Solution Manual For Illustrated Guide to the National Electrical Code, 7th Edition

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’sGuidetoAccompany theIllustratedGuidetotheNEC®,7eCharlesR.MillerTEXTBOOK GUIDE

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iiiCONTENTSTothe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . .. . . . . . . . . . . . . . . .vSECTION1FOUNDATIONALPROVISIONSUNIT1INTRODUCTIONTOTHENATIONALELECTRICALCODE®. . . . . . . . . . . . . . . . . . . . . . . . . .1UNIT2DEFINITIONSCompetencyTestAnswers. . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1UNIT3BOXESANDENCLOSURESCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2UNIT4CABLESCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3UNIT5RACEWAYSANDCONDUCTORSCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . .4SECTION2ONE-FAMILYDWELLINGSUNIT6GENERALPROVISIONSCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5UNIT7SPECIFICPROVISIONSCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6UNIT8LOADCALCULATIONSCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . .7UNIT9SERVICESANDELECTRICALEQUIPMENTCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11SECTION3MULTIFAMILYDWELLINGSUNIT10COMPREHENSIVEPROVISIONSCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12UNIT11LOADCALCULATIONSCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . 14

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ivSECTION4COMMERCIALLOCATIONSUNIT12GENERALPROVISIONSCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19UNIT13NONDWELLINGLOADCALCULATIONSCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . 21UNIT14SERVICES,FEEDERS,ANDEQUIPMENTCompetencyTestAnswers. . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . 25SECTION5SPECIALOCCUPANCIES,AREAS,ANDEQUIPMENTUNIT15HAZARDOUS(CLASSIFIED)LOCATIONSCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . ... . 27UNIT16HEALTHCARECompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . 28UNIT17INDUSTRIALLOCATIONSCompetencyTestAnswers. . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . 29UNIT18SPECIALOCCUPANCIESCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .30UNIT19SPECIFICEQUIPMENTCompetencyTestAnswers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . .31FINALEXAM1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . .. . . . . . . . . . . . . . 32FINALEXAM1ANSWERS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . 34FINALEXAM2. . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . 36FINALEXAM2ANSWERS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . .. . 38

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vTOTHEIllustratedGuide totheNEC®7eisanexcitingnewtoolforthosewhoteachtheNationalElectricalCode.Thistextrepresentsadramaticblendofnewpresentationstyleswithtried-and-trueinstructionalpractices.Symbolizinga revolutionary breakthrough in teaching material, the text communicates with the reader primarily throughvisualization.Ifapictureistrulyworthathousandwords,thisbookisavirtualencyclopediaontheNationalElectricalCode.Whiletechnicallyaccurateandhighlydetailedillustrationstellastoryalltheirown,theyarefurtherenhancedthroughclearlywritten,conciseblocksoftextthatcanbereadveryquicklyandunderstoodwithease.Notonlyisthepresentationmethodexceptional,butalsotheorganizationofmaterialisunique.AftercoveringfundamentalprovisionsinSection1,IllustratedGuide totheNECproceedstoaddresscoderequirementsaccordingtothetypeofoccupancy. Comprehensiveinformationisgivenforone-familydwellings,multifamilydwellings,commerciallocations,andspecialoccupancies.InformationfoundscatteredthroughouttheCodebookhasbeenlogicallygatheredandconcentratedundertheappropriateoccupancy.Allrelevantaspectsarethoroughlydiscussedandillustratedaccordingly.Asateachingtool,thistextstandsalone,unlikeanypreviouslyoffered. Restassured,however,thatproventrainingmethodshavenotbeensacrificedforthesakeofbeingdifferent.Unitobjectivesstillintroducenewideastothe reader, summaries review the material after presentation, and competency tests reinforce what has beenlearned.Asavaluableresourcetotheinstructor,this’sGuideprovidesunitcompetencytestquestionanswersandexplanations, and twofifty-question comprehensive finalexams, which can be given independently or as asingletest. Unequaledasateachingtool,IllustratedGuidetotheNECstrivestomaketheentireprocesseasierandmoreenjoyable.From beginners to master electricians, this text has somethingforeveryone practicing a trade in the electricalindustry.ThevarietyofteachingstylesfacilitatedbyIllustrated GuidetotheNationalElectricalCodeisessentiallylimitless.WhethertheinstructorfocusesonaspecificareaofapplicationorwantstoteachtheCodefromcovertocover,IllustratedGuide totheNECoffersavisuallypleasingformatthatholdsstudentinterestandawakenscomprehension. Intendednotasareplacement,butasanindispensablesupplementtotheNationalElectricalCode,thetexttranslatesthesometimesvague,oftenrambling,languageoftheCodeintoclearer,cleaner,simplerterms.OncetheinstructorhascommunicatedtheseconceptssothatthestudentunderstandshowtheCodetranslatesinaparticulararea,thesametechniquescanbeappliedthroughoutthiscourseofstudy.Asthetitleimplies,frequentreferencesaremadetotheNationalElectricalCode.Haveeachstudentkeepacopyofthecurrenteditioncloseathand.Oncountlessoccasions,theCodeprovidesthedefinitivesourceofinformation. Should,forexample,anyconfusionaboutterminologyexistthatisnotclearedupbytheDefinitionssection(Unit2),consultingtheCode’sArticle100—Definitionssectionmaywelloffertheneededclarification.WheneverdirectreferencesaremadetotheCode, theclasswillbenefitbytakingthetimetoreadthesuggestedarticleorsection.Thetruesuccessofanyteachingendeavorrestsinthehandsoftheinstructor.Nomatterhowgoodthematerial,itisultimatelytheinstructorwhoenrichesthemindofeachandeverystudent. Itistheintentionoftheauthor and Delmar, Cengage Learning to lighten this imposing responsibilityby placingexceptional resources at theinstructor’sdisposal.

