Amendment A1 of I.S.10101:2020 was published by the NSAI in September 2024. The amended standard is now referred to as IS10101:2020+A1:2024/AC2:2025. The main changes are listed below:

• Part 718: 'Communal Facilities and Workplaces' – This a new section in Chapter 7;
• Part 722: 'Supply of Electric Vehicle' – Completely rewritten but limited changes;
• Annex 8A: 'Energy Efficiency' has been changed to Chapter 8 Energy Efficiency with a new section on Prosumers Electrical installations.

Other changes include minor modification to a number of clauses which are listed on the NSAI's website. It is worth mentioning one of these changes, ie, Rule 551.9.3 where the rating of an RCD used as the input from a microgenerator has changed from 30mA to 100mA. 'AC2 2025' refers to a minor correction to Table 6E1. This can be downloaded as a PDF from the NSAI's website.

This article deals with the changes to Parts 718 and 722. Chapter 8 Energy Efficiency including Prosumers Electrical installations will be discussed at a later stage.

Communal Facilities and Workplaces – (718)

Introduction

Section 718 provides additional requirements for electrical installations in communal facilities and workplaces. Typical examples of such locations include assembly halls, assembly rooms; exhibition halls; theatres and cinemas; sports arenas; sales areas; restaurants; hotels, guest houses; residential care homes; schools; enclosed car parks; meeting places; swimming halls; airports, railway stations; high-rise buildings; workshops; factories and industrial plants.

The scope is far reaching and covers almost every type of building beyond a dwelling.

The risks associated with electrical installations in such locations are not defined in the standard but possibly relate to their complexity compared to other buildings. For example, isolation of the electricity supply may be more complex, there may be a higher density of people or escape routes may be longer and more complex. The following are some of the key issues in Section 718.

Condition of Evacuation in an Emergency (718.422)

For communal facilities and workplaces the appropriate 'Condition of Evacuation in an Emergency' shall be established and the appropriate clauses of Part 42 taken into account. The 'Conditions of Evacuation' as referred to in Annex 51ZA of IS10101. These range from 'BD1 – Low density easy to exit' to 'BD –High density difficult to exit'. Such an assessment should perhaps be made in consultation with the fire consultant for the project.

Main Isolation (718.537)

The distance between the means of switching off for the electrical installation, ie, the main isolator and the place where the corresponding supply cables enter the building shall be as short as practicable.

This issue is also covered in the ESB’s 'Code of Practice for Customer Interface'. Figure 1 is an interpretation of ESB requirements for the maximum distances of their cables within a customer’s premises.

Figure 1: Requirements for max distances for isolation.

Maintenance of Lighting Circuits (718.559)

Maintenance of adequate levels of illumination shall be determined by a risk assessment of the premises taking account of the classification of evacuation as per Annex 51ZA of IS10101.

Two different arrangements for lighting the final circuit are specified as follows: (i) Locations with low risk (Condition BD1) where a single normal lighting final circuit is adequate and (ii) other locations: (Condition BD2 , BD3 or BD4). For the latter, ie, the vast majority of buildings, two or more lighting circuits are required with luminaires supplied in such a way that failure of either circuit will not leave any part of the location with an insufficient level of illumination.

This rule also states that if RCDs are used they shall protect no more than one final circuit. RCDs are not generally required for protection of lighting circuits other than in domestic installations. However, where they are deemed necessary, eg, in a room containing a bath or a shower, this rule means that a common or RCCB protecting a group of MCBs (which is common in domestic installations) cannot be used in communal facilities and workplace, ie, each lighting circuit which requires RCD protection must be protected by an individual RCBO.

If the normal lighting of a location accessible to the public can be dimmed, means shall be provided to reinstate the full level of illumination by an appropriately located switch. In some locations it may be necessary to ensure lighting cannot be operated by unauthorised persons.

Figure 2 below shows a simplified example of compliance with 718.559 for a building meeting Condition of Evacuation BD2, BD3 or BD4. The corridor is illuminated using two separate circuits with lighting points interleaved such that failure of either circuit will not leave the corridor in darkness. Likewise the emergency fittings are balanced across both circuits.

Figure 2: Simplified example of compliance with Rule 718.559.

