LIGHTING SYSTEM FOR SUBSTATIONS
- Design
- General
- The following have to be considered when planning for the design of lighting installation;
- i) Level of illumination (lm/m² or lux(
- This is measured at a horizontal surface raised by 85cm from floor level.
- The required level of illumination depends on the place, on the nature of work in this place, and on the required quality of work for the substation, the following figures are used:-
- - Control room 500lux
- - Offices, meeting room 300lux.
- - staircase, toilet, kitchen, corridors. 100 lux.
- - Switchyard. 50 lux.
- - Switchgear room 200lux.
- - Transformer room 200 lux.
- - Battery room 200 lux.
- - Communication room 300 lux.
- - AC/DC room 200 lux.
- - Roads, gates 20 lux.
- - Workshop 300 lux.
- - Stores. 150 lux.
- For other locations refer to the attached table.
- ii) Spatial Distribution of Light :
- A good distribution of lighting sources is required in order to get sufficient light to feel comfortable and without glare and this depends on the following :-
- a. Lighting fitting and its fixation method.
- b. Distances between lighting sources itself, lighting sources to the work level, and lighting sources to the walls.
- iii) Selection of lamps according to the nature of activity in the place.
- iv) Area of the room.
- A.C Lighting for Indoor
- i) General
- 1-Indoor electrical installation
- The AC indoor electrical installation shall be supplied from more than one sub-distribution board (DB). Which are fed from the main low voltage AC distribution board.
- - The lighting and power sub-distribution boards of the control building shall be located in the control room. Power outlets circuits will be supplied from a sub-distribution board. Lighting circuits will be supplied from another separated sub-distribution board.
- - All indoor light fittings, switches, and power outlets shall have a minimum degree of protection IP 30 except those of battery room shall be anti-acid weatherproof with a minimum degree of protection IP 54.
- 2- Control Building and switchgear building
- - The lighting installation shall be designed to give the illumination levels for the respective areas set out in the table (2) which gives types of lamps to be used, type of suitable mounting for each area, type of power sockets, and the limits of glare index requirements.
- - One single phase socket 16 A, shall be installed in the basement every 20 meters along their perimeter as a minimum.
- - A minimum of three sockets - single-phase shall be installed in each room except in Control room, and 11/22 KV hall , basement,(66 KV switchgear corridor for indoor s/s) where a single-phase socket shall be installed every 10 meter along their perimeters and every 20meter for the basement.
- - Luminaires shall be selected for ease lamp changing, cleaning, and durability.
- - Fluorescent lamps shall be equipped with electronic ballast .
- - Discharge lamps shall be equipped with appropriate control gear.
- - Light fittings selected for the control room shall be low brightness type.
- - Fluorescent lamps shall generally be (36 watts) warm white, cool white, or white.
- - Lights for Control room, basement, and 11/22 KV hall (66 KV switchgear corridor in indoor s/s) are to be switchable from all entry points .
- 3- Guard room & dormitory building
- - The minimum illumination level shall not be less than 100 lux.
- - Fluorescent lamps shall be installed in all parts of the building except on the outside wall of the building where incandescent lamps shall be used.
- ii) Lighting Inside Transformer Room (if applicable)
- The light fittings shall be located on the walls and the fittings shall be of the type of fluorescent lamps & with built-in power factor improvement device level of illumination shall be according to item 4.4.1.
- A.C Lighting for Outdoor
- i) General
- - The lighting installation shall be designed to achieve the specified level.
- - All lighting equipment shall have a minimum degree of protection of IP55.
- - The lighting fitting should be fitted on a 6 to 8-meter pole.
- For switchyard fittings may be mounted on steel structures of busbars and feeders.
- - All poles shall be connected to the main grounding system by a separate conductor. Each pole shall have a built-in fuse box at a height of 1.5m from the ground concrete foundation.
- ii) Lighting in The switchyard and around the Transformers
- - The horizontal illumination level shall not be less than specified values.
- - The light fitting should be located on separate poles.
