ARTIFICIAL LIGHTING Outdoor Prepared by ISR University of

ARTIFICIAL LIGHTING Outdoor Prepared by ISR – University of Coimbra July 2017

Summary 1. Types of Lamps 1. 1. Gas Discharge Lamps 1. 2. Solid State lamps – LEDs and OLEDs 2. Luminaires 3. Ballasts 4. Drivers 2

1. Types of Lamps Thermal Incandescent (Conventional) Halogen Incandescent • High Voltage • Low Voltage Gas Discharge Solid State High Pressure • Sodium • Mercury LED Low Pressure • Sodium • Mercury (fluorescent) OLED IN BLUE – Types of lamps most commonly used for outdoor lighting 3

1. Types of Lamps 1. 1. Gas Discharge Lamps A Gas Discharge Lamp is a light source that generates light by creating an electrical discharge through an ionized gas, a plasma. Low-pressure Lamps High-pressure Lamps • • Gas pressure from 5 k. Pa to greater than atmospheric pressure Examples: • metal halide lamps • high pressure sodium lamps • high pressure mercury-vapor lamps 4

1. Types of Lamps 1. 1. Gas Discharge Lamps Low-pressure Sodium Lamp • • • Low pressure sodium lamp generates light from a discharge in sodium vapor at the low pressure (0, 7 - 1 Pa). Great efficacy: between 150 and 200 lm/W. Made in ratings from 18 to 180 W. Lifetime of between 16000 and 23000 hours. Monochromatic lighting producing very poor colour rendering (<5). 5

1. Types of Lamps 1. 1. Gas Discharge Lamps High-pressure Sodium Lamp • • High pressure sodium lamp (HPS) operates a a pressure of 5 -10 k. Pa. A higher pressure sodium improves the colour rendering, but decreases efficacy: 100 to 125 lm/W depending on size. Made in ratings from 35 -1, 000 W. Have a life of between 20, 000 and 24, 000 hours. 6

1. Types of Lamps 1. 1. Gas Discharge Lamps High-pressure Mercury Lamp • • • It uses an arc through vaporized mercury in a high pressure tube to create very bright light directly from it's own arc. Made in ratings from 35 -2 000 W. Typical efficacy: 45 to 55 lm/W. Have a life of between 20 000 and 24 000 hours. Phased-out starting in 2015 (Ecodesign Regulation) 7

1. Types of Lamps 1. 1. Gas Discharge Lamps High-pressure Metal Halide Lamp • • Metal Halide lamps are similar to mercury vapor lamps but use metal halide additives inside the arc tube along with the mercury and argon. These additives enable the lamp to produce more visible light per watt with improved color rendition. Made in ratings from 35 -2 000 W. 80– 100 lumens per watt Have a life of between 10 000 and 20 000 hours. 8

1. Types of Lamps 1. 1. Gas Discharge Lamps Metal Halide Lamps 9

1. Types of Lamps 1. 1. Gas Discharge Lamps Gas Discharge Typical Performance Specification Characteristic Low pressure Sodium High Pressure Sodium Metal Halide Luminous Efficacy Range 150 - 200 lm/W 105 - 125 lm/W 80 - 100 lm/W Lamp Lifetime 16000 – 23000 hr 20000 – 24000 hr 10000 - 20000 hr Colour Rendering Index <5 25 65 - 85 Correlated Colour Temperature 1800 – 2000 K 2000 - 2100 K 4000 - 5000 K Dimmable? With dimmable ballast 10

1. Types of Lamps 1. 1. Gas Discharge Lamps UPs • • Greater lifetime than incandescent halogen lamps. More energy efficient than incandescent lamps Moderate cost, but LEDs are reaching similar prices. Diffused Light (good for general, even lighting, reducing harsh shadows) • Contains mercury. • Needs a warm-up time to get full brightness. • Flicker of the high frequency can be irritating to humans (eye DOWNs strain, headaches, migraines). • Not the best colour rendering index (CRI). • Not the best technology for dimming purposes. • Irritating flicker at the end of the life cycle 11

