Attachement 4 Code for Electrical Installations in Buildings.pdf

UVRI - LABORATORY OFFICE BLOCK – BIDDING DOCUMENTS (VOLUME 2 OF 3)

FLYSHEET:

Volume 2B of 3 - Code for Electrical

Installations in Buildings

B1

THE REPUBLIC OF UGANDA

MINISTRY OF WORKS AND TRANSPORT

CODE FOR ELECTRICAL

INSTALLATIONS IN BUILDINGS

December 2012

FOREWORD

The mission of the Ministry of Works and Transport (MoWT) is to promote an adequate, safe and well maintained works and transport infrastructure and services so as to effectively contribute to the socio-economic development of the country.

In exercising this mission and in discharging its responsibilities, the Ministry is issuing a series of Design Manuals, Guidelines, Codes and Standards, of which the “Code for Electrical Installations in Buildings” is one part thereof.

The Code for Electrical Installations in Buildings will be a nationally recognized document which will serve as a standard reference for the regulation of design and construction of electrical installations and equipment in buildings.

The major benefits to be gained in applying this document are the harmonization of professional practice in the building construction in Uganda and curtailment of informal developments so as to ensure well-planned, well-maintained, safe, cost effective and decent building developments and human settlements throughout the country.

The Code will be periodically updated and new editions issued to cater for the dynamic technological developments in the construction industry.

Abraham Byandala

Minister of Works and Transport

December 2012

Code for Electrical Installations and Equipment in Buildings

Ministry of Works and Transport i

TABLE OF CONTENTS

Definitions ...............................................................................................................iv

SECTION 1 SCOPE AND DEFINITIONS .............................................................. 1.1

1.1 Scope ............................................................................................................. 1.1

1.2 Definitions ...................................................................................................... 1.1

SECTION 2 GENERAL REQUIREMENTS ........................................................... 2.1

2.1 Administrative ................................................................................................. 2.1

2.2 Technical ........................................................................................................ 2.2

2.3 Planning and Designing .................................................................................. 2.3

SECTION 3 METHODS OF INSTALLATION ........................................................ 3.1

3.1 General .......................................................................................................... 3.1

3.2 Fundamental Requirements for Safety ........................................................... 3.1

3.2.1 Workmanship and Materials ................................................................ 3.1

3.2.2 Protective Devices .............................................................................. 3.1

3.2.3 Portable Appliances ............................................................................. 3.2

3.3 Switchboard and Switchgear .......................................................................... 3.3

3.3.1 General ............................................................................................... 3.3

3.3.2 Isolation (Protection against direct contact) ......................................... 3.6

3.3.3 Cable Terminations to Switch Gear ..................................................... 3.7

3.4 Wiring and Wiring Accessories ....................................................................... 3.8

3.4.1 Cable Wiring ....................................................................................... 3.8

3.4.2 Cable Trunking .................................................................................... 3.9

3.4.3 Conduit Wiring .................................................................................. 3.10

3.4.4 Mounting Heights of Wiring Accessories ........................................... 3.11

3.4.5 Ceiling Roses and Lamp Holders ....................................................... 3.12

3.4.6 Switches and Socket Outlets ............................................................. 3.12

3.4.7 Motors ............................................................................................... 3.12

3.4.8 Final Circuits ..................................................................................... 3.13

3.5 Underground Cables .................................................................................... 3.13

3.5.1 Cable Specification ............................................................................ 3.13

3.5.2 Cable Laying ...................................................................................... 3.14

3.5.3 Warning Covers ................................................................................. 3.15

3.5.4 Earthenware Ducts and Fiber Conduits ............................................. 3.15

3.5.5 Concrete Cable Markers ................................................................... 3.16

3.5.6 Cables Jointing .................................................................................. 3.16

3.5.7 Identification of Cables and Cable Joints ........................................... 3.16

3.5.8 Position of Cable Routes ................................................................... 3.16

3.5.9 Bonding and Earthing of Cables ........................................................ 3.16

3.6 Excavation and Reinstatement ..................................................................... 3.17

3.7 Consumer Mains .......................................................................................... 3.18

3.7.1 Feeder Pillars .................................................................................... 3.18

3.7.2 Earthing ............................................................................................. 3.18

3.8 "AS INSTALLED" Drawings ........................................................................... 3.19 ii

3.9 Inspection and Testing ................................................................................. 3.19

SECTION 4 MISCELLANEOUS ........................................................................... 4.1

4.1 Street Lighting ................................................................................................ 4.1

4.2 Lightning Protection and Earthing ................................................................... 4.1

4.3 Lifts ................................................................................................................ 4.2

