IET
IET Wiring Regulations Eighteenth EditionBS7671:2018 RequirementsforElectrical Installations
IET
ON-SITEGUIDE BS 7671:2018
PublishedbytheInstitutionofEngineeringandTechnology London UnitedKingdom
TheInstitutionofEngineeringandTechnologyisregisteredasaCharityinEngland&Wales(no.211014) and Scotland (no. SC038698).
The Institutionof Engineering andTechnologyisthe institutionformed by the joining together of the IEE（The Institution ofElectrical Engineers)and thelE(TheInstitutionof IncorporatedEngineers).
1992 1995 1998 2002 004TheInstitutionoflectricalEnginers2008 011 2015 018TheInstitutionofEngineeringandTechnology
Firstpublished1992()Reprinted(with amendments toAppendix9) July 1993 Reprinted(withamendments)May1993Revised edition(incorporatingAmendment No.1 toBS7671:1992) 1995 Reprinted(withamendments)1994Revisededition(incorporatingAmendmentNo.2toBS7671:1992)1998 Reprinted(withnewcover)1996Secondedition(incorporatingAmendmentNo.1toBS7671:2001)2002()Thirdedition(incorporatingAmendmentNo.2toBS7671:2001)2004() Reprinted(withnewcover)2003Fourth edition(incorporatingBS7671:2008)2008(978-0-86341-854-9)Fifth edition(incorporating Amendment No.1 to BS7671:2008)2011(978-1-84919-287-3) Reprinted(withamendments)October2008Reprinted(withminorcorrections)2013 Reprinted2012Reprinted2014 Sixthedition(incorporatingAmendmentNo.3toBS7671:2008)2015(978-1-84919-887-5)Reprinted(withminorcorrections)2015
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ISBN978-1-78561-442-2(wirobound) ISBN978-1-78561-443-9(electronic)
TypesetintheUKbytheInstitutionofEngineeringandTechnology StevenagePrintedintheUKbyAMcLayandCompanyLtd ongwoodDrive ForestFarm CardiffCF14B
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Section1
Introduction
1.1 Scope 111.2 Building Regulations 121.3 Basicinformationrequired 151.4 IntendeddeparturesfromBS7671 15
Section2
The electrical supply 17
2.1 General layoutofequipment2.2 Functionof ponents2.3 Separationofgasinstallationpipeworkfromtheelectricalinstallation2.4 Portablegenerators
Section3 Protection
3.1 Typesofprotectivedevice 313.2 Protectionagainstoverloadcurrent 313.3 Protectionagainstshort-circuitcurrentandearthfaultcurrent 313.4 Protection againstelectricshock 323.5 Automaticdisconnection 333.6 Residual current devices(RCDs) 34Surge protective devices(SPDs)3.7 383.8 ArcFault Detection Devices(AFDD) 45
Section4
Earthing and bonding 47
4.1 Protective earthing 474.2 Legal requirements 474.3 Main protective bonding 474.4 Earthing conductor andmain protectivebonding conductorcross-sectional areas 484.5 Mainprotectivebondingofplasticservices 494.6 Supplementary bonding 50Additional protection-supplementaryequipotential bonding 514.74.8 Supplementarybondingof plasticpipeinstallations 514.9 Earthelectrode 514.10 Typesof earthelectrode 514.11 52
On-SiteGuideTheInstitutionofEngineering andTechnology
Section5 Isolation and switching 53
5.1 Isolation5.25.3 Emergencyswitching5.4 Functional switching5.5 Firefighter'sswitch
53Switching off for mechanical maintenance
Section 6 Labelling
6.1 Retention of a dangerous electrical chargeWhere the operator cannot observe theoperation ofswitchgear and controlgear6.26.3 Unexpectedpresenceofnominalvoltageexceeding230V6.4 Earthingandbondingconnections6.5 Purposeofswitchgearandcontrolgear6.6. Identificationofprotectivedevices6.7 Identificationof isolators6.8 Isolationrequiring more than one devicePeriodic inspection and testing6.96.10 Diagrams6.11 Residual currentdevices6.12 Warningnotice-non-standardcolours6.13 Warningnotice-alternativesupplies6.14 Warningnotice-highprotectiveconductorcurrent6.15Warningnotice-photovoltaicsystems
Section7 Final circuits
7.1 Final circuits7.2 Standardfinal circuits7.3 Installationconsiderations7.4 Proximitytoelectricalandotherservices7.5 Earthingrequirementsfortheinstallation of equipment having highprotectiveconductor current7.6 Electricalsuppliestofurniture7.7 Trunking installations7.8 Additionsandalterations7.9 Installationanduseofnon-standardcables7.10 EMCDirectiveandpatibility7.11 Wiringsystemsinescaperoutes
Section 8 Locationscontainingabathorshower
8.1 Summaryofrequirements8.2 ShowercubicleinaroomusedforotherpurposesUnderfloorheatingsystems8.3
Section9 Inspection and testing
9.1 Inspection and testing9.2 InspectionTesting9.3
Section10 Guidance on initial testing of installations
10.1Safety and equipment10.2Sequence of tests10.3Testprocedures
On-Site GuideThe Institutionof Engineering and Technology