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1Section1FOUNDATIONALPROVISIONSUNIT1ThereisnocompetencytestforUnit1.UNIT2COMPETENCYTEST1.Answer:generalpurposeReference:Article100(Branch-Circuit,GeneralPurpose)2.Answer:remote-controlcircuitReference:Article100(Remote-ControlCircuit)3.Answer:multiwireReference:Article100(Branch-Circuit,Multiwire)4.Answer:periodicdutyReference:Article100(Duty:PeriodicDuty)5.Answer:mainbondingjumperReference:Article100(BondingJumper,Main)6.Answer:groundingelectrodeReference:Article100(GroundingElectrodeConductor)7.Answer:weatherproofReference:Article100(Weatherproof:InformationalNote)8.Answer:effectiveground-faultcurrentpathReference:Article100(EffectiveGround-FaultCurrentPath)9.Answer:bypassisolationswitchReference:Article100(Switch,BypassIsolation)10.Answer:multioutletassemblyReference:Article100(MultioutletAssembly)11.Answer:wetReference:Article100(Location,Wet)12.Answer:thermalprotectorReference:Article100(ThermalProtector:InformationalNote)13.Answer:cabinetReference:Article100(Cabinet)14.Answer:hoistwayReference:Article100(Hoistway)15.Answer:c)eitherIorIIReference:210.4(C)ExceptionsNo.1and216.Answer:fuseReference:Article100PartB.Over1000Volts, Nominal(Fuse)17.Answer:FestoonlightingReference:Article100(FestoonLighting)18.Answer:Oneitemnamedmustbeabasin(lavatoryorsink);theotheritemcanbeatoilet,aurinal,atub,ashower,abidet,orsimilarplumbingfixtures.Reference:Article100(Bathroom)19.Answer:c)maximumReference:Article100(ContinuousLoad)20.Answer:resistorReference:Article100(Grounded,Solidly)21.Answer:outletReference:Article100(Outlet)22.Answer:branch-circuitReference:Article100(Branch-Circuit)23.Answer:RaintightReference:Article100(Raintight)24.Answer:d)anindefinitelylongtimeReference:Article100(Duty,Continuous)25.Answer:itstemperatureratingReference:Article100(Ampacity)26.Answer:50Reference:Article100(InSightFrom[WithinSightFrom,WithinSight])27.Answer:multifamilydwellingReference:Article100(Dwelling,Multifamily)28.Answer:theearthReference:Article100(Ground)29.Answer:vectorialsumReference:Article100(NeutralPoint:InformationalNote)30.Answer:YesReference:Article 100 (Accessible, Readily[Readily Accessible])

