ABC Project_Design Breif

8/12/2019 ABC Project_Design Breif

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ABC Project COLOMBO 1.

Renovation and Restoration of ABC Building

Employer :

MEP Consultant

Building Description.The building consist of One(01) Basement floor, Six(06) Over ground floors including mezzanine floor.

Schedule of Floor Area

Item Description Floor Area(Sqft)

1

2

3

4

5

6

7

Basement Floor

Mezzanine Floor

Ground Floor

First Floor

Second floor

Third Floor

Fourth Floor

6905

710

4434

6550

6023

5760

4835

Total Floor Area 35217sqft (=3271 sqm)

DESIGN BRIEF - ELECTRICAL INSTALLATION

The purpose of this report is to establish principal design criteria, which forms the basis for development of the

design.

1. SCOPE OF WORKS.

The scope of the electrical installation shall consist of the following.

Power receiving system(Low voltage, 400V, 3 Phase from CEB)

Low voltage generator system Low voltage power distribution

Interior lighting provision

Lightning Protection system

Telephone PABX system and Data system/ Structured Cabling

Master Antenna Television System (MATV)- (optional)

Security System(CCTV system)

Fire Detection system

2. CODES AND REGULATIONS

IEE (UK) Wiring regulations - 17TH Edition. (BS 7671)

Code of Practice of Energy efficient building in Sri Lanka- 2008

Applicable Sri LankaFire Authority regulations

3. DESIGN DESCRIPTIONS

01. Power receiving System

a) The work shall exclude high voltage incoming line and transformers form local Electrical Power

Authority. The metering facility at the low voltage(400V, 3 Phase, 4W, 50Hz) intake point to be

provided by the Authority.



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b) Receiving Voltage

3 phase 4 wire 400v 50hz through one feeder .

c) Distribution Transformer

The distribution transformer location shall be the meter room at ground floor as per the

requirement laid down by the CEB.

d) Estimate of Maximum Electrical Demand

The maximum demand of the development is approximately 400 KVA (with 10% Spare capacity)

and shall be calculated on following basis. Diversities of the loads shall be based on recoded data

of the International Practice.

The lighting load as per Energy Efficient Building Code- Sri Lanka

General purpose outlets (GPOs) - 180 VA/per outlet

Plant and mechanical loads as per the Mechanical Services Design

02 Low Voltage Generator System

In the event of mains power failure one number 300 kva prime rated generator set is provided

(diesel engine driven built-in radiator type) to supply power to total load of the building.

The stand by generator for the development shall be interlocked with the normal main supply to

sense power supply failure so that it will automatically start up. Upon restoration of the mains

supply the generator sets shall automatically stop after a pre-set interval which is adjustable.

A day tank (sized for 8 hrs continues operation) shall be provided for the generator.

03 Low Voltage System

a) The electrical distribution system shall be designed for 400/230V 3 phase 4 wire 50hz

rated voltage and all equipment shall be suitable to operate under the rated voltage.

b) The type of the feeder cable should be as follows.

i) Sub-main feeder from - PVC/PVC-Cu

MSB to SDBS & DBS or XLPE/PVC- Cu

Cables through

Cable tray/ladder

ii) Final circuits from - PVC-Cu single core

DBS to lighting, switch cables through UPVCSocket outlets conduit / Trunking

(In concealed area)

c) Supplies shall be distributed from the main switch board at Ground floor. Vertical

distribution shall be through cables installed within main electrical riser. Voltage drop in

cables shall not exceed 4% according to the IEE Regulations. Power Factor correction

capacitor banks shall be installed at the main switch board.



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d) The power distribution to each tenant to be separately metered serving at least three

tenants per floor. All Energy meters must be clustered at ground floor or remotely located

with a display being located at ground floor.

04. Interior Lighting Provision and Socket Outlet

Electrical scope of work considered only for point wiring . Supply luminaries is not included to

the electrical work.

a) General lighting for areas such as staircases, corridors, plant rooms, car-parks and circulation

areas shall have fully enclosed fluorescent luminaries and point wiring shall be carried out

under electrical work. Time switch c/w manual override switch will be used to operate

extension and staircase lighting during certain interval of the day.

b) Lighting for building façade, lift lobby’s, function rooms, snack bar etc. Will take into

consideration aesthetic aspects. The selection of special lighting fixtures for these areas shall

be under the guidance of the interior designer.

c) Maintained type emergency lighting and illuminated Exit sign shall be provided to illuminate

the escape paths, staircases, public areas and toilets during power failure. Supply of

emergency lighting including point wiring shall be provided to the electrical work.

d) To decide the number of lighting points required for different areas, recommended

illuminance is considered as follows.

