ELECTRICAL UTILISATION AND TRACTION

1. ELECTRICAL UTILISATION&TRACTION IIDEEE IV SEM Subject code:EE-403 Prepared by: V.C.SEKHAR M.Tech

2. Introduction As we know that almost all human activities depends on light. Sun is a prime natural source of light but artificial lighting plays almost main role in our daily life. These artificial lights are produced by mechanical lamps and electrical lamps. But due to poor performance the mechanical light are totally replaced by electrical lights. The electrical lighting are mainly used for decorative purpose, advertising, traffic control , medical field and street lighting etc. 11/03/2013

3. Electrical Lighting Electrical lighting has following advantages : 1. Cleanliness 2. Easy to control 3. Economical 4. Easy to handle 5. Steady output 6. Better reliability 7. Suitable for almost all purposes etc. 11/03/2013

4. Sensitivity of Human Eye As we know natural light consists of seven colors having different wavelengths. The average human eye is most sensitive to a wave length of 5500 0A. The relative sensitivity of eye for a particular wave length is the visual effect produced by the light on the average human eye as compared with the effect of light having wave length 5500 0A on human eye. 11/03/2013

5. Sensitivity of Human eye This is also known as Relative luminosity Factor. 11/03/2013

7. Terms used in Illumination 1. Light 2. Luminous flux 3. Lumen 4. Plane angle 5. Solid angle 6. Steradian 7. Candle power 8. Luminous intensity reduction factor 9. Glare 10.Lamp efficiency 11/03/2013

8. light • That part of radiant energy from a hot body which produced the visual sensation on human eye is called light. 11/03/2013

9. Luminous Flux • The total quantity of radiant energy per second responsible for visual sensation from a luminous body is called Luminous Flux. • It is represented as F of Ø and measured in lumens. 11/03/2013

10. Lumen • It is the unit of luminous flux. One lumen is defined as the luminous flux emitted per unit solid angle from a point source of one candle power. 11/03/2013

11. Plane Angle The angle subtended at a point by two converging lines lying in the same plane is called plane angle. It is measured in radians and equal to the ratio of the length of the arc too its radius, θ = arc/ radius = l/ r radians 11/03/2013

12. Solid Angle The angle subtended by the partial surface area of a sphere at its centre is called as solid angle. It is measured in steradians and equal to the ratio of area of the surface to the square of radius of sphere, ω = area of surface/ square of radius = A/ r2 steradians 11/03/2013

13. Steradian • the unit of solid angle. One steradian is defined as the solid angle that is subtended at the centre of a sphere by its surface having area equal to radius square, ω = surface area/ (radius)2 = r 2 / r2 = 1 steradian 11/03/2013

14. Candle Power • The light radiating capacity of a source is called its candle power. The number of lumens given out by a source per unit solid angle in a given direction is called its candle power. It is denoted by C.P. Total flux emitted = CP X solid angle = 1 X 4π = 4π lumens = 4π lumens 11/03/2013

15. Luminous Intensity • Luminous intensity in any particular direction is the luminous flux emitted by the source per unit solid angle in that direction. • It is denoted by I and its unit is candela or candle power (CP) . • Luminous intensity of source in a particular direction, I = φ / ω 11/03/2013

17. light • That part of radiant energy from a hot body which produced the visual sensation on human eye is called light. 11/03/2013

18. Luminous Flux • The total quantity of radiant energy per second responsible for visual sensation from a luminous body is called Luminous Flux. • It is represented as F of Ø and measured in lumens. 11/03/2013

19. Lumen • It is the unit of luminous flux. One lumen is defined as the luminous flux emitted per unit solid angle from a point source of one candle power. 11/03/2013

21. Solid Angle The angle subtended by the partial surface area of a sphere at its centre is called as solid angle. It is measured in steradians and equal to the ratio of area of the surface to the square of radius of sphere, ω = area of surface/ square of radius = A/ r2 steradians 11/03/2013

22. Steradian • the unit of solid angle. One steradian is defined as the solid angle that is subtended at the centre of a sphere by its surface having area equal to radius square, ω = surface area/ (radius)2 = r 2 / r2 = 1 steradian 11/03/2013

23. Candle Power • The light radiating capacity of a source is called its candle power. The number of lumens given out by a source per unit solid angle in a given direction is called its candle power. It is denoted by C.P. Total flux emitted = CP X solid angle = 1 X 4π = 4π lumens = 4π lumens 11/03/2013

