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E l e ct r i c S w i t c h :- PowerPoint Presentation
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E l e ct r i c S w i t c h :-

E l e ct r i c S w i t c h :-

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  1. ElectricSwitch:- ElectricSwitch,adeviceforcompletingandbreakinganelectriccurrent,or forchangingthepathofacurrent.Electricswitchesareamongthemost commontypesofcontroldevicesandareinwideusewhereverelectricityis available. Initssimplestform,aswitchconsistsoftwocontacts,onefixedandone movable.Whenthecontactsarebroughttogether,theswitchandthecircuit areclosedandcurrentflowsthroughthecircuit.Operatingtheswitchto disconnectthecontactsopensthecircuitandstopstheflowofcurrent.This typeofswitch,knownasasingle-poleswitch,iscommonlyusedinthehome forturninglightsonandoff. Three-wayswitchesareoftwodifferenttypes.Inone,currentisdirectedto oneorbothfilamentsofadouble-filament(threeway)lightbulb.Theothertypeisusedinpairstocontrolasinglelightfromtwolocations,suchasthetopandbottomofastaircase. Electricsocket:-socketisfixedonequipmentorabuildingstructureand connectedtoanenergisedelectricalcircuit. Electricalsocketsforsinglephasedomestic,commercialandlightindustrial purposesgenerallyprovideeithertwoorthreeelectricalconnectionstothesupplyconductors. Twopinsocketsnormallyprovideneutralandlineconnections,bothof whichcarrycurrentandaredefinedasliveparts.Neutralisusuallyverynear toearthpotential,usuallybeingearthedeitheratthedistributionboardorat thesubstation.Line(alsoknownasphaseorhot,andcommonly,but technicallyincorrectly,aslive)carriesthefullsupplyvoltagerelativetothe neutral(andtoearth). Threepinsocketsprovide,inaddition,aprotectiveearth[14]connectionfor exposedmetalpartsofanappliance.Ifinternalinsulationshouldfail,ashort-

  2. circuittotheearthedexposedmetalpartswillholdthematalowpotential,circuittotheearthedexposedmetalpartswillholdthematalowpotential, andshouldoperatefusesorcircuitbreakerstoisolatethefaultyappliancefromthesupply. Lampholder:- Lampholdertypes Therearetwotypesoflampholder,plasticandmetal.Theymaybefoundas partofatablelamp,orasapartofapendantlightfitting.Themethodofconnectionissimilarforbothpendanttypeandtablelamp,butthemetalandplastictypesrequiredifferentconsiderations. Thefirstdifferencetonoteisthatplasticfittingshavenoearthconnectionand shouldthereforeonlybeconnectedviaatwocoreflex.Metalfittingsmustalwaysbeconnectedviaaflexwithanearthwire. Metalversusplasticlampholders Thesecondconsiderationisthatmetalfittingsarenotsuitableinsome locations–themostnotableofwhichisbathrooms.Plasticonesmaybeusedinbathrooms,butchoosethetypewithalongerplasticshroudwhichshieldsthecomponentsbetter.Inpractice,metallampholdersaregenerallyonlyusedforcertaintypesoftablelamps. Connectingtheflextoalampholder 1.Switchoffthepowerattheconsumerunitforthecircuitconcerned.Ifyou haveremovablefusesatyourconsumerunit,switchoffthepowerattheconsumerunitandremovethefuseforthiscircuit.Or,inthecaseofatablelamp,switchoffandremovetheplugfromthepowersupply. 2.Unscrewthefittingtoexposetheseparatecomponents.Theconstructionof metalandplasticonesisalittledifferentasyouwillnoticefromthepictures.

  3. 3.Feedthetopcover(andretainingpiecesinthecaseofthemetalfitting)over3.Feedthetopcover(andretainingpiecesinthecaseofthemetalfitting)over theflexandpushthemalongoutoftheway. 4.Notethelengthrequiredfortheconductorstoreachtheirterminals,then stripandpreparetheflex.Moredetailedinformationcanbefoundinour StrippingandPreparingFlexarticle. 5.Usingapairofsidecutters,cutbacktheoutersheathoftheflexaccordingly andtrimofftheexcess. 6.Separatetheconductorsandstriptheinsulationofeachbackbyabout1/2". Twisttogethertheseparatefilamentsofeach. 7.Connectthebrown(live)tooneterminalandsecurewiththeretaining screw.

