This document provides information on various types of building services and electrical systems. It discusses inverters which convert DC to AC power, types of current (DC and AC), batteries, lighting types, building classifications, wiring systems, and the roles of architects regarding mechanical, electrical and plumbing systems. Electrical systems in buildings include power generation, distribution through transformers, and domestic single-phase and three-phase supply. Common wiring types are cleat, wooden casing, lead casing, PVC and conduit wiring.

1. Buildingservices-2
QuestionBank
1.Inverter:InvertersareusedinPVsystemstoconvertdirectcurrent(DC)power
frombatteriesorPVarraysintoalternatingcurrent(AC)power.
2.Directcurrent(DC):Directcurrent(DC)isaunidirectionalflowofelectrical
chargethatdoesnotvaryinpolaritybetweenpositiveandnegativevaluesover
time.
3.DCcircuits:DCcircuitsaredefinedbyapositiveandnegativepolarity,orpoles.
Electronsflowinonedirection.
4.Alternatingcurrent(AC):Alternatingcurrent(AC)isanoscillatingflowofelectrical
chargethatperiodicallychangesdirectionovertime.
5.Battery:
a.Batteryhasmetalorplasticcase.
b.Insidecasearecathode,anode,andelectrolytes.
c.Separatorcreatesbarrierbetweencathodeandanode
d.Currentcollectorbrasspininmiddleofcellconductselectricitytooutside
circuit.
6.AlkalineBattery:
a..Zincpowered,basicelectrolyte
b.Higherenergydensity
c.Functioningwithamorestablechemistry
d.Shelf-life:8yearsbecauseofzincpowder
e.Longlifetimebothontheshelfandbetterperformance
f.Canpoweralldeviceshighandlowdrains
g.Use:Digitalcamera,gameconsole,remotes
7.Zinc-CarbonBattery:
a.Zincbody,acidicelectrolyte
b.Caseispartoftheanode
c.Zinccasingslowlyeatenawaybytheacidicelectrolyte
d.CheaperthenAlkaline
e.Shelf-life:1-3yearsbecauseofmetalbody
f.Intendedforlow-draindevices
g.Use:Kidtoys,radios,alarmclocks
8.SecondaryCells:
a.Rechargeablebatteries
b.Reactioncanbereadilyreversed
c.Similartoprimarycellsexceptredoxreactioncanbereversed
d.Recharging:–Electrodesundergotheoppositeprocess
e.Discharging–Cathodeisoxidizedandproduceselectrons.Electrons
absorbedbyanode
9.Typeoflighting:
a.Naturallight
b.IndoorLighting
c.Outdoorlighting
d.TaskLighting
e.Façadelighting
f.Direct/IndirectLighting

2. 10.Illumination:Illuminanceisameasureofhowmuchluminousfluxisspreadover
agivenarea.Onecanthinkofluminousflux(measuredinlumens)asameasure
ofthetotal"amount"ofvisiblelightpresent,andtheilluminanceasameasureof
theintensityofilluminationonasurface
11.ClassificationOfBuildings:AccordingtoNationalBuildingcodeofIndia1970,
Differentclassification(or)typesofbuildingsonthebasisofoccupancyare,
a.GroupA–ResidentialBuildings
b.GroupB–EducationalBuildings
c.GroupC–InstitutionalBuildings
d.GroupD–AssemblyBuildings
e.GroupE–BusinessBuildings
f.GroupF–MercantileBuildings
g.GroupG–IndustrialBuildings
h.GroupH–StorageBuildings
i. GroupI–HazardousBuildings
12.GroupA–ResidentialBuildings:
a.Sleepingaccommodationisprovided
b.Permanentlyortemporarilydwelling
c.Withorwithoutcookingordiningorfacilities
d.Example:apartments,flats,bungalows,dormitories,privatehouses,hotels,
hostels,cottages,holidaycampus,clubs,motels,etc.,
13.GroupB–EducationalBuildings:
a.Buildingsmeantforeducation
b.Nurserytotheuniversity
c.Example:schools,colleges,universities,traininginstitutes,etc
14.GroupC–InstitutionalBuildings:
a.Anybuildingusedforthepurposessuchasmedical,health,recovering
healthafterillness,physicalormentaldisease,careofinfantsoraged
persons,paneldetention,etc.
b.Normallyprovidesleepingaccommodationfortheoccupants
15.GroupD–AssemblyBuildings:
a.Buildingwheregroupsofpeopleassembleorgatherforamusement,
recreation,social,religious,patrioticorsimilarpurpose,
b.Example:theatres,cinemahalls,assemblyhalls,auditorium,exhibition
halls,museums,gymnasiums,restaurants,placesofworship,passenger
stations,publictransportationservices,etc.