24. Luminous Intensity • Luminous intensity in any particular direction is the luminous flux emitted by the source per unit solid angle in that direction. • It is denoted by I and its unit is candela or candle power (CP) . • Luminous intensity of source in a particular direction, I = φ / ω 11/03/2013

25. Illumination When light falls on a surface, it becomes visible, the phenomenon is called as illumination. It is defined as luminous flux falling on a surface per unit area. It is denoted by E and measured in lumen per square meter or meter- candle. E = Ф / A lux 11/03/2013

26. Lux One meter candle or lux is defined as the illumination produced by a uniform souce of one CP on the inner surface of a sphere of radius one meter. 11/03/2013

27. Lamp Efficiency It is defined as the visible radiations emitted by it in lumens per watt. Usually, the light sources do not radiate energy only in the visible spectrum. The radiant energy is also accompanied with infrared and ultra violet radiations. Sun light produces majority of radiations in the visible spectrum. The tungsten lamp produces small radiations so its efficiency is very poor. 11/03/2013

28. Lamp efficiency The efficiency of fluorescent lamp is more than tungsten lamp. 11/03/2013

29. Glare In the human eye, the opening of pupil is controlled by its iris which depends upon the intensity of light received by the eye. If the eye is exposed to a very bright source of light, the pupil of the eye contracts automatically in order to reduce the amount of light admitted and prevent damage to the retina. This effect is called glare. Glare is defined as the brightness within the field of vision of such a character so as to cause discomfort and interference in vision. 11/03/2013

30. How is Light Produced? Methods of Light Production

31. Luminous: An object which produces visible light Ex: candle, sun, flashlight, neon lights Non-luminous: An object which does not produce visible light; reflects or allows light to pass through allow us to see the object Moon, stained glass windows, coloured liquids, textbook, pen, etc.

32. Electrical method of producing Light Following are the methods of producing light : 1. By developing arc between two electrodes 2. By passing a current through a filament 3. By electric discharge through vapors or gases 11/03/2013

33. Methods of Light Production • Incandescence: – Production of light as a result of high temperature – Ex: Candle, incandescent light bulb

34. glass bulb Conducting wire tungsten filament inert gas (argon) electrical contact

35. How does an incandescent light bulb work?  The light bulb produces light when the fine coil of tungsten (called a filament) is heated  Temperature rises to ~2500°C when an electric current passes through it!  Tungsten is used because other metals at this high of a temperature melts  Incandescent lamps are very inefficient sources of light because most energy is lost as heat  Filled with a non-reactive gas because a more reactive gas could combust

36. • Fluorescence: – Immediate emission of visible light as a result of absorption of ultraviolet light – Ex: fluorescent lights

37. How does a fluorescent light bulb work? 1. A long cylindrical glass tube is filled with mercury vapour 2. Electrical current flows through the tube, from the electrode which donates electrons to the electrode which accepts electrons 3. As the current flows through the tube, it excites atoms of mercury 4. The excited mercury atoms produce ultraviolet light (which we cannot see) 5. The UV light strikes the fluorescent coating on the inside of the glass tube and releases visible light

38. How does a fluorescent light bulb work? Electrical contact Electron discharge Glass tubing Fluorescent coating Mercury (Hg) atoms Electrode (electron donor ) Electrode (electron acceptor) Visible light produced

39. • Electric discharge: – Production of light by passing an electric current through a gas – Aurora borealis, lightning, neon signs

40. • Phosphorescence: – Production of light by absorbing UV light and emitting visible light over an extended period of time – Ex: glow in the dark stickers which contain phosphors

41. Lighting Schemes Lighting schemes are classified according to the location, requirement and purpose etc. are as under : 1. Direct lighting 2. Indirect lighting 3. Semi direct lighting 4. Semi indirect lighting 5. General lighting 11/03/2013

42. Direct Lighting As is clear from the name, in this system almost 90 to 95 % light falls directly on the object or the surface. The light is made to fall upon the surface with the help of deep reflectors. Such type of lighting scheme is most used in industries and commercial lighting. Although this scheme is most efficient but it is liable to cause glare and shadows. 11/03/2013

44. Indirect Lighting In this system, the light does not fall directly on the surface but more than 90 % of light is directed upwards by using diffusing reflectors. Here the ceiling acts as a source of light and this light is uniformly distributed over the surface and glare is reduced to minimum. It provides shadow less illumination which is useful for drawing offices and composing rooms. It is also used for decoration purposes in cinema halls, hotels etc. 11/03/2013