4.4 Air Conditioning and Refrigeration Systems ................................................... 4.2

4.5 Radiation Emissions ....................................................................................... 4.2

4.6 Special Services ............................................................................................. 4.3

4.6.1 Data Network ....................................................................................... 4.3

4.6.2 Other ................................................................................................... 4.3

SECTION 5 SOLAR PHOTOVOLTAIC (PV) POWER SUPPLY SYSTEM

MODULES AND BATTERIES ................................................................................ 5.1

5.1 Scope ............................................................................................................. 5.1

5.2 Photovoltaic (PV) Modules ............................................................................. 5.1

5.2.1 PV Modules (Panels) Specifications .................................................... 5.1

5.2.2 PV Modules Position ........................................................................... 5.1

5.2.3 PV Modules Orientation ...................................................................... 5.1

5.2.4 PV Modules Lightning Protection......................................................... 5.1

5.2.5 PV Modules Support Structure ............................................................ 5.2

5.2.6 PV Modules Roof Mounting ................................................................. 5.2

5.2.7 PV Modules Ground Mounting ........................................................... 5.2

5.3 Batteries ......................................................................................................... 5.2

5.3.1 Type .................................................................................................... 5.2

5.3.2 Installation ........................................................................................... 5.3

5.3.3 Controllers and Circuit ......................................................................... 5.3

5.4 Samples ......................................................................................................... 5.4

5.5 System Design - Essential and Non- Essential Service (ES and NES) ........... 5.4

5.5.1 Design data ......................................................................................... 5.4

5.5.2 Calculations ........................................................................................ 5.4

5.5.3 System Autonomy ............................................................................... 5.5

5.5.4 Essential Services (ES) ....................................................................... 5.5

5.5.5 Non-Essential Services (NES) ............................................................. 5.5

5.6 Labels............................................................................................................. 5.5

5.7 Inspection and Testing ................................................................................... 5.6

5.8 Maintenance, Spare Parts and Warranties ..................................................... 5.6

5.9 Registration, Approval and Acceptance for Photovoltaic Installations ............. 5.6

5.10 Field of Application ......................................................................................... 5.7

5.11 Installation Design .......................................................................................... 5.7

5.12 Wiring Methods and Cables ............................................................................ 5.8

5.12.1 Conduit Wiring ..................................................................................... 5.8

5.12.2 Cable Wiring ....................................................................................... 5.8

5.12.3 Conductor Cross-section and Voltage Drop ....................................... 5.8

5.12.4 Use of Existing 240V AC Wiring .......................................................... 5.9

5.12.5 Cable Connections .............................................................................. 5.9 iii

5.12.6 Power Intake - Underground and Overhead ........................................ 5.9

5.13 Workmanship and Finishing ......................................................................... 5.10

5.14 Light Fixtures ................................................................................................ 5.10

5.15 Sockets ........................................................................................................ 5.10

5.16 Switches ....................................................................................................... 5.11

5.17 Installation .................................................................................................... 5.11

SECTION 6 FIRE ALARM SYSTEM ..................................................................... 6.1

6.1 Scope ............................................................................................................. 6.1

6.2 General Design Considerations ...................................................................... 6.1

6.3 Manual Call Points Location, Construction and Requirements ........................ 6.2

6.4 Selection of Fire Detectors ............................................................................. 6.2

6.5 Sitting of Detectors ......................................................................................... 6.3

6.6 Audible and Visual Alarms .............................................................................. 6.3

6.7 Cables and Wiring .......................................................................................... 6.4

6.8 Power Supply System .................................................................................... 6.5

APPENDICES

Appendix 1 : Measurement of earth electrode resistance (e.e.r) using a four-terminal earth tester megger

Appendix 2 : Overhead line clearances

Appendix 3 : Current carrying capacity

Appendix 4 : Capacities of conduits for single-core pvc cables

Appendix 5 : Referenced documents

BIBLIOGRAPHY

iv

Definitions

Alarm box control room: A facility from which the necessary firefighting measures can be initiated at all time.

Alerting facility : A facility which issues the fire alarm –e.g. by means of audible and visual signaling devices – and which is not contained in the fire alarm control and indicating panels.

Automatic fire alarm system: A system which detects the occurrence of fire in its incipient stage and immediately signals this without human intervention.

Automatic fire detector: A part of a fire alarm system which, either continually or at periodic intervals, observes a suitable physical and/or chemical identifier for detecting a fire in the monitored area.

Flame detector : A detector which responds to the radiation emitted in the air.

Fire identifier : Physical variables which are subject to measurable changes in the environment of a fire in its incipient stage; e.g. rise in temperature, smoke, flame radiation.

Fire alarm signal: A signal which alerts the fire fighting forces.

Fire alarm system : The entirety of the equipment and parts, matched for correct interaction, used in a fire alarm system.

False alarm : A fire alarm signal caused by technical malfunctions in the fire alarm system(alarm resulting from disturbance) or spurious alarms resulting from the fire detector being “mislead”.

Heat detector : A detector which respond to an increase in temperature.