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2UNIT3COMPETENCYTEST1.Answer:d)72;6(ft)x12(in.)=72in.Reference:314.28(B)2.Answer:2Reference:382.15(A)3.Answer:“X”=24in.,and“Y”=12in.The“X”dimensioncontainsbothstraightandanglepulls.Usethelargerofthetwo.“X”(straightpull)=3x8=24.“X”(anglepull)3x6+2=20.The“Y”dimensionhasananglepullonly.“Y”=2x6+0=12.Reference:314.28(A)4.Answer:½Reference:314.24(A)5.Answer:8.Thetotal12AWGconductorspermittedbyTable314.16(A)is18.Theflatplasterringdoesnotprovideanyadditionalcubicin.capacity.Tworeceptaclescountas4[314.16(B)(4)],twointernalcableclampscountas1[314.16(B)(2)],four12AWGTHHNcopperconductorscountas4[314.16(B)(1)],andtwogroundingconductorscountas1[314.16(B)(5)]12AWGconductors.Thereare10existing12AWGconductors.Threewirenuts,twopigtails,andoneequip-mentbondingjumperdonotcount.Reference:314.166.Answer:¼Reference:312.27.Answer:0.0625in.Reference:314.40(B)8.Answer:bushingsReference:314.429.Answer:a)noneReference:314.23(F)10.Answer:separateboxReference:314.28(D)11.Answer:4(6–2=4)Reference:314.16(B)(4)andTable314.16(A)12.Answer:equipmentgroundingconductorReference:314.40(D)13.Answer:¼Reference:314.2014.Answer:temperature-ratedReference:314.17(C)15.Answer:0Reference:312.2Exception16.Answer:6Reference:Table314.16(A)17.Answer:8Reference:382.30(A)18.Answer:4Reference:314.28(A)(2)ExceptionandTable312.6(A)19.Answer:individualholesReference:314.17(C)20.Answer:6Reference:314.27(A)(1)Exception21.Answer:48timesReference:314.71(A)22.Answer:1/8 in.,1/4in.Reference:314.1523.Answer:substantially equivalentReference:110.12(A)

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3UNIT4COMPETENCYTEST1.Answer:12Reference:334.302.Answer:39.37Reference:324.413.Answer:4½Reference:320.30(B)and(C)4.Answer:35Reference:Table326.245.Answer:TypeMC(Metal-cladcable)Reference:330.26.Answer:moistureReference:332.40(B)7.Answer:c)8(two6AWGorthree8AWGconductors)Reference:334.15(C)8.Answer:TypeMV(Mediumvoltagecable)Reference:328.29.Answer:d)I,II,andIIIReference:340.11610.Answer:transitionassemblyReference:324.40(D)11.Answer:c)24.Thequestionrequirestheanswerinin.,notft(2ft=24in.).Reference:320.30(D)(2)12.Answer:groundedcircuitconductorReference:404.2(C)13.Answer:sevenReference:330.24(B)14.Answer:1¼Reference:300.4(A)(1)15.Answer:7ftSection334.23statesthatnon-metallic-sheathedcableinstalledinatticsmustcomplywith320.23.Reference:320.23(A)16.Answer:c)IandIIIonlyReference:324.120(A)17.Answer:TypeMI(Mineral-insulatedorMineral-insulated,metal-sheathedcable)Reference:332.218.Answer:c)90°CReference:320.80(A)19.Answer:d)72.Thequestionislookingforin.6(ft)x12(in.)=72(in.).Reference:330.30(B)and(C)20.Answer:168Reference:Table326.8021.Answer:b)12Reference:Table300.522.Answer:solderedReference:394.5623.Answer:1/16Reference:300.4(A)(1)24.Answer:20,30Reference:324.10(B)(2)25.Answer:6Reference:332.3026.Answer:18Reference:Table300.5

