Corrigendum2018 incorporatingAmendment 1:2020Amendment 2:2022 Corrigendum 2020
Requirements for Electrical Installations
IET Wiring RegulationsEighteenth Edition
incorporating Cnrrigenum2018Amendment1:2020 Corrigendum2020Amendment2:2022
Requirements for Electrical Installations
IETWiringRegulations EighteenthEdition
PublicationInformation
Published by the Institution of Engineering and Technology London United Kingdom in agreement with BSI.
Scotland (no. SC038698). The Institution of Engineering and Technology is registered as a Charity in England & Wales (no. 211014) and
IThe Institution of Engineering and Technology is the institution formed in 2006 by the joiningtogether of the IEE (the Institution of Eleetrical Engineers) and the IIE (the Institution of Incorporated Engineers).
dsqu d s ssStandards. It presents the UK view on standards in Europe and at the international level. It isincorporated by Royal Charter.
bsi.
C 2008 2011 2013 2015 2018 2020 2022 the Institution of Engineering and Technology and BSI.
p o pd s ps s Standards Policy and Strategy Committee on 28 March 2022.
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A list of organizations represented on this mitte can be obtained on request to its Committee Manager. The UK participation in its preparation was entrusted to Joint Technical Committee JPEL/64 Electrical Installations.
This publication does not purport to include all the necessary provisions of a contract. Users are responsible for iscorrect application. Compliance with a British Standard cannot confer immunity from legal obligations.
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J In oqposss puesnpud nooeb s oud o I pu I jo e uesu s anyone finding an inaccuracy orambiguity while using this British Standard would inform the Committee Manager G D Cronshaw (gcronshaw@) The IET Six Hills Way Stevenage SGI 2AY United Kingdom.
IET Technical Regulationsstaff
as at August 2021
Joint IET/BSI Technical CommitteeJPEL/64 Elecrical Installations G D Cronshaw CEng FIETJPEL/A/64 Verification Thermal Effects M Peace CEng MIET MCIBSE Eur Ing L D Markwell MSc BSc(Hons)JPEL/B/64 CEng MIET MCIBSE LCGIJPEL/C/64 Shock Protection External Infuences S G Devine IEng MIET M Coles BEng(Hons) MIETAssociate Committee Manager JPEL/D/64 R H Giddings IEng MIET AC1BSE
ISBN 978-1-83953-218-4 (paperback)
ISBN 978-1-83953-220-7 (vitalsource)
Proofread by M Doughton IEng MIET LCGI and G Gundry MIETPrinted and bound in the UK by CPI Group (UK) Ltd Croydon CR40 4Y Y Typeset in the UK by the Institution of Engineering and Technology Stevenage
CONTENTS
CHAPTER 12 OBJECTAND EFFECTS 22CHAPTER 13 PART 2 FUNDAMENTALPRINCIPLES DEFINITIONS 22 29PART 3 CHAPTER 30 ASSESSMENT OF GENERALCHARACTERISTICS ASSESSMENT OFGENERAL CHARACTERISTICS 50 51CHAPTER 31 CHAPTER 32 CHAPTER 33 PURPOSES SUPPLIES AND STRUCTURE CLASSIFICATION OF EXTERNAL INFLUENCES 51 56CHAPTER 34 CHAPTER 35 COMPATIBILITY SAFETY SERVICES 57 57 58CHAPTER 36 PART4 CONTINUITY OF SERVICE PROTECTIONFORSAFETY 58 59CHAPTER 41 CHAPTER 42 PROTECTION AGAINST ELECTRIC SHOCK PROTECTIONAGAINST THERMALEFFECTS 62 84CHAPTER 43 PROTECTION AGAINST OVERCURRENT PROTECTION AGAINST