ebcs 10 ethiopian building code standard electrical installation of buildings

EBCS-10

Ethiopian Building Code Standard ELECTRICAL INSTALLATION

OF BUILDINGS

FOREWORD

TheProclamationto definethepowersanddutiesof theCentralandRegionalExecutiveOrgansof theTransitionalGovernmentof EthiopiaNo.41/1993empowerstheMinistryof WorksandUrbanDevelopmentto preparetheCountry'sBuildingCode,issueStandardsfor designandconstructionworks,andfollowupandsupervisetheimplementationof same.

In exerciseof thesepowersandin dischargeof itsresponsibility,theMinistryis issuingaseriesof BuildingCodeStandardsof generalapplication.

The purposeof thesestandardsis to serveas nationallyrecognizeddocuments,the

applicationof whichis deemedtoensurecomplianceof buildingswiththeminimumrequirementsfordesign,constructionandqualityof materialssetdownbytheNationalBuildingCode.

The majorbenefitsto be gainedin applyingthesestandardsaretheharmonizationofprofessionalpracticeandtheensuringof appropriatelevelsof safety,healthandeconomywithdueconsiderationof theobjectiveconditionsandneedsofthecountry.

As thesestandardsaretechnicaldocum~ntswhich,bytheirverynature,requireperiodicupdating,revisededitionswill beissuedbytheMinistryfromtimetotimeas.appropriate.

TheMinistrywelcomescommentsandsuggestionsonallaspectoftheEthiopianBuildingCodeStandards.All feedbackreceivedwill becarefullyreviewedbyprofessionalexpertsin thefieldof buildingconstructionwith a view to possibleincorporationof amendmentsin futureeditions.

HaileAssegidieMinister

Ministryof WorksandUrbanDevelopment1995

INTRODUCTION

ThisCodeStandardfor theElectricalInstallationof Buildingsispartof theBuildingCodeof Ethiopia:

This CodeStandardfor theElectricalInstaijationof Buildingsis mairilyadoptedfromlEE RegulationsforElectricalInstallationsandCanadianElectricalCode,Part 1,to suit

theEthiopianconditions.Otherpublicationsquotedareshownin therespectivesectionsof the Code andtheEthiopianAuthorityfor Standardizationmaintainsregistersof a

numberof foreignnationalandinternationalstandards.

The Codeembr~cesseveralaspectsof electricalinstallationworkandsetsstandardsandprovisionsfor safeutilizationof electricity.

The TechnicalCommitteefor CodeStandardsfor theElectricalInstallationof BuildingscomprisesofthefollowingInstitutionsrepresentingbalancedinterestofallsegmentsofthepublicconcernedwiththesubjectmatter:

Ministryof Works&UrbanDevelopment(MWUD) BuildingDesignEnterprise(BDE)

EthiopianElectricLight&PowerAuthority(EELPA) AddisAbabaUniversity,Facultyof Technology(AAU)

EthiopianAuthorityfor Standardization(BAS).

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ETHIOPIAN BUILDING CODE STANDARDEBCS-10 ELECTRICAL INSTALLATION OF

BUilDINGS

TABLE OF CONTENTS

Section1 ScopeAnd Definitions

1.1 Scope 11.2 Nonnativereferences 11J Defmitions 2

Section2 Gen~ralRequirements

2.1 Administrative 20

2.1.1 Authorityforrules i . i 202.1.2 Pennit 20

2.1.3 Applicationfor inspection 202.1.4 Postingof pennit ', , 202.1.5 Notificationre-inspection 202.1.6 Plansandspecifications 212.1.7 Connectionauthorization 21

2.1.8 Re-inspection 212.1.9 Renovationof existinginstallation 21

2.1.10 Useof approvedequipment 222.1.11Deviationorpostponement 222.1.12Powersof rejection 222.1.13Installationof electricalequipment 222.1.14Damageandinterfer.~e 22

2.2 Technical 23

2.2.1 Conventionalsymbols '.' 232.2.2 Co-ordination 23

2.2.3 Locationandrequirementof substation 232.2.4 Rooms(spaces)required 232.2.5 Locationandrequirementsof distributionboards 242.2.6 Locationandrequirementsof PBX/PABX rooms 24

2.3 Planninganddesigning 252.3:1 General 25

2.3.2 Layoutandinstallationdrawing 25

2.3.3 Design 25

2.4 Markingof equipment " 262.4.1 General , , 26

2.4.2 Workmanshipandmaterials 27

2.4.3 Materialfor anchoring 272.4.4 Protectionof personsandproperty ,. 27

2.4.5 Maintainability , 272.4.6 Enclosures ,. 28

Section3 Illumination

3.1 Scope 293.2 Normativereferences 29

3.3 Definitions , 30

3.4 Lightingrequirements 353.4.1 IllumiQance " 353.4.2 Luminance '.. " 35

3.4.3 Glare' ' 36

3.4.4 Light directionandmodelling 363.4.5 Colour rendering , .. , 36

3.5 Emergencylightingrequirements 37

3.5.1 Escapelighting 37

3.5.2 Safetylightingfor particularhazardousworkplaces 373.5.3 Standbylighting 38

3.6 Lightingrequirementsfor varioustypesof buildings 383.6.1 General 383.6.2 Industrial 39

3'.6.3 Offices.,., ' ' 39

3.6.4 Hotelsandrestaurants, 39

3.6.5 Educationalestablishments."" 40

3.6.6 Hospitals , 40

3.7 Outdoorlightingrequirements 423.7.1 Illuminance , , 42

3.7.2 Colourr~nderinggroup 42

3,7.3 Limitationof glare : ' .' , 433.7.4 Lightingof outdoorfixedlocationwork spaces 43

II

Se~tion4 Conductors

4.1 Scope ',' " 66.

4.2 Nonnativereferences 66

4.3 Definitions 67

4.4 Size of conductors 69

4.4.1 Ph~econductorsin a.c.Circuitsandliveconductorsin d.c.circuits.. 69

4.4.2 Neutralconductors , 69

4.5 Ampacityof wires,cablesandflexiblecords 70

4.5.1 Conductoroperatingtemperature 70

4.5.2 .Cablesconnectediri parallel 70

4.5.3 Cablesconnectedto bareconductorsor busbars 70

'4.5.4 Voltagedrop ~ 70

4.6 Flexible cords " 70

4.7 Colour of conductors '.' : 71

4.8 Maximumpermissibletemperll,ture 71

Annex (preface)

AnnexA (Normative)- Correctionfactors

AnnexB (Normative)- Typeof cableandampacity

Section5 ServiceAnd ServiceEquipment

74

85

90

5.i Scope " 141

5.2 Normativereferences '.' 141

5.3 Definitions 141

5.4 Generalrequirements ' " 142

5.4.1 Numberof servicespermitted 142

5.4.2 Consumer'sinstallationnottobesuppliedthroughanotherbuilding 143

5.4.3 .conductorsconsideredoutsideof a building 143

5.4.4 Other'conductorsin racewayor cable 144

5.4.5 Clearancefrombuildingopenings 144

5.5 Serviceequipment 1445.5.1 General 144

5.5.2 Control .. 145

III

5.6 Wiring methods 148

5.6.1 Undergroundconsumer'sserviceconductors 1485.6.2 Overheadconsumer'sserviceconductors 148

5.7 Meteringequipment 1495.7.1 Connection 149

Section6 CircuitLoadingandDemandFactor


6.3 Defmitions 150

6.4 General 151

6.4.1 Currentcalculation 151

6.4.2 Voltagedrop 1516.4.3 Maximumcircuitloading 1516.4.4 Useof demandfactor 151

6.5 Servicesandfeeders 151

6.5.1 Single-familydwellings 151

6.5.2 Apartmentandsimilarmulti-familybuildings , 1526.5.3 Schools 153

6.5.4 Hospitals 153

6.5.5 Hotels,motels,dormitories,andbuildingsof similaroccupancy 154

6.5.6 Othertypesof occupancy 1556.5.7 Branchcircuits 155

6.5.8 Feederdemandfactorsfor lifts 155

Section7 Earthing,Bonding,andLightningProtection

Part I - Earthing,andBonding


7.3 Systemand circuitsearthing 158

7.3.1 Directcurrent.systems 158

7.3.2 Alternating- currentsystems 158

IV

7.4

7,6

Locationof systemearthingconnections 1597.4.1 D.C.systems 1597.4.2 A.C. systems 1597.4.3 Isolatedsystems , , , '.' 1597.4.4 Singleservicesupplytotwoormorebuildingsorstructures., 1607.4,5 Conductorstobeearthed , , 160

7.4.6 Currentoverearthingconductor , , , , .. 160

Bonding 1617.5.1 Non-currentcarryingmetalparts , , , 1611.5.2 Exposednon-current-carryingmetalpartsof equipment....... 1617.5.3 Non-metallicwiringsystems 1617.5.4 Non-electricalservices 1617.5.5 Extraneousfixedmetalwork 164

Methodof earthing , , 164

7.6.1 Effectiveearthing _ 1647.6.2 Commonearthingconductor , 1647.6.3 Commonearthingelectrode '. , , , . , 1647.6.4 Undergroundservice 1657.6.5 Shortsectionof raceway 1657.6.6 Fixedequipment , .. ", ,. 165

7.7 Bondingmethods , \. , 166

7.7.1 CleansUifaee , 166

7.7.2 Bondingatserviceequipment......................... 1667.7.3 Meansof assuringcontinuityatserviceequipment , 1667.7.4 Metalannourortapeof servicecable, 167

7.7.5 Bondingatotherthanserviceequipment , 1677.7.6 Looselyjointedmetalraceways 1677.7.7 Bondingjumpers ,., , 167

7.8 Earthingelectrodes.. , , 168

7.8.1 General, , 168

7.8.2 Servicepipeelectrode, , 1687.8.3 Artificialearthingelectrodes 169

v

7.9 Earthingandbondingconduc;tors 171

7.9.1 General 171

7.9.2 Installationof systemearthingconductors 172

7.9.3 Installationof equipmentbondingconductors 1737.9.4 Earthingconductorsizefor d.c. circuits 1747.9.5 Earthingconductorsizefor a.c.system 174

7.9.6 Bondingconductorsize 174

7.10 Earthingandbondingconductorconnections 175

7.10.1Bonding.conductorconnectionto raceways 1757.10.2 Earthingconductorconnectionto waterpipeelectrodes 1757.10.3 Earthingconductorconnectionstootherthanwaterpipeelectrodes.. 1757.10.4 Bondingconductorconnectionto circuitsandequipment 1767.10.5 EarthingconductorcQJ111Cctionto electrodes 176

Section7 Earthing,BondingandLightninlZProtectionPart n-pghtningProtection

7.11 Scope .' 1787.12 Normativereferences 1787.13 Definitions 179

7.14 Materials 1807.14.1 General 180

7.14.2 Galvaniccompatibility 1807.14.3 Corrosionprotection , 1817.14.4Mechanicalprotection 1817.14.5 Useof aluminium 181

7.15 Form andsize 1847.15.1Air termination 184

7.15.2 Conductors 1857.15J Earthtermination 1857.15.4 Minimumdimension 185

7.16 Air termination 1857.16.1 General 185

7.16.2 Support 1857.16.3 Metallicprojections 1857.16.4 Metallicmaterials 186

7.16.5 Structurewithinzone.ofprotection ' 1867.16.6 Air terminationon roof 1867.16.7 Air terminationon reinforcedconcretestructure 186

VI

!

