homewiring.pdf

Wiring diagram of home

1. BASIC CONCEPT OF
HOUSE WIRING
By HarminderPal Singh, MMS
PGSC conducts “Assistant Electrician”
Skill development Course
under
PradhanMantriKaushalVikasYojna.
Interested candidates may contact
HarminderPal Singh (81465 68350)
For Age Group > 15 years

2. Some basics :
What is Electricity ?
Electricity is a form of energy resulting from the existence of charged particles
(such as electrons or protons)
An electric currentis the rate of flow of electric charge past a point or region. In
electric circuits this charge is often carried by electrons moving through a wire.
Voltage, also called electromotive force, is the potential difference in charge
between two points in an electrical field
It results in Current
There are two types of currentused widely:
o Directcurrent(DC), in which electrons flow in one direction.DCpower is
widely used inlow voltage applications such as charging batteries,
automotive applications, aircraft applications and low current applications.
Solar panels produce DCpower
o Alternating current, ( AC) in which the electric charge changes direction
periodically.Householdoutlets are Alternating Current

3. Importance of Electricity
•Electricityhasmanyusesinourdaytodaylife.Itisusedfor
lightingrooms,workingfansanddomesticapplianceslikeusing
electricstoves,ACandmore.
•Infactories,largemachinesworksonelectricity.
•Onecannotimaginecomfortwithoutelectricity.Allhospitals,
agriculture,cinemahouses,educationalinstitutes,railways,
business,entertainmentsandmanymoredependsupon
electricity.
•Hence,electricityplaysawideroleintheprogressofanynation.

4. > Volts : Electromotive force or potential difference, expressed in volts(V)
> W: Wattis the unit of power. One wattis defined as the energy consumption
rate of one joule per second. 1W = 1J / 1s. One wattis also defined as the
current flow of one ampere with voltage of one volt.
It is named after James Watt, the inventor of the steam engine.
> kW: 1000 Watt
> kWh: The kilowatt-houris a unit of energy equal to 3600 kilojoules (3.6
megajoules). 1 kWhequals one hour of electricity usage at a rate of 1 kW, and
thus the 2 kWappliance would consume 2 kWhin one hour, or 1 kWhin half an
hour.
> The equation is simply kWx time = kWh
> The kilowatt-houris commonly used as a billing unit for energy delivered to consumers
by electric utilities.
Some common terms used

5. MCB: Miniature circuit breaker : Itautomatically switches off electrical circuit during an
abnormal condition or overload of the network. Nowadays we usean MCBin low voltage
electrical network instead of a fuse
SP-MCB:A Single Pole Breakeris used with a typical 120v circuit, having one hot wire and one
neutral wire.
DP-MCB: However, a Double Pole Breaker is used with a typical 220v circuit (like for a dryer or
heater) having two hot wires. If there is a short circuit to either hot wire, both poles are ganged
together so both trip together
Based on the number of poles, the breakers are classified as : SP –Single Pole, SPN–Single Pole
and Neutral, DP–Double pole, TP–Triple Pole, TPN–Triple Pole and Neutral, 4P–Four Pole.
ELCB: An Earth-Leakage Circuit Breaker (ELCB) is a safety device used in electrical installations
with high Earth impedance to prevent shock. It detects small stray voltages on the metal
enclosures of electrical equipment, and interrupts the circuit if a dangerous voltage is detected.
PSPCL: Punjab State Power Corporation Limited, the agency which supplies electric power in
Punjab
Some common terms used

6. House Wiring (Single Phase)
•Singlephasesupplyconsistsofonephasewirecalledhotwireandoneneutralwire
connectedinEnergymeterbyPSPCLasinputsupply220V.
•Theoutput220VsupplyistakenfromEnergymetertoMCBdistributionbox.
•ELCB,DPMCB/Isolatorareusedasmaincontrol.
•NumberofSP-MCBsareinstalledinMCBBoxtoprovidephasetoindividualswitch
boardofroomsetc.inahouse.
•NeutralwirefromMCBBoxneutrallinkisconnectedtoeachswitchboardsocketand
otherloads.
•Switchesareinstalledonswitchboardofeachroomtooperateitsrespectiveloadi.e.
fan,lightandTV,fridge,press,washingmachineetc.throughsockets.
•Anyload(singlephase)whenconnectedwith220Vsupplydulycontrolledbyswitchis
calledacircuit.