Non-automatic (manual) fire alarm devices: Alarm devices which can be used to initiate the fire alarm signals manually.

Smoke : Particulate product of combustion generated by fire, whether this be of smouldering or open-flame type.

Sounders: Devices in which electric signals are converted into sound signals.

Smoke detector : A detector which responds to products of combustion and/or pyrolysis (suspended matter) contained in the air.

PV cell: Basic PV device which can generate electricity when exposed to light such as solar radiation

PV module: Smallest completely environmentally protected assembly of interconnected PV cells

PV string: Circuit in which PV modules are connected in series, in order for a PV array to generate the required output voltage.

PV array: Mechanically and electrically integrated assembly of PV modules and other necessary components, to form a d.c.

power supply unit.

v

PV array junction box: Enclosure where all PV strings of PV array are electrically connected and where protection devices can be located if necessary.

PV generator: Assembly of PV arrays

PV generator junction box: Enclosure where all PV arrays are electrically connected and where protection devices can be located if necessary.

PV string cable: Cable connecting PV modules to form a PV string.

PV array cable: Output cable of a PV array.

PV d.c. main cable: Cable connecting the PV generator junction box to the d.c.

terminals of the PV inverter

PV inverter : Device which converts d.c. voltage and d.c. current into a.c.

voltage and a.c. current

PV supply cable : Cable connecting the a.c. terminals of the PV inverter to a distribution circuit of the electrical installation.

Code for Electrical Installations and Equipment in Buildings Section 1

1.1

SECTION 1 SCOPE AND DEFINITIONS

1.1 Scope

This Code for Electrical Installations and Equipment in Buildings establishes general principles for the wiring, selection, erection and testing of electrical installations for residential commercial and public premises. They are applicable to electrical installations that operate at a voltage up to and including 1000V a.c or d.c., supplied from the public supply or from a private generating plant.

a) residential, commercial and public premises, and

b) is applicable to electrical installations that operate at a voltage up to and including

1000V a.c. or d.c., and

c) are supplied from an external source or from a private generating plant.

1.2 Definitions

For the purpose of this Code, the following definitions shall apply:

Accessory: A device, other than current-using equipment, associated with such equipment or with the wiring of an installation.

Ambient temperature: The temperature of the air or other medium where the equipment is to be used.

Appliance: An item of current-using equipment other than a luminaire or an independent motor.

Apparatus: An electrical apparatus, and includes all apparatus, machines and fittings in which conductors are used, or of which they form a part.

Authority: means Uganda Electricity Regulatory Authority.

Authorized person: a person employed or appointed, by the Authority to carry out certain duties incidental to the generation, distribution or use of electrical energy, such a person being competent for the purposes transmission in which the term is used, and holds an appropriate certificate of competency issued in accordance with the provisions of the Electricity Act of Uganda.

Barrier: A part providing a defined degree of protection against contact with live parts from any usual direction of access.

Basic insulation: Insulation applied to live parts to provide basic protection against electric shock and which does not necessarily include insulation used exclusively for functional purposes.

Bonding conductor: A protective conductor providing equipotential bonding.

Building void, accessible: A space within the structure or the components of a building only at certain points.

Building void, non-accessible: A space within the structure or the components of a building which has no ready means of access.

Bunched: Cables are said to be bunched when two or more are contained within a single conduit, duct, ducting, or trunking or, if not enclosed, are not separated from each other by a

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Ministry of Works and Transport specified distance.

Cable bracket: A horizontal cable support system, consisting of elements fixed at one end only, spaced at intervals along the length of the cable and on which the cable rests.

Cable channel: An enclosure situated above or in the ground, ventilated or closed, and having dimensions which do not permit the access of persons but allow access to the conductors and/or cables throughout their length during and after installation. A cable channel may or may not form part of the building construction.

Cable cleat: A component of a support system, which consists of elements spaced at intervals along the length of the cable or conduit and which mechanically retains the cable or conduit.

Cable coupler: A means of enabling the connection or disconnection, at will, of two flexible cables. It consists of a connector and a plug.

Cable ducting: A manufactured enclosure of metal or insulating material, other than conduit or cable trunking, intended for the protection of cables which are drawn-in after erection of the ducting.

Cable ladder: A cable support consisting of a series of supporting elements rigidly fixed to main supporting members. The supporting elements occupy les than 10% of the plan area.

Cable tray: A cable support consisting of a continuous base with raised edges and no covering. A cable tray is considered to be non- perforated, where less than 30% of the material is removed from the base.

Cable trunking: A manufactured enclosure for the protection of cables, normally of rectangular cross-section, of which one side is removable or hinged.

Cable tunnel: An enclosure (corridor)containing supporting structures for conductors and or cables and joints and whose dimensions allow persons to pass freely throughout the entire length.