  4. 8.Connecttheblue(neutral)totheotherterminalandsecurewiththeretaining8.Connecttheblue(neutral)totheotherterminalandsecurewiththeretaining screw. 9.Makesurethatbotharefedroundthesupportswhichpreventstrainonthe connections. Earthformetallampholders 10.Inthecaseofmetalfittingswhich,asnotedearlier,mustbeearthed,you willfindasmallexternallymountedearthterminal.Thisexampleisametallampholderonatablelamp. 11.Thegreenandyellowearthconductorisfedtothisfrominsidethefitting andsecuredwiththeretainingscrew.

  5. Reassemblethelampholder 12.Doublecheckyourconnectionsthenslidethepreviouslythreaded componentsbackdowntheflexandreassemblethefitting,takingcarenottodamageorpullthewiresintheprocess WiringaPlug Preparetheplugandflex 1.Openupthenewplugbyundoingthescrewonitsbasebetweenthe rectangularpins.Insidetherewillbethreeterminals,afuseinaholderandaclampforsecuringtheflex.

  6. 2.Manynewplugshaveatemplateshowingpreciselyhowmuchsheathand conductorinsulationtotrim.Ifyoursdoesn’thavethisyoucanmeasurethelengthsasyougo. 3.Useapairofsidecutterstocuttheoutersheathoftheendoftheflex. 4.Peelthisbackandremovetheexcesswiththesidecutters. 5.Holdthesheathedsectionnexttotheflexclampandseparatethe conductors.Markthelengthrequiredforeachconductor–allowingfortheactualconnection.Cuttheconductorstolength.

  7. 6.Usingapairofwirestrippers,trimtheinsulationofeachconductorbackby6.Usingapairofwirestrippers,trimtheinsulationofeachconductorbackby about5mmorasdetailedonthetemplate. 7.Twisttogethertheindividualfilamentsofeachconductormakingthem easiertoconnect. Connectthewirestotheplug 8.ConnectthebrownconductortotheterminalmarkedLorlive. 9.ConnecttheblueconductortotheterminalmarkedNorneutral.

  8. 10.Ifyouarefittingaplugtoanappliancerequiringanearth,youwillhavea10.Ifyouarefittingaplugtoanappliancerequiringanearth,youwillhavea greenandyellowconductor,whichshouldbeconnectedtotheterminalmarkedwithanearthsymbolorlabelledEarth. Doubleinsulatedappliances 11.Ifyouarefittingaplugtoadoubleinsulatedappliance(labelledwiththe doubleinsulatedsymbol),youshouldnothaveanearthconductorinyourflex. Securingtheflex 12.Fitthesheathedsectionofflexintotheclamp(screwtypeorpushfit).This securestheflexandreducestheriskofthewiresbeingpulledoutoftheirterminals.

  9. Fittingthefuseintheplug 13.Checkwhatratingoffuseisinthecarrier.Mostnewplugsaresupplied with13ampfuses.However,dependingontherecommendedfuseratingforyourappliance,youmayneedtochangethis.Alwaysusethefuserecommendedintheinstructionsordetailedontheappliance.Ifnodetailsaregiven,usea3ampfuseforappliancesupto720Watts,anda13ampforappliancesfrom720Wattsto3000Watts. 14.Doublecheckallyourconnections.Replacethecoverandfastenwiththe retainingscrew. NewLightBulbs-WhytheChange? Weareallawarethatitisnowalmostimpossibleto buytheoldstyleincandescentlightbulbs.Thisis becausethegovernmenthasbannedthesaleofthem andhasinsistedthatalllight-bulbssoldinstoresare thelowenergytype.

