Wiring Regulations Bitesize Guide Update

I.S.10101 Wiring Regulations – A Bitesize Guide

In February 2021, the new standard for the national rules regarding electrical installations came into force to replace the old Wiring Regulations.

The main changes impacted common areas such as RCD use, distribution boards and protection against transient overvoltages. Installers & contractors should take the time to understand what is required to remain compliant now.

What you need to know
All installations designed after February 2021 must comply with the revised set of regulations.

The new regulations are designed to enhance safety and clarify issues around the design, erection, and verification of all electrical installations, as well as additions and alterations to existing installations.

It’s worth noting that although existing applications installed in accordance with previous editions of the Wiring Regulations may no longer comply with I.S.10101, but this does not necessarily mean that they are unsafe for continued use or require upgrading.

Wiring Regulations: 5 Key Changes

1 – Distribution boards in domestic premises

The new requirements state:

  • Distribution boards shall comply with I.S. EN 61439-1 and I.S. EN 61439-3 within domestic premises.
  • Wall-mounted distribution boards now need to be mounted at a height no greater than 2.15m measured from the floor to the top surface of the highest protective device.
  • In a household or similar installation, the main isolator must interrupt both live and neutral conductors of a singlephase supply.
  • Where the enclosure for the main overcurrent device in the ESB Networks meter cabinet is fitted with Earth and Neutral terminals, the requirement for double pole isolation now also applies.

2 – Protection against transient overvoltages of atmospheric origin or due to switching

The new requirements state:

  • Protection against transient overvoltage is now required where the consequence caused by overvoltage affects:
    • a) human life, e.g. safety services, and medical care facilities;
    • b) public services and cultural heritage, e.g. loss of public services, IT centres, museums; commercial or industrial activity, e.g. hotels, banks, industries, commercial markets, farms. A large number of individuals, e.g. large buildings, offices, schools.
  • In all other cases, a risk assessment is required to be performed.
  • If a risk assessment is not undertaken, then protection against transient overvoltage is required.
  • In the case of a single dwelling unit, an assessment needs to be made on whether the total value of the installation and equipment justifies the inclusion of such protection.

3 – Residual current devices on lighting circuits in domestic premises

The new requirements state:

  • Additional protection with an RCD with a rated residual operating current not exceeding 30 mA should be provided for A.C. final circuits supplying luminaires in domestic premises.
  • An overcurrent protective device rating of 6A for 1.5mm copper cable and 10A for 2.5mm cable should be used in lighting circuits.
  • To meet this instruction, it is recommended to use a consumer unit with a ‘dual RCBO’ arrangement for lighting circuits.
  • It is recommended that lighting and socket circuits should not be mixed on the same RCD.

4 – Selection of types of RCD

The new requirements state that the designer or installer is required to select the appropriate RCD device for a specific application from the following list:

  • Type AC – detect AC residual currents – not recommended for new installations.
  • Type A – general purpose use, including equipment incorporating electronic components.
  • Type F – equipment with frequency-controlled speed drives.
  • Type B – electric vehicle chargers, PV supplies.

5 – Protection against fire caused by electrical equipment

  • I.S.10101 introduces a new kind of protection device – an Arc Fault Detection Device (AFDD).
  • It is designed to detect and disconnect dangerous electrical arcs in both fixed wiring and connected equipment which could be the source of a fire.
  • The fitting of an AFDD conforming to IEC 62606 is recommended to provide additional protection against fire caused by arc faults in AC final circuits.
  • The AFDD shall be placed at the origin of the circuit being protected, such as in sleeping premises, locations where stored materials are a fire risk, locations with combustible construction materials, and locations housing irreplaceable goods.

Our team is on hand to support any queries you may have and you can download our handy guide here.


Kempston Controls is committed to finding you the ideal solution for your application. Call us today on 042 9359393, email us at electrical@kempstoncontrols.ie, or alternatively contact us here, we will be happy to help.

Kempston Controls

Leave a Reply

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

You may use these HTML tags and attributes:

<a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>