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4UNIT5COMPETENCYTEST1.Answer:d)listed or approvedforuseinwetlocations andarrangedtodrain.Reference:225.22and230.532.Answer:quarter,¼,or90°Reference:Theanswercanbefoundinmostofthe raceway articles, such as 344.26forrigidmetalconduit.3.Answer:3.356Reference:Chapter9,Table4.Thecross-sec-tionalareaisthetotalarea(100%).4.Answer:¾Reference:344.28and346.285.Answer:c)IandIIonlyReference:380.12(5)and380.766.Answer:75%Reference:376.56(A)and378.567.Answer:headerReference:374.28.Answer:1¼Reference:300.4(A)(1)9.Answer:4Reference:Table348.2210.Answer:16Reference:342.30(B)(2)andTable344.30(B)(2)11.Answer:20%Reference:376.22(A)and378.2212.Answer:inductionReference:300.20(A)13.Answer:multioutletassemblyReference:Article100(MultioutletAssembly)14.Answer:galvanicactionReference:342.14and344.1415.Answer:10Reference:InformativeAnnexC,TableC916.Answer:six(6)Reference:314.28(A)(2)17.Answer:¼Reference:300.6(D)18.Answer:6Reference:250.102(E)(2)19.Answer:c)IandIIIonlyReference:372.18(B)20.Answer:3Reference:362.30(A)21.Answer:wetReference:Article100(Location,Wet)22.Answer:b)shallberemovedfromtherace-way.Reference:390.823.Answer:corrosionprotectionReference:344.10(B)(1)24.Answer:8AWGReference:310.106(C)25.Answer:180Reference:Table300.19(A)26.Answer:4AWGReference:300.4(G)27.Answer:3ftReference:378.30(A)28.Answer:10,3Reference:342.30(B)(4)29.Answer:1.496sqin.Thecross-sectionalareaisthetotalarea (100%),regardlessofconductors.Reference:Chapter9,Table430.Answer:equipmentbondingjumpersReference:250.9831.Answer:3Reference:344.3032.Answer:7Reference:Table352.3033.Answer:0.8Reference:Chapter9,Note734.Answer:30°(30degrees)Reference:376.23(A)and378.23(A)35.Answer:60Reference:310.15(B)(2)(c)36.Answer:unobstructedReference:376.56(B)(5)

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5Section2ONE-FAMILYDWELLINGSUNIT6COMPETENCYTEST1.Answer:b)20ampereReference:Table210.21(B)(3)2.Answer:b)multiwirebranch-circuitsReference:300.13(B)3.Answer:5½Reference:210.52and210.52(4)4.Answer:6Reference:300.145.Answer:b)mustbethesamesizeastheinsulatedcircuitconductorsReference:Table250.1226.Answer:15Reference:406.3(B)7.Answer:16Reference:410.30(A)8.Answer:b)25amperesReference:210.189.Answer:receptacleoutletReference:210.50(A)10.Answer:b)IandIIIonlyReference:406.4(A)11.Answer:70Reference:314.27(C)12.Answer:18Reference:210.52(A)(3)13.Answer:current,voltage,temperatureReference:410.5214.Answer:50Reference:314.27(A)(2)15.Answer:15or20Reference:Table210.21(B)(3)16.Answer:individualReference:Article100(Branch-Circuit,Individual)17.Answer:12Reference:210.52(A)(1)18.Answer:c)IIandIIIonlyReference:406.4(D)(2)(c)19.Answer:receptacleoutletReference:Article100(ReceptacleOutlet)20.Answer:d)0.0in.Reference:314.2021.Answer:d)hallwayReference:210.70(A)(1)and(2)22.Answer:40or50Reference:Table210.21(B)(3)23.Answer:groundedconductorReference:Article100(GroundedConductor)24.Answer:c)thecircuitconductorsbetweenthefinalovercurrentdeviceprotectingthecircuitandtheoutlet(s)Reference:Article100(Branch-Circuit)25.Answer:d)IIorIIIonlyReference:240.15(B) and(B)(1)