7.17 Down conductor , , 186

7,17.1 General " , ' 186

7.17.2 Routing , 1877,17.3 Recommendednumber ,., 187

7.17.4 Mechanicalprotection 1877.17.5 Corrosivesoil .................................... 187

7.17.6 Externalroutesnotavailable , , .. , " 187

7.17.7 Lift shafts , , , . , 188

7.17.8 Re-entrantloops . , '.' 188

7.17,9 Sharpbends , 188

7.17.10 Bondingto preventsideflashing 1887.17.11 Bonds ' 188

7.17.12 Testpoints , : 189

7.18 Earthtermination ...................................... 190

7.18.1 Termination, , , 1907.18,2 Resistanceto earth , ' , , . 190

7.18.3 Earthelectrodes., , , . , .. , , . , .. , 190

7.18.4 Connectionpoint .. ,.".', , , , 190

7.19 Commonearthing : . , , 192

7.19.1 Commonearthpotential , 192

7.19.2 Commonearthbonding , . , . 192

7.20 Use of reinforcementfor earthingin concreteStructures.. , .. : .. , 1937.20.1 General, , , ,', . , . , , , , 193

7.20.2 Electricalcontinuity . , . , , , , .. , , , .. , .. 193-7.20.3Prestressedconcretemembers ' , 193

7.20.4 Precastconcretemembers "" .. , .. 193

7.21 Structural~teelframingfor lightningprotection , ".,. 1947.21.1 General '.' ' " . , . 194

7.21.2 Air termination ,.,., 1947.21.3 Connection ' , 194

7.21.4 Earthing .. , , , 1947.21.5 Interconnection , ,., ' 194

Annex(Informative)

AnnexA - Systemdesign 219AnnexB - Consultation , .. , 220

VII

Section8 Wiring Methods

8.1 Scope 2238.2 Normativereference 223

8.3 Generalrequirements 2238.3.1Methodsof-installatiOns 223

8.3.2 Wiringinductsandplenumchambers , 2248.3.3 Undergroundinstallations 2248.3.4 Conductorsin hoistways 225

8.4 Conductors 226

8.4.1 Typesof conductors 2268.4.2 Radiiof bendsinconductors 2268.4.3 Conductorjointsandsplices 227

8.4.4 Supportingof conductors 228

8.5 Openwiring 228

8.5.1Openandclippeddirect 2288.5.2 Spacingof conductors 2288.5.3 Conductorsupports 229

8.5.4 Spacingof supports 22?

8.6 Exposedwiringon exteriorof buildingsandbetweenBuildingsonthesamepremises 2298.6.1 Locationof conductors 2298.6.2 Clearanceof conductors 229

8.6.3 Powersupplyconductors 229

8.7 Barebusbarsandrisers 2308.8 Installationof boxes,cabinets,outletsandterminalfittings 230

8.8.1 Numberof outletspercircuit 230

8.8.2 Outletboxes 2318.8.3 Conductorsinboxes 2318.8.4 Terminalfittings , 231

8.9 Cables,conductorsandwiringmethods 232

AnnexA (Normative):Scheduleof methodsof installationof cables 233

VIII

Section Protection and Control

9.1

9.2

9.3

; 9.4I./

9.5

9.6

9.7

9.8

9.9

Section10

10.1

10.2

10.3

10.4

Scope 237

Normativereferences ' 237

Generalrequirements 2379.3.1 Protectiveandcontroldevices 237

9.3.2 Typesandratingsof protectiveandcontroldevices 238

Protectivedevices 238

9.4.1 Overcu.rrentdevices 238

9.4.2 Earthfaultprotection 239

Fuses 240

Circuit breakers 240

Controldevices 240

Switches 241

Protectionandcontrolof miscellaneousapparatus 241

Class1andClass2 Circuits

Scope 245Normativereferences 245'

Classification .10. \ 245

10.3.1General 245

10.3.2Class1extra-low-voltagepowercircuits 246

10.3.3Class 2 low-energypowercircuits 24610.3.4Hazardouslocation 246

10.3.5Circuitsto safetycontroldevices 246

10.3.6Circuitsin communicationcables \ 246

Class1circuits 247

10.4.1Limitationof Class1 circuits 247

10.4.2Methodsof installationfor Class1circuits 247

10.4.3Overcurrentprotectionof Class1 circuits 24710.4.4Locationof overcurrentdevicesin Class1circuits .; 247

10.4.5Class I extra-low-voltagepowercircuit~ourcesincludingTransfonners . 24810.4.6Conductormaterialandsizes 248

10.4.7Insulatedconductorsfor Class1wiring " 248

10.4.8Conductorsof differentcircuitsin the,sameenclosure,cable,or Raceway 24810.4.9Mechanicalprotectionof remote-controlcircuits 249

10.4.10 Class1circuitsextendingaeriallybeyonda building 249

IX

10.5 Class2 circuits , 249

10.5.1Limitationsof Class2 circuits 249

10.5.2Methods of installationon supply side of overcurrentprotectionorTransformersor otherdevicesfor Class2 circuits 250

10.5.3Marking 25010.5.4Overcurrentprotectionfor Class2 circuits 25010.5.5Locationof overcurrentdevices '" 251

10.5.6Conductorsfor Class2 circuitwiring 25110.5.7Separationof Class2 circuitconductorsfromothercircuits 25110.5.8Conductorsof differentClass2 circuitsin thesamecable,enclosure,or

raceway 252

10.5.9Penetrationofa fire separation 25210.5.10 Conductorsin verticalshaftsandhoistways ; . 252

10.5.11 Class2 conductorsandequipmentin ductsandplenumchambers.. 25210.5.12 Equipmentlocatedontheloadsideof overcurrentprotection,transformers,or

current-limitingdevicesforClass2 circuits , , , 252

10.5.13 Class2 circuitsextendingbeyonda building 25310.5.14 Undergroundinstallations , , 253

Section11 Installationof ElectricalEquipment

11.1 Scope 25411.2 Normativereferences , .., 25411.3 General , 254

11.3.1Fusibleequipment ' 25411.3.2Connectionto identifiedterminalsor leads 25~

11.3.3Equipmentovercombustiblesurfaces 25511.3.4Installationof ventilatedenclosures , ". 255

11.3.5Outdoorinstallations 255

11.4 Electricheatingandcookingappliances 25511.4.1Locationof non-portableappliances 255

11.4.2Ratingof portableappliances 25511.4.3Applianceexceeding1500w 256

11.5 Heatingequipment ; , 256

11.6 Submersiblepumps 25611.7 Motorsandassociated,circuits 257

11.7.1 Wiring methodsandconductors 25711.7.2 Overcurrentprotection 26011.7.3Overloadandoverheatingprotection 26211.7.4Undervoltageprotection ~ 26511.7.5Control 266

11.7.6Disconnectingmeans 267

x

11.8 Air conditioningandrefrigeratingequipment '.' 26811.8.1General 268

11.82 Branchcircuit 268


11.8.4Supplycords , 269

11.9 Storagebatteries ',' 269

11.9.1Locationof storagebatteries 269

11.9.2Ventilationof batteryroomsor areas 269

11.9.3Batteryvents 269

11.9.4Batteryinstillatio~ ' 269

11.9.5Wiring ; .......... 270

Section12 HazardousLocations

12.1 Scope , ; 279

12.2 Nonnativereference 27912.3 Classification 279

12.3.1Division of ClassI locations ........................... 279

12.3.2Division of ClassII locations 280

12.3.3Division of ClassIII locations 281

12.4 Generalrequirements 281

12.4.1Electricalequipment 28112,.4.2Marking .. " 282

12.4.J Non-essentialelectricalequipment 283

12.4.4Equipmentrooms ' 283

12.4.5Cabletrays ; 284

12.5 ClassI locations 284

12.5.1Installationsin ClassI, Division 1 locations 284

. 12.5.2Installat~onsin ClassI, Division 2 locations 286

12.6 ClassII locations '.' 287

12.6.1Installationsin ClassII, Division 1 locations 287

12.6.2Installationin ClassII, Division 2 locations............... ~289

12.7 ClassIII locations 290

12.7.1Installationsin ClassIII, Division 1 locations 290

12.7.2Installationsin ClassIII; Division2 locations 293

XI

Section13 FhimmableLiquid DispensingandServiceStations,Garages,Bulk StoragePlants,FinishingProcessesandAircraftHangars

13.1

13.2

13.3

Scope 294Nonnativereferences 295

Gasolinedispensingandservicestations 29513.3.1Hazardousareas 295

13.3.2Wiring andequipmentwithinhazardousareas 296

13.3.3Wiring andequipmentabovehazardousareas 297

13.8 Aircraft;hangars.:. 0 0 o' 0 0 305

Bulk storageplants ' 299

13.6.1Hazardousareas : , .. 0 .' 299, .

13.6.2Wiring and'eq~ipmentin hazardol,lsareas 30213.6.3Wiring andequipmentabovehazardousareas 302

Finishingprocesses 0' 30213.7:1Hazardouslocations ,0 .. ; ........ 302

13.7.2Wiring and'equipmentin hazardousareas 304

13.7.3Wiring andequipmentaqove.hazardousareas .. 0 0 305

Hazardousareas.. 0 .' .' 0 '. 0 \ , ' 305.... ..Wiring.andequipmentin,hazardous'areas... '0' o. : 0 306

Wiring notwithin'hazardousarea. " '.' 0.' 0 306

Equipment-notwithinhazardous'areas 0 307

Residentialstoragegarages 29813.5.1Non-hazardouslocation. 0 0 298

13.5.2Hazardouslocation. ; 299

13.5.3Wiring : 299

Commercialgarages,repairsandstorage 29713.4.1 Hazardousareas 297

13.4.2Wiring andequipmentinhazardousareas 298

13.4.3Wiring abovehazardousareas 298

13.4.4EqUIpmentabovehazarqousareas 298

13.8.1

13.8.2

13.8.3

13.8.4

13.4

13.5

13.6

13.7

Section 14'PatientCare'Areas

14.1 Scope , 0 ' ,; 0 , 0 30814.2 Nonnativereferences ' : , 308

XII

14.3 Definitions 308'

14.4 Circuitsin basiccareareas 31i14.4.1Branchcircuits '..... 311

14.4.2Bondingto earthin basic-careareas ,311

14.4.3Socketoutletsin basic-careareas ' '.' .: ' 312

14.5 Circuitsin intermediateandcritical-careareas 313

14.5.1Branchcircuits 313

14.5.2Bondingto earthin intermediateandcritical-careareas '.' 31314.5.3Receptaclesin intermediate-andcritical-careareas 313

14.6 Isolatedsystems ' 314

14.6.1Sourcesof supply " , 31414.6.2Single-phaseisolatedcircuits , : 314

14.6.3Three-phaseisolatedsystems \ 315

14.7 Essentialelectricalsystems ' 315

14.7.1Circuitsin essentialelectricalsystems.. ,\ ~ 315

14.8 Transferswitches ,' 316

14.9 Emergencysupply , 316

Section 15 Installation of Lighting Equipment

15.1 Scope : 318

15.2 Normativereferences " , . :.' .. '.' . " 318

15.3 Interiorlighting:quipment: '.' , . '.. ~.~.. , 31815.3.1General ' ' 318

15.3.2Locationof lightingequipment........................ 320

15.3.3Installation.of ligptingequipment ' 323

15.3.4Wirin~of lighting.equipment .' ~ 323

15.3.5Earthingof-lightingequipment : . " 32615.3.6Electric-dischargelightingsystemsoperatingat 1000Vor less 326

