The book is a clearly written practical guide to completing electrical installation projects in a competitive manner, while ensuring full compliance with the recently updated Wiring Regulations. The book is a clearly written practical guide to completing electrical installation projects in a competitive manner, while ensuring full compliance with the recently updated Wiring Regulations. Preface to the Fourth Edition1 IntroductionWiring RegulationsCompetence and responsibilityProceduresCompletionWorking methods and materialsAmendments to BS 7671VoltagesVoltage drop2 Three Bedroom HouseThe bare minimumStandardsLoad assessmentProject specificationWiring systems and cable sizesCircuit protectionEarth leakage protectionArrangement of circuitsMain switchEarthing and bonding3 A Block of Retirement FlatletsEarly considerationsOther interested partiesBuilding detailsPart 1 - FlatsMains distributionElectrical requirements in flatsLoad assessment and maximum demandWiring systemCable sizesArrangement of circuitsConsumer unitEarthing and bondingPart 2 — Landlord's AreasMeter cupboardLandlord's electrical requirementsDiversityCable sizes and circuitryDistribution boardSwitchgearEarthingEmergency systems4 Overcurrent ProtectionOverloadOverload protective devicesFault currentFault current protectionShort-circuit ratingEarth loop impedanceSummary of circuit-breaker specificationConclusion5 An Architect's OfficeOther interested partiesBuilding structure and finishesElectrical requirementsLoading and diversityWiring systemLow voltage lightingArrangement of circuitsDistribution boardsCable sizesSwitchgearEarthing and bondingComputer installations6 A High Street ShopSpecial considerationsBuilding structure and finishesElectrical requirementsLoading and diversityPhase balanceWiring systemsFinal selection and cable sizesDistribution boardCable sizesSwitchgearIsolation and switchingEarthing and bonding7 Earthing and BondingTerminologyDefinitionsGreen-and-yellow conductorsEquipotential bondingProtective multiple earthing (PME)Main bondingSingle fault conditionSupplementary bondingCircuit protective conductorsSteel conduit and trunkingSteel wire armoured cableInformation Technology equipment8 Car Service WorkshopBuilding structure and finishesElectrical requirementsHealth and Safety Executive Guidance and RegulationsLoad assessment and maximum demandPhase balanceEstimate of maximum demandWhat about a sub-main?Wiring systemsArrangement of circuitsDistribution boardsCable sizesIsolation and switchingEarthing and bonding9 CircuitsLighting circuitsSocket-outlet circuitsAlternative methodsIntroducing the treeSwitching and controlComparison of systems10 Farming and HorticultureWhy farms are differentEquipotential zonesEarthing systemsSpecial earthing regulations on farms with TTsystemsEarth electrodesAlternative electrodesBondingResidual current devicesShock protectionFire protectionSwitchgearWiring systemsArmoured cableTwin and earth cableOverhead and underground wiringUnderground cablesGeneral rules regarding farm electricalinstallations11 Isolation and SwitchingTerminologyIsolationMechanical maintenanceEmergency switchingAccessibility of switchgear12 A Village Sports CentreBuilding detailsElectricity supply and requirementsLoad assessment and diversityWiring systemsCircuitry and cable sizingArrangement of circuitsSwitchgearShock protectionEarthingAn occasional problem13 An Indoor Swimming PoolSpecial conditionsOther interested partiesBuilding detailsElectrical requirementsZonesApplication of zoning to this projectChanging room/Shower areaLoading and diversityWiring systemsCable sizesDistribution board110 V supplyEarthing14 Cables and Wiring SystemsExternal influencesCost considerationsChoosing suitable cable routesFire barriersHidden cablesFire and smokeWiring systems and cable managementCare with wiring systems15 Inspection, testing and certificationRegulationsElectrical installation certificateExtensions and alterationsLimits of responsibilityDeviations and departuresParticulars of the installationInspections and test schedulesInspection proceduresTestingContinuity testingInsulation resistanceEarth loop impedanceProspective fault currentOperation of residual current devices16 Caravan parkAdvanced IdeasMeasures for protection against electric shockPME must not be used for caravansWiring systemsCaravan pitch electrical supply equipmentPlugs and socket-outlets17 Residual Current Devices (RCDs)Advanced IdeasHow does an RCD work?Fault protectionRequirements to provide additional protection by RCDsProtection against fireAvoiding hazards and minimising inconveniencedue to the tripping of an RCDWays of meeting the requirements where the RCDsfor additional protection are incorporated in a consumer unitLabelling18 Flood lighting projectAdvanced IdeasProtective measuresWiringsystemsExternal influencesVoltage drop19 Circuit design calculationsAdvanced IdeasDesign processSteps 1 - 5Worked exampleIndex