46. Semi direct Lighting This is also an efficient system of lighting and chances of glare are also reduced. Here transparent type shades are used through which about 60 % light is directed downward and 40 % is directed upward. This also provides a uniform distribution of light and is best suited for room with high ceilings. 11/03/2013

47. Semi indirect Lighting In this system about 60 to 90 % of total light is thrown upward to the ceiling for diffused reflection and the rest reaches the working plane directly. A very small amount of light is absorbed by the bowl. It is mainly used for interior decoration. 11/03/2013

48. Semi indirect Lighting

49. General Lighting This system employs such type of luminaries, shades and reflectors which give equal illumination in all the directions. 11/03/2013

50. Law of Illumination The illumination on a surface depends upon the luminous intensity, distance between the source and surface and the direction of rays of light. It is governed by following laws : 1. Inverse square law 2. Lambert’s cosine law 11/03/2013

51. Inverse Square Law It states that the illumination of a surface is inversely proportional to the square of the distance of the surface from the source. E α 1/d2 11/03/2013

52. Lambert’s Cosine Law This law states that the illumination on any surface is proportional to the cosine of angle between the direction of the incident flux and perpendicular to the area. E = 1/d2 cos θ 11/03/2013

53. Factors required for Light Scheme The following factors are required to be considered while designing the lighting scheme : 1. Illumination level 2. Quality of light 3. Co efficient of utilization 4. Depreciation factor 5. Space height ratio 11/03/2013

54. Illumination Level This is the most vital factor in deciding the number and wattage of luminaries so that we are able to see and recognize the object properly. Colors of the body have the property of reflecting the light in different proportions, degree of illumination, its distance from the viewer, contrast between the object to be seen and its surroundings. 11/03/2013

55. Illumination Level Type of work recommended illumination level Offices 100-400 lumens/ meter square Schools 250-400 lumens/ meter square Industry 1000 lumens/ meter square Shops 250-500 lumens/ meter square Hotels 80-100 lumens/ meter square Hospitals 250-3500 lumens/ meter square 11/03/2013

56. Quality of Light This means that the illumination should not be harmful to the viewers. It should be glare free, shadow less and contrast free. Direct glare from the source of light is most common factor. Presence of polished and glassy surface will cause indirect glare unless diffused light is used. Hard and long shadows can be avoided by using a large number of lamps and adjusting the mounting height. 11/03/2013

57. Co – efficient of Utilization A surface to be illuminated receive light either directly from the lamps or reflected from the ceiling and walls or both. In this case, the total flux reaching the surface will never be equal to the flux emitted by the lamp, due to absorption by reflectors, ceiling and walls. Utilization factor = lumens reaching at the working place total lumens emitted by the source Usually it varies from 0.5 to 0.8. 11/03/2013

58. Depreciation Factor The total flux emitted by the source and its fitting may be reduced due to deposition of dust upon the surfaces. Similarly quantity of light reflected from the ceiling and walls also decreases with the passage of time. This is called as depreciation facto. Usually it varies from 1.3 to 1.6. 11/03/2013

59. Space Height Ratio The ratio of space (horizontal distance ) between the two adjacent lamps to the vertical height of the lamps above the working plane is called space height ratio. So the distance between the lamps is not too much. An ideal scheme could be when there is large number of small size lamps are used also it increases the cost of installation. So the space height ratio is 1 to 1.5. 11/03/2013

60. Space Height Ratio The ratio of space (horizontal distance ) between the two adjacent lamps to the vertical height of the lamps above the working plane is called space height ratio. So the distance between the lamps is not too much. An ideal scheme could be when there is large number of small size lamps are used also it increases the cost of installation. So the space height ratio is 1 to 1.5. 11/03/2013

61. ELECTRICAL UTILISATION&TRACTION IIDEEE IV SEM Subject code:EE-403 Prepared by: V.C.SEKHAR M.Tech

63. UNIT-2 ELECTRIC HEATING

64. WHAT IS ELECTRIC HEATING ? WHAT IS THE PRINCIPLE BEHIND IT ? Electric heating is any process in which ELECTRICAL ENERGY is converted to “HEAT ENERGY”. Electric heating works on the principle of ”JOULE HEATING” (an electric current through a resistor converts electrical energy into heat energy.)