15.4 q~tdoorlightingequipment '.' ., , 32715..4.1 General, : 327

15.4.2:Permanentoutdoorfloodlightinginstallation ; 3281,5.4.3'Exposedwirin~for permanentoutdoorlighting 331

AnnexA (Normative).' ; .. , 334

XIII

Section16 Fire Alarm Systemand Fire. Pumps

16.1 Scope , , ' ,:,. ~ , , , 34416.2 Normativereferences , , 344

16.3 Definitions ",., -,' , , . , , , . , ........ ,'344

16.4 Designconsideration.. , ~ , , .. : , .. , 346, .. . . '16.4.1General, , , .. , . , , , 346

16.4.2

, '

Section17 SignsandOutlineLighting

..17.1"'Scope ' 37117.2 Normativereferences 371

17.3 Generalrequirements 371

17.3.1' Construction 371


17.3.3Ratingof.disconnectingmeansandcontroldevices 3/217.3.4Thermalprotection ' 372

17.3.5Branch.circuitcapacity ' 372

17.3.6Location ,':.'. : 372

17.3.7Bonding ' ' 373

17.3.8Protectionof signleads ' '.' 37317.3.9Installationof conductors : ' ' : 373. '17.3.10 Fuseholdersandflashers ' 373

17.4 High-voltageluminousdischargetubesignsandoutlineLighting ' 373

17.4.1Enclosure .' ~. '.. : .. '.: .. , ; .. 373

17.4.2Protectionof uninsulat.edpart : , 37417.4.3Transformers : ' : .. 374

17.4.4High-voltagewiringmethods '.< 375

Section18 Lifts, Escalatorsand Similar Equipment

18.1 Scope : .. ~ " .' . '.' ' : : 37718.2 Normativereferences ,".. , ,,''' 377

18.3 General : " : : 37718.3.1Voltage limitation ' 3i718.3.2Live partsenclosed,: ' 377

18..4Conductors 378, , '18.4.1Installationof conductors 378

18.4.2Minimumsizeof conductors 378

18.4.3Motor circuitconductors 379

18.5 Wiring : 37918.5.1Wiring methods 379

18.5.2Branchcircuitsfor auxiliarysystems 380

xv

XVI

18.6 Installationof conductors ' 380

18.6.1Numberof conductorsin raceway ~ 380

18.6.2Supports 380

18.6.3Differentsystemsin oneracewayor travellingcable , 380

18.6.4Wiring in hoistway 381

18.6.5Electricequipmentin garagesandsimilaroccupancies 381

18.6.6Sidewalklifts 381

18.7 Travellingcables 381

"18.7.1Suspension ~,_ 381

18.7.2Hazardousjclassified)location 38218.7.3Protectionagainstdamage 382

18.7.4Installation 382

18.8 Disconnectingmeansandcontrol 38218.8.1General 382

18.8.2Type : 38318.8.3Location \ 383

18.8.4Phaseprotection , 383

18.9 Overcurrentprotection..~ ; 38318.9.1Controlandopet~ltingcircuits 38318.9.2Motors 384

18.10 Machineroom ; 384

18.10.1 Guardingequipment 38418.10.2 Clearancearoundcontrolpanelsanddisconnectingmeans 384

18.11 Earthing " 38418.11.1 Metalracewayattachedto cars 38418.11.2 Electriclifts 385

18.11.3 Non-electriclifts 385

18.11.4 Methodof bonding 385

18.12 Overspeed , 38518.12.1 Overspeedprotection 38518.12.2 Motor-generatoroverspeeddevice 386

18.13 Emergencypower 386

18.13.1 Supply 38618.13.2 Disconnection 386

18.13.3 Hydrauliclifts disconnectingmeans 386

18.14 Machineroomsandhoistwaypits lightingandAuxiliary 38618.14.1 Machineroom 386

llU4.2 Hoistpits 387

Section19 Theatrelnstallation

19.1 Scope ; 38819.2 Normativereferences 388

19.3 Wiringmethod 388

19.4 Fixedstageswitchboard ' 38919.4.1Fuses 389

19.4.2Overcurrentprotection :: 38919.4.3Dimmers 390

19.4-4Controlof stageandgallerypockets : 39019.4.5Conductors 390

19.5 Portableswitchboardon stage 391

19.5.1Constructionof portableswitchboards 391

19.5.2Supplyfor portableswitchboard 391

19.6 Fixed stageequipment 391

19.6.1Footlights 39119.6.2Metalwork 391

19.6.3Clearanceatterminals 392

19.6.4Mechanicalprotectionof lampsin borders,etc 39219.6.5Suspendedfixtures 392

19.6.6Connectionsat lampholders 392

19.6.7Ventilationfor mogullampholers, ~ 39219.6.8Conductorinsulationfor field-assembledfixtures 392

19.6.9Branchcircuitovercurrenfprotection 392

19.6.10 PendantlightsratedmorethanlOOW 393

19.6.11 Cablesfor borderlights 393

19.6.12 Wiring to arcpockets 393

19.6.13 Socketoutletsandplugs 39319.6.14 Curtainmotors 394

19.6.15 Flue dampercontrol 394

19.7 Portablestageequipment 394

19.7.1Fixtureson scenery 394

19.7.2Stringor festoonedlights , - 395

19.7.3Flexibleconductorsfr?m portableequipment 39519.7.4Portableequipmentfor stageeffects 395

XVII

Section20 EmergencySystems,Unit Equipment,andExit Signs

20.1 Scope 39620.2 Normativereference 396

20.3 General 396

20.3.1 Adequatecapacity 39620.3.2 Instruction 397

20.3.3 Batteriesmaintenance 397

20.3.4 Lamps 39720.3.5 Circuits 397

20.3.6 Methodof wiring 397

20.4 Emergencysystems 398

20.4.1 Supply 39820.4.2 Control 398

20.4.3 Overcurrentprotection 398

20.4.4 Audibleandvisualtrouble-signaldevices 398

20.5 Unit equipment 399

20.5.1 Mounting ,.. ' 399

20.5.2 Supplyconnections 400

20.6 Exit signs 401

20.6.1 Powersupply 40I

20.6.2 Wiring 401

Section21 MotionPictureStudios,ProjectionRooms,Film ExchangesandFactory


21.3 General 402

21.3.1 Wiring method 402

21.4 Viewing, cuttingandpatchingtablefixture 403

21.5 Film-vaultsandstoragerooms 403

21.5.1 Equipmentin film vaultsandstoragerooms 403

21.5.2 Wiring methodin film-vaults 403

21.5.3 Lightingfixturesin film-vaults 40321.5.4 Film-vaultcircuits 404

XVIII

~_. ------ ~I

21.6 Motion pictureprojectionrooms.. i 404

21.6.1 Lampsin projectionrooms 404

21.6.2Arc lampcurrentsupply 40421.6.3Ventilation 404

21.7 Motorsandgenerators 404

Section22 DiagnosticImaging Installation

22.1 Scope 405

22.2 Nonnativereferences " 40522.3 Definitions 405

22.4 High-voltageguarding 406

22.5 Connectionsto supplycircuit 406

22.6 Disconnectingmeans 406

22.7 Transfonnersandcapacitors ; 40722.8 Control 407

22.9 Ampacityof supplyconductorsandratingof overclirrentprotection 408

22.10 Bonding 408

Section23 ElectricalCommunicationSystems

23.1 Scope - 40923:2 Nonnativereference 409

23.3 General 409

23.3.1Circuitsin communicationcables 409

23.3.2Hazardouslocations 410

23.3.3 Approvedtransfonners 410

23.4 Insideconductors 410

23.4.1Conductorsarrangement 41023.4.2 Insulation 410

23.4.3 Earthingconductorswith anoutermetalcovering 410

23.4.4 Separationfromotherconductors 410

23.4.5 Penetrationof a fire separation 411

23.4.6 Communicationcablein hoistways 411

23.4.7 Communicationconductorsin ductsandplenumchambers 4.12

23.4.8 Dataprocessingsystems 412

23.4.9 Conductorsunderraisedfloors _ 41223.4.10 Conductorsin concealedinstallations 412

23.4.11 TypeCFC under-carpetwiring system 413

XIX

23.5 Equipment 414

23.5.1 Communicationequipmentin bathrooms 414

23.5.2 Equipmentin air ducts,plenums,or suspendedceilings 414

23.5.3 Exposedequipmentandterminations : 41523.5.4 Earthcircuits 415

23.5.5 Communicationsystemsin hospitals 415

23.6 Outsideconductors 415

23.6.1 Overheadconductorsonpoles 41523.6.2 Overheadconductor$on roofs ~ 415

23.6.3 Lightningconductors 416

23.6.4 Swimmingpools 416

23.7 Undergroundcircuits ; 41623.7.1 Directburiedsystems " l .41623.7.2 Undergroundraceway ' ~ 417

23.8' Earthing 417

23.8.1 Bondingof cablesheath ." : 417

23.8.2 Cable-sheathbondingconductor - A18

23.8.3 Earthingelectrode '.. 418

23.8A Earthingelectrodeconnection : 41923.8.5 Bondingof electrodes 419

Section24.. CommunityAntennaInstallationFor Radio And televisionReception

.24.1 Scope ",: : . ~ 420.24.2 Normativereferences'.: 420

24.3 Technicalrequirements' 42124.3.1 Mechanical 421

24.3.2 Electrical 421

24.4 Equipment 421

24.4.1 Communityantennadistributionamplifiersandotherpowersources . 421

24.4.2 Exposedequipmentandterminations 422

24.4.3 Equipmentearthing 422

24.5 Communityantennadistributionnetwork : 42224.5.1 Conductor 422

24.5.2 Voltagelimitation 42224.5.3 Hazardouslocations 423

xx

)

\

24.5.4 Supports 423

24.5.5Earthingof outerconductiveshield'ofa coaxialcable 423

24.5.6Earthingconductor 42324.5.7Earthingelectrode 424

24.5.8Earthingelectrodeconnection 424

24.6 Conductorswithinbuildings~ ; ;' 42~

24.6.1Separationfromother.~onductors '" .. ; ; .42424.6.2Conductorsina verticalshaft.. ; . ; ................ , 425

24.6.3'Penetrationof aJire separation : ' 426

''24.6.4CommuriityantennadistributionconductorsinductsandplenumCambers.. 426'24.6.5Raceways ' '.' .................. 426

24.7 Conductorsoutsideof buildings : " 42624.7.1Overheadconductorson poles ; 426.24.7.2Overheadconductorson roofs ',' 426

24.7.3 Conductorson buildings ............................. 426

24.7.4 Conductorsenteringbuildings 427

24.7.5 Swimmingpools ' '. 427

24.8 Undergroundconductors , .......................... 427

. 24.8.1Directburiedsystems ' ; '~ 427

24.8.2Undergroundraceway.............................. 428. 24.8.3.UndergroundbluckdIstribution 429

