Chapter 7 Lighting Systems & Emergency Lightings PDF

Chapter 7 Lighting Systems & Emergency Lightings 8 Oct 2013, V00 Electrical Facilities 1  Lesson Objectives Identify different Components of Luminaires Understand the five different installation method of Luminaires Difference between Direct/Indirect ligh...

Chapter 7 Lighting Systems & Emergency Lightings 8 Oct 2013, V00 Electrical Facilities 1  Lesson Objectives Identify different Components of Luminaires Understand the five different installation method of Luminaires Difference between Direct/Indirect lighting Understand the two categories of lamps Purpose of Emergency Lighting and three methods The three Operating Modes of Emergency Lighting systems Purpose of Exit Lights Two types of Maintenance of Luminaires 8 Oct 2013, V00 Electrical Facilities 2  Luminaire 8 Oct 2013, V00 Electrical Facilities 3  Luminaire Apparatus which controls the distribution of light Lamp and Holder Starter, Ballast Reflector Diffuser Lamp housing 8 Oct 2013, V00 Electrical Facilities 4  Luminaire The various components… Housing Lamp Louvres Control gears & wirings 8 Oct 2013, V00 Electrical Facilities 5  Recessed mounted Housed above the ceiling, or in a wall or floor. Also called ‘flush fitting’. With ceiling grid, luminaire Ceiling described as ‘modular’. recessed Found in commercial Floor offices & shops where recessed false ceiling system is used. 8 Oct 2013, V00 Electrical Facilities 6  Recessed luminaire, modular setting Fluo. fixtures fit into ceiling grid of either 2ft x 2ft (shown) or 2 ft x 4ft ceiling tile: Ceiling Fitting 8 Oct 2013, V00 Electrical Facilities 7  Surface Mounted Fixed directly to the ceiling or wall surface. Ceiling Fitting 8 Oct 2013, V00 Electrical Facilities 8  Pendant Mounted Suspended below ceiling level by: – flexible cable, – chain or – rod. Suspended by rods Provide direct or indirect lighting. Suspended by flex cables 8 Oct 2013, V00 Electrical Facilities 9  Pole Mounted Mounted on metal pole Used as outdoor lighting 3 main types: – Low pole-mounted fittings of about 1m high called bollards to light up pathways. – 3m high pole-mounted fittings for general area lighting such as carpark. – V00 pole-mounted fittings 8 Oct 2013,High 7-10mFacilities Electrical high for street lightings. 10  Portable Can be easily moved from one place to another Used for maintenance! 8 Oct 2013, V00 Electrical Facilities 11  Direct Lighting Light rays focused downwards to provide direct illumination of objects. Typically recessed, surface or pendant mounted. Ceiling Fitting Direct lighting 8 Oct 2013, V00 Electrical Facilities 12  Indirect Lighting Light rays are focused upwards towards ceiling to provide general illumination of space below from the reflected light rays. Applications include cove lighting, uplights Cove lighting etc. Such luminaires reduce glare effectively. 8 Oct 2013, V00 Electrical Facilities 13  Lamps family Current passes Current passes through the gas through the filament Lamps Incandescent Gaseous Discharge Filament Tungsten Fluorescent Sodium, Mercury Halogen 8 Oct 2013, V00 Electrical Facilities 14 Incandescent Filament Lamp Consists of a tungsten filament inside a gas- filled, sealed glass envelope. Electric current passes through the filament Gradual evaporation of filament causes blackening of bulbs & eventual filament rupture (lamp failure). Very short burning life about 1000 hrs Applications: Infrequent Use Low initial cost Dimming is easy Colour is true Problems: Evaporation of the tungsten! Deposited on the bulb walls Light output affected () by darkened bulb wall Filament becomes thinner & eventually fails 8 Oct 2013, V00 Electrical Facilities 15  Color Rendering The colour that a particular object or surface appears under a lamp and how true its actual colour is known as Colour rendering. 