  10. Theoldstylebulbswerecompletelyphasedoutatthe beginningofthisyear.ThisputstheUKaheadof othercountriesintheEUwhohaveuntilnextyearto removethesalesofallincandescentbulbs. Therearethreetypesofenergysavingbulbswhich canbepurchased •Compactfluorescentlamps-thesecomeinavariety ofshapesandarethemostcommontypeofbulb •Energysavinghalogenbulbs-Theseuse30%less energythanstandardhalogenbulbs. •LEDs-Goodforuseinplaceofspotlightsandoffergoodlightingatlowenergylevels. Whiletherehasbeensomecontroversyregardingthis change,duetothefactthatlowenergybulbsemita differentsortoflightandtakesomegettingusedto, thebenefitsofthenewrulescannotbe underestimated. Anenergysavingbulbisslightlymoreexpensivetobuy,howevertheyneedtobereplacedlessoftenandwillmakebacksavingsinelectricitybills.Anenergy

  11. savingbulbwilllasttentimesaslongasastandard bulb. •Energysavingbulbsusejustonefifthoftheenergy ofstandardwattagebulb.Sofora60wattbulbyou onlyneedan11wattlowenergyone. Negatives Therehasbeensomeconcernthatlowenergybulbs emitatypeoflightwhichcangivesomepeople headaches.Ifthisisaproblemforyou,pleasetry someoftheothertypesofbulbsavailable.LEDlights maybejustwhatyouarelookingfor. Itisalsotruethatlowenergybulbscontainasmall amountofmercurywhichcanbeharmfulifexposed toskin.Clearlythisisonlyaproblemifthebulb breaks. EnergySavingLamps Theseareusuallycompactfluorescentlampsanduselessenergythan traditionalincandescentlamps.Theyareabletoproducethesameoverallleveloflightingasstandardlampsbut,manypeoplefindthelight

  12. colourtobelessthansatisfactory.Withmanylowenergylamps,they taketimetowarmupandreachfullillumination. FireRatedLighting Arangeoflightfittingsdesignedtomeetbuildingrequirementsinterms offireregulations.Theymayhavecoversandprotectiveelementstosafeguardagainstthespreadoffireandsmoke.Manyfirerateddownlightsincludeasmokehoodmountedoverthefitting.Inloftsandceilingvoids,thepotentialspreadoffirecanbedelayed. FloodlightsandPIRs Theselightsaredesignedtoprovideoutdoorlightingandarecommonly controlledbyPIRdeviceswhichdetectmovementinthevicinity.Thisallowsthefloodlightstocomeononlywhenneededandtoprovideameasureofsecurity.Floodlightsgenerallyprovidealargeamountofilluminationoverawidearea. FluorescentTubes Fluorescenttubesarecommonlyusedinofficesandshops.Although theyareusedinresidentialproperties,thisisusuallylimitedtoutilityareaandgarages.Thelampsuselessenergythanstandard

  13. incandescentlampsbutthelightgivenoffisgenerallynotconsidered pleasing.Theunitsarefrequentlyfittedwithdiffusers. HalogenLamps Halogenlampsarecommonlyusedinlowvoltagedownlighters.They produceasharpcleanlight.Theycanreduceutilitybillsastheyproducemuchmorelightthanastandardlampwiththesamewattage.Theyareknowntolastlongerandhavebecomeverypopularfordomesticlighting. HIDLamps HIDstandsforHighIntensityDischargeandtheselampsgeneratelight byarcingbetweentungstenelectrodes.Thegasinsidethelampfacilitatestheincreasedlightlevelproducedand,comparedtostandardlamps,theygiveoffagreateramountoflightforthesamewattage. IncandescentLamps Incandescentlampsarewhatwewouldallconsidertoberegularlight bulbs.Asanelectricalcurrentpassesthrough,thefilamentisheatedandlightsup.Thereenergyconsumptionishigherthanequivalentlowenergylampsandthelightoutputisrelativelypoorcomparedtootherlampsavailable.

  14. InspectionLights Inspectionlampsarecommonlyusedasworklampswhencarryingout workinpoorlylitareassuchasatticsandunderfloors.Theyareoftenmountedinsideaprotectivecagereducingthechanceofdamage.Theirportabilityenablesthemtobesetupandusedeasilyasandwhenrequired. LED ViewPrices LEDstandsforLightEmittingDiodeandisbecomingmorecommonplaceindomesticsettings.LED lampslastwellandproduceapleasinglight.LEDlightsproducemuchlessheatthanincandescent lampsandaremoreenergyefficient.AdvancedLEDfittingscanproducechangeablelightcolour allowingformoodlighting.