24.9 Lightningarrestersfor receivingstations 429

24.9.1 Lightningarrester 429. ,24.94 Earthingconductor 429

.24.9.3Earthingelectrode 430

AnnexA (Informative) 431

---Section25 SwimmingPools,Fountainsand Similar Installations

25.1 Scope ' 44625.2 Normativereference ' 446

25.3 Definitions 446

25.4 General 447

25.4.1 Equipmentinstallation 447

25.4.2 Overheadwiring 448

25.4.3 Undergroundwiring 448

XXI

25.4.4 Bondingto earth 44925.4.5 Junctionanddeckboxes 450

25.4.6 Transformersandtransformerenclosure 451

25.4.7 Socketoutlets 452

25.4.8 Luminariesandlightingequipment 45225.4.9 Earth-faultcircuitbreakers 454

25.5 Permanentlyinstalledswimmingpools 45525.5.1 General 455

25.5.2 Conduittype 455

25.5.3 Circuit segregation 455

25.5.4 Drainage 455

25.6 Storableswimmingpools 455

25.6.1 Electricalequipment 455

25.6.2 Pumps ' 456

25.7 Hydromassagebathtub 45625.7.1 Protection 456

25.7.2 Control 456

25.7.3 Otherelectricequipment 457

25.8 Spasandhottubs 457

25.8.1 Bondingto earth 457

25.8.2 Controlsandotherelectricalequipment 457

25.8.3 Leakagecurrent ~ 45825.8.4 Field-assembledunits 458

Annex A (Informative) 460

Section26 GraphicalSymbols


26.3 Definitions 462

XXII

26.4 Symbols 463

AnnexA - (Infonnative) 470

Annex B - (Infonnative) 471

Appendices

AppendixI Inspectionandtesting A-I

Appendix2 Fonnsof completionandinspectioncertificate A-9

XXIII

1.1 SCOPE

1.2 NORMATIVE REFERENCES

(2)ThisCodedoesnotapplyto:

ETHIOPIAN BUILDING CODE STANDARD

SCOPE AND DEFINITIONS

a) IEC 364-1:1972 Electrical Installationsof Building, Part 1, Scope, Object andDefinitions.

a) electrictractionequipment,

b) electricalequipmentof automobiles,

c) electricalequipmenton boardships,

d) electricalequipmentin aircraft,

e) publicstreet-lightinginstallations,f) installationsin mines,

g) radio interferencesuppressionequipment,exceptso far as it affectssafetyof theinstallation,

h) fixedwiring for telecommunication,signalling,controlandthelike,

i) internalwiring-of apparatus,

j) systemsfor distributionof energyto thepublic,or powergenerationandtransmission

for suchsystems.

ECTION 1

(1)This Codeappliesto the design,selection,erection,~nspectionandtestingof electricalinstallationsfor residential,commercial,publicandindustrialpremisesincludingprefabricated

buildings,constructionsites,exhibitions,fairs and othertemporaryinstallationsup to and

includinglOOO.OY a.c.or I500.0Y d.c.

(I) Thefollowingreferencescontainprovisionswhich,throughreferencein thistext,constitute

provisionsof theEthiopianBuildingCodeStandardson ElectricalInstallationof Buildings.

1 EBCS-10 1995

ELECTRICAL INSTALLATION OF BUILDINGS

b) lEC 50:1982

c) BS 7671:1992

d) C 22.1:1992

InternationalElectrotechnicalVocabulary.

Requirementsfor ElectricalInstallations,lEE Wiring Regulations,SixteenthEdition.

CanadianElectrical Code, Part I, Safety Standardfor Electrical

Installations,SixteenthEdition.

(2) At thetimeof publicationof thisBuildingCodeStandard,theeditionsindicatedwerevalid.

All referencesare subjectto revisions,andpartiesto agreementandbasedon this Ethiopian

BuildingCodeStandardareencouragedto investigatethepossibilityof applyingthemostrecent

editionsof the referencesindicatedbelow. The EthiopianAuthority for Standardization

maintainsregistersof a numberof foreignnationalandinternationalstandards.

1.3 DEFINITIONS

(1) For thepurposeof thisCode,thefollowingdefinitionsshallapply.

acceptable

accessible(asappliedto wiring methods)

. accessory

ambienttemperature

ampacity

acceptabletotheAuthorityenforcingthisCode.

not permanentlyclosedin by thestructureor

finish of the building and capableof being

removed without disturbing the buildingstructureor finish.

a device,otherthancurrent-usingequipment,

associatedwith such equipmentor with the

wiring of an installation.

the temperatureof the air or othermedium

wheretheequipmentis to beused.

a steadyvalueof currentwhichcanbecarried

by a conductorunder specifiedconditions

withoutits steadystatetemperatureexceeding

a specifiedvalue.

ETHIOPIAN BUILDING CODE STANDARD EBCS-10 1995 2

appliance

arms'sreach

barrier

basicinsulation

bondingconductor

branchcircuit

buildingvoid,accessible

SECTION 1: SCOPE AND DEFINITIONS

anitemof current-usingequipmentotherthana luminaireor

an independentmotor.

a zoneof accessibilityto touch,extendingfrom anypointon

a surfacewherepersonsusuallystandor moveabout,to the

limitswhichapersoncanreachwithhis handin anydirectionwithoutassistance.

a partprovidinga defineddegreeof protectionagainstcontact

with liveparts,fromanyusualdirectionof access.

insulationappliedto live partsto providebasic protection

againstelectricshockandexclusivelyfor functionalpurposes.

aprotectiveconductorprovidingequipotentialbonding.

that portion of the wiring installationbetweenthe final

overcurrentdeviceprotectingthecircuitandtheoutlet(s).

a spacewithinthe structureor thecomponentsof a building

accessibleonlyatcertainpoints.

buildingvoid,non-accessible a spacewithin a structureor the componentsof a building

whichhasnoreadymeansof access. ()

bunchedcables

bus

busway

3 EBCS-10 1995

cablesaresaidto bebunchedwhentwoormorearecontained

within a singleconduit,duct,ducting,or trunkingor, if not

enclosed,are not separatedfrom eachotherby a specifieddistance.

a conductorwhich servesas a commonconnectionfor the

correspondingconductorsof two or morecircuits.

.a raceway-consistingof metaltroughing(includingelbows,

tees, crosses, in addifion to straight runs) containing

conductors,theconductorsbeingsupportedon insulators.



cabinet

cablebracket

cablechannel

cablecleat

cablecoupler

cableducting

cableladder

cabletray

cabletrunking

anenclosureof adequatemechanicalstrength,composedentirelyof

noncombustibleandabsorption-resistantmaterial,designedeither

for surfaceor flushmounting,andprovidedwith a frame,mat,or

trim, in whichswingingdoorsarehung.

a horizontalcablesupportsystem,consistingof elementsfixed at

oneendonly, spacedat intervalsalongthelengthof thecableandon whichthecablerests.

anenclosuresituatedaboveor in theground,ventilatedor closed,

andhavingdimensionswhichdonotpermittheaccessof persons

but allow accessto theconductorsand/orcablesthroughouttheir

lengthduringandafterinstallation.A cablechannelmayor may

not formpartof thebuildingconstruction.

a componentof a supportsystem,which consistsof elements

spacedat intervalsalongthelengthof thecableor conduit.

ameansof enablingtheconnectionor disconnection,atwill, of two

flexiblecables. It consistsof a connectoranda plug.

amanufacturedenclosureof metalor insulatingmaterial,otherthan

conduitor cabletrunking,intendedfor the protectionof cables

whicharedrawn-inaftererectionof theducting..

acablesupportconsistingof aseriesof supportingelementsrigidly

fixed to main supportingmembers. The supportingelements

occupylessthan10%of theplanarea.

a cablesupportconsistingof a continuousbasewith raisededges

andno covering.A cabletrayis consideredto benon-perforated,wherelessthan30%of thematerialis removedfromthebase.

a manufacturedenclosurefor theprotectionof cables,normallyof

rectangularcross-section,of whichonesideisremovableorhinged.

4 EBCS-1 0 1995 ETHIOPIAN BUILDING CODE STANDARD



a protectiveconductorconnectingexposedconductive

partsof equipmentto themainearthlingterminal.

5EBCS-10 1995

equipmentin which protectionagainstelectricshock

does not rely on basic insulationonly, but which

includes means for the connection of exposed

conductivepartsto a protectiveconductorin thefixed

wiring of theinstallation.

a devicecapableof making,carryingand breaking

normalloadcurrentsandalsomakingandautomatically

breaking,underpredeterminedconditions,abnormal

currentssuchas short-circuitcurrents. It is usually

requiredto operateinfrequentlyalthoughsometypes

aresuitablefor frequentoperation.

anenclosure(corridor)containingsupportingstructures

for conductorsand/orcablesand joints and whose

dimensionsallowpersonsto passfreelythroughoutthe

entirelength.

a circuit-breakerthecontactsof whicharesoarranged

as to makeor breakall polessimultaneouslyor in a

definitesequence.

a devicecomprisinga fuse elementor severalfuse

elementsconnectedin parallelenclosedin a cartridge

usually filled with arc-extinguishingmedium andconnectedto terminations.Seefuselink.

anassemblyof electricalequipmentsuppliedfrom the

sameorigin andprotectedagainstovercurrentby the

sameprotectivedevice(s).

ClassI equipment

circuitprotectiveconductor(CPC)

circuit-breaker(linked)

circuit-breaker

circuit

cartridgefuse link

cabletunnel

ELECTRICAL INSTALLAtiON OF eUILDINGS

ClassII equipment

conduit

cutren/-permit

conneC/or

contractor

current-carryingcapacityof a conductor

cu"ent-usmgequipment

6 EBCS-101995

'equipmentin which protectionagainstelectricshock

doesnot rely on basic insulationonly, but in which

additionalsafetyprecautionssuch as supplementaryJ

insulationateprovided,therebeingnoprovisionfor the

connectionof exposedmetalworkof theequipmentto

a protective conductor, and no refianc-eupon

precautionsto be taken in the fixed wiring of theinstallation.

a partof aclosedwiring systemfor cablesin electrical

installati()fis,allowing them to be drawn in and/or

replaced,butnot insertedlaterally.

awrittenpetrfiissionfrom Authorityhavingjurisdiction

to a supplyauthorityto theeffectthatelectricenergy

maybesuppliedto a particularinstallation.

thepartof a cablecoupleror of an appliancecoupler

whichis prOVidedwith femalecontactsandis intendedto be attachedto theendof the flexiblecableremote

fromthesupply.

any personwho as principal, servantor agent,by

himselfor his'associates,employees,servantsor agents

perfOIinSor engagestoperformeitherfor hisown useandberrefitOr for thatof 'anotherandfor o-rwithout

remunefationor gain any work with respectto any

electricalinstallationor any otherwork to which this

Codeapplies.

the maximumcurrentwhich can be carned by a

cowductotunderspecifiedconditionswithoutitssteady

statetemperatureexceedinga specifiedvalue.

equipmentwhichconverfselectricalenergyintoanother

formof energy,suchaslight,heat,or motivepower.


ETHIOPIAN BUILDING CODE STANDARD 7EBCS-10 1995

SECTIQN 1: SCQPE AND DEFINITIONS

risk of injury to persons(and livestockwhere expectedto be

present)from:

insulationcomprisingboth basic insulationand supp'lementaryinsulation.

a) fire,electricshock,andbumsarisingfromtheuseof electrical

energy;b) mechanicalmovementof electric~llycontrolledequipment,in

sofar assuchdangeris intendedto bepreventedby electrical

emergencyswitchingorby ~lectrical~witchingfor mechanical

maintenanceof nop-electricalpartsof suchequipment.

anassemblycontainingswitchingor prote~tivedevices(e.g.fusesor circuit-breakers)associatedwith oneor moreoutgoingcircuits

fedfromoneormoreincomingcircuits,togetherwithtenninalsfor

theneutralaridprotectivecircuitconductors.it mayalso includesignallingandothercontroldevices. Meansof isolationmay be

includ~din theboardQrmaybeprovideds~parately.

a) an itemof switchgear,

b) an itemof controlgear,or

c) a distributionboard

themagnitudeof thecurrent(r.m.s.valll,efor a.c.)to becarriedbythecircuitin normalservice.

circuitcQnn~ctingtheoriginof theinstallationto:

contactof perSOnSor livestockwith livepartswhichmayresultinelectricshock.