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6UNIT7COMPETENCYTEST1.Answer:4.Themaximumdistancetoareceptacleis2ftReference:210.52(C)(1)2.Answer:8Reference:410.10(D)3.Answer:c)15or20amperesReference:Table210.21(B)(3)4.Answer:b)10AWGReference:210.19(A)(3)ExceptionNo.25.Answer:194Reference:410.11and410.115(A)6.Answer:2.Avehicledoorinagarageisnotconsideredanoutdoorentranceorexit.Reference:210.70(A)(2)7.Answer:clothesclosetsReference:240.24(D)8.Answer:b)100%Reference:210.21(B)(1)9.Answer:6Reference:210.50(C)10.Answer:20Reference:210.19(A)(3)ExceptionNo.111.Answer:9200;4+5.5+5.5=15kW.IncreaseColumnAby15%(15–12=3x5%=15%)8x15%=1.2kW8+1.2=9.2kW9.2x1000=9200watts.(Ananswerof9.2isincorrectbecausetheanswershouldbegiveninwatts,notkW.)Reference:Table220.55,Note412.Answer:80Reference:210.23(A)(1)13.Answer:6Reference:410.16(C)(3)14.Answer:50Reference:Article100(InSightFrom)15.Answer:oneReference:210.52(H)16.Answer:c)IorIIonlyReference:422.31(B)17.Answer:sixReference:210.70(A)(2)(3)18.Answer:readilyaccessibleReference:240.1019.Answer:6.5.Thecordmustbebetween3and6.5ftforbuilt-in dishwashercords.Reference:422.16(B)(2)(3)20.Answer:b)IandIIonly.Areceptacleinadetached garage is required only ifthegaragehaselectricalpower.Reference:210.52(G)21.Answer:d)I,II,orIIIReference:210.52(B)(1)and210.52(B)(1)ExceptionNo.222.Answer:c)IIorIIIReference:Thelaundrycircuitmustbea20-amperecircuit[210.11(C)(2)].Asinglereceptaclecannotexceedtheratingofthecircuit[Article100].Aduplexreceptaclerated15amperesisper-mittedona20-amperecircuit[Table210.21(B)(3)].23.Answer:3Reference:210.52(D)24.Answer:6Reference:210.52(C)(5)Exception25.Answer:b)IorIIonlyReference:210.11(C)(3)and210.11(C)(3)Exception26.Answer:20Reference:210.11(C)(4)27.Answer:22, 30Reference:110.26(A)(4)

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719.Answer:2AWGcopper.Multiplytheserviceratingby83percent[310.15(B)(7)(1)]125×83%=103.75=104amperes.Inaccordancewiththe75°CcolumnofTable310.15(B)(16),theampacityofa2AWGcopperconductoris11520.Answer:amperes.8AWGcopper21.Answer:4AWGcopperUNIT8COMPETENCYTEST1.Answer:75,fourReference:220.532.Answer:7092volt-amperes.First,findthetotalfloorareaofthehouse.Multiplythedimensionsofeachfloorandaddthetwo:30x48=1440sqft(firstfloor);22x42=924sqft(secondfloor);1440+924=2364totalsqft.Next,multiplythetotalsquareftbythree(3)volt-amperespersquarefoot:2364x3=7092volt-amperes.Thishousehasalightingdemandloadof7092volt-amperes.Reference:220.123.Answer:NoneReference:220.14(J)4.Answer:1500Reference:220.52(A)5.Answer:d)6.6kW.Thequestionisaskingfortheservicedemandload,notthebranch-circuitdemandload.3.5+3.5+5=12kW(forthreeunits).Table220.19,ColumnBforthreeunitshasademandfactorof55%.12x55%=6.6kW.Reference:220.55andTable220.556.Answer:14.58.5kVA(5000VA)istheminimumdryerload.5000÷240=20.83(amperes)20.83x70%=14.58(neutralamperes).Reference:220.54and220.61(B)7.Answer:2495volt-amperes;dishwasher1x1000=1000(single-phasemotorcurrentratingsarelocatedinTable430.148);disposer5.8x115=667;compactor7.2x115=828;1000+667+828=2495volt-amperes.Note:Nodemandfactorsareallowedonthreeorfewerfastened-in-placeappliances.Reference:220.538.Answer:100Reference:230.79(C)9.Answer:6AWG.Multiplytheserviceratingby83percent[310.15(B)(7)(1)]175x83%=145amperes.Inaccordancewiththe75°CcolumnofTable310.15(B)(16),theminimumsizeser-viceconductorsare1/0AWGcopper.Table250.66requiresa6AWGcop-pergroundingelectrodeconductorfor1/0service-entranceconductors.Reference:Table250.6610.Answer:7314volt-amperes.Heat=6(units)x3000(watts)=18,000;[Four(ormore)separatelycontrolled,spaceheatershaveademandfactorof40%.(220.30(C)(6)];18,000x40%=7200watts(volt-amperes).A/C=2(units)x10.5(amperes)x230(volts)=4830volt-amperes;3(units)x7.2(amperes)x115(volts)=2484volt-amperes.Air-conditioningloadshaveademandfactorof100%(220.30(C)(1).Totalair-conditioningload4830+2484=7314volt-amperes.Theair-conditioningloadislargerthantheheatingload.Reference:220.82(C)11.Answer:1500Reference:220.52(B)12.Answer:8000Reference:Table220.5513.Answer:145amperes14.Answer:150amperes15.Answer:1AWGcopper.Multiplytheserviceratingby83percent[310.15(B)(7)(1)]150x83%=124.5=125amperes.In accordance with the 75°C columnof Table 310.15(B)(16), the ampacityof a 1 AWG copper conductor is 130amperes.16.Answer:6AWGcopper17.Answer:114amperes18.Answer:125amperes