8 Oct 2013, V00 Electrical Facilities 16  Tungsten-Halogen Lamp Same working principle as standard incandescent lamp. Contains small amount of halogen gas in bulb. Evaporated tungsten from filament combine with halogen gas to form a tungsten-halogen compound, which will drift & deposit back to filament. Longer lamp life. Higher cost Applications: Floodlighting Sports lighting Display lighting Photographic lighting Projectors Motor car headlamps 8 Oct 2013, V00 Electrical Facilities 17  Fluorescent Lamps Fluo powder excited by uv gives out visible radiation Heated Collision electrod Current creates e heats up uv discharg electrode Cylindrical glass tube radiation es Mixture of inert gas – argon, Mercury electron vapor s Collision of electrons Ultraviolet light Tri phosphorous powder converts to visible light 8 Oct 2013, V00 Electrical Facilities 18  Fluorescent Lamps Ballast 2 3 1 1. Starter electrodes close (small gap) Warms up, bends Starter cools, spring apart 2. Very high voltage – Main arc strikes 3 Ballast is to reduce the current during high voltage Starter – Only required for starting. After light is ON, removal of starter will not affect Lamp operation Capacitor –Not compulsory, Reduces emission and improves waveform. 8 Oct 2013, V00 Electrical Facilities 19 8 Oct 2013, V00 Electrical Facilities 20  Compact fluorescent lamp SLLamps (Integral) PL Lamps (Non-Integral) Has its own starter/ballast Separate ballast is required Direct replacement for Not directly replaceable Incandescent lamp B S H Lamp 8 Oct 2013, V00 Electrical Facilities 21  Comparison of efficacy of lamps Efficacy: Lumens output from the lamp Watts input to the lamp Higher the better 7.5 times more Type of lamps Typical Efficacy Average Lamp lifespan Incandescent lamp 10 lm/W 1000 hours Tungsten halogen lamp 15 lm/W 2000 hours Fluorescent lamp 75 lm/W 8000 hours Low Pressure sodium lamp 150 lm/W 20000 hours High Pressure mercury lamp 50 lm/W 20000 hours High Pressure sodium lamp 100 lm/W 20000 hours 8 Oct 2013, V00 Electrical Facilities 22  Example 7.1 A retail shop unit is fitted with 100 nos. of 60W incandescent luminaires. Eachincandescent lamp have efficacy of 10 lm/W. In a cost-saving drive, the shop owner wants to replace all incandescent bulbs with 10W fluo energy-saving bulbs while maintaining the same brightness for the shop. Fluo lamps have efficacy of 75 lm/W. How many fluorescent luminaires would be required and how much would the cost-saving in electricity consumption be? 8 Oct 2013, V00 Electrical Facilities 23  Solution to Example 7.1 1kWh = 26.7 cents or $0.267 (from 1Apr 2013 to 30th June 2013) Each lamp 10W Each lamp 60W 1 W can give 75 lumens 1 W can give 10 lumens Efficacy is 75 lm/W Efficacy is 10 lm/W Each lamp can give 750 lm Each lamp can give 600 lm Total lumens (after) should be Total is 100 lamps 60000 lm So total lumens (before) is # of Lamps = 60000/750 = 100 X 60 = 60000 lm 80 lamps Power consumed = 100X60W = Power consumed = 80X10W = 6000 W = 6 kW 800W = 0.8 kW 8 Oct 2013, V00 Electrical Facilities 24  Low Pressure Sodium Lamp Type of lamps Typical Efficacy Average Lamp lifespan Incandescent lamp 10 lm/W 1000 hours Tungsten halogen lamp 15 lm/W 2000 hours Fluorescent lamp 75 lm/W 8000 hours Low Pressure sodium lamp 150 lm/W 20000 hours High Pressure mercury lamp 50 lm/W 20000 hours High Pressure sodium lamp 100 lm/W 20000 hours Operating Principle is the same as Fluorescent lamps Very High efficacy Street lights need lots of lumens at low cost Good Application is in Streetlighting 8 Oct 2013, V00 Electrical Facilities 25  High Intensity Discharge lamp Mercury Vapour Metal halide Sodium Vapour Operating Principle is the same as Fluorescent lamps Very High efficacy Good penetrating depth (Badminton court) Indoors and Outdoors 8 Oct 2013, V00 Electrical Facilities 26  Illuminance Minimum (Based on task Concert Hall – 100 lux Lecture theatre – 300 lux General Office – 500 lux Factory – 1500 lux 750 lux 100,00 0 lux 3000 lux 10,000 lux 8 Oct 2013, V00 Electrical Facilities 27  Lesson Objectives Lighting Systems and Emergency Lightings Reasons for power failure in buildings Need for emergency power Sources of emergency power How do the emergency powers work? Mode of operation 8 Oct 2013, V00 Electrical Facilities 28  Emergency lights must Failure of source at turn ON automatically Singapore Power Occupants can safely exit the building Generator UPS Single Point lighting systems