A distributioncircuitmayalsoconnecttheoriginof an installation

to an outlying building or separateinstallation,when it issometimescalleda sub-main.

to which one or more final circuits or itemsof currentusmg

equipmentareconnected.(~eealsofinal circuit.)

directcontact

designc14rrent(of a circuit)

danger

distributionboard

distributioncircuit

doubleinsulation


duct a closedpassagewayformedundergroundor in a structureand

intende~to receiveoneor morecableswhichmaybedrawnin.

ducting (seecableducting)

earth

earthelectrode

theconductivemassof theEarth,whoseelectricpotentialat any

pointis conventionallytakenaszero.

a conductoror groupof conductorsin intimatecontactwith, and

providinganelectricalconnectionto, earth.

earthelectroderesistancetheresistanceof anearthelectrodeto earth.

earth-faultcurrent a faultcurrentwhichflows to earth.

earth-faultloopimpedance theimpedanceof theearth-faultcurrentloopstartingandendingat

the point of earthfault. The earthfault loop comprisesthe

followiBg,startingatthepointof fault:

(a) thecircuitprotectiveconductor;

(b) theconsumer'searthingterminalandearthingconductor;

(c) theearthreturnpath;

(d) thepaththroughtheearthenneutralpointof thetransformer

andthetransformerwinding;andthephaseconduCtorfromthe

transformerto thepointof fault.

earth-leakagecurrent a currentwhich flows to extraneous-conductive-parts,in a circuit

which is electricallysound. This currentmay havea capacitive

componentincludingthat resultingfrom the deliberateuse of

capacitors.

earthenequipotentialzone a zone within which exposed-conductive-partsand extraneous-

conductive-partsaremaintainedatsubstantiallythesamepotential

by bonding,suchthat,underfault conditions,the differencesin

potential between simultaneouslyaccessible exposed and

extraneous-conductive-partswill notcauseelectricshock.

earthing theactof connectingtheexposed-conductivepartsof aninstallation

to themainearthingterminalof an installation.

8 EBCS-10 1995 ETHIOPIAN BUILDING CODE STANDARD

-- -- --------~---------------------'---

)electrodeboUer, electrodewaterheater equipmentfor theelectricalheatingof wateror electrolyteby

thepassageof anelectriccurrentbetweenelectrodesimmersed

in thewateror electrolyte.


emergencystopping emergencyswitchingintendedto stopa dangerousmovement.

9EBCS-10 1995

earthingconductor a protectiveconductorconnectingthemainearthingterminalof an installationto an earthelectrodeor to othermeansof

earthing.

electricallyindependentearthelectrodes earthelectrodeslocatedat sucha distancefrom oneanother

thatthemaximumcurrentlikely to flow throughoneof them

doesnotsignificantlyaffectthepotentialof theother(s).

electricalequipment any item for such purposesas generation,conversion,

transmission,distributionor utilizationof electricalenergy,

such as machines, transformers,apparatus,measuring

instruments,protectivedevices,wiring materials,accessories,

appliancesandluminaries.

electricalinstallation anassemblyof associatedelectricalequipmentsuppliedfrom

acommonoriginto fulfil aspecificpurposeandhavingcertaincoordinatedcharacteristics.

electricshock a dangerousphysiologicaleffectresultingfromthepassingof

anelectriccurrentthrougha humanbodyor livestock.

emergencyswitching rapidcuttingoff of electricalenergyto removeanyunexpected

hazardto persons,livestock,or property.

enclosure a part providing an appropriatedegreeof protectionof

equipmentagainstcertainexternalinfluencesand a defined

degreeof protectionagainstcontactwith live partsfrom anydirection.

equipment(abbr., seeelectricalequipment).



equipotentialbonding electricalconnectionmaintainirigvariousexposed-conductive-partsatsubstantiallythesamepotential.

equipotentialzone (seeearthenequipotentialzone).

exposed-conductive-partaconductivepartof equipmentwhichcanbetouchedandwhichisnota livepartbutwhichmaybecomeliveunderfaultconditions.

externalinfluence anyinfluenceexternaltoanelectricalinstallationwhichaffectsthedesignandsafeoperationof thatinstallation.

extraneous-conductive-parta conductivepart liableto introducea potential,generallyearthpotential,andnotformingpartof theelectricalinstallation.

fault

fault current

feeder

final circuit

fIXedequipment

flexiblewiringsystem

a circuitconditionin whichcurrentflows throughanabnormalor

unintendedpath. This mayresultfroman insulationfailureor the

bridgingof insulation.Conventionallytheimpedancebetweenlive

conductorsor betweenlive conductorsandexposedor extraneous-

conductive-partsatthefaultpositionis considerednegligible.

a currentresulting'froma fault.

a conductoror groupof conductorsthattransmitelectricalenergy

fromaservicesupply,transformer,switchboard;distributioncentre,

'generator,or othersourceof supplyto branchcircuitovercurrentdevice.

a circuit connecteddirectlyto current-usingequipment,or to a

socket-outletor socket-outletsor other outlet points for the

connectionof suchequipment.

equipmentfastenedto a supportor otherwisesecuredin specificlocation.

a wiring systemdesignedto providemechanicalflexibility in use

withoutdegradationof theelectricalcomponents.


funcJionaJearthing

functionalextra-Iowvolt4ge

fuse

fuseelement

fuselin~

hotairsauna

indirectcontact


connectionto earthnecessaryfor properfunctioningof electrical.equipment.

any extra-lowvoltagesystemin which not all of the protective

measuresrequiredfor SELV havebeenapplied.

adevicethatby thefusingof oneor moreof itsspeciallydesignedand proportionedcomponents,opensthe circuit in which it is

insertedby breakingthercurrentwhenthis exceedsa give~value

for a sufficienttime. Thefusecomprisesall thepartsthatformthe

completedevice.

a partof a fusedesignedto meltwhenthefuseoperates.

a part of a fuse, includingthe fuse element(s),which requires

replacementby a new or renewablefuse link afterthe fusehas

operatedandbeforethefuseis putbackintoservice.

a roomor locationin whichair is heatedtoahightemperatureand

in which the rekrtivehumidityis normallylow, rising for short

periodsof timeonlywhenwateris pouredovertheheater.

contactof personsor livestockwithexposed-conductive-partsmade

live by a faultandwhichmayresultin electricshock.

installation(abbr.,seeelectricalinstallation).

insulation

isolation

isoilltor

ladder(seecableladder)

suitable non-conductivematerial enclosing, surrounding, or

supportinga conductor.

a functionintendedto cutoff for reasonsof safetythesupplyfrom

all, or a discretesection,of the installationby separatingthe

installationor sectionfrom~verysourceof electricalenergy.

a mechanicalswitchingdevicewhich providesthe function ofisolation.

ETHIOPIANBUILDING CODE STANDARD EBCS-10 1995 11


livepart

luminaire

luminairesupportingcoupler(LSC)

mainearthingterminal

mechanicalmaintenance

EBCS-1 0 1995

aconductoror conductivepartintendedtobeenergised

in nonnaluse,includinga neutralconductor.

bquipmentwhichdistributes,filters,or transfonnsthe

light fromoneor morelamps,andwhich includesany

partsnecessaryfor supporting,fixingandprotectingthe

lamps, but not the lamps themselves,and where

necessary,circuit auxiliariestogetherwith the means

for connectingthemto thesupply. For thepurposeof

the regulationsa lampholder,however,supportedisdeemedto bea luminaire.

a means,comprisinganLSC outletandanLSC plug,

providingmecl1a.n-malsupportfor a lu.minaireandtheelectricalconnectionto anddisconnectionfroma fixed

wiring installation.

a combinationof oneor morelow-voltageswitching

devicestogetherwith associatedcontrol, measuring

signalling protective, regulating equipment, etc.,

completelyassembledunderthe responsibilityof themanufacturerwith all the internal electrical and

mechanicalinterconnectionand structuralparts. The

componentsof theassemblymaybeelectromechanical

or electronic.The assemblymaybeeithertype-tested

or partiallytype-tested.

the tenninalor bar providedfor the CC/lili".:tlOnof

}lrotectiveconductors,includingequipotentialbonding

conductors,andconductorsfor functionalearthingif

any,to themeansof earthing.

the replacement,refurbishmentor cleaningof lamps

and non-electricalparts of equipment,plant and

machinery.


overloadcurrent anovercurrentoccurringin a circuitwhich is electricallysound.

nominalvoltage (seevoltage,nominal).

originof an installation thepositionatwhichelectricalenergyis deliveredto anelectricalinstallation.

13EBCS-10 1995


a conductorconnectedto the neutralpoint of a systemand

contributing'to thetransmissionof electricalenergy.

neutralconductor

phaseconductor a conductorof an a.c. systemfor the transmissionof electrical

energyotherthana neutralconductor. The termalsomeansthe

equivalentconductorof a d.c.systemunlessotherwisespecifiedinthisCode.

permit theofficial writtenpermissionof theAuthorityhavingjurisdiction

on a form providedfor the purpose,authorizingwork to be

commencedon anyelectricalinstallation.

overcurrentdetection a methodof establishingthatthe value of currentin a circuit

exceedsa predeterminedvaluefor a specifiedlengthof time.

obstacle a part preventingunintentionalcontactwith live parts but not

preventingdeliberatecontact.

overcurrent acurrentexceedingtheratedvalue. For conductorstheratedvalue

is thecurrent-carrying-capacity. \

plug a device,providedwith contactpins, which is intendedto be

attachedto a flexible cable,and which can be engagedwith asocket-outletor with a connector.

portableequipment electricalequipmentwhich is movedwhile in operationor which

caneasilybemovedfromoneplaceto anotherwhile connectedto

thesupply.

point a terminationof the fixed wiring intendedfor the connectionof

current-usingequipment.



protectiveconductor a conductorusedfor somemeasuresof protectionagainstelectricshockandintendedfor connectingtogetherany of thefollowing

parts(referto Figure 1.1):

prospectivefault current thevalueof overcurrentatagivenpointin acircuitresultingfrom

a faultof negligibleimpedancebetweenlive conductorshavingadifferenceof potentialunder normal operatingconditions,or

betweena live'conductorandanexposed-conductive-part.

(a) exposedconductiveparts

(b) extraneousconductiveparts

(c) themainearthingterminal

(d) earthelectrode(s)

(e) theearthenpointof thesource,or anartificialneutral.;-an enclosedchanneldesignedexpresslyfor holdingwires,cables,

or busbars,with additionalfunctionaspermittedin thisCode.

a systemin which thenominalphaseto phasevoltagedoesnot

exceed110.0Vahdthe nominalphaseto earth'voltagedoesnotexceed63.5V.

singleinsulationappliedto live parts,whichproyidesa degreeofprotectionagainstelectricshockequivalentto doubleinsulationstandard.

reducedlow voltagesysiem

raceway

reinforcedinsulation

. 14 EBCS-10 1995 ETHIOPIAN BUILDING CODE STANDARD


4

residualupet'atlngcurrent residualcurrentwhichcausestheresidualcurrentdevicetooperate

underspecifiedconditions.

c

p

B MainearthingterminalM Exposedconductivepart

C ExtraneousconductivepartP MainmetallicwaterpipeT Earthelectrode

E Othermeansof earthing

z

amechanicalswitchingdeviceor associationof devicesintendedto

causetheopeningof thecontactswhentheresidualcurrentattains

a givenvalueunderspecifiedconditions.

the vector sum of the instantaneousvaluesof currentflowing

throughall live conductorsof a circuitata point in theelectricalinstallation.