16.GroupE–BusinessBuildings:
a.Buildingwhichisusedforpurposessuchastransactionofbusiness,
keepingofaccountsandrecords,dispensariesandclinics,newsstands,
barbershops,banks,cityhalls,etc.,
17.GroupF–MercantileBuildings:
a.Buildingwhichisusedasshops,stores,marketforsaleanddisplayof
productsorwareseitherwholesaleorretail.
18.GroupG–IndustrialBuildings:
a.Buildingorstructure,inwhichproductsarefabricated,assembledor
processed.
b.Example:laboratories,assemblyplants,laundries,gasplants,power

3. plants,refineries,diaries,etc.,
19.GroupH–StorageBuildings:
a.Buildingstructureswhichareprimarilyusedforstorageorshelteringof
goods,wares,merchandise,vehiclesoranimals.
b.Example:warehouses,coldstorages,depots,storehouses,truck
terminals,garages,etc.,
20.GroupI–HazardousBuildings:
a.Buildingstructureswhichareusedforthestorage,handling,manufacture
ofmaterialswhichareliabletoburnwithextremerapidityandprove
hazardoustohealth,buildingorbuildingcontents.
b.Buildingsusedforstorageofgasesunderhighpressureorforstorage
andhandlingofhighlyflammableliquidsorexplosivematerials,
explosives,fireworks,etc.,areincludedinthisgroup.
21.WHATISABUILDING:Astructurethathasaroofandwallsandstands
permanentlyinoneplace
a.Theprimaryfunctionofbuildingsistoprovidesheltertoitsoccupants
22.WHATARESERVICES:Buildingfunctioncannotbelimitedtoprovideshelteronly.
Basically“BUILDINGSERVICES”iswhatmakethebuildingcomestolifei.e.
whatmakesthebuildingwork.
Buildingshouldbedesignedinsuchawaytoprovideanenvironment
wherepeoplecanfeelcomfortable,work,liveandachieve
23.ClassificationofBuildingServices:Buildingservicesaremainlydividedinto:
MechanicalSystems,
ElectricalSystemsAnd
BuildingOperationSystem.
Theyareallveryimportantpartofplanning,designingandconstructionofa
building
24.Mechanicalsystems:
a.HVACSystems:Standsfor“heating,ventilatingandair-conditioning”and
includesavarietyofactivemechanical/electricalsystemstoprovide
thermalcontrolinbuildingsControlofthethermalenvironmentisakey
objectiveforvirtuallyalloccupiedbuildings.Betterthermalcomfortwill
influenceoccupanthealth,satisfactionandproductivity.
b.SiteDrainage:water,drainage,sanitarydisposal,Removalofwastewater
fromkitchens,bathrooms,sinks,soilwaste(toiletwaste),stormwater
managementandsurfacerunofftolocalseweragesystem.
c.GasSupply:cookinggas,commercialgas,oxygen&nitrogengasin
hospitalsStorage,Piping,PressureRegulation&Supplyofgasfromits
containertorequiredarea.
d.Plumbing:waterdistribution,watertreatment,sanitaryfacilities.Storage,
distribution(piping),sanitaryfixtures(taps,WC’s,showers,etc)
e.Fireprotection:watersupply,watersprinklers,fireandsmokedetection,
announcement
25.Electricalsystems:
a.Electricalpower:Normal,standby,emergencypowersupplyand
distribution
b.Transportation:Elevators,escalators,movingwalkways/travelators,

4. parking,etc.
c.Lighting:Interior,exterior,emergencylight.
d.Auxiliary:Telephone,data,audioandvideosound
26.Buildingoperationsystems:
a.Transportation:Elevators,escalators,movingwalkways/travelators,
parking,etc.
b.Processing:Products,foodservice,etc.
c.Automation:Environmentalcontrols,management,automatedlighting,
automatedparking,etc.
27.ImportanceOfBuildingServices
a.Buildingservicesareindispensableforbuildings.
b.Asanexamplecertaintypesofbuildingsuchasdepartmentstoreor
industrialbuildingsarealmost100%dependentonelectricallighting,
ventilatingandair-conditioningand
c.Highrisebuildingsrelyonverticaltransportationandhighspeedpressure
forwatersupply
d.Theimplementationofservicesdemandsaconsiderableamountoffloor
andceilingsoproperplanningisnecessaryfortheirallocation.