7. House Wiring (Single Phase) Wiring Diagram

8. Circuit
•Following load point are usually provided in each room:
oTube lights
oFan
oLamp Point/s
oSockets
oTV
oAC etc.
Each load / point (on/off) is controlled by its switch connected
through wire/s, MCB / fuse, etc. which makes a circuit.

9. •Opencircuit:Circuitisopenwhentheswitchisnot
closed,lampisOFFinthiscircuit.
•Closedcircuit:Circuitisclosedwhentheswitchis
closed,nowlampisON
•Shortcircuit:Whenany(+)wireor(-)wirebreaks
anditgetsconnectedwithoppositepolarity,the
circuitiscalledshortcircuit.Itisabnormalcondition
andnotdesiredtohappeninanyelectriccircuit.
Withoutproperselectionofsafety,itmaycause
damagetocostlyitems,wire,switches,etc.
Types of Circuit

10. General Items required as per load
•PVC wires: Generally 4.0 mm
2
, 2.5 mm
2
, 1.5 mm
2
, 1.0 mm
2
, 0.75
•MCB distribution Board: 6 Way, 8W, 10W, 12W, 16W
•MCB’s: 6 AMP,10A, 16A, 20A, 25A, 32A, (SP/SPN)
•RCCB or ELCB: 16A, 25A, 32A
•Switches: 6Amp, 16 Amp, 20 Amp
•Sockets: 5 Pin 6 Amp, 6 Pin-16Amp, 20A, 25A, 32A
•Bell Switch: 6Amp
•2-Way Switch: 6 Amp
•Various loads in rooms
•DP Isolator, etc.

11. Functions of different items used in house wiring
•Energymeter:ThemeterisinstalledbyPSPCLtochargeelectricity
beingconsumedbyconsumer.TheunitrateisfixedbyGovt.,units
areconsumedbyconsumeraspertheirload/requirementsand
hastopaytoGovt.
1 Unit = 1000 Watt x 1 hr. OR 1 kwh
E.g. if we operate the following per day
Ceiling fans –(5Nos. x 100W each) x 8 hrs. = 4000 Wh
Geyser-(1 No. x 1500 W) x 1 hr. = 1500 Wh
Tube Lights –(10 Nos. x 40 W each) x 8 hrs. = 3200 Wh
Total = 8700 Wh
OR 8.7 kwhOR 8.7 units
•Say Unit Rate is Rs.10/-
Per day Expense: (8.7 units x Rs.10/-) =
Monthly Expense: (Rs.80.70 x 30 days)=
Rs.87.00
Rs.2610/

12. •ResidualCurrentCircuitBreaker(RCCB)isadevicewhich
providesprotectioninanelectriccircuitincaseofoverload,
shortcircuitandearthfault.Usually,itistobeusedasamainin
theMCBdistributionboard.
•EarthLeakageCircuitBreaker(ELCB)isaprotectiondeviceand
usedforprotectionofelectriccircuitandhumansfromelectric
shock.e.g.whenanyitem/equipmentbodycomesincontact
withhotlineorduetoanyinsulationfailure.
•Thereisacoil,bimetalandhammerarrangementinsidethis
device,whichoperatesatitsdesignedvaluewithout
interruptingthecircuitundernormalcondition.
ResidualCurrentCircuitBreaker(RCCB)/EarthLeakage
CircuitBreaker(ELCB)

13. •Whensomefaultarises,thecircuitbecomesabnormalandmore
currentpassesthroughthecoils,bimetalstripsetc.Thenatureof
bimetalistoexpandwhenitgetshot.Sowhen,morecurrentfromthe
designedvalvepassesthroughit,itexpandsandoperateshammerdue
towhichthematchedcontactsgetstucktoeachother.Thus,thecircuit
isopenedwhichprovidesprotectiontocircuit/human,etc.
•Itisimportanttonotethat‘Earthing’mustdoneinhousewiringand
wiringshouldbeofgoodqualitytoprotecthumansfromelectricshock.
•Deathsduetoshockfromelectricalapplianceslike,cooler,press,
washingmachineandotherapparatusbeingusedinnormallifehas
beenobservedmanytimes.Topreventthiswiringshouldbeofgood
qualityandhighstandard.