Protectiveconductors

circuitprotectiveconductor

mainequipotentialbondingconductorsearthingconductOrsupplementaryequipotentialbondingconductors(whererequired)

B

1,2,3,4.12

34

Figure1.1Enmple of earthingarrangements

residualcurrent

residualcurrentdevice

ETHIOPIAN BUIL.DING CODE STANDARD EBCS-10 1995 15


resistancearea(for anearthelectrodeonly)

restrictiveconductivelocation

ringfinal circuit

safetyservice

1iLV

service

shock (seeelectricshock).

shockcurrent

short-circuitcurrent

simultaneouslyaccessibleparts

thesurfaceareaof ground(aroundanearthelectrode)on whicha significantvoltagegradientmayexist.

a locationcomprisedmainlyof metallicor conductive

surroundingparts.withinwhichit is likelythataperson

will comeintocontactthrougha substantialportionof

his body with the conductivesurroundingpartsand

where the possibility of preventingthis contactislimited.

a final circuit arrangedin the form of a ring and

connectedto a singlepointof supply.

an electricalsystemfor electricalequipmentprovided

to protector warnpersonsin theeventof a hazard,oressentialto theirevacuationfroma location.

an extra-low voltage systemwhich is electrically

separatedfromEarthandfromothersystemsin sucha

way thata singlefault cannotgive rise to therisk ofelectricshock.

the conductorsand equipmentfor deliveringenergy

fromtheelectricitysupplysystemto thewiring system

of thepremisesserved.

a currentpassingthroughthe body of a personor

livestocksuchas to causeelectricshock and having

characteristicslikelyto causedangerouseffects.

an overcurrentresultingfrom a fault of negligible

impedancebetweenliveconductorshavingadifference

in potentialundernormaloperatingconditions.

conductorsor conductivepartswhich can be touched

simultaneouslyby apersonor, in locationsspecifically

intendedfor them,by livestock.

16 EBCS-10 1995 ETHIOPIAN BUILDING"CODESTANDARD


Simultaneouslyaccessiblepartsmay be Live parts, eXPQsed-

conductive-parts, extraneous-conductive-parts, protectiveconductors,or earthelectrodes.

socket-ouNet a device,providedwith femalecontacts,which is intendedto be

installedwith thefixedwiring,andintendedto receivea plug. A

luminairetracksystemis not regardedasa socket-outletsystem.

spur a branchfroma ring final circuit.

stationaryequipment electricalequipmentwhich is eitherfixed,or equipmenthavinga

massexceeding18.0kgandnotprovidedwith a carryinghandle.

supplementaryinsulation independentinsulationappliedin additionto basic insulationin

orderto provideprotectionagainstelectricshockin theeventof afailureof basicinsulation.

supplyauthority

switch

switch,linked

switchboard

switchgear

any municipal corporation,commission,company or person

supplying electrical power or energy intended for sale or

distributionto thepublic.

a mechanicaldevicecapableof making,carryingand breaking

current under.normal circuit conditions,which may include

specifiedoperatingoverloadconditions,andalsoof carryingfor a

specifiedtimecurrentsunderspecifiedabnormalcircuitconditions

suchasthoseof short-circuit.It mayalsobe capableof making,

butnotbreaking,short-circuitcurrents.

a switchthecontactsof whicharesoarrangedasto makeor break

all polessimultaneouslyor in a definitesequence.

anassemblyof switchgearwithorwithoutinstruments,buttheterm

doesnotapplyto groupsof localswitchesin final circuits.

an assemblyof main and auxiliary switching apparatusfor

operation,regulation,protectionor othercontrolof an electricalinstallation.



system

temporarysupplyunit

an electricalsystemconsistingof a single sourceof electrical

energyand an installation. For the purposeof this'Code, the

.systemadoptedshallbe IT system.A systemhavingonepointof

thesourceof energydirectlyearthen,theexposed-conductive-parts

of the installationbeingconnectedto.earthelectrodeselectrically

ihdependentof theearthelectrodesof the.source,(seeFigure1.2).

an enclosurecontaining"equipmentfor the purposeof taking a

temporaryelectricalsupplysafelyfroman itemof streetfurniture.

trunking (seecabletrunking).

voltage,nominal

18 EBCS-10 1995

voltageby which an installation(or part of an installation)is

designated.Thefollowingrangesof nominalvoltage(r;m.s.values

for a.c.)aredefined:

extra-low:Normally not exceeding50.0Y a.'C.or 120.0Yripple

freed.c.,whetherbetweenconductorsor to earth,

low: Normally exceeding extra-low voltage but not

exceedinglOOO.OYa.c. or 1500.0Y d.c. between

conductors,-or 600.0Y a.c. or 900.0Y d.c. betweenconductorsandearth.

The actualvoltageof theinstallationmaydiffer fromthenominal

valueby a quantitywithinnormaltolerance.


E


SOURCE OF ENERJi1I

L2

L3

~

__ INSlAUAllOi

fARlH ELCCTROfl:

-----,II,II,I,1

.JEXPOSEDCONDUCTJV

PARlS

CONSUMERS

J'~'~\.--I ,I II ,II EQUf'tolENl IN I

INStALLAllON - I.

r-III,II,L _

INSlALLAlI~fAR1H

ELE:ClROOE

SOURCE EARlH


voltagereduced (seereducedlow voltagesystem).

an assemblymadeup of cableor busbarsandpartswhich secure

and,if necessary,enclosethecableor busbars.

19EBCS-10 1995

wiringsystem.

Figure1.2 TT System

SECTION 2

9ENERAL REQUIREMENTS

2.1 ADMINISTRATIVE

2.1.1 AuthorityforRules

(1) By virtueof theauthorityvestedin theAuthorityhavingjurisdiction,thisCodehasbeen

adoptedandherebyordersanddirectsitsobservance.

2.1.2 Permit

(1) Electric~lcontractorsor othersresponsiblefor thecarryingout of thework shallobtaina

permit from the Authority havingjurisdiction before commencingwork with respectto

installation,alteration,repair,or extensionof anyelectricalequipment.

2.1.3 ApplicationforInspection

(1) An applicationfor inspectionshallbefixedwiththeAuthorityhavingjurisdictionona form

providedby the latteratthetimethepermitis obtained;

2.1.4 PostingoCPermit

(1) A copyof thepermitshallbepostedin aconspicuousplaceonthesiteof thework andshall

notberemoveduntil theinspectionis completed.

2.1.5 NotificationRe-inspection

(1) TheAuthorityhavingjurisdictionshallbenotifiedin writingbytheelectricalcontractor~atwork is readyfor inspectionatsuchtimeor timesaswill permitinspectionbeingmadebefore

anywork or portionthereofis commenced.


SECTION 2: GENERAL REQUIREMENTS

2.1.6 PlansandSpecifications

(1)Plansandspecificationsin duplicateor ingreaternumberif requiredbytheAuthorityhavingjurisdictiononecopyto beretainedby theAuthority,shallbe submittedby theowneror his

agentto, andacceptanceobtainedfrom,theAuthoritybeforework is commencedon:

a) wiring installationsof publicbuildings,industrialestablishments,factories,andother

buildingsin whichpublicsafetyis involved:

b) largelightandpowerinstallationsandtheinstallationor apparatussuchasgenerators,transformers,switchboards,largestoragebatteries:

c) suchotherinstallationsasmaybeprescribedby theAuthorityhavingjurisdiction.

2.1.7 ConnectionAuthorization

(I) Whereanyelectricalinstallationor partthereofto whichelectricalpoweror energyhasnot

previouslybeensuppliedis madein or uponanylandbuildingorpremises,whereanyelectrical

installationor partthereofhasbeendisconnectedor cutoff fromanyserviceor othersourceof

supplyunderthis Code,no supplyauthority,contractoror otherpersonshallconnector re-

connectthe installationor partthereofto anyserviceor othersourceof supplyunless:

a) theinstallationandall work in respectthereofhavebeeninspectedby an inspector;and

b) aconnectionauthorizatiofthasbeenissuedbytheAuthorityhavingjurisdictionin respectof the installation.

2.1.8 Re-inspection

(1)The Authority havingjurisdictionreservesthe right to re-inspectat any time electrical

installationnotwithstandinganypreviousinspectionandacceptance,if andwhenit considers

suc~actionto benecessary.

2.1.9 Renovationof ExistingInstallation

(1)TheAuthorityhavingjurisdictionmayrequiresuchchangesasmaybenecessarytobemade

toexistinginstallationswhere,throughhardusage,wearandtear,or asa resultof alterationor

extensions,dangerousconditionshavedeveloped.



2.1.10Useof ApprovedEquipment

(1) No oneshalluseanyelectricalequipmentotherthanapprovedelectricalequipmentof akind

or typeandratingapprovedfor thespecificpurposefor which it is to b e employed.

2.1.11Deviationor Postponement

(1) 10 any casewheredeviationor postponementof this Code may be necessary,special

permissionshallbeobtainedbefo~proceedingwiththework,butthisspecialpermissionshall

applyonly to theparticularinstallationfor whichit is given.

2.1.12Powersof Rejection

(1) Even thoughapprovalhaspreviouslybeengranted,theAuthorityhavingjurisdictionmay

reject,atanytime,anyelectricalequipmentunderanyof thefollowingconditions:

a) If the equipmentis substandardwith respectto the sample'on which approvalwas

granted.

b) If theconditionsof useindicatethattheequipmentis notsuitable.

c) If thetermsof theapprovalagreementarenotbeingcarriedout.

2.1.13Installationof ElectricalEquipment

(1) Electricalequipmentshallbe installedas to ensurethat,after installation,,thereis ready

accessto nameplatesandaccessto partsrequiringmaintenance.

2.1.14DamageandInterference

(1) No personshallinterferewithanyelectricalinstallationor componentthereofexceptwhen,

in the courseof alterationsor repairsto non-electricalequipmentor structures,it may be

necessaryto disconnector movecomponentsof anelectricalinstallations.

(2) It shallbetheresponsibilityof thepersGiDiCarryingoutthelalterationsorrepairstoensurethat

theelectricalinstallationis restoredto a safeoperatingconditionassoonastheprogressof the

alterationsor repairwill permit.

22 EBCS-1 0 1995 ETHIOPIAN BUILDING CODE STANDARD


1.1 TECHNICAL

1.1.1 ConventionalSymbols

(1)Graphicalsymbolsthat are to be usedin all drawings,wiring plans,etc for electrical

installationsof buildingsshallbeasindicatedin Section26 of thisCode.

1.1.1 Coordination

(1)Propercoordinationand collaborationbetweenthe architect,building engineerand the

electricalengineershallbeeffectedfromtheplanningstageof theinstallation.

(2)Theprovisionsthatwill beneededfor tile accommodationof substation,transformer,switch

room,lift wellsandotherappurtenantrooms,servicecableducts,risingmainsanddistribution

cables,sub-distributionboards,openingsandchasesin floor andwallsfor all requiredelectrical

installation,etc,shallbespecifiedin advance.