1. Types of Lamps 1. 2. Solid State lamps – LEDs and OLEDs • • A Light Emiting Diode (LED), also referred to as SSL (Solid State Lighting), is an electronic device that produces light when an electrical current is passed through it. A diode is a semi-conductor junction that will, once excited, allow current to cross the junction leading to the emission of white light. LEDs are the most efficient white lighting technology on the market. An Organic Light Emitting diode (OLED) are made with organic compounds that light up when fed electricity. Because they can be made extremely thin, flexible and small, they are used in TV screens, mobile phones and ceiling lights. 12

1. Types of Lamps 1. 2. LED Lamps Typical Performance Specification Characteristic LED Lamp Typical Quantity LED Luminaire Typical Quantity Luminous Efficacy Range 60 - 130 lm/W 80 - 150 lm/W Lamp Lifetime 15, 000 - 30, 000 hr 20, 000 - 60, 000 hr Colour Rendering Index 70 - 95 80 - 95 Correlated Colour Temperature 2, 700 - 6, 500 K Dimmable? With dimmable driver 13

1. Types of Lamps 1. 2. LED Lamps UPs • • • Technology that can have efficiency Class A+, A++ LEDs have, by far, the longest lifetime of all lighting technologies Lowest cost of ownership. Extremely flexible technology for aesthetic and controling purposes. Low temperature when functioning avoids any possibility of burning at touch. Compared to other technologies, LEDs withstand many more switching cycles and light up immediately. • Its initial cost is somewhat higher than other technologies (but the prices are getting lower and lower each year) and is most often offset by their low electricity consumption. • LEDs are temperature sensitive. Efficacy and lifetime is strongly reduced if lamps are overheated. DOWNs 14

2. Luminaires What is a Luminaire? According to EN 60598 -1 Standard, a luminaire may be defined as a lighting apparatus which distributes, filters or transforms light emitted by a lamp or lamps, including all components necessary for supporting, fixing and protecting the lamps, (except for the lamps themselves). Should the need arise, the auxiliary circuits combined with the media for the connection to the power supply can be also integrated in the luminaire. 15

2. Luminaires A traditional street lighting luminaire includes the following components: 1. Housing that contains all parts and the ballast/driver. 2. Optical System which controls and distributes the luminous flux from the light source 3. Lamps (also called light sources) and their respective lamp holder or socket 4. Support to hold the luminaire in the correct position 16

2. Luminaires Optical System The luminaires optical system may contain: Reflectors used to redirect and shape the light output. The reflector mirrors create multiple images of the light source which are used to create a relatively uniform luminance pattern on the lighted surface Refractors redirect the light of the lamp itself and the light from the reflector, as well as providing some additional protection against external damage. Diffuser: This forms the cover of the luminaire in the direction of the luminous radiation. May be used to improve visual comfort. 17

2. Luminaires Why are there so many and different luminaires? • Each luminaire is designed to direct light to a desired location, creating the required visual environment without causing glare or discomfort. Luminaires are adapted for many human different tasks and environments. • There are many types of luminaires, opaque or translucent and they can vary a lot concerning the type of light source they have. 18

2. Luminaires 19

2. Luminaires Luminaire efficacy factor (LEF), also known as luminaire efficacy ratio, measures the lumen output of a fixture as a function of input power, enabling comparisons between fixtures. The higher the LEF, the more efficient the luminaire. 20

2. Luminaires Classification The C. I. E. luminaire classification, is based on three basic properties of luminaires: 1. The extension to which the luminaire light is distributed along a path: the “throw” of the luminaire. 2. The amount of lateral dissemination of light, widthways of a path: the “spread” of the luminaire. 3. The reaching of the installation to control glare produced by the luminaire: the “control” of the luminaire. 21

2. Luminaires Classification The throw is defined by the angle ϒmax which forms the axis of the beam with the vertical plane going downwards. The axis of the beam is defined by the direction of the angle bisector formed by two directions of 90% Imax in the vertical plane of maximum identity. Luminous Intensity polar curve in the plane which contains the maximum luminous intensity, indicated by the angle used to determine throw. 22