65. INTRODUCTION Electrical heating is based on the principle of that when electric current passes through a medium heat is produced. Let us take the case of solid material which as resistance ‘R’ ohms and current flowing through it is I amps for ‘t’ seconds than heat produced in the material will be H=I²Rt Joules.

66. • Modes of heating: a) Conduction b) Convection c) Radiation

67. • REQUIREMENTS OF HEATING: • It should have; a. High specific resistance b. High melting point c. Should not oxidize at electrode temperature d. Should not low temperature coefficient e. Positive temperature coefficient f. High ductility and flexibility g. High mechanical strength

68. • TYPES OF HEATING MATERIAL:

69. • Applications: 1. DOMESTIC PURPOSE: • Hot plates for cooking • Room heaters • Immersion heaters for water heating • Electric irons • Electric toasters • Electric ovens for baking etc. 2. INDUSTRIAL PURPOSES: • Melting of metals • Moulding of glass • Heat treatment processes • Baking of insulators • Enamelling of copper wires etc.

70. • Advantages of heating: 1. Cleanliness 2. Absence of flue gases 3. Ease of control 4. Better working conditions 5. Ease of adaption 6. Very high efficiency of utilization 7. Uniform heating 8. Heating of non-conducting materials 9. Cheap furnaces 10. Nolimit to upper maximum temperature

71. CLASSIFICATION OF ELECTRIC HEATING  Power Frequency Heating Resistance heating o Direct resistance heating o Indirect resistance heating Arc heating o Direct arc heating o Indirect arc heating  High Frequency Heating Induction heating o Direct core type o Core less type Dielectric heating

72.  POWER FREQUENCY HEATING In this method, electrical power is directly utilised to heat substance i.e., standard frequency of the power supply is used to heat the substance.  RESISTANCE HEATING In these method heating is done using the Ohmic loss in a highly resistive heating element. Ohmic losses cause the conversion of electrical energy into heat. This may be direct or indirect.

73. .  Direct Resistance Heating In direct resistance heating, the substance to be heated is the heating element itself. The flow of current offers a stirring action.  Indirect Resistance Heating In indirect resistance heating, heat is conducted and radiated from the heating element to the substance to be heated.

74.  ARC HEATING ⚫ Arc heating utilizes the energy of electric arc to heat substances. ⚫ In direct arc heating, the substance to be heated acts as an electrode for the formation of arc and is heated through direct contact with thearc. ⚫In indirect arc heating, heat is radiated from the arc between two sets of electrodes to the heating substance. Fig- DirectArc Heating Fig- IndirectArc Heating

75.  HIGH FREQUENCY HEATING It is a thermal process of heating , which is used to eliminate microorganisms. This provide the rapid and uniform heat distribution and therefore minimize quality reduction of products. TYPES OF HIGH FREQUENCY HEATING: 1) Induction heating a) Direct core types b) Core less type 2) Dielectric heating

76.  INDUCTION HEATING  It is heating of electrical conducting object generally metals by electromagnetic induction.  Eddycurrent are generated within metal and due to resistance of object lead to joule heating of metals. Fig- Induction Heating

77. . Direct Core Type: The direct core furnace is essentially a transformer in which charge to be heated forms the secondary this is designed for low frequency.  Core Less Type: No core is provided to core less induction furnace. A crucible of more convenient shape can be employed. For coreless induction furnace power is obtained from ordinary supply system and its frequency is converted to the higher value by means of oscillators. Fig: Direct Core Type Fig: Core Less Type

78.  DIELECTRIC HEATING  It is also is also known as electronic heating.  Radio frequency heating, and high-frequency heating, is the process in which a radio frequency (RF) alternating electric field, or radio wave or microwave electromagnetic radiation heats adielectric material.  Dielectric polarized by an applied electric field, when a dielectric is placed in an electric field. Fig: Dielectric Heating

80. Electrical Lighting Electrical lighting has following advantages : 1. Cleanliness 2. Easy to control 3. Economical 4. Easy to handle 5. Steady output 6. Better reliability 7. Suitable for almost all purposes etc. 11/03/2013

81. Sensitivity of Human Eye As we know natural light consists of seven colors having different wavelengths. The average human eye is most sensitive to a wave length of 5500 0A. The relative sensitivity of eye for a particular wave length is the visual effect produced by the light on the average human eye as compared with the effect of light having wave length 5500 0A on human eye. 11/03/2013