Solution Manual For Illustrated Guide to the National Electrical Code, 7th Edition - Page 14 preview image

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1General Lighting and Receptacle Loads 220.12Do not include open porches, garages, or unused or3×=1unfinished spaces not adaptable for future use.(sq ft using outside dimensions)2Small-Appliance Branch-Circuits 220.52(A)At leasttwosmall-appliance branch circuits1500×=2must be included. 210.11(C)(1)(minimum of two)3Laundry Branch Circuit(s) 220.52(B)At leastonelaundry branch circuit1500×=3must be included. 210.11(C)(2)(minimum of one)4Add lines 1, 2, and 34Lines 5 through 8 utilize the demand factors found in Table 220.42.5– 3000 =56– 117,000 =6(line 4)(if 117,000 or less, skip to line 8)(line 5, if more than 117,000)7×25% =78×35% =8(line 6)(smaller of line 5 or 117,000)9Total General Lighting and Receptacle Load3000 ++=9(line 7)(line 8)10Fastened-In-Place Appliances 220.53Use the nameplate rating.Do not include electric ranges,clothes dryers, space-heatingequipment, or air-conditioningequipment.If fewer than four units, put total volt-amperes on line 10.×75% =10If four or more units, multiply total volt-amperes by 75%.(volt-amps of four or more)11Clothes Dryers 220.54(If present; otherwise skip to line 12.) Use 5000 watts or the nameplate rating, whichever is larger.11The neutral demand load is 70% for feeders. 220.61(B)12Ranges, Ovens, Cooktops, and Other Household Cooking Appliances Over 1750 Watts 220.55(If present; otherwise skip to line 13.) Use Table 220.55 and all of the applicable Notes.12The neutral demand load is 70% for feeders. 220.61(B)13Heating or Air-Conditioning System (Compare the heat and A/C, and omit the smaller.) 220.60Include the air handler when using either one. For heat pumps, include the compressor and the13maximum amount of electric heat that can be energized while the compressor is running.14Largest Motor (one motor only) 220.50 and 430.24×25% =Multiply the volt-amperes of the largest motor by 25%.(volt-amps of largest motor)1415Total Volt-Ampere Demand Load:Add lines 9 through 14 to find the minimum required volt-amperes.1516Minimum AmperesDivide the total161717volt-amperes by÷=the voltage.(line 15)(voltage)(minimum amperes)18Size the Service or Feeder Conductors.Use 310.15(B)(7) to find the service conductors up to 400 amperes.Ratings in excess of 400 amperes shall comply with Table 310.15(B)(16).18310.15(B)(7) also applies to feeder conductors supplying the entire load.19Size the Neutral Conductor. 220.61310.15(B)(7) states that the neutral service or feeder conductorcan be smaller than the ungrounded (hot) conductors, provided therequirements of 215.2, 220.61, and 230.42 are met.19250.24(C)(1) states that the grounded conductor shall not besmaller than specified in Table 250.102(C)(1).20Size the Grounding Electrode Conductor (for Service). 250.66Use line 18 to find the grounding electrode conductor in Table 250.66.Size the Equipment Grounding Conductor (for Feeder). 250.12220Use line 17 to find the equipment grounding conductor in Table 250.122.Equipment grounding conductor types are listed in 250.118.water heater/compactor//dishwasher///disposer///Minimum SizeService orFeeder 240.6(A)Minimum SizeConductorsMinimum SizeNeutralConductorMinimum SizeGroundingElectrodeConductorStandard Method Load Calculation for One-Family DwellingsUnit 8 . . . Questions 13 through 16250021750012,00012,00090009000--------40001500828----3/503/5063285000800076/3161034,7011501copper6copper644034,7012401456/5030001500

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