2. Luminaires Classification The spread is defined by the positioning of the line, running parallel to the axis of the path. Virtually, it does not touch the furthest side from the 90% Imax on its path. The positioning of this line is defined by the ϒ 90 angle. 23

2. Luminaires Classification In this figure, the three degrees of throw and spread are shown. h - luminaire mounting height. 24

2. Luminaires Classification Control is defined by the specific index, the luminaire SLI, determined by the features of the luminaire. Where, Ixx - Luminous intensity at an elevation angle of xx°, in a parallel plane to the axis of the roadway (cd). A - Light emission area for the luminaires (m 2) projected on the direction of the elevation at 76°. 25

2. Luminaires Classification Control is also classified into three levels: • SLI < 2 : limited control. • 4 ≥ SLI ≥ 2 moderate control. • SLI > 4 tight control. 26

3. Ballasts • Discharge lamps need a ballast to work • There are two types of ballasts: Electronic Ballasts and Magnetic Ballasts. • A ballast has two main functions. It starts the lamp and it controls lamp operation. Depending on their characteristics they can also: transform the voltage, dimming the lamp and correct power factor. 27

3. Ballasts Electronic ballasts • Control the starting voltage and the operating currents of gas discharge lamps. • Use solid-state technology to operate at much higher frequency ( about 30 k. Hz) resulting in energy conservation through lower power loss (compared with magnetic ballasts) and higher lamp efficacy. • These ballasts can also improve the power factor values close to 1. Ballasts Classes of Efficiency Class A 1 Dimmable electronic ballasts Class A 2 Electronic ballasts with reduced losses Class A 3 Electronic ballasts Class B 1 Magnetic ballasts with very low losses Class B 2 Magnetic ballasts with low losses 28

3. Ballasts Magnetic Ballasts • Use a magnetic reactance to control the electric current and to start the lamp. • Are an old technology, with a core of steel plates wrapped in copper windings. Joule losses that occur in the copper windings, and magnetic losses in the iron core, increase the power losses between 10 and 25%. This value will depend on ballast dimension and construction. 29

3. Ballasts Classes of Efficiency Class A 1 Dimmable electronic ballasts Class A 2 Electronic ballasts with reduced losses Class A 3 Electronic ballasts Class B 1 Magnetic ballasts with very low losses Class B 2 Magnetic ballasts with low losses Dimmable ballasts are classified A 1 if they fulfil the following requirements: - at 100% light output setting the ballast fulfills at least the demands belonging to A 3; - at 25% light output setting the total input power is equal to or less than 50% of the power at the 100% light output setting; - the ballast must be able to reduce the light output to 10% or less of the maximum light output. Magnetic ballasts conforming to energy efficiency scheme classes B 1 and B 2 have a thicker copper wire and an iron core subject to less power dissipation reducing internal losses. Electronic ballasts (A 1, A 2 and A 3) even reduce the power consumption of ballast lamp circuits to less than the rated power of the lamp at 50 Hz. This is caused by the increased lamp efficiency at high frequencies (>20 k. Hz), leading to about 10% less lamp power and a decrease of the ballast losses. 30

3. Ballasts • UPs • • The output of the lamps degrades more slowly Longer lamp lifetime Higher efficiency Lamp flicker is eliminated Multiple lamp operation (1 to 4) Electronic Ballast DOWNs • They can originate harmonic distortion • UPs • The materials can easily be recycled Small initial cost Magnetic Ballast • Less energy efficient • Heavier than electronic ballasts DONWs • Noisier than electronic ballasts 31

4. Drivers A unit that is located between the power supply and the LED module(s) in order to provide the LED module(s) with an appropriate voltage and current. The driver is also called electronic control gear. 32

4. Drivers The lifetime of an LED driver is determined by the lifetime of the individual electronic components inside. The weak link, normally are the electrolytic capacitors. The electrolyte inside is typically a gel that gradually evaporates over the life of the component. The evaporation rate depends upon the temperature inside the driver — which, in turn, correlates to the external temperature on the driver case. Higher operating temperatures speed evaporation and hence shorten the life of the capacitor. Semiconductor lifetime is also affected by the operating temperature. 33