INDUSTRIAL LIGHTNING SYSTEM
Lighting Principles and Terminology
Illumination
The distribution of light on a horizontal surface. The purpose of all lighting is to produce illumination.
Circuit Watts
It is the total power drawn by lamps and ballasts in a lighting circuit under assessment.
Lumen
A measurement of light emitted by a lamp. As reference, a 100-watt incandescent lamp emits about 1750 lumens.
Footcandle
A measurement of the intensity of illumination. A footcandle is the illumination produced by one lumen distributed over a 1-square-foot area. For most home and office work, 30–50 footcandles of illumination is sufficient. For detailed work, 200 footcandles of illumination or more allows more accuracy and less eyestrain. For simply finding one's way around at night, 5–20 footcandles may be sufficient.
EfficacyThe ratio of light produced to energy consumed. It's measured as the number of lumens produced divided by the rate of electricity consumption (lumens per watt).
Color temperatureIt is color of the light source. By convention, yellow-red colors (like the flames of a fire) are considered warm, and blue-green colors (like light from an overcast sky) are considered cool. Color temperature is measured in Kelvin (K) temperature.
Glare
The excessive brightness from a direct light source that makes it difficult to see what one wishes to see. A bright object in front of a dark background usually will cause glare. Bright lights reflecting off a television or computer screen or even a printed page produces glare. Intense light sources—such as bright incandescent lamps—are likely to produce more direct glare than large fluorescent lamps. However, glare is primarily the result of relative placement of light sources and the objects being viewed.
Dimming:-
A procedure of varying the luminous flux from lamps in a lighting installation, by way of an electrical or electronic component.
Discharge Lamp
Lamp in which the light is produced, directly or indirectly, by an electric discharge through a gas, a metal vapour, or a mixture of several gases and vapours.
Light:-
Electromagnetic radiation with a wavelength of between 380-720nm. Ultraviolet light has a wavelength of less than 380nm whilst infrared light is greater at 720nm. i.e. the cooler and warmer end of the lighting spectrum.
Lux:-
The unit of illuminance, equal to one lumen per square metre (lm/m2)
High-pressure mercury (vapour) lamp:-
Mercury vapour lamp, with or without a coating of phosphor, in which during operation the partial pressure of the vapor is of the order of 105 Pa - for example: HPL and HPL-N lamps.
High-pressure sodium (vapour) lamp:-
Sodium vapour lamp in which the partial pressure of the vapour during operation is of the order of 104 Pa - for example, SON and SON-T lamps.
Incandescent lamp:-
Lamp in which an electric current is passed through a filament thus creating heat. The light is the glow produced.
Low-pressure mercury (vapor) lamp:-
Mercury vapor lamp, with or without a coating of phosphor, in which during operation the partial pressure of the vapor does not exceed 100 Pa - for example a 'TL' lamp.
Low-pressure sodium (vapor) lamp:-
Sodium vapor lamp in which the partial pressure of the vapor during operation does not exceed 5 Pa - for example a SOX lamp.
Metal halide lamp:-
Discharge lamp in which the major portion of the light is produced by the radiation from a mixture of a metallic vapor (for example, mercury) and the products of the dissociation of halides (for example, halides of thallium, indium or sodium) - for example: HCI-T/HQI-TS lamps.
Power Factor Correction (pfc):-
Electricity supply require that the companies require that the power factor at which the supply is used shall be maintained at not less than 0.9 lagging, on average between one meter reading and the next. Low power factors increase the KVA demand from the supply, reduces the useful load that can be safely handled by the cables and distribution equipment, and in some cases can attract additional tariff penalties. Lamp circuits which incorporate a choke, leakage reactance transformer, or an electronic ballast can have low power factors, often between 0.3 and 0.6. Low power factor from these circuits can be corrected by the addition of a compensation capacitor. These can be placed at the central point of the supply, locally for each group of luminaries , or integral within each luminaire.
Starter:-
Device for starting a discharge lamp (in particular a fluorescent lamp) that provides for the necessary preheating of the electrodes and/or causes a voltage surge in combination with the series ballast.
Types of Lighting
You'll find that you have several options to consider when selecting what type of lighting you should use
Types of lighting include:
1) Fluorescent lighting
2) High-intensity discharge lighting
3) Incandescent lighting
4) Low-pressure sodium lighting
5) Outdoor solar lighting
Lamp is equipment, which produces light. The most commonly used lamps are described briefly as follows:
INCANDESCENT LIGHT BULBSIncandescent light bulbs consist of a glass enclosure (the envelope, or bulb) which is filled with an inert gas to reduce evaporation of the filament. Inside the bulb is a filament of tungsten wire, through which an electric current is passed. The current heats the filament to an extremely high temperature (typically 2000 K to 3300 K depending on the filament type, shape, size, and amount of current passed through). The heated filament emits light that approximates a continuous spectrum. The useful part of the emitted energy is visible light, but most energy is given off in the near-infrared wavelengths.
(Incandescence : The state of glowing from intense heat, as when a metal becomes white hot from an electric current flowing through it.)