Normal lightings Failure Failure of electrical Lighting circuit trip/ system at Building accidentally switched OFF 8 Oct 2013, V00 Electrical Facilities 29  Mains Failure Standby Generators Exhaust fan Computers Fire man Lift BCA & FSB requirements: All public buildings must be provided with Generators For essential equipments such as : Emergency - emergency lighting Lamps - mechanical ventilation fans - Computers - Lifts 8 Oct 2013, V00 Electrical Facilities 30  Mains Failure Standby Generators Waste Gas exhaust Genset Radiator control panel Engine block Battery for engine starting Alternator 8 Oct 2013, V00 Electrical Facilities 31  Exhuast Gas Diesel Emergency Panel Air OFF ON PG Fan Cooling Water Battery 8 Oct 2013, V00 Electrical Facilities 32  Components of a Generator E x h Diesel a Tank u s t Radiato Engin Alternat r e or Generat or Control System 8 Oct 2013, V00 Electrical Facilities 33  Components of a Generator Fuel System – consists of a day service fuel tank of 700 litres capacity connected to combustion engine. Engine – machine that combusts fuel (or diesel) & converts energy into mechanical power Radiator – large fan located at end of the genset for cooling & ventilating. Exhaust System – consists of a pipe, silencer & connection bellows & flexible pipes for purging out flue caused by combustion of fuel. Alternator – converts the mechanical power into electricity. Generator Control System – controller that detects mains failure, & starts up genset; connects essential loads. 8 Oct 2013, V00 Electrical Facilities 34  Noise and Vibration Airborne Noise – As an industrial standard, noise level limited to < 70 dB at 1m away from genset. – Silencers are used to reduce noise Structural vibration – Vibration from the genset when it operates; If not controlled to pass to building walls/floors. – Use vibration isolation devices (steel springs placed on neoprene rubber pads) http://auto.howstuffworks.com/4660-how-mufflers-work-video.htm 8 Oct 2013, V00 Electrical Facilities 35  Uninterrupted Power supply 8 Oct 2013, V00 Electrical Facilities 36  UPS Central system with battery Seamless transfer Most suited for Banks, Hospitals (Mission critical) Advantage : – Economical and Neat – Reliable Disadvantage  – Expensive UPS is also known as Static No break Power supply. 8 Oct 2013, V00 Electrical Facilities 37  Single Point light system 230 V AC Battery Rectifier Inverter Normal times – 230V ac power to the lamp Battery will be charged using the rectifier During Power failure, the battery will discharge through the inverter 8 Oct 2013, V00 Electrical Facilities 38  Single Point lighting system This symbol tells us that the lamp is an Emergency lamp (with battery back up) Push Out (default) : Normal condition Push In : Power failure condition simulated Red Lamp ON : Battery fully charged. Red Lamp OFF : Power failure condition. Red Lamp flashing : Charging after power failure 8 Oct 2013, V00 Electrical Facilities 39  Comparison Generator UPS Single Point lighting System Suitable for large Suitable for medium Suitable for individual loads loads loads 12 seconds No interruption No interruption interruption is expected Suitable for long Only until the battery Only until the battery hours of power lasts lasts failures (need diesel supply) Not as neat Neat Neat Required for supply to Best suited for Suitable for safely Lifts/smoke extraction mission critical exiting building fans etc applications 8 Oct 2013, V00 Electrical Facilities 40  3 modes of Operation Normal Power Fail Maintained Non - Maintained Sustained 8 Oct 2013, V00 Electrical Facilities 41  3 modes of Operation Maintained Operation: – Lighting system in which emergency lamps are energized at all times whether or not mains power available. Non-maintained Operation: – Normally off. Emergency lighting operates only when the normal supply fails! Sustained Operation – 2 lamps are used – One lamp – Normal Power – Other lamp – battery power 8 Oct 2013, V00 Electrical Facilities 42  EXIT Lighting Singapore code requires all EXIT signs (with directional arrows where appropriate): – be illuminated all the time – source of supply for