Supplies for Electric Vehicles (722) 

Introduction

Section 722 applies to circuits intended to supply energy to electric vehicles and circuits intended for feeding electricity from electric vehicles into the grid (V2G). While the entire section has been rewritten, the basic requirements for domestic and similar installations has not changed.

Selectivity shall be maintained between the RCD protecting an EV charging point and an RCD installed upstream. In a typical domestic system, while there are other RCDs in the consumer unit (ie, those supplying socket circuits, lighting circuits, immersion heaters and electric showers), these would be in parallel rather than in series with the RCD serving the EV charging point and, therefore, there is no concern regarding selectivity.

Figure 3 below shows a typical installation for 7kW EV supply equipment/charging point in a domestic situation. Many of the EV charging point/charging points on the market have in-built d.c. earth leakage detection which disconnects the supply if the fault current exceeds 6 mA. They also have active load management systems which monitor the incoming mains to the consumer unit and regulate the output from the EV charging point to ensure the main OCPD is not overloaded.

Figure 3: Typical 7kW domestic EV supply equipment/charging point.

Wireless Power Transfer (WPT)

Amendment +A1 2024 also makes reference to Wireless Power Transfer (WPT) technology for EVs. There are two broad categories of WPT: (i) Static Wireless Charging System (SWCS) – charging while the car is parked/static, and (ii) Dynamic Wireless Charging System (DWCS) – charging while the car is in motion

In a SWCS installation the vehicle parked over a base transmitter. High frequency a.c. power is transferred by magnetic induction to the vehicle receiver. This is then converted back to d.c. to charge the battery. While this technology is still in the developmental stage, it is likely to become commercially available as an option to current wired arrangements in the coming years.

Open PEN detection in BS 7671

It is worth noting that the draft for public enquiry of the A1 Amendment (NSAI: – Draft IS 10101:2020/prA1:202x) proposed Open PEN detection similar to what has been included in BS 7671:2018 Amendment 2:2022.

An open neutral or open PEN fault can cause significant deviations in the L-N voltage especially when there is significant load imbalance in the network. If the voltage falls outside the normal window (230 V a.c. ±10% ie, 207 V to 253 V), an open PEN condition is deemed to have occurred presenting a risk of electric shock.

Upon detecting an open PEN condition, the system must automatically disconnect the supply to the EV charging point including line neutral and earth conductors. This requirement was not included in the in the actual published A1 amendment. Such a method of protection cannot be used in Ireland as there is no allowance anywhere in IS10101 for switching a protective earth conductor.

ESB’s – National Code of Practice

The requirements of Part 722 should be read and construed in conjunction with Annex I of the ESB’s – National Code of Practice which covers requirements for four main types of EV recharging installations ie: (i) Home Recharging; (ii) Destination and Workplace Recharging; (iii) On-Street Recharging and (iv) Fast and Ultra-Fast Recharging.

Courses at Engineers Ireland 

Fundamentals of M&E Consultancy: Thursday, September 25, 2025;

National Rules For Electrical Installations – IS10101 (+A1 2024) – WR2 – New Wiring Rules – Chapter 7 Explored: Tuesday, September 30;

Fire Alarm System Design to I.S. 3218 (2024) – Online Classroom (4201): Tuesday, October 7;

Fundamentals of Electrical Services Design – Online Classroom (4200): Thursday, November 20, 2025;

National Rules For Electrical Installations – IS10101 (+A1 2024) – WR1 – Understanding the New Wiring Rules – Online Classroom (4200): Tuesday, January 27, 2026.

Author: Brendan Dervan is the author of 'The Wiring Rules in Ireland, An Illustrated Guide to I.S.10101'.This guidebook can be purchased directly here. Dervan is a Chartered Engineer with more than 45 years’ experience in Building Services. He was the founder of Dervan Engineering Consultants (DEC) established in 1999. The company provided M&E consultancy and project management services to a diverse range of clients in multiple sectors. In 2016 his practice merged with Cundall, a global multi-disciplinary engineering consultancy firm. He retired from mainstream consultancy in 2019 and set up Best Training. He is a member of the Electrical Division of Engineer’s Ireland and from 2020 to 2023 represented them on NSAI’s ETC/TC 02 committee which oversees the development of the Wiring Rules. He provides specialist CPD courses on a wide range of topics to consulting engineers, contractors, public bodies etc. For further information on these training courses please visit: www.besttraining.ie