28.WhatIsTheRoleOfAnArchitect
a.Responsibleforthedesignandplanningofthemechanical,electricaland
publichealthsystemsrequiredforthesafe,comfortableand
environmentallyfriendlyoperationofmodernbuildings.
b.Buildingshouldbedesignedsuchthatitprovidesbetterlighting,
comfortablespace,temperatureandairquality,convenientpowerand
communicationcapability,highqualitysanitationandreliablesystemsfor
theprotectionoflifeandproperty.
29.WHATISEARTHING:Theprocessofconnectingmetallicbodiesofallthe
electricalapparatusandequipmentstoearthbyawirehavingnegligible
resistanceiscalledEarthling.
QualitiesOfGoodEarthling
a.Musthavelowelectricalresistance.
b.Mustbecorrosionresistance.
c.Mustbeabletodissipatehighfaultcurrentrepeatedly
30.PurposeofEarthing
a.Tosavehumanlifefromdangerofelectricalshockordeathbyblowinga
fusei.e.toprovideanalternativepathforthefaultcurrenttoflowsothatit
willnotendangertheuser
b.Toprotectbuildings,machinery&appliancesunderfaultconditionsI.e.to
ensurethatallexposedconductivepartsdonotreachadangerous
potential.
c.Toprovidesafepathtodissipatelightningandshortcircuitcurrents
d.Toprovidestableplatformforoperationofsensitiveelectronic
equipmentsi.e.tomaintainthevoltageatanypartofanelectricalsystem
ataknownvaluesoastopreventovercurrentorexcessivevoltageonthe
appliances.
e.Toprovideprotectionagainststaticelectricityfromfriction.
31.ElectricalSystemsinaBuilding:

5. a.Sincetheendofthenineteenthcenturyvirtuallyallbuildingsareprovided
withelectriclightingsinstallationforuseatnight.Withtheadventof
fluorescentlampthatiscompatiblewithdaylight,cheaptorunandnot
emittingheatgaininbuildings,itmadepossibletoinstallelectriclighting
supplementingdaylightandinextremecasesprovidetheonlysourceof
lightinawindowlessenvironment.
b.Severalfactorscanexerciseacriticalinfluenceonthesuccessoflighting
installationsapartfromproperlevelofilluminationontheworkplane.The
firstuseofelectricsupplywereestablishedin1882byThomasEdison,
Thereaftertherehavebeenconstanteffortthroughouttheworldtoset-up
powerstationsformorethanonepurposes.
c.ThepowergenerationinIndiain1947-48wasonly4.1billionandtodaywe
generatemorethan600billionKW.
32.Electricity:
a.ElectricGenerator:Electricityisgeneratedfromthestoredenergyofwater
thatmakesturbinerunandgenerateelectricity.Theothermethod
includesfuels(Coal,dieselorgas)tofireboilersandpassstreamand
generateelectricitythroughgenerators.
Transformerstepupseveralthousandorevenhundredsofthousandsof
voltsbeforeitissuppliedtothetransmissionlinesorcable.By
transmittingelectricityathighvoltageslesspowerislostinthecables.At
thereceivingendofvoltageissteppeddownbytransformsinlocalsub-
stationstoconsumersat240volts.
b.Entryinthebuildings:InUrbanareaselectricalcablesareUsually
undergroundandarebroughtuptoentrypointatgroundlevelorinto
basementservicecablecannotbebenttosmallradieeandthisshouldbe
borneinmindwhenconsideringpointofentry.Insmallbuildingsthecable
runiskeptasshortaspossible,terminatinginadistributionboardatthe
firstconvenientposition.Inthesebuildingsthedistributionboardwillbe
fittedwithasealboxtopreventmoisturefromenteringtheinsulationof
theservicecable,amainfuseforthepremisesinaboxsealedbythe
supplyauthorityandtheconsumerunitorotherswitchandfusegear
belongingtothebuilding.Thepositionchosenforthedistributionboard
shouldbereadilyaccessiblebothformeterreadingandforreplacing
fuses.Insomecasesspecialglassesareprovidedsothatmetercanbe
readwithoutenteringthepremises.
c.DomesticSupply:Domesticelectricitysupplyusuallyeffectedthrough
distributionsystemanddescribeassingleandthreephases.Normally
smallbuildingsaresuppliedwithelectricitybytwowires,onephasewire
andtheotherneutral.Thisisknownassinglephasesupplyandgivesa
voltageforthepremisesof240volts.Theloadingofthesupplywiringis
balancedbetweenthephasesbyusingthephasesinrotationsothateach
oneserviceseverythirdbuilding.
