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EMCOLITE 174 DIMMING FLUORESCENT LIGHTING GUIDE Dimming a fluorescent lamp is d

EMCOLITE 174 DIMMING FLUORESCENT LIGHTING GUIDE Dimming a fluorescent lamp is different from a standard dimming circuit for GLS or Halogen Lamps. All of the dimming is managed by the ballast, not by the amount of voltage fed into the fitting as is the case with a traditional dimmer switch. Types of Dimming- Quick Guide Split into two main categories ANALOGUE - also known as 0-10v or 1-10v Switch type: A potentiometer, rotary, slider, with a separate control for turning on/off Advantages • An older system which some contractors feel more comfortable with • No interference with the switching of the luminaire. Disadvantages • A separate ‘dimming pair’ must be wired to each fitting in the circuit. • Limited control options, i.e. working with further applications, such as • Daylight linked dimming, or movement detectors. DIGITAL - also known as touch dim, switch dim, DSI or DALI Switch type: Bell push, push to make, retractive. Advantages • Simple installation, only a 4 core cable needed, as in an emergency lighting fitting, so sometimes no need to re-wire. • Greater control over dimming, down to as low as 1%. • Can be used in simple applications in conjunction with PIR’s and daylight sensors. Disadvantages • Interference can occur with switching, as control wire and switch wire run together. Analogue Dimming Analogue dimming is known as 1-10v dimming. This is because the dimmable ballast produces a 1-10v DC supply that can be increased or decreased by using a potentiometer (Also known as a high frequency push/rotary or slide dimmer switch). The DC supply can be increased or decreased by the switch to affect the resistance, hence the dimness of the lamp. This form of dimming requires a ‘dimming pair ’of cables to be run around to each fitting in the circuit in order for it to operate. Digital Dimming Digital dimming can be split into 3 sub sections - Switch dim/Touch dim, DSI and DALI Switch Dim/ Touch Dim This is the most popular and simplest option for digital dimming. It is operated by a push to make or retractive switch, which is then wired to each luminaire in the circuit via a 4 core cable consisting of a switched live, (via a push to make) neutral, earth, and an un-switched live. The switch controls the switching on and off of the luminaire, and also the dimming. Each push on the button sends a pulse to the ballast which then reads it and controls the lamp accordingly, Long push / Hold down-Dim down/up - Short push- Turns lamp on off DSI DSI stands for Digital Series Interface, and is a more controllable version of digital dimming. It enables the user to group luminaires, operate daylight linked dimming and other controlling options. This is wired using a dimming pair, run to each luminaire in the circuit (similar to the analogue system). DSI is am Tridonic based technology, and can be set up with a variety of control options and controllers, some of which are offered by other manufacturers, designed purely to work with the DSI ballast. DSI ensures there are no issues with interface from the switching of the luminaire and the dimming of the luminaire which can affect switch on. DALI DALI stands for Digitally Addressable Lighting Interface. This is a uniform standard employed by all ballast manufacturers that offer DALI ballasts. This system assigns an individual address to each luminaire, i.e. 001, 002, 003 and so on, for the complete installation. These ballasts can then be controlled via their address. This means that scenes can be set, groups controlled, all this is achieved through a desktop PC. It can be manually over ridden at a wall switch, or can be used in conjunction with a daylight sensor, or a PIR. DALI can offer 2 way communications between the fitting and the controller, and includes invaluable information such as ballast run time and operating status. Emcogroup can supply Analogue dimming control gear for the Emcolite modular compact fluorescent range from stock. Should you require any other format; we can usually make conversions within a week. Please contact for quote. sales phone: 01992 582033 sales fax: 01992 582044 EMCOLITE 175 world wide web: www.emcogroup.co.uk email: sales@emcogroup.co.uk The Principles of lighting Design One of the most important aspects of lighting design is to determine the number of luminaires required, based on the given illuminance value. The room utilisation factor method is a sufficiently accurate , and relatively simple