Cartridge fuse link: A device comprising a fuse element or several fuse elements connected in parallel enclosed in a cartridge usually filled with arc-extinguishing medium and connected to terminations (see fuse link).

Ceiling rose: An accessory for connection to the fixed wiring of an installation to pass current to a lampholder or a luminaire by means of the conductors of a flexible cord.

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Ministry of Works and Transport

Ceiling rose - surface type: A ceiling rose provided with a seating surface such that when mounted as intended it projects wholly outside the surface on which it is mounted.

Ceiling rose - semi-recessed or flush-type: A ceiling rose intended for mounting with its base partially or completely sunk into a box complying with BS 31, BS 4568: Part 2, BS 4607:

Part 5 or BS 4662.

Circuit: An assembly of electrical equipment supplied from the same origin and protected against over current by the same protective device(s).

Circuit-breaker: A device capable of making, carrying and breaking normal load currents and also making and automatically breaking, under pre-determined conditions, abnormal currents such as short-circuit currents. It is usually required to operate infrequently although some types are suitable for frequent operation.

Circuit-breaker, linked: A circuit-breaker the contacts of which are arranged as to make or break all poles simultaneously or in a definite sequence.

Circuit protective conductor (cpc): A protective conductor connecting exposed-conductive-parts of equipment to the main earthing terminal.

Conduit: A part of a closed wiring system for cables in electrical installations, allowing them to be drawn in and/or replaced, but not inserted laterally.

Connector: The part of a cable coupler or of an appliance coupler which is provided with female contacts and is intended to be attached to the end of the flexible cable remote from the supply.

Consumer unit: A particular type of distribution board comprising a co-coordinated assembly for the control and distribution of electrical energy, principally in domestic premises, incorporating manual means of double pole isolation on the incoming circuits(s) and an assembly of one or more fuses, miniature circuit-breakers, residual current operated devices or signaling and other devices purposely manufactured for such use.

Current-carrying capacity of a conductor: The maximum current which can be carried by a conductor under specified conditions without its steady state temperature exceeding a specified value.

Current-using equipment: Equipment which converts electrical energy into another form of energy, such as light, heat or motive power.

Danger: Risk of injury to persons (and livestock where expected to be present) from:-

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Ministry of Works and Transport

a) fire, electric shock and burns arising from the use of electrical energy, and

b) mechanical movement of electrically controlled equipment, in so far as such danger is intended to be prevented by electrical emergency switching or by electrical switching for mechanical maintenance of non-electrical parts of such equipment.

Dead: At, or about, zero potential, and disconnected from any live system.

Direct contact: Contact of persons or livestock with live part which may result in electric shock.

Disconnector: A mechanical switching device which, in the open position, complies with the requirements specified for isolation. A disconnector is otherwise known as an isolator.

Distribution board: An assembly containing switching or protective devices (e.g. fuses, circuit-breakers, residual current operated devices) associated with one or more outgoing circuits fed from one or more incoming circuits, together with terminals for the neutral and protective circuit conductors. It may also include signaling and other control devices.

Means of isolation may be included in the board or may be provided separately.

Distribution circuit: A category I circuit connecting the origin of the installations to:-

a) an item of switchgear, or

b) an item of control gear, or

c) a distribution board to which one or more final circuits or items of current-using equipment are connected (see also definition of Final circuit).A distribution circuit may also connect the origin of an installation to an outlying building or separate installation, when it is sometimes called a sub-main.

Double insulation: Insulation comprising both basic insulation and supplementary insulation.

Duct: A closed passageway formed underground or in a structure and intended to receive one or more cables which may be drawn in.

Fault: A circuit condition in which current flows through an abnormal or unintended path. This may result from an insulation failure or a bridging of insulation. Conventionally the impedance between live conductors or between live conductors and exposed or extraneous-conductive-parts at the fault position is considered negligible.

1.5

Fault current: A current resulting from a fault.

Final circuit: A circuit connected directly to current-using equipment, or to a socket-outlet or socket-outlets or other outlet points for the connection of such equipment.

Flexible cable: A cable whose structure and materials make it suitable to be flexed while in service.

Flexible cord: A flexible cable in which the cross-sectional area of each conductor does not exceed 4 mm

Fuse carrier: The movable part of a fuse designed to carry a fuse link.

Fuse element: A part of a fuse designed to melt when the fuse operates.

Fuse link: A part of a fuse, including the fuse element(s), which requires replacement by a new or renewable fuse link after the fuse has operated and before the fuse is put back into service.

Fused plug: A plug having provision for a replaceable cartridge fuse link.

Fused socket-outlet: A socket-outlet having provision for a replaceable cartridge fuse link.

Indirect contact: A contact of persons or livestock with exposed-conductive-parts which have become live under fault conditions.

Insulation: Suitable non-conductive material enclosing, surrounding or supporting a conductor.