82. Sensitivity of Human eye This is also known as Relative luminosity Factor. 11/03/2013

86. Solid Angle The angle subtended by the partial surface area of a sphere at its centre is called as solid angle. It is measured in steradians and equal to the ratio of area of the surface to the square of radius of sphere, ω = area of surface/ square of radius = A/ r2 = 4π steradians 11/03/2013

87. light • That part of radiant energy from a hot body which produced the visual sensation on human eye is called light.it is denoted by letter Q and units is lumens-hr 11/03/2013

96. Lamp efficiency The efficiency of fluorescent lamp is more than tungsten lamp. 11/03/2013

97. How is Light Produced?

98. Luminous: An object which produces visible light Ex: candle, sun, flashlight, neon lights Non-luminous: An object which does not produce visible light; reflects or allows light to pass through allow us to see the object Moon, stained glass windows, coloured liquids, textbook, pen, etc.

99. Electrical method of producing Light Following are the methods of producing light : 1. By developing arc between two electrodes 2. By passing a current through a filament 3. By electric discharge through vapors or gases 11/03/2013

100. PRODUCTION OF LIGHT

101. ELASTIC COLLISION

102. EXCITATION

103. IONISATION

104. Methods of Light Production • Incandescence: – Production of light as a result of high temperature – Ex: Candle, incandescent light bulb

105. glass bulb Conducting wire tungsten filament inert gas (argon) electrical contact

106. How does an incandescent light bulb work?  The light bulb produces light when the fine coil of tungsten (called a filament) is heated  Temperature rises to ~2500°C when an electric current passes through it!  Tungsten is used because other metals at this high of a temperature melts  Incandescent lamps are very inefficient sources of light because most energy is lost as heat  Filled with a non-reactive gas because a more reactive gas could combust

107. • Fluorescence: – Immediate emission of visible light as a result of absorption of ultraviolet light – Ex: fluorescent lights

108. How does a fluorescent light bulb work? 1. A long cylindrical glass tube is filled with mercury vapour 2. Electrical current flows through the tube, from the electrode which donates electrons to the electrode which accepts electrons 3. As the current flows through the tube, it excites atoms of mercury 4. The excited mercury atoms produce ultraviolet light (which we cannot see) 5. The UV light strikes the fluorescent coating on the inside of the glass tube and releases visible light

109. How does a fluorescent light bulb work? Electrical contact Electron discharge Glass tubing Fluorescent coating Mercury (Hg) atoms Electrode (electron donor ) Electrode (electron acceptor) Visible light produced

110. • Phosphorescence: – Production of light by absorbing UV light and emitting visible light over an extended period of time – Ex: glow in the dark stickers which contain phosphors

111. Glare In the human eye, the opening of pupil is controlled by its iris which depends upon the intensity of light received by the eye. If the eye is exposed to a very bright source of light, the pupil of the eye contracts automatically in order to reduce the amount of light admitted and prevent damage to the retina. This effect is called glare. Glare is defined as the brightness within the field of vision of such a character so as to cause discomfort and interference in vision. 11/03/2013

112. TYPES OF GLARE • DIRECT GLARE • INDIRECT GLARE • How to reduce glare By increasing the height of lamp By using reflectors

113. REQUIREMENTS OF GOOD LIGHTING • ILLUMINATION LEVEL 1. Size of the object 2. State of object 3. Contrast between object and back ground. • UNIFORMITY OF ILLUMINATION • ABSENCE OF GLARE • COLOUR OF LIGHT • ELIMINATION OF SHADOWS • CONTRAST

114. TYPES OF LAMPS WITH THEIR COLOUR OF LIGHT

115. TYPES OF LAMPS FOR DIFFERENT LIGHTING SCHEMES DOMESTIC LIGHTING INDUSTRIAL LIGHTING DECORATION LIGHTING ADVERTISEMENT LIGHTING STREET LIGHTING FLOOD LIGHTING

116. LAMPS FOR DIFFERENT SITUATIONS

117. Lighting Schemes Lighting schemes are classified according to the location, requirement and purpose etc. are as under : 1. Direct lighting 2. Indirect lighting 3. Semi direct lighting 4. Semi indirect lighting 5. General lighting 11/03/2013

118. Direct Lighting As is clear from the name, in this system almost 90 to 95 % light falls directly on the object or the surface. The light is made to fall upon the surface with the help of deep reflectors. Such type of lighting scheme is most used in industries and commercial lighting. Although this scheme is most efficient but it is liable to cause glare and shadows. 11/03/2013