2.1.3 .LocationandRequirementof Substation

(1)Theideallocationof anelectricalsubsbttionfor a groupof buildingswouldbeattheload

centreandshallbe locatedon thegroundfloor.

(2) In multi-storeyedbuildings,thesubstationshallpreferablybe installedon thelowestfloor

level,butdirectaccessfrom the streetfor installationor removalof the equipmentshall be

provided.The floor levelof thesubstationor switchroomshall!>eabovethehighestflood level

ofthelocality.'In thiscase,theloadcentrewouldbesomewherebetweenthegeometricalcentre

andtheair-conditioningplantroom.

(3)Theavailabilityof powerlinesnearbymayalsobekeptin viewwhiledecidingthelocationofthesubstation.

2.2.4 Rooms(Spaces)Required

(I) In allocatingareaof a substation,it shallbenotedthattheflow of electricpower is from

su~lycompany'sroomtohightensionroom,thento transformerandfinallytothelow voltage

switchgearroom. The layoutof roomsshallbe in accordancewiththis flow.

ETHIOPIAN ,BUILDING CODE STANDARD EBCS-10 1995 23


(2) The following roomsarerequiredin a substation:

a) SwitchgearRoom- Supply60mpany'sswitchgearroomand/orspacefor meters.

b) TransformerRooms- The numberandsizeof transformerroomsshallbe ascertained

fromthetotalpowerrequirementof theconsumer.

c) Low-VoltageSwitchRoomS- The floor arearequirementin respectof low voltage

switchgearroomshallbeascertainedfromthenumberof feeders.

d) Stand-byGenerators. A roomspacenot lessthan6.0mx 9.0mmaybe providedforhousinga stand-bygenerator.

e) Location of SwitchRooms- In larg~installationsotherthanwherea substationisprovided,a separateswitchroomshallbeprovided;this s,hallbe locatedascloselyas

possibleto the electricalload centreand suitableductsshallbe laid with minimum

numberof bendsfrom the point of entryof the supplyto the positionof the main

switchgear.The switchroom shallalsobeplacedin sucha positionthatrising ducts

may readilybe providedtherefromto theupperfloors of thebuildingin onestraight

verticalrun~In largerbuildings,morethanonerisingductandhorizontalductsmayalso

be requiredfor runningcablefrom theswitchroomto thefoot of eachrising main.

Suchcableductsshallbereservedfor .theelectricalservicesonlywhichmay,however,

include mediumand low voltageinstallation,such as call-bell system,s;telephone

installationsshouldbesuitablysegregated.

2.2.5 Location and Requirementsof Distribution Boards

(1) The electricalcontrolgeardistributionboardsandotherapparatus,whicharerequiredon

eachfloor mayconvenientlybemouutedadjacenttotherisingmains,andadequatespaceshould

beprovidedateachfloor for thispurpose.

2.2.6 Location and Requirementsof PBXlPABX Rooms

(1) Informationregardingprovjsionfor andlocationofPBXlPABX shallbeobtainedfromthe

relevantauthorityandadequatespaceshouldbeprovidedfor installationof t!teboards.



2.3 PLANNING AND DESIGNING

2.3.1General

(1)Thedesignandplanningof anelectricalinstallationshalltakeintoaccountall theprevailing

conditionswhichmayincludesome.orall of thefollowing:

a) Typeof supply.

b) Envisagedloadhavingregardto therequirementsof theowneror occupant.

c) Theprobablemodificationsandfutureextensions.

d) Thedegreeof electricalandmechanicalprotectionnecessary.

e) Theprobableoperationandmaintenancecosttakingintoaccounttheelectricitysupplytariffsavailable.

) Therelativecostof variousalternativemethods.

g) Theneedfor radioandtelecommunicationinterferenceabatement.

2.3.2LayoutandInstallationDrawing

(1)Theelectricallayoutshouldbe consideredafterproperlocationsof all outletsfor lamps,

fans,appliances- bothfixedandtransportable,motors,etc,havebeenselectedandbestmethods

ofwiringdetermined.

(2)All runsof wiring andexactpositionsof all pointsof switch-boxesandotheroutletsshall

befirstmarkedontheplansof thebuildingandapprovedbytheengineerin chargeortheownerbeforetheactualcommencementof thework.

2.3.3Design

(1)Thedesignof electricalinstallationshallensure:

a) theprotectionof persons,livestockandproperty;

b) theproperfunctioningof theelectricalinstallationfor the intendeduse.

(2)Theinformationrequiredasa basisfor designshallbe:

a) natureof current:a.c.and/ord.c.


ELECTRICAL INSTALLATION OF BUILDtNGS

b) natureandnumberof conductors:i) fora.c.:

- phaseconductor(s);- neutralconductor;- protectiveconductor.

ii) ford.c.:- conductorsequivalentto'thoselistedabove.

c) voltageandvoltagetolerances;d) frequencyandfrequencytolerance;e) maximumcurrentallowable;f) prospectiveshort-circuitcurrent;g) natureof demand;h) emergencysupplyor supplies;i) environmentalconditions.

(3)Thedesignshallcomplywiththerequirementsof thisCode.

2.4 MARKING OF EQUIPMENT

2.4.1 General

(1)Eachpieceof electricalequipmentshallbearsuchof thefollowingmarkingsasmaybenecessaryto identifytheequipmentandensurethatit issuitablefortheparticularinstallation:

a) Themaker'sname,trademark,orotherrecognizedsymbolof identification.b) Cataloguenumberortype.c) Voltage.d) Ratedloadamperes.e) Watts,volt-amperes,orhorsepower.f) Whetherfora.c.,d.c.,or both.g) Numberof phases.h) FrequencyinHertz.i) Ratedloadspeedinrevolutionperminute.D Designationof terminals.k) Whetherforcontinuousor intermittentduty.1) Evidenceof approval.m) Suchothermarkingasmaybenecessarytoensuresafeandproperoperation.


'SECTION 2: GENERAL REQUIREMENTS

(2)Eachservicebox,atthetimeof installation,shallbemarkedin a conspicuous,legible,and

pennanentmannerto indicateclearlythemaximumratingof theovercurrentdevicewhichmaybeusedfor thisinstallation.

(3)At eachdistributionpoint,circuitbreakers,fuses,andswitchesshallbe marked,adjacent

thereto,in aconspicuousandlegiblemannerto indicateclearly:

a) whichinstallationor portionof installationtheyprotector control;

b) themaximumratingof overcurrentdevicethatis permitted.

2.4.2WorkmanshipandMaterials

(1)Carefulattentionshallbepaidto them~chanicalexecutionof thework in connectionwith

anyelectricalinstallation.

(2)Anyinsta1!ationthathasbeenbadlyarrangedor poorlyexecuted,eithergenerallyor in any

particularway,will notbeacceptedby theAuthorityhavingjurisdjction.

2.4.3Materialfor Anchoringto MasonryandConcrete

(1)Woodor othersimilarmaterialsshallnotbeusedasananchorintomasonryor concretefor

thesupportof anyelectricalequipment.

2.4.4Protectionof PersonsandProperty

(1)Electricalequipmentshallbe installedandguardedso thatadequateprovisionis madefor

thesafetyof personsand propertyand for the protectionof the electricalequipmentfrom

mechanicalor otherinjury to which it is liableto beexposed.

2.4.5Maintainability

(1)An assessmentshallbe madeof thefrequencyandqualityof maintenancethe installation

canreasonablybeexpectedto receiveduringits intendedlife.

(2)Whereanauthorityis to beresponsiblefor theoperationof the installation,thatauthorityshallbeconsulted.



(3) The following characteristicsareto betakenintoaccountin applyingtherequirementsof

thisCode, havingregardto thefrequencyandqualityof maintenanceexpected:

a) Any periodicinspectionandtestingandmaintenanceandrepairslikely to benecessary

duringtheintended.life canbereadilyandsafelycarriedout.

b) The effectivenessof the protectivemeasuresfor safetyduring the intendedlife ISensured.

c) The reliabilityof equipmentfot properfunctioningof theinstallationis appropriatetothe intendedlife.

2.4.6 Enclosures

(1) Degreeof protectionprovidedby enclosuresfor ~lectricalequipmentshallbe in accordancewith mc 529.


3.1 SCOPE

3.2 NORMATIVE REFERENCES

(a)BS 8206:1985 Part 1- Lightingfor Building.

EBCS-10 1995 29

(c)DIN 5035:1990 Part 2 - Artificial Lighting, RecommendedValues for LightingParametersfor IndoorandOutdoorWorkplaces.

(b) DIN 5035:1990 Part 1- Artificial Lighting,TerminologyandGeneralRequirements.

LJ..JUMINA TION

SECTION 3

(d)DIN 5035:1988 Part~- Artificial Lightingof Interiors,HospitalLighting.

(e)DIN 5035:1983 Part4- Artificial Lightingof Interiors,SpecialRecommendationsforLightingEducationalestablishments

(t) DIN 5035:1987 Part 5 - Artificial Lightingof Interiors,EmergencyLighting.

(g)DIN 5035:1988 Part7- Artificial LightingofInteriors,Lightingof RoomswithVDU

Workstationor VDU AssistedWorkplaces.

(I) ThisSectionof theCode givesguidanceon designand installationof artificial lightingsystemsin interio.rs;it alsoappliesto artificiallightingof outdoorareas.

(l) Thefollowingreferencescontainprovisionswhich,throughreferencein thistext,constitute

provisionsof theEthiopianBuildingCodeStandardsonElectricalInstallationof Buildings.

ETHIOPIANBUILDING CODE STANDARD


3.3 DEFINITIONS

.(1) For thepurposeof thisSectionof theCode,thefollowingdefinitionsshallapplyin additionto thetermsdefinedin Section1.

meanilluminance(E)

ratedilluminance(E,)

lightlossfactor(V)

depreciationfactor(P)

reflectance(Pc)

generallighting

localizedlighting

locallighting

30 EBCS-10 1995

thearithmeticalmeanof the illuminancein a roomor in a room

zonebeingdefinedasthatareaof a roomin whichthesametype

of activityis performedat a numberof work-placesor which is

usedfor similarpurposes.

the nominal value of the mean illuminancethat the lighting

installationis{fesignedto illuminate.

the ratioof the ratedilluminance,En' to the designvalueof the

meanilluminanceof a lightingsystem.

thereciprocalof thelight lossfactor.

the ratio of the luminousflux reflectedfrom a surfaceto the

luminousflux incidenton it.

the required averageilluminancewith a certain degree of

uniformity over the total area; and is obtainedby a regular

arrangementof luminariesovertheceilingarea(seeFigure3.1).

a non-uniform illuminanceover the whole work area (see

Figure3.2).

lightingfor individualworkplaceinadditiontothegenerallighting

producedby placing luminariesclose to the visual task and

supplementedby a generallighting(seeFigure 3.1).


AB

1\ 1\/ V \

I II \ I \

b)awitched

;. a) grouped

EBCS-10 1995 31

SECTION 3: ILLUMINATION

Figure3.2LocalizedLighting

" I \I \ I \

/\ 1\/ V \

/\/ \/\I \

Figure3.1 Generallighting

Figure3.3 Locallighting

- - . - :-;-.-./\ 1\ 1\ /\ 1\1\/ \/ \/ \/ \

---.----.-----.-.- - --------~~-._ .._---_ ..---.-



glare

Note:

directglare

a conditionin whichvision is affectedby anexcessiveluminance

and/orexcessivedifferencesin luminancein thevisualfield (i.e;

partsof this field areexcessivelybright).