Isolator: A mechanical switching device which, in the open position, complies with the requirements specified for isolation. An isolator is otherwise known as a disconnector.

Live part: A conductor or conductive part intended to be energized in normal use, including a neutral conductor but, by convention, not a PEN conductor.

Luminaire: Equipment which distributes, filters or transforms the light from one or more lamps, and which includes any parts necessary for supporting, fixing and protecting the lamps, but not the lamps themselves, and, where necessary, circuit auxiliaries together with the means for connecting them to the supply. For the purpose of this Code, a lamp holder, however supported, is deemed to be a luminaire.

Main earthing terminal: The terminal or bar provided for a connection of protective conductors, including equipotential bonding conductors, and conductors for functional

1.6

Ministry of Works and Transport earthing, if any, to the means of earthing.

Neutral conductor: A conductor connected to the neutral point of a system and contributing to the transmission of electrical energy. The term also means the equivalent conductor of an IT or d.c system unless otherwise specified in the Code.

Non-rewirable plug: A plug so constructed that it forms a complete unit with the flexible cord after connection and assembly by the manufacturer of the plug.

Origin of an installation: The position at which electrical energy is delivered to an electrical installation.

Over-current: A current exceeding the rated value. For conductors the rated value is the current-carrying capacity.

Over-current detection: A method of establishing that the value of current in a circuit exceeds a predetermined value for a specified length of time.

Overload current: An over-current occurring in a circuit which is electrically sound.

Phase conductor: A conductor of an a.c. system for the transmission of electrical energy other than a neutral conductor, a protective conductor or a PEN conductor. The term also means the equivalent conductor of a d.c.

system unless otherwise specified in the Code.

Plug: A device, provided with contact pins, which is intended to be attached to a flexible cable, and which can be engaged with a socket-outlet or with a connector.

Point (in wiring): A termination of the fixed wiring intended for the connection of current-using equipment.

Portable equipment: Electrical equipment which is moved while in operation or which can easily be moved from one place to another while connected to the supply.

Protective multiple earthing (PME): An earthing arrangement, found in TN-C-S systems, in which the supply neutral conductor is used to connect the earthing conductor of an installation with Earth.

Public supply: The supply of electrical energy to the premises of any person by licensed electricity service provider.

Rewirable plug: A plug so constructed that a flexible cord can be fitted or replaced using general purpose tools.

Reduced low voltage system: A system in which the nominal phase to phase voltage does not exceed 110 volts and the nominal phase to earth voltage does not exceed

63.5 volts.

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Ministry of Works and Transport

Ring final circuit: A final circuit arranged in the form of a ring and connected to a single point of supply.

SELV (separated extra-low voltage): An extra-low voltage system which is electrically separated from Earth and from other systems in such a way that a single fault cannot give rise to the risk of electric shock.

Short-circuit current: An over-current resulting from a fault of negligible impedance between live conductors having a difference in potential under normal operating conditions.

Skilled person: A person with technical knowledge or sufficient experience to enable him/her to avoid dangers which electricity may create.

Socket-outlet: A device, provided with female contacts, which is intended to be installed with the fixed wiring, and intended to receive a plug. A luminaire track system is not regarded as a socket-outlet system.

Shutter: A movable device arranged to shield the current-carrying socket-outlet contacts automatically when a corresponding plug is removed.

Street furniture: Fixed equipment, located on a highway, the purpose of which is directly associated with the use of the highway.

Street located equipment: Fixed equipment, located on a highway, the purpose of which is not directly associated with the use of the highway.

Supplier: A person who supplies electrical energy, and, where electric lines and apparatus used for that purpose are owned otherwise than by that person, shall include the owner of those electric lines and apparatus.

Supplier’s works: Electric lines, supports and apparatus of, or under the control of, a supplier used for the purposes of supply, and cognate expressions shall be construed accordingly.

Substation: Any premises, or that part of any premises in which electrical energy is transformed or converted to or from voltage above low voltage, except for the purpose of working instruments, relays, or similar auxiliary apparatus, if such premises or part of the premises are large enough for a person to enter after the apparatus is in position.

Switchboard passage-way: A passage-way or compartment large enough for a person to enter, and used in connection with a switchboard when live.

Switched socket-outlet: A socket-outlet with an associated switch to

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Ministry of Works and Transport disconnect the supply from the line socket contact or from both line and neutral socket contacts.

Switch: A mechanical device capable of making, carrying and breaking current under normal circuit conditions, which may include specified operating overload conditions, and also of carrying for a specified time currents under specified abnormal circuit conditions such as those of short-circuit. It may also be capable of making, but not breaking, short-circuit currents.

Switchboard: An assembly of switchgear with or without instruments, but the term does not apply to groups of local switches in final circuits.

Switchgear: Main switches, cut-outs or fuses, conductors and other apparatus in connection therewith, used for the purpose of controlling or protecting electrical circuits or machines or other current using appliances.