120. Indirect Lighting In this system, the light does not fall directly on the surface but more than 90 % of light is directed upwards by using diffusing reflectors. Here the ceiling acts as a source of light and this light is uniformly distributed over the surface and glare is reduced to minimum. It provides shadow less illumination which is useful for drawing offices and composing rooms. It is also used for decoration purposes in cinema halls, hotels etc. 11/03/2013

122. Semi direct Lighting This is also an efficient system of lighting and chances of glare are also reduced. Here transparent type shades are used through which about 60 % light is directed downward and 40 % is directed upward. This also provides a uniform distribution of light and is best suited for room with high ceilings. 11/03/2013

123. Semi indirect Lighting In this system about 60 to 90 % of total light is thrown upward to the ceiling for diffused reflection and the rest reaches the working plane directly. A very small amount of light is absorbed by the bowl. It is mainly used for interior decoration. 11/03/2013

125. General Lighting This system employs such type of luminaries, shades and reflectors which give equal illumination in all the directions. 11/03/2013

127. There are 5 systems of artificial lighting: 1. DIRECT LIGHTING: 99-100 % of light is directed towards the working area. 2. SEMI-DIRECT: 10 – 40 % of the light is projected upwards. 3. INDIRECT: 99 – 100 % of the light is directed towards the roof. 4. SEMI-INDIRECT: Here 60 – 90 % of the light is directed upwards and the rest downwards. 5. DIRECT –INDIRECT: Here the light is directed equally upwards and downwards.

128. Law of Illumination The illumination on a surface depends upon the luminous intensity, distance between the source and surface and the direction of rays of light. It is governed by following laws : 1. Inverse square law 2. Lambert’s cosine law 11/03/2013

129. Inverse Square Law It states that the illumination of a surface is inversely proportional to the square of the distance of the surface from the source. E α 1/d2 11/03/2013

130. Lambert’s Cosine Law This law states that the illumination on any surface is proportional to the cosine of angle between the direction of the incident flux and perpendicular to the area. E = 1/d2 cos θ 11/03/2013

131. Factors required for Light Scheme The following factors are required to be considered while designing the lighting scheme : 1. Illumination level 2. Quality of light 3. Co efficient of utilization 4. Depreciation factor 5. Space height ratio 11/03/2013

132. Illumination Level This is the most vital factor in deciding the number and wattage of luminaries so that we are able to see and recognize the object properly. Colors of the body have the property of reflecting the light in different proportions, degree of illumination, its distance from the viewer, contrast between the object to be seen and its surroundings. 11/03/2013

133. Illumination Level Type of work recommended illumination level Offices 100-400 lumens/ meter square Schools 250-400 lumens/ meter square Industry 1000 lumens/ meter square Shops 250-500 lumens/ meter square Hotels 80-100 lumens/ meter square Hospitals 250-3500 lumens/ meter square 11/03/2013

134. Quality of Light This means that the illumination should not be harmful to the viewers. It should be glare free, shadow less and contrast free. Direct glare from the source of light is most common factor. Presence of polished and glassy surface will cause indirect glare unless diffused light is used. Hard and long shadows can be avoided by using a large number of lamps and adjusting the mounting height. 11/03/2013

135. Co – efficient of Utilization A surface to be illuminated receive light either directly from the lamps or reflected from the ceiling and walls or both. In this case, the total flux reaching the surface will never be equal to the flux emitted by the lamp, due to absorption by reflectors, ceiling and walls. Utilization factor = lumens reaching at the working place total lumens emitted by the source Usually it varies from 0.5 to 0.8. 11/03/2013

148. INDOOR LIGHTING SCHEMES • DRAWING HALLS • ASSEMBLY HALLS • FACTORY LIGHTING

151. OUTDOOR LIGHTING SCHEMES • FLOOD LIGHTING • STREET LIGHTING

153. • //PROBLEMS ON ILLUMINATION ENGINEERING//

154. THANK YOU FOR UR ATTENTION

155. THANK YOU FOR UR ATTENTION

ELECTRICAL UTILISATION AND TRACTION

More Related Content

What's hot (20)

Similar to ELECTRICAL UTILISATION AND TRACTION (20)

Recently uploaded (20)

ELECTRICAL UTILISATION AND TRACTION