- - The lighting fixtures shall be of floodlighting fitted with H.P.S lamps and built in an electronic ballast.
- - The pole shall have built-in fuse boxes and concrete foundations.
- - The poles shall be made of hot-dip galvanized steel bolted to a concrete foundation.
- iii) Road Lighting
- - Main road & access road to and around all buildings shall be provided with fittings of street lighting H.P.S lamps and with built-in power factor improvement capacitor.
- - The fittings shall be located on separate poles of 8mt. height.
- - The poles shall make of hot-dip galvanized steel bolted to a concrete foundation.
- - The poles shall have built in the cable junction box.
- iv) Lighting for guard towers, main gates, and boundary fence
- - Outdoor lighting fittings for fences should be located on separate hot dipped galvanized steel poles to illuminate both sides of the fence by high pressure Sodium vapor lamp, comply with IEC standard (250watt).
- - Guard towers shall be provided with movable fixtures for floodlight projectors (400-1000w) with H.P.S inside an enclosure, the reflector is one piece made of anodized high purity Aluminium with a flat thermally hardened glass fixed to the reflector by means of silicon rubber gasket to protect against dust. The fixture shall have a degree of protection IP65.
- v) Lighting Control
- - The outdoor lighting shall be fed the several independent circuits, each electric circuit shall be operated by means of photocell relays & manually by the switch with three position on – photocell – off from the control room.
- vi) Other buildings and areas
- Rather than those items mentioned herein, the whole substation structures illumination and all electrification works are a part of the contractor’s works. Such as residential buildings, parking areas, …etc.
- Emergency Lighting
- - Emergency lighting shall be supplied from the DC distribution board in case of AC supply failure.
- - Emergency lighting system shall be automatically supplied in the event of:
- • AC supply failure of substation's main AC.
- • AC supply failure of main Lighting board.
- • Lighting's miniature circuit breaker failure for any one of the lighting circuits.
- - Emergency lighting should be installed in all the substation rooms, switchyard, main roads, access roads, guard room and main gate and operated as follows:.
- The emergency indoor lighting system shall be:
- 1- Directly operated automatically in the following mentioned areas:
- • control room
- • PLC room
- PLC room
- • 22/11KV hall
- • AC / DC room
- • Corridors and entrance
- • 66 KV switchgear building (in indoor s/s)
- 2- Manually operated by means of DC switches which shall be installed in the following places:
- • Offices
- • Workshop / store
- • Kitchen / WC
- • Auxiliaries transformers rooms
- • Fire fighting room
- • Battery room Rectifier room.
- - Emergency lighting shall be designed to give lux level not less than 5% of the normal lighting lux level with a minimum level of 10 lux.
- - Only incandescent lamps with porcelain holders are allowed to be used.
- - Emergency exit signs are required at all exist and along escape routes.
- - The control room is also to be fitted with a portable emergency lantern which will automatically light a pilot lamp in the event of an A.C power failure.
- - Light fittings are to be provided at all exit door and along catwalk (switchgear building).
- Sockets And Switches
- i) Sockets
- - The socket will be provided with a switch & signal lamp.
- - The socket will be fitted a height of 40cm above the floor except the kitchen and toilet shall be mounted at 120 cm above floor level.
- - All sockets provided with separate earthing pins connected to the yellow/green part in the feeder cable.
- - The socket with a rated current higher than 16A will be provided with a locking device to prevent insertion or removal of the plug if there is tension on its terminal.
- - Sockets of battery room shall be anti-acid, weather-proof with a minimum degree of protection IP54. Each socket should be provided with its plug.
- i) Switches
- - Switches shall be 10 Amp. and 26A - 250 volt.
- - It shall be flush mounting singular or multi-gang and on a height about
- t 120cm.
- - Cover plates shall be ivory or white plastic.
- - Switches of battery room shall be anti-acid weatherproof with a minimum degree of protection IP 54.
- - Wiring terminals shall be of the screw type or of the solder-less pressure type.
- - Each switch will not be operated more than one circuit.
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