Inthreephases,fourwirebring420/240volts,50cyclepersecond.The
voltage.Thevoltagebetweenanytwoofthephaseswiresis415Volts.
Andbetweenanyphasewireandtheneutralis240volts.Thebalancingof
loadisthenachievedbyservingdifferentareasofthebuildingbydifferent
phases.Electricmotorareusuallydesignedforthreephaseoperation.
d.BasicwiringSystems:Wiringinbuildingsisruneitheronthesurfaceor

6. canceledintheconstruction.Surfacewiringischeaperbutitsappearance
limitsitsuse.Thetypeofwiringsystemavailableforuseinbuildingsare
sheatedandconduit.Twoormorewiresconsistingofmetalconductors
eachhavingitsowninuationisenclosedinaprotectivesheathknownas
TRSCtoughrubbersheated.UseofPVCforinsulationandsheatingis
preferredasitgivessmootherandneatercables.Thistypeofwirearewell
suitedtosurfaceuse.Foruseinconcealedwiring,conduitormetal
channelsshouldprovidetoprotectwiring.
33.Typesofwiring:Thereiswidechoiceofwiring;howeveronemustkeepinmind
thesafetyofmen&material.Thevarioustypesofwiringusedarediscussed
below
a.CleatWiring:Inthissystemofwiring,V.I.RorPVCInsulatedwiresare
heldtothewallsandceilingbymeansofporcelaincleatswhicharefixed
atdistanceof0.5mhorizontallyand0.75mverticallyabovethewallsThe
cleataremadeontwohalves,oneisknownasbaseandtheotheris
knownascap.Thewiringsaredrawningrovesandfinallytightened.This
wiringischeapestandrequirelittleskillandcanbequicklyinstalled.
b.WoodenCasing,CappingWire:Inthistypeofwiring,thecasingisfitted
onthewallsandceilingsonthewoodenguttieswhicharefixedThesize
ofcasingandcappinggenerallyusedis20mmx12mmforhousewiring.
Thistypeofwiringisgenerallyusedforhousewiring.Itischeaperas
comparedtoleadsheatedandconduitwiring,easytoinstall.
c.LeadCasingWire:Inthissystemofwiring,thewiringprocedureissame
exceptthewireusedinVIRcoveredwithanoutersheathmadeoflead-
aluminumalloyitisusedinhousesandindustrialwiring.Ithasgood
mechanicalprotectionandpossibilityoffireisless.
d.C.T.S&T.R.SorPVCwire:Inthissystemofwiringfirstofallteakswood
isfittedonthewallsandceiling.Thebatternistightenedbydrawing
woodenscrewsintheguttiesfittedinthewallanceiling.PVCorCTSwire
runonthebatternandfinallygrappledbythejointclip.Thistypeofwiring
issuitablefordomesticinstallations,commercial&Industrialbuildings
exceptwhereitisliabletomechanicalinjury.
e.ConduitWiring:InthistypeofwiringsystemVIRorPVCarecarried
throughsteelorPVCtubesasconduitincaseofsurfaceconduitwiring,
theconduitisfittedonthesurfaceofthewallsbymeansofsaddlesandin
caseofconcealedconduitwiringtheconduittofacilitatethedrawingof
wires
f.DuctsforElectricalDistribution:
•Inadditiontothewiringsystemsthereareanumberofductsavailable
speciallydesignedtocontainelectriccablesinparticularbuildingstations
•Ducttube:Itconsistsofaninflatablerubbertube,whichisplaced,in
concreteformworkbeforepouringconcrete.Aftertheconcretehassetthe
ducttubeisdeflated,withdrawnfromconcrete,leavingaductforelectric
wiring,orotherpurpose.
•Skirtingtrunking:Itisveryusualtoruncabletrunkinginorabovethe

7. skirtingroundtheperimeterwalls.Thissystemsismostlyemployedin
officebuildings.
•FloorTrunking:Systemisemployedinlargeofficeswheredesksare
placedremotefromwalls.Usefulwheretherearecomparativelyfew
points,thepositionsofwhichareknown,andwhereflexibilityforfuturere-
planningmustbeachieved.