System: An electrical system consisting of a single source of electrical energy and an installation. For the purpose of this Regulation (Code), the system adapted shall be protective multiple earthing (PME), in accordance with the Uganda Electricity Distribution Company.

Voltage, nominal: Voltage by which an installation (or part of an installation) is designated. The following ranges of nominal voltage (r.m.s values for a.c.) are defined:-

Extra-low voltage: Normally not exceeding 50 V a.c. or 120 V ripple free d.c., whether between conductors or to earth.

Low voltage: Normally exceeding extra-low voltage but not exceeding 1000V a.c. and d.c. between conductors, or 600 V a.c. and d.c. between conductors and earth.

Medium voltage: Normally exceeding 1kv but not exceeding 35 kv.

High voltage: Normally exceeding 35kv but not exceeding 230 kv.

The actual voltage of the installation may differ from the nominal value by a quantity within normal tolerances.

Code for Electrical Installations and Equipment in BuildingsSection 2

2.1

SECTION 2 GENERAL REQUIREMENTS

2.1 Administrative

2.1.1 In exercise of the powers conferred upon the Minister by Section 47 of the BuildingControl Act, this Code for Electrical Installations and Equipment in Buildings has been adapted and hereby orders and directs its observance.

2.1.2 This Code shall be cited as the Code for Electrical Installations and

Equipment in Buildings.

2.1.3 Electrical contractors or other responsible for the carrying out the work shall obtain a permit from the Authority before commencing work with respect to installation, alteration, repair, or extension of any equipment

2.1.4 An application for inspection shall be fixed with the Authority on a form provided by the later at the time the permit is obtained.

2.1.5 A copy of the permit shall be posted in a conspicuous place on the site of the work and shall not be removed until the inspection is completed

2.1.6 The Authority shall be notified in writing by the electrical contractor that work is ready for inspection at such time or times as will permit inspection being made before any work or portion thereof is commenced.

2.1.7 Plans and specifications in duplicate or in greater number if required by the

Authority, one copy to be retained by the Authority shall be submitted by the owner or his agent to, and acceptance obtained from, the Authority before work is commenced on:

a) wiring installation of residential, commercial, public buildings, and other establishments in which public safety is involved;.

b) large light and power installations and the installation or apparatus such as generators transformers switchboards, large storage batteries;

c) such other installations as may be prescribed by the Authority.

2.1.8 Where any electrical installation or part thereof to which electrical power or energy has not previously been supplied is made in or upon any land building or premises, where any electrical installation or part thereof has been disconnected or cut off from any service or other source of supply under this code, no Private Generating Plant, contractor or other person shall connect or reconnect the installation or part thereof to any service or other source of supply unless:

a) the installation and all work in respect thereof have been inspected by an authorized person;

b) a connection authorization has been issued by the Authority in respect of the installation.

2.1.9 The Authority reserves the right to re-inspect at any time electrical installation notwithstanding any previous inspection and acceptance, if and when it considers such action to be necessary.

2.1.10 The Authority may require such changes as may be necessary to be made to existing installations where, through hard usage wear and tear, or as a result of alteration or extensions, dangerous conditions have developed.

2.1.11 No one shall use any electrical equipment other than approved electrical

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Ministry of Works and Transport equipment of a kind or type and rating approved for the specific purpose for which it is to be employed.

2.1.12 In any case where deviation or postponement of the Regulation (Code) may be necessary, special permission shall be obtained before proceeding with the work, but this special permission shall apply only to the particular installation for witch it is given.

2.1.13 Even though approval has previously been granted, the Authority may reject, at any time any electrical equipment under any of the following conditions:

a) if the equipment is substandard with respect to the sample on which approval was granted;

b) if the condition of use indicate that the equipment is not suitable;

c) if the terms of the approval agreement are not being carried out.

2.1.14 Electrical equipment shall be installed as to insure that, after installation, there is ready access to nameplates and access to parts requiring maintenance.

2.1.15 No person shall interfere with any electrical installation or component thereof except when, in the course of alteration or repairs to non-electrical equipment or structures, it may be necessary to disconnect or move components of an electrical installation.

2.1.16 It shall be the responsibility of the person carrying out the alteration or repairs to issue that the electrical installation is restored to a safe operating condition as soon as the progress of the alterations or repair will permit.

2.2 Technical

2.2.1 Graphical symbols that are to be used in all drawings, wiring plans, etc. for electrical installation of buildings shall be issued by Authority having jurisdiction or reference may be made to other recognized Code of practice.

2.2.2 Proper coordination and collaboration between the architect, building engineer and the electrical engineer shall be effected from the planning stage of the installation.

2.2.3 The provisions that will be needed for the accommodation of substation, transformer, switch room, lift wells and other equipment rooms, service cable ducts, rising mains and distribution cables, sub-distribution boards, openings and chases in floor and walls for all required electrical installations etc. shall be specified in advance.

