Requirements for ElectricalInstallations
IETWiringRegulationsEighteenthEdition
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JPEL/64 Joint IET/BSI Technical Commite as at June 2018 G D Cronshaw CEng FIETJPEL/64/A Verification Electrical Installations Eur Ing Leon Markwell MSe BSc(Hons) CEng. MIET MCIBSE LCGIJPEL/64/B Thermal Effects Eur Ing Leon Markwell MSe BSc(Hons). CEng MIET MCIBSE LCGIJPEL/64/C Shock Protection S G Devine MIETJPEL/64/D Associate secretary to all submittees Extemal Influences G Gundry MIET M Coles BEng(Hons) MIET
ISBN 978-1-78561-170-4 (paperback)
ISBN 978-1-78561-171-1 (electronic)
Proofread by P E Donnachie BSc CEng FIET and Gary Gundry MIETTpeset in the UK by the Institution of Engineering and Technology. Stev enageKCnCRY
CONTENTS
Foreword
This British Standard is published under the direction of the British Electrotechnical Committee (BEC) and theInstitution of Engincering and Technology (IET).
Following a full review this Standard replaced the 17th Edition of the IEE Wiring Regulations BS 7671:2008 as1 amended. Copyright is heid jointly by the IET and BS1.
Technical authority for this Standard is vested in the Joit IET BSI Technical Committe JPEL/64. This JointCommittee and the BSI Technical Committee PEL/64 meers the constiutional and operational requirements of both parent bodies. JPEL/64 hasthe responsibility for the conet this British Standard under the joint authority of theIET and the BSI Standards Board.
All refereces n this texttheWirng egulationsor teRgultions) whrentthewise ecifically identifi shall he taken to refer to BS 7671:2018 Requirements for Electrical Installations.
Additions or alterations to the regulations owing to the issue of BS 7671:2018 are indicated by a side bar in themargin.
IntroductiontoBS7671:2018
BS 7671:2018 Requirements for Electical Installations was issued on 1st July 2018 and is intended to e intoeffeet on Ist January 2019. Installations designed affer 31st December 2018 are to ply with BS 7671:2018.
oe The Regulations apply to the design erection and verification of clectrical installations. also additions and alterationsRegulations may not ply with this dition in every respect. This does not necessarily mean that they are unsafefor contimued use or require upgrading.
A summary of the main changes is given below.
NOTE: This is not an cxhaustive list.
Part 1 Scope objct and fundamental principles
Regulation 13.1.3 (Selection of equipment) has been modified and now requires ertain usage of equipment to berecorded on the appropriate electrical certification specified in Part 6.
Part 2 Definitions
Definitions have been expanded and modified.
Chapter 41 Protection against eleetrie shock
Section 411 contains a number of significant changes Some of the main ones are mentioned below.
Metallic pipes entering the building having an insulating section at their point of enry need not be conected to the protective equipotential bonding Regulatiom 411.3.1.2).
The maximum disconmection times stated in Table 41.1 mow apply to final circuits rated up to 63 A with one ormore socket-outlets and final circuits rated up to 32 A supplying only fixed connected current-using equipment (Regulation 411.3.2.2).
Regulation 411.3.3 has been revised and now applies to socket-outlets with a rated current not exceeding 32 A.There is an exception to omit RCD protection where. otiher than for a dwelling. a documented risk assessmentdetermimes that RCD protection is not necessary.
A new Regulation 411.3.4 requires that within domestic thousehold) premises. additional protection by an RCD with a rated residual operating current not exceeding 30 mA shall be provided for AC final circuits supplyingluminaires.
Regulation 411.4.3 has an addition that states that no switching or isolating device shall be inserted in a PEN conductor.
Regulations 411.4.4 and 411.4.5 have been redrafted.
The regulations concerning IT systems (411.6) have been reorganized. Regulations 411.6.3.1 and 411.6.3.2 havebeen deleted and 411.6.4 redrafied and a new Regulation 411.6.5 inserted.
uo o up e ps q s:e such as eiectronic equipment with limited short-circuit current.
(hapter 42 Protection against thermal effects
: it:gate the risk of fire in AC final circuits of a fixed installtion due to the effects of arc fault currents. ^ 二 Rgulation 421. 1.7 has been introduced remending the installation of are fault detection devices (AFDDs)
Rgulation 422.2.1 has been redrafted. Reference to conditions BD2. BD3 and BD4 has been deleted. A note hasn aded sating that cables need to satisfy the requirements of the CPR in respect of their reaction to fire and mking reference to Appendix 2. item 17. Requirements have also been inclded for cables that are supplying safetycircuits.
Chapter 44 Protection against voltage disturbances and electromagneti disturbances
Section 443 which deals with protcction against overvolages of atmospheric origin or due to swinching has been
The AQ criteria (conditions of extemal inffuence for lightning) for determining if protection against transiento ervoltages is needed are no longer included. Instead protection against transient overvoltages has to be providedwhere the consequence caused by overvoltage (sce Regulation 443.4):
(i) could result in serious injury to or loss of human life or(ii)could result in interruption of public services/or damage to and cultural heritage or(i) could result in interruption of mercial or industrial activity or(iv) could affect a large number of co-located individuals.
For all other cases a risk assessmem has o be perfomed in order to determine if protection against transient overvoltage is required.
There is an exception not to provide protection for single dwelling units in certain situations.
Chapter 46 Isolation and switching
A new Chapter 46 has been introduced. This deals with non-automatic local and remote isolation and switchingmeasures for the prevention or removal of dangers associated with electrical installations or electrically powered cquipment. Also switching for the control ofcircuits or equipment. Where electrically powered equipment is withinthe scope of BS EN 60204 only the requirements of that standard apply.
Chapter 52 Selection and erection of wiring systems
Regulation 521.10.202 which gives requirements for the methods of support of wiring systems has replacedsuporied against their premature collapse in the event of a fire and applies throughout the installation not just inescape routes as previously.
Regulation 527.1.3 has also been modified and a note added stating that cables also need to satisfy the requirements of the CPR in respeet of their reaction to fire.
Chapter 53 Protection isolation switching control and monitoring
This haptehas been cmletlyrevisdand dals with genera rqurmnts for rotetin olation withing control and monitoring and with the requirements for selection and erection of the devices provided to fulfil such functions.
Seetion 534 Devices for protection against overvoltage
has been pletely revised. The most significant technical change refers to the selection requiremens for thevoltage protection level.
Chapter 54 Earthing arrangements and proteetive conductors
Two new regulations (542.2.3 and 542.2.8) have been introduced concerming earth electrodes.
Chapter 55 Other equipment
Regulation 550. 1 introduces a new scope.