•Overheaddistribution
•Overheaddistributionsystemsareclearlymoreeconomicalandmore
flexiblethanunderfloorones.Theyaremainlyusedinindustrialunits
whenpendantsconnectiontoapparatusisnotconsideredunsightly.
g.Conductor:Cables•Acableisalengthofsingleconductor,usuallyhaving
severalwiresstrandedto-gather,oroftwoormoreconductors,each
providewithitsowninsulationandlaidupto-gather.Theinsulated
conductor(s)mayormaynotbeprovidedwithanoverallprotective
covering.Theconductorwithitsinsulationbutwithoutmechanical
protectioniscalledcoreofthecable.Thusa,cableconsistsofthreeparts:
Conductor,InsulationandExternalProtection
h.Insulations:
•Onthebasisofinsulations,thecablesmaybeclassifiedasfollows:
(i) PaperInsulatedcables.Inthesecablespaperiswoundonthe
conductorinsuccessivelayertoarchiverequireddielectricstrength.
Suchcablesaremanufacturedinvarioussizesfrom5mm2to500
mm2cross-sectionconductorsandvoltageratingsupto33kv
(ii) PVCcables
(iii) Oilfilledinsulatedcables
(iv) HighPressureoffilledcables
(v) Compressedgasinsulatedcables
(vi) Vulcanizedcable
34.ExternalProtection:
a.Againstmechanicaldamageorelectrochemicalattack,fireoranyother
deteriousinfluencesexternaltothecablescanbeminimized.Ifcertain
pointsaretakeninaccount
b.Abruptbendingincablesisnotdesirable;thebendingradiusrangesfrom
12to30,timesthediameter..
c. Cablesshouldbeatleast1mawayfromthefoundationofthebuildings.
d.Cablesshouldbeatleast0.5mawayfromthecommunicationcables
e.Wheneveracablecrossesaroadorrailwayline,itshouldbelaidinpipes
orconduits.
35.Electricalappliances:
a.Therearemanywaysinwhichelectricitycanbeusedtosavelabourinthe
home.Avastnumberofappliancesaredesignedtorunontheordinary
domesticsupply.Thethreebasicapplicationofelectricityare–the
productionofheat,lightandpowerandinmanydevicestheyareusedin
combination.Electronicappliancessuchasradioandtelevisionsets,and
recordplayersconstituteafourthclassandtelephoneafifth.
b.Alltheelectricalappliancesrequiringacurrentofmorethan5Ashouldbe
fittedwithanearthorgroundwiretosafeguardtheuseragainstshocks
fromleakagesofcurrent.Theirsupplycablesthuscarrythree-pinplugs,

8. andinthebesttypeofsocketnocurrentcanflowuntiltheearth-pincan
bemadeitscontact.
c.Therearefourmainwaysinwhichelectricitycanbeconvertedintolight
d.Itcanflowthroughawire,sothatitglows(lamps),modernfilamentlamps
usecoiloftungstenwirewhichgivesamuchwhiterlightthancarbon,and
thebulbcontainsnitrogenandargon.Mosthouseholdbulbsare25to150
wattofelectricpower,butsomelargetungstenlampsusedinsearch
lightsanintelevisionstudiosuseasmuchas30kw.
e.Dischargelampsarelongtubescontainingagasorvapour.When
electricitypassesthroughapuregasatlowpressure,energyis
transferredtothegasatoms,causingthemtoemitradiations.The
wavelengthofthisradiation,whichdeterminescolor,dependsonthegas
e.g.,sodiumvaporandneonemitvisibleradiation.Sodiumproducesan
efficientyellowlight,mercuryproducesabluishwhitelightandsomeultra
-violetradiations,andneongivesoffastrongredlight.
f.Fluorescentlamps:
36.123
37.
38.ClassificationOfBuildings:AccordingtoNationalBuildingcodeofIndia1970,
Differentclassification(or)typesofbuildingsonthebasisofoccupancyare,
j. GroupA–ResidentialBuildings
k.GroupB–EducationalBuildings
l. GroupC–InstitutionalBuildings
m.GroupD–AssemblyBuildings
n.GroupE–BusinessBuildings
o.GroupF–MercantileBuildings
p.GroupG–IndustrialBuildings
q.GroupH–StorageBuildings
r. GroupI–HazardousBuildinGroupA–ResidentialBuildings:•Sleeping
accommodationisprovided•Permanentlyortemporarilydwelling•Withor
withoutcookingordiningorfacilities•Example:apartments,flats,
bungalows,dormitories,privatehouses,hotels,hostels,cottages,holiday
campus,clubs,motels,etc.,