14. Double Pole (DP) or Single Pole and Neutral Miniature
Circuit Board (SPN MCB)
•DPMCBcanbeusedfor2-PhasesupplyorOnepoleforphaseandother
polefornatural
•DP/SPNMCBcanbeusedforphaseandneutral.
•DP/SPNMCBcanbeusedasmainswitchinMCBDistributionBoard.
•ActuallyMCBisamoderndeviceandhasreplacedtheuseoffusein
electriccircuitduetomoresafety.MCBandfuseareprotectiondevices.
•Therewerelimitationsandlackofknowledgetoselectthepropersize
fusewiretomeettherequiredprotectionswhilereplacingburntfuse
wire.MCBshaveovercomethislimitationandthereisnoneedtoputany
fusewirebecauseMCBtrips(off)whenthereisanyshortcircuit/over
loadinginthecircuit.
•Itdoesnotrestart(getON)untilfaultisremoved,thusprotectingcircuit.
•OneshouldbecarefultoselectproperratingofdevicesusedintheCKTto
achieveprotectioninelectriccircuit.
•SinglePole(SP)MCBshavethesamerole,itisusedforsinglephasesupply.

15. •ItlookslikeaDP-MCBandiscommonlyusedasamainswitchin
ahouseMCBDBox.
•Asitsnameisisolator,itcanswitchON&OFFloadjustlike
ordinaryswitchesdo.
•Thereisnotrippingarrangementinthisdevice,sonoprotection
canbeachievedfromthis.
•BeingmuchcheaperfromDPMCB,itiscommonlyusedasa
mainswitchofhouse,asindependentMCB’s(SP)arealways
availableroomwise/loadwiseintheMCBBox.
•DPIsolatorisavailableintherating16A,20A,25A,32Aand63
Amp.
•AproperselectionofDPIsolatorisrequiredtomeettheload
requirement.
DP Isolator

16. •GenerallyPVCcopperflexiblewiresareusedinwiring.PVCisan
insulatingmaterialcoveringcopperthinwiresinsideit.
•Generally,220Visavailableforsinglephasesupplyandwire
insulationisratedforminimum660Vor1100V.
•GoodqualitywiresareofFR/FRLS,whicharefireretardantand
superqualitywiresareboth,fireretardantandlowsmoke.
•Now-a-days,flexiblePVCwirescopperareusedinthesizes0.75
mm
2
,1.0mm
2
,1.5mm
2
,2.5mm
2
,4.0mm
2
.
•Foreconomicalwiring,itisdesiredtocalculatetotalloadof
house,rooms,etc.toselectpropersizeofwiretobeused.
•Normally,0.75mm
2
wireisusedasEarthwire.1.0mm
2
canbe
withstand1KWload(6Amp.).1.5mm
2
canbeusedfor1.5KW
load(7-8Amp.)and2.5mm
2
for2.5KWload(16-17Amp.).
Poly Vinyl Chloride (PVC) Wires
Contd.

17. •Inpast,PVCcopperwirestrandedtypeconductorwasusedforwiringandtheirsizes
were3x22SWG,7x16SWG,3x20SWG,1x18SWG.
•3x22SWGmeans3wirecopper,eachof22GaugecoveredwithPVCinsulation.
•Beingnotflexible,itwasdifficulttodrawthemthroughconcealedconduitpipesand
also,itsreplacementwasverydifficult.So,flexiblePVCcopperwiresarenowwidely
used.
•Currentcarryingcapacityofflexiblewiresismore,hence,itdoesnotheatup.
•Itissuggestedtousealwaysbranded,ISImarkedwiresonlyandcheapwiresshould
notbeused.
Poly Vinyl Chloride (PVC) Wires