2.2.4 The ideal location of an electrical substation for a group of buildings would be at the load center and shall be located on the ground floor.

2.2.5 In multi–storeyed buildings, the substation shall preferably be installed on the lowest floor level, but direct access from the street for installation or removal of equipment shall be provided. The floor level of the substation or switch room shall be above the highest flood level of the locality. In this case, the load center would be somewhere between the geometrical center and the air-conditioning plant room.

2.2.6 The availability of power lines nearby may also be kept in view while deciding the location of the substation.

2.2.7 In allocating area of a substation it shall be noted that the flow of electric power is from supply company‟s line to transformer where required and finally to the

2.3 low voltage switchgear room. The layout shall be in accordance with this flow.

2.2.8 The following rooms are required in a substation:

a) switchgear room-Supply company‟s switchgear room and/or space for meters.

b) transformers room-The number and size of transformer rooms shall be ascertained from the total power requirement of the consumer where required.

c) stand-by generator room-A room for housing a stand-by generator in accordance with the requirement of the supplier where required.

2.2.9 In large installations other than where a substation is provided, a separate switch room shall be provided; this shall be located as closely as possible to the electrical load center and suitable ducts shall be laid with minimum number of bends from the point of entry of the supply to the position of the main switchgear.

2.2.10 The switch room shall be placed in such a position that rising ducts may readily be provided there from to the upper floors of the building in one straight vertical run.

2.2.11 In larger buildings, more than one rising duct and horizontal ducts may also be required for running cable from the switch room to the foot of each rising main.

2.2.12 Suitably segregated cable ducts shall be reserved for the electrical services which may, include low and extra-low voltage installations, such as bell call-systems; fire alarm and computer net work system and telephone installations.

2.2.13 The electrical control gear distribution boards and other apparatus, which are required on each floor, may conveniently be mounted adjacent to the rising mains, and adequate space should be provided at each floor for this purpose.

2.2.14 Information regarding provision for and location of PBX/PABX shall be obtained from the relevant authority and adequate space should be provided for the installation of the boards.

2.3 Planning and Designing

2.3.1 The design and planning of an electrical installation shall take into account all the prevailing conditions which may include some or all of the following:

a) type of supply;

b) envisaged load having regard to the requirements of the owner or occupant;

c) the probable modifications and future extensions;

d) the degree of electrical and mechanical protection necessary;

e) the probable operation and maintenance cost taking into account the electricity supply tariffs available;

f) the relative cost of various alternative methods;

g) the need for radio and telecommunication interference abatement.

2.3.2 The electrical layout should be considered after proper locations of all outlets for lamps, fans, and appliances- both fixed and transportable, motors, etc, have been selected and best methods of wiring determined.

2.3.3 All runs of wiring and exact positions of all points of switch-boxes and other

2.4

Ministry of Works and Transport outlets shall be first marked on the plans of the building and approved by the engineer in charge or the owner before the actual commencement of the work.

2.3.4 The design of electrical installation shall insure:

a) the protection of persons livestock and property;

b) the proper functioning of electrical installation for the intended use.

2.3.5 The information required as a basis for design shall be:

a) nature of current; a.c and/or d.c

b) nature and number of conductors:

i) fora.c

- phase conductor(s)

- neutral conductor;

- protective conductor,

ii) ford.c

- conductors equivalent to those listed above

c) voltage and voltage tolerances;

d) frequency and frequency tolerances;

e) maximum current allowable

f) prospective sort-circuit current;

g) nature of demand;

h) emergency supply or supplies;

i) environmental conditions;

2.3.6 The design shall comply with the requirements of this Regulation (Code).

2.3.7 Each piece of electrical equipment shall bear such of the following markings as may be necessary to identify the equipment and ensure that it is suitable for the particular installation.

a) the maker‟s name, trademark or other recognized symbol of identification;

b) catalogue number or type;

c) voltage;

d) rated load amperes;

e) watts volt-amperes or horsepower;

f) whether for d.c ,a.c or both;

g) number of phases;

h) frequency in Hertz;

i) rated load speed in revolution per minute;

j) designation of terminals;

k) whether for continuous or intermittent duty;

l) evidence of approval;

m) such other marking as may be necessary to ensure safe and proper operation.

2.3.8 Each service box, at the time of installation, shall be marked in a conspicuous, legible and permanent manner to indicate clearly the maximum rating of the over-current device which may be used for this installation.

2.3.9 At each distribution point, circuit breakers, fuses and switches shall be marked, adjacent thereto, in a conspicuous and legible manner to indicate clearly:

a) which installation or portion of installation they protect or control;

b) the maximum rating of over-current device that is permitted.