Reflector lamps:Reflector lamps are basically incandescent, provided with a high quality internal mirror, which follows exactly the parabolic shape of the lamp. The reflector is resistant to corrosion, thus making the lamp maintenance free and output efficient.
Gas discharge lamps:
The light from a gas discharge lamp is produced by the excitation of gas contained in either a tubular or elliptical outer bulb.
The most commonly used discharge lamps are as follows:
• Fluorescent tube lamps (FTL)
• Compact Fluorescent Lamps (CFL)
• Mercury Vapour Lamps
• Sodium Vapour Lamps
• Metal Halide Lamps
HALOGEN BULBS
Halogen light bulbs produce light in a similar method to a regular incandescent bulb. A halogen bulb has a filament made of Tungsten, which glows when electricity is applied, same as a regular incandescent bulb. What makes a halogen bulb different is that it is filled with halogen gas instead of argon gas like a regular bulb is. The halogen gas removes the carbon deposits on the inside of the bulb, caused by the burning of the tungsten filament, and re deposits it back on to the filament, resulting in a light bulb which can be burned at a higher temperature therefore creating, both a whiter as well as a brighter light per watt than a regular bulb. The average rated life of halogen bulbs are typically between 2,000 and 4,000 hours.
Types of Fluorescent Lamps
Two general types of fluorescent lamps include these:
Compact fluorescent lamps (CFLs)
Fluorescent tube and circline lamps
FLOURESCENT TUBE LIGHT
A fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapor. The excited mercury atoms produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. Compared with incandescent lamps, fluorescent lamps use less power for the same amount of light, generally last longer, but are bulkier, more complex, and more expensive than a comparable incandescent lamp. Fluorescent lamps - namely CFL's - are significantly more expensive than incandescent, but they are about 3 to 4 times as efficient as incandescent and last 10 times longer or more
COMPACT FLOURESCENT LIGHTS/ENERGY SAVER
A compact fluorescent lamp (CFL), also known as a compact fluorescent light bulb (or less commonly as a compact fluorescent tube [CFT]), is a type of fluorescent lamp. Many CFLs are designed to replace an incandescent lamp and can fit in the existing light fixtures formerly used for incandescents. Compared to general service incandescent lamps giving the same amount of visible light, CFLs use less power and have a longer rated life, but generally have a higher purchase price. Compact fluorescent lamps (CFLs) combine the energy efficiency of fluorescent lighting with the convenience and popularity of incandescent fixtures
CFLs can replace incandescents that are roughly 3–4 times their wattage, saving up to 75% of the initial lighting energy. Although CFLs cost 3–10 times more than comparable incandescent bulbs, they last 6–15 times as long (6,000–15,000 hours).
Low-Pressure Sodium Lighting
Low-pressure sodium lamps provide the most energy-efficient outdoor lighting compared to high-intensity discharge lighting, but they have very poor color rendition. Typical applications include highway and security lighting, where color isn't important.
Low-pressure sodium lamps work somewhat like fluorescent lamps. Like high-intensity discharge lighting, low-pressure sodium lamps require up to ten minutes to start and have to cool before they can restart. Therefore, they are most suitable for applications where they stay on for hours at a time. They are not suitable for use with motion detectors.
Mercury Vapor Lamps
Mercury vapor lamps—the oldest types of high-intensity discharge lighting—are used primarily for street lighting. Mercury vapor lamps provide about 50 lumens per watt. They cast a very cool blue/green white light. Most indoor mercury vapor lamps in arenas and gymnasiums have been replaced by metal halide lamps. Metal halide lamps have better color rendering> and a higher efficacy. However, like high-pressure sodium lamps, mercury vapor lamps have longer lifetimes (16,000–24,000 hours) than metal halide lamps.
Control Gear
The gears used in the lighting equipment are as follows:
Ballast:
A component that is used to stabilize the current flow through, or operation of, a circuit, stage or device. 2. An iron-core choke connected in series with one of the electrodes in a fluorescent or other gas-discharge lamp.
Ignitors:These are used for starting high intensity Metal Halide and Sodium vapour lamps.
