non-combustible enclosure.
The wording of the regulation is this:

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 from non-combustible material, or
(ii) be enclosed in a cabinet or enclosure constructed of non-combustible material and complying with Regulation 132.12.
NOTE 1: Ferrous metal, e.g. steel, is deemed to be an example of a non-combustible material.
NOTE 2: The implementation date for this regulation is the 1st January 2016, but does not preclude compliance with the regulation prior to that date.


Simple really, more and more fires have been found to have been found to involve consumer units. Whether that be poor workmanship or lack of maintenance, the most important thing is that if the enclosure had been non combustible or metal it would have contained the fire. Whereas the previous thermoplastic ones would melt and allow the flames to escape as these pictures show.

Damaged House boards

Does this apply to outbuildings, such as garages or sheds? Well the regulation actually uses the term ‘premises’ which brings us to the question what is the definition of ‘premises’ and what does it include? The regulation was primarily introduced to cover the interior of a house, but it is good practice to question the proximity of the outbuilding to the main house. Is it an integral garage or attached to the main building and of course does it contain anything combustible.
Regulation 421.1.201 is not intended to apply to a consumer unit that is not within a building, such one mounted outdoors i.e. the outside of a building.

But if in doubt use a metal clad enclosure!!


Damaged BoardsAll Chint Distribution Boards and pre-Assembled Garage and Shower Units comply with the Regulations. The boards have certification by 3rd Party Test Houses, copies of which are available on request.

Chalon Components Ltd are pleased to be able to offer the full Chint NX3 range of Metal consumer units from 3 ways to 36 ways, download the full brochure here.

Share this post

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.