Code for Electrical Installations and Equipment in Buildings Section 3

3. 1

SECTION 3 METHODS OF INSTALLATION

3.1 General

3.1.1 Requirements for approval of building plans shall include drawings, for electrical installations and equipment in accordance with Section 2, Clause

2.1 (8).

3.1.2 All works shall be finished, completed and ready for service. It shall be tested in accordance with this Code and to the satisfaction of the Building Committee, through its nominated supervising officer.

3.1.3 The Contractor shall supply all superintendence and labour, skilled and unskilled, necessary to carry out the work in the best possible manner. Trade custom in the various classes of work must be followed.

3.1.4 All of the installation and components thereof shall be in accordance with the latest edition of and current amendments to:-

(a) "Regulations for the Electrical Equipment of Buildings", issued by the Institution of Electrical Engineers (IEE), Great Britain;

(b) Uganda Government Electricity Rules currently in force.

3.2 Fundamental Requirements for Safety

3.2.1 Workmanship and Materials

3.2.1.1 All Equipment shall be constructed, installed and protected and shall be capable of being maintained, inspected and tested, so as to prevent danger so far as is reasonably practicable.

3.2.1.2 All equipment shall be suitable for the maximum power demanded by the current-using equipment when it is functioning in its intended manner.

3.2.1.3 All electrical conductors shall be of sufficient size and current carrying capacity for the purpose for which they are intended.

3.2.1.4 All conductors shall either be insulated and where necessary further effectively protected or be so placed and safeguarded as to prevent danger, so far as is reasonably practicable.

3.2.1.5 All conductors and equipment likely to be exposed to weather, corrosive and explosive atmospheres, inflammable surroundings, or other adverse conditions shall be so constructed or protected as may be necessary to prevent danger arising from such exposure.

3.2.2 Protective Devices

3.2.2.1 Every installation and every circuit thereof shall be protected against over current by devices which:

a) will operate automatically at values of current which are suitably related to the safe current rating of the circuit, and

b) are of adequate breaking capacity and where appropriate, making capacity, and

c) are suitably located and are constructed so as to prevent danger from overheating, arcing or the scattering of hot particles when they come into operation, and

3. 2

d) to permit ready restoration of the supply without danger.

3.2.2.2 Every switch, circuit-breaker, and isolating link shall be:

(a) so constructed, placed or protected as to prevent danger;

(b) so constructed and adjusted as accurately to make and to maintain good contact;

(c) provided with an efficient handle or other means of working, insulated from the system and so arranged that the hand cannot inadvertently touch live metal;

(d) so constructed or arranged that it cannot accidentally fall or move into contact when left out in off position.

3.2.2.3 Every switch intended to be used for breaking a circuit and every circuit-breaker shall be so constructed that it cannot with proper care be left in partial contact. This applies to single pole, double-pole, or multi-pole switches or circuit.

3.2.2.4 Efficient means, suitably located, shall be provided for cutting off all voltage from every part of a system as may be necessary to prevent danger.

3.2.2.5 Every fuse shall have a fusible metal that shall be readily renewed without any danger.

3.2.2.6 Every electrical joint and connection shall provide durable electrical continuity, insulation and adequate mechanical strength.

3.2.2.7 Where one of the conductors of a system is connected to earth, no single-pole switch, other than a link for testing purposes or a switch for use in controlling a generator, shall be placed in such conductor or any branch thereof.

3.2.2.8 A switch or automatic or other cut-out may, however, be placed in the connection between the conductor and earth at the generating station, for use in testing and emergencies only.

3.2.3 Portable Appliances

3.2.3.1 Every flexible wire for portable apparatus shall be connected to the system either by efficient permanent joints or connections or by a properly constructed connector.

3.2.3.2 The metal-work of a portable apparatus, pendant lamps with switches and any flexible metallic covering of the conductors shall be efficiently earthed.

3.2.3.3 A lamp holder shall not be in metallic connection with the guard or other metal-work of a portable or pendant lamp.

3.2.3.4 Any portable apparatus and its flexible wire shall be controlled by efficient means suitably located and capable of cutting off the supply.

3.2.3.5 Where the voltage exceeds low voltage the metal-work shall be efficiently earthed independently of any flexible metallic cover of the conductors and any such flexible cover shall itself be independently earthed.

3. 3

3.3 Switchboard and Switchgear

3.3.1 General

3.3.1.1 Switchboards for the control of equipment rated at 240V/415V shall conform with BS 5486 (IEC 60439: Part1). Panels shall be free standing of uniform height, flush mounted and totally enclosed protection class not less than IP 43 in accordance with BS 5420:1977.

3.3.1.2 Each switchboard shall be controlled by a suitable isolating switch/circuit breaker. The general arrangement of switchboards shall, so far as is practicable, be such that:

a) all parts which may have to be adjusted or handled are readily accessible;

b) the course of every conductor may where necessary be readily traced;

c) conductors not arranged for connection to the same…