Recommended Illumination
Chemicals
Petroleum, Chemical and Petrochemical works Exterior walkways, platforms, stairs and ladders 30–50–100
Exterior pump and valve areas 50–100–150
Pump and compressor houses 100–150–200
Process plant with remote control 30–50–100
Process plant requiring occasional manual intervention 50–100–150
Permanently occupied work stations in process plant 150–200–300
Control rooms for process plant 200–300–500
Pharmaceuticals Manufacturer and Fine chemicals manufacturer
Pharmaceutical manufacturer Grinding, granulating, mixing, drying, tableting, s 300–500–750
terilising, washing, preparation of solutions, filling,
capping, wrapping, hardening
Fine chemical manufacturers Exterior walkways, platforms, stairs and ladders 30–50–100
Process plant 50–100–150
Fine chemical finishing 300–500–750
Inspection 300–500–750
Soap manufacture
General area 200–300–500
Automatic processes 100–200–300
Control panels 200–300–500
Machines 200–300–500
Paint works General 200–300–500
Automatic processes 150–200–300
Control panels 200–300–500
Special batch mixing 500–750–1000
Color matching 750–100–1500
USEFUL LIGHT CALCULATION FORMULAS FORMULAS
1) Demand for Power (kW) = System Input Wattage (W) ÷ 1,000
2) Energy Consumption (kWh) = System Input Wattage (kW) x Hours of Operation/Year
3) Hours of Operation/Year = Operating Hours/Day x Operating Days/Week x Operating Weeks/Year
4) Lighting System Efficacy (Lumens per Watt or LPW) = System Lumen Output ÷ Input Wattage
5) Unit Power Density (W/sq.ft.) = Total System Input Wattage (W) ÷ Total Area (Square Feet)
6) Watts (W) = Volts (V) x Current in Amperes (A) x Power Factor (PF)
7) Voltage (V) = Current in Amperes (A) x Impedance (Ohms) [Ohm's Law]
SELECTION CHART FOUND ON A TYPICAL INDUSTRIAL LUX METER
SELECTION ON A LUTRON LIGHT METER
1 for TUNGSTEN , SUN
2 for FLUORESCENT
3 for SODIUM
4 for MERCURY
Light Control
The simplest and the most widely used form of controlling a lighting installation is "On-Off" switch. The initial investment for this set up is extremely low, but the resulting operational costs may be high. This does not provide the flexibility to control the lighting, where it is not required.
Hence, a flexible lighting system has to be provided, which will offer switch-off or reduction in lighting level, when not needed. The following light control systems can be adopted at design stage:
• Grouping of lighting system, to provide greater flexibility in lighting control
Grouping of lighting system, which can be controlled manually or by timer control.
•Installation of microprocessor based controllers Another modern method is usage of microprocessor / infrared controlled dimming or switching
circuits. The lighting control can be obtained by using logic units located in the ceiling, which
can take pre-programme commands and activate specified lighting circuits. Advanced lighting
control system uses movement detectors or lighting sensors, to feed signals to the controllers.
• Optimum usage of daylighting
Whenever the orientation of a building permits, day lighting can be used in combination with electric lighting. This should not introduce glare or a severe imbalance of brightness in visual environment. Usage of day lighting (in offices/air conditioned halls) will have to be very limited, because the air conditioning load will increase on account of the increased solar heat dissipation into the area. In many cases, a switching method, to enable reduction of electric light in the window zones during certain hours, has to be designed.
• Installation of "exclusive" transformer for lighting
In most of the industries, lighting load varies between 2 to 10%. Most of the problems faced by the lighting equipment and the "gears" is due to the "voltage" fluctuations. Hence, the lighting equipment has to be isolated from the power feeders. This provides a better voltage regulation for the lighting. This will reduce the voltage related problems, which in turn increases the efficiency of the lighting system.
• Installation of servo stabilizer for lighting feeder
Wherever, installation of exclusive transformer for lighting is not economically attractive, servo stabilizer can be installed for the lighting feeders. This will provide stabilized voltage for the lighting equipment. The performance of "gears" such as chokes, ballasts, will also improved due to the stabilized voltage. This set up also provides, the option to optimise the voltage level fed to the lighting feeder. In many plants, during the non-peaking hours, the voltage levels are on the higher side. During this period, voltage can be optimised, without any significant drop in the illumination level.
Lighting Occupancy Sensor Controls
Occupancy sensors detect activity within a certain area. They provide convenience by turning lights on automatically when someone enters a room. They reduce lighting energy use by turning lights off soon after the last occupant has left the room.
Occupancy sensors must be located where they will detect occupants or occupant activity in all parts of the room. There are two types of occupancy sensors: ultrasonic and infrared. Ultrasonic sensors detect sound, while infrared sensors detect heat and motion. In addition to controlling ambient lighting in a room, they are useful for task lighting applications, such as over kitchen counters. In such applications, task lights are turned on by the motion of a person washing dishes, for instance, and automatically turn off a few minutes after the person stops
Lighting Photosensor Controls
You can use photosensors to prevent outdoor lights from operating during daylight hours. This can help save energy because you don't have to remember to turn off your outdoor lights. Photosensors sense ambient light conditions, making them useful for all types of outdoor lighting. They offer little utility in controlling lights inside the home because lighting needs vary with occupant activity rather than ambient lighting levels.
Types of Solar CellsThe performance of a solar or photovoltaic (PV) cell is measured in terms of its efficiency at converting sunlight into electricity. There are a variety of solar cell materials available, which vary in conversion efficiency.
Semiconductor Materials
A solar cell consists of semiconductor materials. Silicon remains the most popular material for solar cells, including these types:
Monocrystalline or single crystal silicon
Multicrystalline silicon
Polycrystalline silicon
Amorphous silicon
The absorption coefficient of a material indicates how far light with a specific wavelength (or energy) can penetrate the material before being absorbed. A small absorption coefficient means that light is not readily absorbed by the material. Again, the absorption coefficient of a solar cell depends on two factors: the material making up the cell, and the wavelength or energy of the light being absorbed.
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