18th Edition Amendment 2 Guide

18th Edition Amendment 2 Guide

18th edition amendment 2 guide

So it’s finally time to comply with the latest update to the regulations, and thus here is our 18th Edition Amendment 2 Guide in full.

Introduced in April 2022, there was a 6 month ‘grace period’ to enable electricians and contractors to ensure that they are able to comply fully before the regulations must be complied with. That 6 month period ended on 27th September 2022, and all new installations (or alterations to existing installations) must now comply with the latest changes.

The 18th edition amendment 2 has brought a raft of new rules, some quite drastic changes for particular installations (we’ll go into this in more depth below)

So let’s list the ‘main’ changes below, then we’ll explain what each change means and give more information:

  • AFDDs now required in certain installations
  • SPDs are now required except where customer specifically requests not to be fitted
  • Full new chapter on ‘Prosumer Low Voltage Installations’
  • Changes to labelling requirements & notices, particularly on consumer units
  • RCD protection to socket outlets
  • Precautions where particular risks of fire exist
  • Selection of RCDs
  • Generating sets in parallel to supply
  • Inspection & testing
  • EV charging installations

AFDDs Now Required in Certain Installations

Chapter 42 – Protection Against Thermal Effects now has an addition which brings a requirement to install Arc Fault Detection Devices to BS EN 62606 for certain circuits in certain types of installation.

That may sound a bit wishy washy so let me explain! AFDDs are now required to be installed to socket circuits of 32A or less in the following premises:

  • Care Homes
  • Houses Of Multiple Occupation (HMOs)
  • Purpose Built Student Accommodation
  • High Risk Residential Buildings (Defined as those above 18M tall – 6 storeys)

We’ve written a full guide to AFDDs under the 18th edition amendment 2, and you can access it by clicking here: AFDD Regulations Guide

SPDs are Now A Requirement Under AMD2

Amendment 2 has altered the requirements for SPDs which were introduced within the original 18th edition regulations.

The original ‘flash map’ giving recommendations and the risk assessment has been removed altogether and replaced with regulation 443.4.1 which requires that installers provide protection against transient overvoltage to be provided where the overvoltage may:

  • Serious injury to, or loss of, human life
  • Failure of a safety service as defined in Part 2
  • Significant financial or data loss

For all other cases, protection against transient overvoltage is still required to be installed, unless the owner of the installation specifically declares that such protection is not required. They must also declare that they accept the responsibility of any financial or data loss which may occur during such an overvoltage event.

Quite frankly, it’s easier to just fit an SPD at the source of the installation when completing major works (IE: a consumer unit change) as the price point of these has come down to such a level.

Prosumer Low Voltage Installations

Changes To Labelling & Notice Requirements

In a rare ‘lowering’ of the requirements, 18th edition amendment 2 has brought about some changes to the requirements for labelling of installations and the notices which must be fitted.

This has been brought about as a result of the fact that consumer units are now quite often fitted into locations that can be seen by the homeowner. As such, the homeowner can often remove the notices that have been fitted to consumer units to make them look more appealing to the eye.

18th edition amendment 2 now states that such notices need not be fitted to domestic consumer units (or similar installations) where the homeowner receives certification which notifies them of the similar information which would have been contained within the notices previously fitted.

The particular notices affected by this have been:

  • RCD test label
  • Periodic inspection test label
  • Presence of SPD label

The exception to this is the warning notice which applies to ‘additional supplies’. This must still be fitted to the appropriate consumer unit when more than one supply applies to that installation.

RCD Protection To Socket Outlets

The section relating to RCD protection to socket outlets has been rewritten for the 18th edition amendment 2.

Regulation 411.3.3 states that RCD protection not exceeding 30mA must be provided for socket outlets up to 32A

  1. Socket outlets with a rated current not exceeding 32A in locations where they are liable to be used by persons with a capability BA1, BA2 or BA3 (BA1 is an ordinary person, not skilled or instructed. BA2 is children and BA3 is disabled persons, those who are not in command of all their physical or intellectual abilities)
  2. Socket outlets with a rated current not exceeding 32A in other locations
  3. Socket outlets serving mobile equipment with a rated current not exceeding 32A for use outdoors

There is still an exception to this regulation where a risk assessment method may be used to omit RCD protection. This exception is not allowed to be used in situations 1 or 3 above (IE: can only be used in locations which are not expected to be used by persons with a capability BA1, BA2 or BA3, or those which are not expected to serve mobile equipment for use outdoors)

Precautions Where Particular Risks Of Fire Exist

The 18th edition amendment 2 has introduced a new definition, that of a ‘protected escape route’. This is to describe a route which has specific fire-resisting construction designated for escape to a safe place during an emergency.

The main regulation relating to this is 422.2 which requires that:

Cables or other electrical equipment shall not be installed within a protected escape route unless they are part of:

  1. Essential fire or related safety system
  2. General needs lighting
  3. Socket outlets provided for cleaning and/or maintenance

The 18th edition amendment 2 also places requirements on the types of cables and cable management systems which are used within protected escape routes. These are to be flame resistant or installed within flame resistant cable management.

Selection Of RCDs

The latest changes to the regulations have brought some quite radical changes to how RCDs are selected for installation.

18th Edition Amendment 2 Guide

The original 18th edition first introduced using different types of RCD for different situations, however amendment 2 has cemented that much more with a number of hard and fast rules for their selection.

The type AC RCD is now only to be used in instances where there is no chance of a DC component to any fault current. This limits their use to purely resistive loads such as heating or filament lighting.

This section does need quite a bit of further explanation, so we made a dedicated RCD regulations guide

Inspection & Testing

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