illuminating signs must be the same as for emergency lighting. Single Point lighting system emergency exit luminaires used extensively. Emergency lamps http://www.youtube.com/watch?v=FbSlxd2F5Ks 8 Oct 2013, V00 Electrical Facilities 43  Maintenance of luminaires Cleaning – Remove dust as dust lowers light output of lamps Lamp replacement – Spot relamping – lamp replaced individually as they burn out – Group relamping – all lamps replaced before the end of lamps’ ave life & still in operation. Repairs & replacement of lighting components 8 Oct 2013, V00 Electrical Facilities 44  Maintenance of lamps Spot relamping (Home) Spot relamping As and when they get burnout More manhours required Labour cost high Appearance problem Group relamping (Large buildings) Suitable for homes Group relamping Replace in groups Can be scheduled Appearance is better Less chance for unattended lamps Suitable for large buildings 8 Oct 2013, V00 Electrical Facilities 45  Recap Sources of emergency power Generator UPS Single point lighting system Mode of operation Lamp maintenance 8 Oct 2013, V00 Electrical Facilities 46  Recap Worksheet 8 Oct 2013, V00 Electrical Facilities 47  Summary 1 Luminaire Lamp and Holder Control gear – Starter, Ballast, PF correction capacitor Reflector, Diffusers (Louvres) Housing Installation methods Recessed Mounted Surface Mounted Pendant Mounted Pole Mounted Portable Direct and Indirect lighting Light focused downwards Light focused upwards towards ceiling Lamp Types Incandescent Tungsten Tungsten halogen Gaseous Discharge Compact Fluorescent Low Pressure Sodium vapor lamps 8 Oct 2013, V00 Electrical Facilities 48  Summary 2 High Intensity Discharge lamps Mercury vapor Sodium vapor Metal halide Illuminance – measured in Lux Concert Hall – 100 Lecture theatre – 300 General Office – 500 Drawing Office – 750 Factory assembly line – 1500 Emergency Lighting Need for emergency lighting Failure of normal power supply Failure of Electrical system Interruption due to tripping of circuit breaker Three sources Mains failure standby generator Static No-Break Power supply (UPS) Single point systems 8 Oct 2013, V00 Electrical Facilities 49  Summary 3 Operating modes of Emergency lighting Maintained Operation Non maintained operation Sustained Operation Exit lamp Must be illuminated at all times Self contained is very commonly used Typically 8 W Tested once a month Should be tested for 1 hour twice a year Maintenance Spot relamping – replace as the burn out lamps fail Tedious, with high labour cost, total cost of relamping is excessive Group relamping – mass relamping. Time based on lamp life Use lamps burnout as a guide Fluorescent and incandenscent suited for group relamping. 3 advantages - Timing can be conveniently arranged - removes chances of leaving burned lamps unattended - No unsightly effect due to difference in lamp output 8 Oct 2013, V00 Electrical Facilities 50  Summary 4 Mains Failure Standby Generators Supplies to Emergency lighting, Mechanical ventilation fans, computers, lifts Some portion of lighting systems through emergency panels Parts o Engine – Machine that combusts fuel o Alternator – Part that converts mechanical power into electricity o Radiator – large fan located at the end of the generator for the purpose of cooling and ventilating the generator o Exhaust system – Pipe, silencer for purging out the flue caused by the combustion of fuel o Fuel system – day tank of 700 liters capacity that is connected to the combustion engine Two Precautions for Genset Installation Airborne Noise – Silencer at the Engine’s exhaust - < 70 dB Structural Vibration – steel springs on neoprene rubber pads 8 Oct 2013, V00 Electrical Facilities 51  Summary 5 Static No-Break Power supply Also known as Uninterruptible Power supply Utility Power Battery (and Inverter) Switch Single Point lighting system Battery pack Charges during normal times Discharges during power failure times Inverter to convert DC power to AC LED shows that the Normal power is present. On pushing the test switch, fluorescent lamp must be ON but the LED lamp should be OFF 8 Oct 2013, V00 Electrical Facilities 52