18. •Inthesepipes,PVCwireisdrawntovariouslocationsofhousethrough
roofceiling,walls,groundetc.
•Generally,25mmheavyduty(ISImarked)pipeshouldbelaidinLanter
duringconstruction.Ifignored,thepipemaycrackedandcivil(cement,
sand,concrete,etc.)materialbeingusedduringconstructionoflantermay
enterthepipeandblockitspathfordrawingwires.
•Forwalls,mediumweightpipecanbeusedtoreducetheexpense.
PVC Conduit Pipes
•Allconcealedlightboxes,fanboxesandotherboxesshouldbeproperlytiedafterlayingpipeswith
steelwireswithbars.Allunwantedholesshouldbecoveredwithpolytheneetc.
•Itisalwayssuggestedtouse60-65%diameterpipeforlaying/drawingwiresthroughitforlonglife
ofsystemwhilemakingprovisionforfutureuse,ifrequired.
•Theconcealedlayoutofpipesthroughlantershouldbeaccordingtothesizeofroomwhereone
shouldknowhowmanyfans,lights,etc.shallbeinusebyowner.
•Fanboxeswithheavyhooksshouldbeusedalways.
•Allswitchboxesshouldbeplaced/fixedatrelevantlocationsintheroomsatproperheight
generally,1.2Mfromfloorlevelandshouldbeconnectedwithpipe.
•Onwalls,chippingshouldbedonesothatthepipeisapprox.1”deepandcoveredwithplaster,
otherwise,crackswillappearonplastercoveringthepipe.

19. •6Aswitch,6Amp.5pinsocket,16A/20Aswitch,16/20Amp.6-pin
socket,ACplugpoint,Fanregulator,Dummy,plates,coverplate,
etc.,2wayswitch6Amp/16Ampareusedgenerally.
•6Aswitchisusedforalllightpoints,fanpoints,etc.
•6A5-pinsocketisusedforrefrigerator,Iron,washingmachine,tulu
pump,LEDTV,chimney,exhaustfan,chargingmobile,etc.
•16A/20Aswitchand16A/20A6-pinsocketisusedforgeyserpoint,
heavywashingmachine,ACloadetc..
•Fanregulatorisusedtocontrolthespeedoffan.
•Coverplateisusedtocoveralltheswitches,sockets,etc.with
matchingcolourofwalls.
•2wayswitchesareusedforstaircaselightcontrolandentrygate
lights.
Accessories

20. •AllaccessoriesshouldbeofISImarked,brandedbearinggoodlookandasperchoice
ofowner.
•Aftercompetingallwiringconnections,itshouldbecheckedagainforanyloose
connection.Operationofallpoints,MCBtrippingandELCBoperationshouldalsobe
checked.
•Undesirednails,screws,cutpieceofwiresshouldberemovedtoavoidanyinjury.
•Eachmetal&switchboxshouldbeearthedforhumansafety.
•Jointsshouldbealwaysavoided.
•MarkroomwiselocationontheMCB-DB-MCB’s.
Accessories

21. •Inserieswiring,switchisinserieswithphaseandloadisalways
connectedinparallelsothatphaseisgiventoanyloadthrough
switchandneutralisconnectedtoitsN-point.
•Whenswitchispressed,phasewillreachtoloadandthusitworks.
Thisisthewaytoconnectloadsinhouses/industries,etc.
•Ifloadsareconnectedinseriesinhouse,totalvoltageVwillbe
dividedinconnectedloadsaspertheirwattageandcurrentwill
flowaspermaximumwattageofloadfromtheconnectedloads
andsolesswattageloadsmayburnt.
•Voltageshouldberemainsamei.e.220voltforallloadstowork
properlyasallsinglephaselamps,tubes,fridge,iron,geyser,etc.
arealwaysratedat220volt.
•Inparallelwiring,wecanswitchON/OFFanyloadasperour
requirement.
Single line diagram for circuits (Single Phase)