VOLTAGE DISTURBANCES 102 93CHAPTER 46 PART5 CHAPTER 45 ISOLATION AND SWITCHING SELECTIONAND ERECTION OF EQUIPMENT NOT USED 127 123 124CHAPTER 51 CHAPTER 52 SELECTIONAND ERECTION OF WIRING SYSTEMS COMMONRULES 130 139CHAPTER 53 CHAPTER 54 PROTECTION ISOLATION SWITCHING CONTROLAND MONITORING EARTHING ARRANGEMENTS AND PROTECTIVE CONDUCTORS 154 197CHAPTER 55 CHAPTER 56 OTHER EQUIPMENT SAFETY SERVICES 225 206CHAPTER 62 PART 6 CHAPTER 61 NOTUSED INSPECTION AND TESTING NOTUSED 239 231CHAPTER 63 CHAPTER 64 NOTUSED INITIAL VERIFICATION 232 23f 231CHAPTER 65 PART7 PERICOICINSPECTION AND TESTING SPECIALINSTALLATIONSOR LOCATIONS 239 241SECTION700 SECTION 701 LOCATIONS CONTAINING A BATH OR SHOWER GENERAL 241 242SECTION 702 SECTION 703 SWMMING POOLSAND OTHER BASINS ROOMSAND CABINS CONTAINING SAUNAHEATERS 256 247SECTION 704 SECTION 705 SECTION 706 CONSTRUCTION AND DEMOLITION SITE INSTALLATIONS CONDUCTING LOCATIONS WITH RESTRICTED MOVEMENT AGRICULTURALAND HORTICULTURAL PREMISES 258 265 260SECTION 708 SECTION 709 ELECTRICAL INSTALLATIONS IN CARAVAN /CAMPING PARKSAND SIMILAR LOCATIONS MARINAS AND SIMILAR LOCATIONS 267 271SECTION710 SECTION 711 MEDICALLOCATIONS EXHIBITIONS SHOWSAND STANDS 276 288SECTION 712 SECTION 714 SOLAR PHOTOVOLTAIC(PV) POWER SUPPLY SYSTEMS OUTDOOR LIGHTINGINSTALLATIONS 291 302SECTION 715 SECTION 717 EXTRA-LOW VOLTAGE LIGHTING INSTALLATIONS MOBILE OR TRANSPORTABLE UNITS ELECTRICALINSTALLATIONS IN CARAVANS AND MOTOR CARAVANS 304 307SECTION 721 SECTION 722 SECTION 729 ELECTRIC VEHICLE CHARGING INSTALLATIONS OPERATING AND MAINTENANCE GANGWAYS 315 325 331SECTION 730 SECTION 740 ONSHORE UNITS OF ELECTRICAL SHORE CONNECTIONS FOR INLAND NAMGATION VESSELS TEMPORARY ELECTRICAL INSTALLATIONS FOR STRUCTURES AMUSEMENTDEVICES 336SECTION 753 HEATING CABLES AND EMBEDDED HEATING SYSTEMS AND BOOTHSATFAIRGROUNDS AMUSEMENT PARKS AND CIRCUSES 341 346PART8 CHAPTER 82 FUNCTIONAL REQUIREMENTS PROSUMER'S LOW VOLTAGE ELECTRICAL INSTALLATIONS 350 352APPENDICES 1 (Normative) 2 (Infomative) BRITISH STANDARDS TO WHICH REFERENCE IS MADE IN BS 7671 STATUTORY REGULATIONS AND ASSOCIATED MEMORANDA 384 406 3853 (Infomative) (eu TIME/CURRENT CHARACTERISTICS OF OVERCURRENT PROTECTIVE DEVICES CURRENT-CARRYING CAPACITY AND VOLTAGE DROP FOR CABLES 409 4215 (Infomative) MODELFORMS FOR CERTIFICATION AND REPORTING CLASSIFICATION OF EXTERNAL INFLUENCES 492 5088 (Iinformative) 7 Deleted by 8S 7671:201 8A2:2022 CURRENT-CARRYING CAPACITY AND VOLTAGE DROP FOR BUSBAR TRUNKING AND 229 533( POWERTRACK SYSTEMS DEFINITIONS - MULTIPLE SOURCE DC AND OTHER SYSTEMS PROTECTION OF CONDUCTORS IN PARALLELAGAINST OVERCURRENT 535 54311 (Infoemative) 12 WARNING AND USER INSTRUCTION LABELS NOT USED 547 55113 (Informative) 14 (Informative) ESCAPE ROUTES AND FIRE PROTECTION DETERMINATIONOF PROSPECTIVE FAULT CURRENT 554 55215 (Informative) DEVICES FOR PROTECTION AGAINST OVERVOLTAGE RING AND RADIAL FINAL CIRCUIT ARRANGEMENTS REGULATION 433.1 555 557TABLE OF FIGURES TABLE OF TABLES 17 (Infomalve) ENERGY EFFICIENCY 563 569INDEX3
Foreword
This British Standard is published uoder the direction of the British Standards Institution and the Institution of Eugincring and Tccluology (IET).