A distinctionis madebetween:

disabilityglare,defmedasglarecausinganactualphysiologicalreductionin visual

capability(impaired, perceptionof contrastsand forms),and

discomfortglare,definedasglareconsideredsolelyin termsof its psychological

effecton theoccupant.Discomfortglareexperiencedby theoccupantof a room

increaseswithtimeandleadstoprematurefatigueandareductionin performance,

performanceattitude,and well-being.

a glarecauseddirectlyby luminancefromluminariesof luminous

ceilings.

reflectedglare glareandcontrastreductioncausedby reflectionof highluminance

fromglossysurfaces.

Note: The maindisturbancescausedbysuchreflectionarecontrastreduction,andimpairedaccommodationand fusion.

colour appearance thechromaticityof anilIuminantandis generallyexpressedasthe

colourimpressionreceivedwhenlookingata light source.

Note: The colour of the light emittedby a near-whitesourcescan be indicatedby its correlatedcolour

temperature(CCT). EachlamptypehasaspecificCCT; butforpracticaluse,theyhavebeengrouped

into threeclasses(seeTable 3.1).

Table3.1: Correlatedcolourtemperatureclasses

Correlatedcolour temperatureCCT CI18S

-(CCT) H

.

CCT


c%ur rendering therelationshipbetweentheoriginalcolourof an objectandthecolourin whichit is renderedby artificiallighting.

Note: Theabilityof lightsourcetorendercoloursof s~aceaccuratelycanbeconvenientlyquantifiedby'theCIE generalcolourrenderingindex.Thisindexisbasedontheaccuracywithwhichasetoftest

colour'arereproducedbythelampt ofinterestrelativetohowtheyarereproducedbyan appropriate

standardlightsource,identicalagreementbeinggivena valueof tOO.Ou. EachlamptypehasaspecificCIE generalcolourrenderingindex;butforpracticalusetheycanbedividedintoanumberof groups(seeTable3.2)

Whereveraccurate colour matching is required;

e.g. colour printing inspection.

Wherevercolour renderingis 01littlesignificance

but marked distortion01colour is acceptable.

Wherevermoderatecoiour rendering Is required.

Typicalapplication

Wherevercolour rendering Is01no Importanceat

all and.markeddistortion01colour is acceptable.

Wherever accurate colour judgements are

necessary and/or good colour rendering Is

, essential to appearance; e.g. shops and other

commercial premises.

'Table3.2 Colourrenderinggroups

60< R~90

40< R.


escapelighting

sll/ety/iglltinglorpartial/Ju hazardousWOI'kplacu

a specified minimum illuminance foremergencyescapepurposes,thus,permittingbuildingsandplantto besafelyevacuatedatanytimeduringtheirutilization.

safetylightingdesignedtoensurethattheworkperformedat suchworkplacescanbe safelyterminatedin the mannerrequiredand theworkplacesthemselvesevacuated'withoutdanger.

Note: Particularhazardousworkplacesarethosewhichrepresentanimmediateriskof accidentor apotential

sourceof dangerto third partiesif thesupplyto the 'lightingshouldfail, raisedplatfonns,theatre

stages,race-coursesandarenascountingasparticularlyhazardousworkplaces.

standbylighting

responsetime

.ratedduration01operation

Umitduration01operatiOn

an emergencylightingwhichcanassumethe functionof

normalartificiallightingfora limitedperiodsoasto enablenormalactivitiestocontinue.

the intervalbetweena failurein thepowersupplyto,thenormalartificiallightingandtheprovisionof therequiredilluminancebytheemergencylighting.

theperiodof timeforwhichanemergencylightingsystemis

designedtooperate.

theminimumperiodof timeduringwhichan emergencylightingsystemshallstillbecapableofachievingtheminimumilluminancespecifiedforthegivenapplication.

Note: This conceptappliesspecificallyto battery-operatedsystems.

lI$efullife thedurationof anemergencylightingsystemfromthedateofits commissioningupto thepointin timeat whichit onlyachievesthelimitdurationof operation.

safetyluminaries

,34 EBCS-10 1995

a luminarywhichmayormaynotbeprovidedwitll itsownpowersupplyandwhichis usedfor safetylighting.


3.4.2 Luminance

3.4.1 D1umin~nce

3.4 LIGHTINGREQUIREMENTS


amouldedluminairebearingagraphicalsymbolto serveasan

escapesign;it indicatesandassistthe ide~tificationof.escaperoute.

a luminarywhichmayor maynotbe providedwith its own

powersupplyandwhichis usedfor standbylighting.

escapesign luminaries

standbylightingluminaries

(2)For indoorworkplacesthataremannedfull-time,a minimu~ratedilluminanceof 200.01x

shallbeprovidedunlessotherfactors(suchasnatureof operation,physiologicalreasons)require vdifferentvalues.

(b) If tasksareperformedat fixed-locationworkplacesoutdoorsthatcorrespondto tasks

performedindoors(e.g.operationof wood-workmachines),thena ratedilluminance

specifiedfor suchtasksin Table3.5 for indoorworkplacesshallbeprovided.

(1)Recommendedilluminancefor differenttypesof interiors,tasksandworkspacesgiveninTable3.5 andTable 3.6 shallbe takenastherecommendedminimumvalueson which the

designandassessmentof lightinginstall~ionsareto bebased.

(3)(it) In interiorsdesignedfor permanenthumanoccupation,aminimumratedilluminanceof

100.01xis required.

(1) Reflectancein theworkingzoneshallbeplannedsothattheratiobetweentaskluminance

(innerfield) andthatof thesurroundingof thetaskareno greaterthanapproximately3:1.

/ (4)At no stagesin theuseful life of the lightinginstallationshall themeanilluminance,E,

obtainedattheworkplacesbelessthan0.8 timesthevalueofthe ratedilluminance;atno single

workplaceshall illuminanceeverfall to lessthan0.6timestheratedilluminance.

(2)Reflectanceof from 0.2 to 0.5 arerecommendedfor workingsurfacessuchasbenchand,. -------------

dt?,sktops.



3.4.3 Glare

(1) Glare shall notbe causedby lamps0/ luminaries(directglare)nor by reflectionof highluminancefrom glossysurface(reflectedglare).

(2) Lampswith a high luminance(e.g.filamentlampsandhighdischargelamps)shallalwaysbe shielded.\I

(3) In caseof luminariesfor local workplaceslighting,a directview of the lampsshall be

precludedby shieldingor by arrangingthemin a suitableposition.

3.4.4 LightDirectionandModelling

(1) Lighting shallbe directedto producean adequatedegreeof modellingshadowto enable

objectsandsurfacetextureto beeasilyrecognized.

(2) Undulyhardshadowsshallbe,avoide,d.If theratio Ez(cylindrical):En(horizontal)atahight

of I.20m abovefloor is not smallerthan0.3,undulyhardshadowscanbeavoid~d.

(3) Deepshadowsproducingexcessive.luminancecontrastsshallbeavoided.

3.4.5 ColourRendering

(1) For inspectionandcomparisonof colours,theCIE generalcolourrenderingindex~ shallnot exceed90 andtheratedilluminanceshallbe IOOO.O/x.

(2) Only lampsmeetingtherequirementsof ColourRenderingGroup3 (or higher)shallbeused

for lightinginteriors.

(3) Safetycoloursshall beduly recognizableassuch.



3.5 EMERGENCY LIGHTING REQUIREMENTS

3.5.1 EscapeLighting

3.5.1.1 Illuminance

(1)Theminimumilluminanceof the safetylightingfor escaperoutesshall be 1.0/x. This

requirementappliesto thecentreline of anescaperoutealonga horizontalplaneO.2mabovefloorlevel.

(2)Theresponsetimeshallnotexceeda maximumof I5.0sec.

(3)Therateddurationof operationshallatleastequalto thetimethatwill bespecifiedbysafetYlawtobeenactedby theconcernedgovernmentbody.

(4)Thelimitdurationof operationshallbe% (for l.Ohr)or % (for3.0hr)of theratedduration.

(5)Safetyluminariesfor escaperoutesshallbesitedaccordingto their luminancedistribution

soastomeettherequirementsspecifiedfor safetylightingandin sucha waythattheycannot

easilyberenderedineffective.(Principallocationsfor thesittingof safetyluminariesare,thus,

neartheexitsof escaperoutesandatpoil}tswhereit is necessaryto emphasizethepositionsofpotentialhazards.)

3.5.2 SafetyLightingfor ParticularHazardousWorkplaces

3.5.2.1 I/Iuminance

(I) Theminimumilluminancefor suchworkplacesshallbeO.1En(ratedilluminancespecifiedforthetaskandroomof suchworkplacesin Table3.5)butnot lessthan IS.O/x.

(2)Theminimumilluminancefor platformandtheatrestagesshallbe 3.0/x, and I5.0/x forarenasandrace-courses.

3.5.2.2 Colourrendering

(1) Thecolour renderingshallat leastbe equivalentto Group3 so as to ensurethatsafetycoloursremainrecognizableassuch.



3.5.2.3 Responsetime

(1) The responsetimeof safetylightingshallnotexceedamaximumof 6.5s.

(2) In caseof raisedplatform,theatrestages,arenasandrace-courses,themaximumresponsetimeshallbe 1.0s.

3.5.2.4 Rateddurationof operation

(1) For workplaces,the lightingshallbe effectivefor as long as thehazardsubsists,with aminimumdurationof 1.0min.

(2) For raisedplatform,theatrestages,race-coursesandarenas,therateddurationof operation

shallat leastbeequalto thedurationrequiredby law.

3.5.2.5 Sitingof safetyluminariesin hazardousworkspaces

(1) Safetyluminariesshallbesitedsoastoensurethattherequiredilluminanceisprovidedovertheentireareain whichhazardoustasksarecarriedout.

3.5.3 StandbyLighting

(1) The requirementsto bemetby standbylightingareanalogousto thoseapplyingfor normal

artificiallighting. To enablenormalactivitiesto continue,a minimumilluminanceof 10%of

theratedilluminancevalueis generallyrequired.

3.6 LIGHTING REQUJ:.REMENTS FOR VARIOUS TYPES OF BUILDINGS

3.6.1 General

(1) The designobjectivesfor lighting shall be to provideboth good task visibility and a

satisfactoryvisualenvironment.

(2) (a) The lightingof workspacesshallensuregoodvisibilityof thevisualobjects.

(b) The lightingof workplacesshallalsobeconduciveto concentrationandperformance

attitudes,counteractprematurefatigueandpermitanypotentialhazardsto be clearly

recognized.



3.6.2 IndustrialBuildings

(I) In additiontothelightingrequiredfor specifictasks,ageneralilluminationshallbeprovided

toallowsafemovementthroughthebuildingatall materialtimes.

(2)Wherecriticalcolourmatchingis to bedonefor a longperiod,a minimumilluminanceof

IOOO.Olx shallbeprovided.

3.6.3 Offices

(I) As indicatedon ratedilluminancetables,for generalofficesilluminanceof 500.01xandfor

drawingofficesilluminanceof 750.

ebcs 10 ethiopian building code standard electrical installation of buildings

Documents

applicationfor inspection

postingof pennit

authorityforrules i

purposeof thesestandardsis

useof approvedequipment

powersof rejection

j defmitions 2section2