22. •Earthingisveryimportantandcompulsoryworkrequiredtodoneduring
housewiring.Itisveryusefultoprotectthehumanfromelectricshock.
Procedure
•Diggingshouldbedoneuptothelevelofobservingwetclay.
•LayG.I.Pipeorcopperplate/copperstripdeepintothegroundupto
floorlevel.Fillborewithsalt,charcoal,kalmishoraetc.andpourwater.
Thiswillmaintainmoistureforlongduration.
•Afunnel/orpipemouthmaybeusedforfillingwaterperiodically.
•PitshouldbeconnectedwithMCBBoxusingcopperearthwire/G.I.wire.
•FromMCBBox,earthwireshouldbelaiduptoallswitchboxes,fanboxes,
metalboxes,allpowersockets,etc.
•Duringanycurrentleakage,phasecontactwithanymetalbox/apparatus
etc,ELCBinMCBBoxwillsenseandwilltripthemainsupply.ELCBcantrip
at30mAto100mAcurrent.
•Supplycannotbeswitchedonunlessfaultisremoved.
Earthing

23. •Hammer
•Hacksaw&Blade
•Chiesel
•GrooveCutter
•Plier
•ScrewDriver/s
•NosePlier
•Cutterwire
•Crampingtool
•Wiresheather
•Multimeter
•Voltmeter
•Amperemeter
•Megger
•Earthtester
Tools Used
•Bocky
•LampTester
•TestingPen
•Drill(HiltyType)M/cHandheld
•Slowspeedhanddrillmachine
•LevelCheck(waterlevel)
•30Mtaperoll
•5Mtaperoll
•Knife
•SteelWire
•ContinuityTester
•Safetybelts
•Helmet
•SafetyShoes
•InsulatingGloves
•Goggles
•Mask
•ToolBox
•AdjustableWrench

24. •Toolsshouldbekeptneatandclean.
•Toolsshouldbekeptinproperway/sections.PVCsleevesonthehandlesofpliershouldnot
beusediffoundcracked.
•Tipsendsofscrewdrivershouldbeproper.
•Neverusetestpenonhighvoltage,fortighteningofscrews,etc..
•Donotbelieveontestpenindicator,pleaseusetestlamptoascertainthesupply.
•Donotuseplierasahammer.
•Donotgive/bypasstoolsfromfronttosubordinates,itmayhurt.
•Usepropertoolsforproperwork.
•Donotgossips,becool,donothurryupwhiledoingelectricworks.
•Usesimplewords,signalswithoneanothertoseekhelp,instruction,guidance,etc.
•Donotbeoverconfident,checkyourworkandifanydoubt,pleaseclearandgethelpfrom
someone.
Contd.
Some Important Tips

25. •Donotusemobileearphones/mobilephonesfrequently.
•Donotusepoorconditionladder,toolsetc.
•Usesafetybeltsformoreheights.
•Usesafetyshoes.Donotuseoldshoes,thatmaybecomeslippery.
•Donotwearlooseclothes.
•Alwaysdiscusswithoneanother,makeplanandactaccordingtoplan.
•Donotthrowyourtools.
•Cleanworkplaceandyourhands,etc.
Some Important Tips

26. •Allelectrical/electronicappliancesneedstodisplayvoltageandcurrentratingcompulsorye.g
Voltage:220V,Power:9Watt/15W/40W/100W/250W/1500W/2500W,Frequency:50HZ,Rated
Current-In:asperload,Manufacturername/Trademark:ISImarkwithCM/LNo.,PowerFactor:
0.8or0.9,MadeinIndia.
•Theselectionofwires,switches,MCB’s,MainMCB,plugtopsetc.dependsuponthecurrenttobe
drawnbyload.E.g.
Power : 1500W(ACload)
Voltage: 220Volt
Current: Power = 1500= 8.5Ampere
VoltagexP.F. 220x0.8
•UseofitemsforACloadbaseduponitscurrentisasunder:
oSwitch : 16A-220V
oSocket : 16A–220V
oPlugTop : 16A–220V
oMCB/SPN : 16A–220V
oPVCwires : 2.5mm
2
Contd.
Calculation of Current and Selection of Items

27. •Loadusedinthehousesareasunder:
oLEDLamps : 0.2Wto40Wareavailableforhouses
oFans : 50Wto100W
oGeyser : 1500Wto3000W
oAC’s : 1500Wto2500W
oPress : 200Wto300
oFridge : 190Wto300W
Calculation of Current and Selection of Items

28. THANKS
PUSHPA GUJRAL SCIENCE CITY, KAPURTHALA