procedure for finding the required number of luminaires (n) n = 1.25 x E x a x b ________________ ɸ x x hLB x hR Status of the lighting system The planning factor takes into account the reduction in luminous flux and soiling of light fittings. Planning factor =1.25 Rated illuminance E According to DIN 5035, Part 2 for the room in question, depending on the type of activity and usage. Room factor k The room factor k makes allowance for the shape of the room. K = a x b ________ h (a x b) a= Room width b= Room length H= Room height H = H – 0.85m Luminous flux ɸ Taken from the lamp catalogue, depending on the lamp to be used in the luminaire. Luminaire efficiency hLB Taken from the luminaire catalogue, depending on the luminaire selected. Room utilisation factor hR Taken from tables for the selected luminaire, on the basis of its classification. The effect of the light distribution in the room is covered by the value from the appropriate table. It is more common to use a recognised design program on your computer to enable accurate lighting design. Reflectances Reflectances properties of the rooms surfaces are measured in terms of the reflectanaces of the ceilings, walls and work surfaces or floors. Reflectances can be measured with the aid of reflectance tables. Modern computer design programs take all these factors into consideration to enable accurate lighting design. PRINCIPLES OF LIGHTING DESIGN EMCOLITE 176 EMCOLITE TECHNICAL Basic terminology of lighting design Luminous flux (lumen) Unit: Lumen (lm) Lumen is the measure of the perceived power of light. It differs from radiant flux, the measure of the total power of light emitted. Lumen is adjusted to reflect the varying sensitivity of the human eye to different wavelength’s of light. Luminous Intensity (candela) Unit: candela (cd) The candela is the unit of measurement for luminous intensity and it used to indicate how bright a lamp is in a given direction. It is used when specifying the performance of reflector lamps. Candela is a measure of the wave length- weighted power emitted by a light source in a particular direction per unit solid angle. Formula Luminous intensity (cd)= Luminous flux (lm) S. The surface resulted by the specific angle and the intensity I. Luminous intensity Solid angle (sr) Illuminance (lux) Unit: Lux (lx) Lux is the ratio the quantity of light or luminous flux incident on a surface to the area of that surface ( π r 2 ). Used when quantifying the amount of light falling onto a surface. Independent of the direction from which the luminous flux reaches the surface. One lumen of luminous flux, uniformly incident on: 1 square meter of area => produces 1 lux. Note: It is also referred to as a light level, illumination level or illumination value. Formula Illuminance (Lux) [lx]= Luminous flux (lm) Area ( π r 2 ) sales phone: 01992 582033 sales fax: 01992 582044 EMCOLITE 177 world wide web: www.emcogroup.co.uk email: sales@emcogroup.co.uk EMCOLITE TECHNICAL Colour temperature Unit: Kelvin (K) The specific colour shown at a particular temperature is the colour temperature. The colour temperature is normally shown in units of absolute temperature, Kelvin [K]. Colour temperature is related to Planck’s law and to Wien’s displacement law. Higher colour temperatures (5000K or more) - cool colours (bluish white) Middle colour temperatures (3700-5000K) - neutral colours (nearly white) Lower colour temperatures (2600-3700K) - warm colours (yellowish white through red) The colour temperature of light source is the temperature of an ideal blabkbody that emits light of comparable due to that light source. When the blackbody is heated enough and begins to emit light, it becomes dull red. When more heat is applied, it glows yellow and then white, and finally blue. Like a piece of metal is heated, the colour of light of the metal emits will be changed in higher temperature. Colour Rendering Index (CRI) Visable Colour = CRI (Ra) The criterion here is the colour rendering property of a light source. It is called “general Colour Rendering Index”[Ra]. Colour Rendering Index (CRI) is a quantitative measure of the ability of a light source to reproduce the colours of differenr objects faithfully in comparison with an ideal or natural light source. The extent of which light is capable of making objects appear their true colour is known as colour rendering. A lamp’s value on the Ra scale is showing its Colour Rendering Index (CRI). The index from 0-100, for example, the incandescent has 100 Ra uploads/Management/ dimming-fluorescent-lighting-guide.pdf