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Amendment 3 to BS 7671
(17th Edition Wiring Regulations - N.I. & U.K.)

For many years the name Hager has been synonymous with consumer units in the UK, having manufactured more than 4 million at our Telford site. Changes in January 2015 to the wiring regulations with the publication of Amendment 3 have had an impact on the installation practices for household (residential) consumer units.

Amendment 3 states that: 421.1.201.

Regulation 421.1.201 - Protection against therman effects - Consumer Units

Within domestic (household) premises, consumer units and similar switchgear assemblies shall comply with BS EN 61439 3 and shall:
(i). Have their enclosures 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. This does not preclude compliance with this regulation prior to this date.

What the regulations mean:
Guidance from BEAMA (British Electrotechnical and Allied Manufacturers Association) who represent the UK manufacturers. The intent of regulation 421.1.201 is considered to be, as far as is reasonably practicable, to contain any fire within the enclosure and to minimise flames from escaping, caused mainly as a result of poorly installed connections.

The following Q&A’s cover key points.
1. What is a definition of non-combustible?
There is no published definition for ‘non-combustible’ that aligns with the intent of regulation 421.1.201. Ferrous metal is deemed to be one example of a non-combustible material that meets the intent of the regulation.
2. What constitutes a ‘non-combustible enclosure’?
A non-combustible enclosure includes base, cover, door and any components e.g. hinges, covers, screws and catches, necessary to maintain fire containment. See diagram 1. Blanks and devices are contained within the non-combustible enclosure.
3 How is account taken of cable entries into a ‘non-combustible enclosure’ with respect to
containment of internal fire and escape of flames?.
Good workmanship and proper materials must be applied by the installer. The cable installation entry method shall, as far as is reasonably practicable, maintain the fire containment of the enclosure. Account shall be taken of the manufacturers instructions, if any.
4. What is meant by ‘similar switchgear assemblies’?
‘Similar switchgear assemblies’ are assemblies used for the same fundamental application as consumer units.
5. Does regulation 421.1.201 apply to consumer units and similar switchgear assemblies installed in domestic (household) garages and outbuildings?
Yes, the intent of regulation 421.1.201 is that it applies to consumer units and similar switchgear assemblies to BS EN 61439-3 inside all domestic (household) premises including their integral/attached garages and outbuildings or those in close proximity.
Hager