Update on Ireland’s new National Rules for Electrical Installations IS:10101

New Rules
  • Charles Dunn M.Sc MIET MCIBSE MIHEEM 

Since the nationwide presentations by NSAI-TC2 early 2019, much has been happening in the background to get the new Rules on the road. Reaction to the Draft for Public Consultation was huge, with lots of comments received by NSAI to be addressed. Many thanks to you all for your valuable input. Some of the ideas can be implemented now, and others may have to wait until further revisions of the rules. The NSAI system assures that all of your comments have been read and considered by the technical committee TC2. 

ET:101 National Rules for Electrical Installations (4th edition) will be revised and released as an Irish Standard IS:10101. The National Rules for Electrical Installations in the UK has been British Standard BS:7671 for many years, so the move to NSAI and the creation of an Irish Standard for Ireland’s National Rules is a natural progression. The UK revised and released their 18th edition of BS:7671 in 2018, allowing Ireland to benefit from the experience on how to revise and incorporate public comment into the launch of IS:10101.

Right now, the document is having a final check over (there are over 700 pages in it) and the NSAI planned publication date is January 2020. But that’s just getting the book out. Everyone will have time to study the new rules and train up, before implementation date which is planned for around July 2020. CRU will determine the actual implementation date, under the Electricity Regulation Act 1999, so look out for news from CRU for the exact date. 

Publication date will be that date when the new book is available to purchase from NSAI.

Implementation date will be that date from which all new electrical installations will need to be designed to the new rules IS:10101. Electrical installations which have already been designed to the old rules ET:101 can still be installed and certified to the old rules ET:101.

One of the big changes will be the new cables standard, with all cables to be rated Class Dca s2,d2,a2 in accordance with EN50575. Suppliers are already working on this change to ensure that old stocks are run down in time for the new implementation.

Arc Fault Detection devices AFDDs will be “recommended” for certain high risk installations. AFDDs are in use in other countries, and will eventually become mandatory. The AFDD introduction phase will be similar to that experienced with residual current devices, with ELCBs and RCDs RCBOs initially taking some time to understand and accept. Eventually AFDDs will become safety devices that are the accepted norm, and suppliers are already working to provide sample products and wiring installation instructions.

The new requirement for residual current devices for domestic lighting circuits will be a little easier to implement, as RCDs and RCBOs are already widely available.

As a response to the Public Consultation process, the proposed requirement for distribution boards in domestic premises to be “non-combustible” has been changed. Industry representatives questioned how the “non-combustible” could be verified, where nearly every material used could eventually burn at some (albeit very high) temperature. Research also showed that the enclosure itself may not be the primary source of worry, with busbars and connections themselves presenting a fire risk. Switchgear components also present risk, where not installed according to manufacturers instructions. Therefore the new rules will continue the requirement for all distribution boards to comply the existing standard EN:61439, which already deals with the fire risk issues.

Appendix 8 of the new rules will give guidance on Energy Efficiency, which should be incorporated into the design process. With Europe striving to reduce carbon emissions, Appendix 8 proposes that designs consider copper losses in the electrical installation by analysing primary electrical loads early in the design process. Reducing cable lengths and sizing appropriately will reduce energy losses. The addition of alternative energy sources (examples – CHP, solar photovoltaic, wind, biofuel) and future technologies (examples – electric vehicle charging, heat pumps) are to be considered by the designer, to ensure that the electrical installation can adapt as required over its life.

Charles Dunn

Charles Dunn M.Sc MIET MCIBSE MIHEEM is a Chartered Engineer with over 25 years of experience in the Building Services Industry. Having worked as a design consultant for healthcare, industrial, education and retail construction projects, Charles gained a very broad view of the electrical industry which led him to complete a postgraduate Masters in Energy Management. Charles continues to work in the electrical design industry with a consulting engineers O Connor Sutton Cronin based in Dublin. Charles was appointed to NSAI technical committee 2 in 2017 to represent CIBSE in the maintenance and development of Irelands National Rules for Electrical Installations ET:101. As chair of TC2, Charles has worked with specialists across the broad range of the electrical industry to facilitate the transfer of Irelands electrical rules from ETCI to NSAI as well as adapting and adopting IEC harmonised documents to create the first revision of the National Rules in over ten years.