Following a full review this Standard replaced the 17th Edition of the IEE Wiring Regulations BS 7671:2008 asamended. Copyright is held jointly by the IET and BSL
Teclical Couitec wich isessile f e wuk eviously letke by dc IEE Wiing Regulatis Technical authority for this Standard is vested in the Joint IET/BSI Technical Commitee JPEL/64. This JointCommitte and the BSI Technical Committe PEL/64 meets the constitutional and operational requirements of bothparent bodiesJPEL/64 has thc responsibility for the content of this British Standard under the joint authority of the IET and the BSI Standards Board.
All references inthis text totheIETWiring Regulations or theegulations)wherenot therwise specificallyidentifiedshallbe taken torefer toBS7671:2018Requirements for ElctricalInstallationsas amendedby Amendment 1:2020 and Amendment 2:2022.
Auditivus u altietivus o 1egulatiuus vwing lo tle isouc of D3 7671.2018.A2.2022 ae idivaied by a side ba inthe margin.
IntroductiontoBS7671:2018
RS7671n8RriefFlatrilItlltin n 1e Ily 018n ie itend tn me inteffect on 1st January 2019. Installations designed after 31st December 2018 are to ply with BS 7671:2018.
TheRegulatinsaplytothdesignrectionndvenfcatonflcaltalltnsalsaddonsandaltratn to existing installations.Existing installations thathave been installed in accordance with carlierditions of theRegulations may not ply with this edition in every respect. This does not necessarily mean that they are unsafeeadnnbaosn pno
A summary of the main changes is given helow.
NOTE: This ia st ani sahaustivc ist
Part 1 Scope object and fundamental principles
Regulation 133.1.3 (Selection of cquipment) as been modifiedand now requires certain usage o cquipmen to berecorded on tle appropriate clectrical certification specificd in Pat 6.
Part 2 Definitions
Definitions have been expanded and modified.
Chapter 41 Protetion ngainst 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 scction at their point of entry need not be connected to the protective cquipotential bonding (Regulation 411.3.1.2).
The maximum disconnection times stated in Table 41.1 now 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).
There is an cxception to omit RCD protcction where other than for a dwelling a documented risk assessment Rcgulation 411.3.3 has becn rcviscd and now applics to sockct-outlcts with a ratcd currcnt not cxccding 32 A.determines that RCD protcction is not necessary.
luminaires.
A new Regulation 411.3.4 requires that within domestic (household) premises additional protection by an RCD with a rated residual operating current not exceding 30 mA shall be provided for AC final circuits supplying
Rcgulation 411.4.3 has an addition that states that no switching or isolating devicc shall be inserted in a PEN conductor.
Regulations 411.4.4 and 411.4.5 have been redrafted.
The regulations conceming T systems (411.6) have been reorganized. Regulations 411.6.3.1 and 411.6.3.2 havebeen deleted and 411.6.4 redrafled and a new Regulatiou 411.6.5 inscrted.