RECOMMENDED ILLUMINANCE

(GENERAL LIGHTING)

Location/AreasRecommended

Illuminance (LUX)

Entrance Halls / Lobbies 300

Store Rooms 200

General Offices 500

Circulation areas, corridors and

Staircases

150

Lift lobbies 200

Plantroom/ Gen Room/ Meter Room 300

e) The wiring to lighting points shall either be using lighting trunking or through neatly arranged

casing made to BS standards.

f) The wiring to socket outlet shall also be through three compartment trunking along the wall in

order to accommodate for ELV services. As the tenant requirement may vary from one toother trunking system shall be with modular type outlets.

g) The number of socket outlet shall be so selected in order cater the tenants requirement as well

as landlord common facilities.

06 Lightning Protection System



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A complete lightning protection system will be installed in accordance with the relevant

British Standards or French standards. The lightning protection system will consist of a

network of horizontal conductors on the roof and vertical down conductors which shall

be terminated to the Earth Electrodes (Ground Floor Level), through inspection pits. The

earthing resistance of the earth electrodes shall not be less than ten(10) ohms. If the

system follows to French standard an early streamer type lightining rod and one or two

down conductors with necessary earthing shall be provided.

07 Telephone PABX System and Data system/ Structured Cabling system

Multipair cat 3 telephone cabling shall be run from Main Equipment Cabinet(MEC) to

Secondary Equipment Cabinet(SEC). The wiring to telephone outlet shall be using 1 pair

cat3 cables or 0.5mm telephone cables

All Equipment cabinet shall have sufficient space to accommodate tenants PABX and or

Data Switches.

The work scope of Telephone System will cover the following.

i) Provide underground pipes from the boundary of the premises to location of

MDF for incoming telephone cable supplied by the authority.

ii) Wiring of the internal distribution network through vertical shaft cable Trays

and conduits.

iii) The PEO TV requirement shall also be coordinated with the telecom authority if

needed.

The data system in order to provide LAN and internet facilities within the facility shall be

provided. The data system shall comprise of

i) Cat 6 cabling to RJ45 outlets from SECs

ii) Cat 6 patch panels, 19” EIA racks, cable management panels, power rails, etc

iii) Active componenets such as data switches- By others

iv) Rack mounted UPSs

v) Termination and Certification

vi) Provide necessary routers in order to obtain ADSL or other internet services

from the telecom authority.

08 Master Antenna Television System (MATV)

The MATV System shall provide effective television reception over the frequency range

on various bands available, VHF, and UHF . The signal received will be amplified by the

receptive channelised amplifiers housed in a head and equipment cabinet located in the

Fourth/Roof Floor.



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The amplified signal will be distributed to each outlet by using splitters, couplers via co-

axial cables in trunking/conduits.

There will be TV outlets in public areas, function room , reception etc.

In addition to terrestrial broadcast signals, PEOTV or Dialog TV facility for 16 channels

shall be obtained from the relevant service provider.

09 Security System(Closed Circuit television System)

The following security system are recommended.

- Closed Circuit Television (CCTV) System

a) CCTV System

The CCTV system will comprise the following.

i) CCTV Cameras will be placed un-obstructively at strategic points

throughout the building. In general, cameras will be installed atselected location of public areas such as Entrance lobby’s, lift lobbies,

and areas where high security is concerned within respective tenants

occupied areas.

ii) Monitors for the cameras will be installed in the security office. These

monitors shall be LCD colour monitors and connected to respective

Digital Video recorder.

iii) The Digital Video recorder shall consist of 16 channels with recording

storage facility for 14 days.

iv) All cabling shall be coaxial type of RG 59 or RG 6 with suitable

braiding as recommended by the respective manufacturer.

v) As an alternative solution, an IP based CCTV system shall be proposed

in order to add value to the building under consideration.

10) Fire Alarm System

a) Fire Alarm System

i) Fire Alarm System shall be designed and installed in accordance with

the BS 5489 part 1.

ii) An Addressable fire alarm panel with respective smoke, heat detectors

and manual call points, sirens shall be provided.

iii) Fire detection and alarm equipment such as manual call points, smoke

detectors, heat detectors, alarm bell shall be in accordance to provided

and wired to the FA panel.

iv) This requirement shall be coordinated with respective fire authority.

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ABC Project_Design Breif