Hydrogen Energy and Fuel Cells
Published on January 25, 2015
Hydrogen is a colourless, odourless, tasteless and flammable gas. Hydrogen has highest energy content per unit mass of 120.7 MJ/kg among known fuels
India's National Action Plan on Climate Change
Published on December 8, 2013
The following are the guiding principles of NAPCC—protecting the poor and vulnerable sections of society through an inclusive and sustainable development strategy, sensitive to climate change, achieving national growth objectives through a qualitative change in direction that enhances ecological sustainability, leading to further mitigation of greenhouse gas emission, devising efficient and cost-effective strategies for...
Energy Conservation
Published on December 1, 2013
As per Wikipedia, energy conservation refers to reducing energy through using less of an energy service. Energy conservation differs from efficient energy use, which refers to using less energy for a constant service . For example, using a incandescent bulb for lesser hours...
Energy Conservation Building Code
Published on November 24, 2013
Energy conservation aspect has not been a factor in building design in India. Buildings has been designed for its aesthetics, cost, uniqueness and saleability. This has resulted into tremendous increase in operating energy cost. Energy Ceonservation Building Code (ECBC) is a step forward for...
Energy Conservation Act
Published on November 17, 2013
Energy Management Center (EMC) was set up in 1989, with a mandate to promote energy efficiency and energy conservation. EMC created initial awareness of energy conservation. In 1997, Ministry of Power realized to strenghten EMC with statutory powers to promote energy conservation, considering the vast potential of energy saving and benefits of energy efficiency...
Utilization Factor of Liminaires
Published on November 10, 2013
Utilization factor tables of luminaries are...
Ventilation Systems
Published on November 3, 2013
Size of a ceiling fan should be chosen based on the actual working area and not on the basis of total room area so that unnecessary energy is not wasted. The design criterion based on number of air changes results in excess requirement. For a working zone with longer dimension...
Selection of Lamps
Published on October 27, 2013
The first step in the selection of lamp is to select the range of lamps satisfying the quality requirements such as colour properties, glare etc. and then select the lamp which has the highest efficacy within the group. Selection criterion are...
Lighting System Design
Published on October 20, 2013
Following items are helpful in selecting a proper luminaire: Utilization Factor, Photometric Data (Luminous Intensity Diagram & Zonal Luminous Flux Diagram) and Glare Data (Glare Quality Class & Glare Limitation Curves). y considering utilization factor along with its photometric data and glare data, complete design of a lightning system...
Carbon Trading
Published on October 13, 2013
Global warming is the increase in the average temperature of the Earth's near-surface air and the oceans since the mid-twentieth century and its projected continuation. Global surface temperature increased 0.74±0.18 °C during the 100 years ending in 2005. The Intergovernmental Pane...
Energy Scenario in India
Published on September 29, 2013
During the Eleventh five year plan (FY2007-12), nearly 55 000 MW was created against target of adding 78 700 MW. Before, in the Tenth plan period (FY02-07), capacity added was 21 100 MW against target of 41 100 MW. Additional 100 000 MW required by 2012 for which approximately ₹ 800 000 Cr. investment required...
Standards & Labeling
Published on September 22, 2013
Standards and Labeling has been identified as one of the key activities for energy efficiency improvements, for: having proven track record of being one of the most cost effective ways of reducing energy use; providing direct benefit...
Solar Energy
Published on September 15, 2013
India is a tropical country, where sunshine in greater intensity is available for longer hours per day. Annually about 5000 TW⋅h energy is incident over India's land area, with most parts receiving 4–7 kW⋅h∕m² on a typical day, with 250–300 sunny days in a year or 2300–3200 sunshine hours per year. The highest amount...
Maintenance of Fire System
Published on September 8, 2013
The fire detection, alarm and fire fighting equipment shall be kept in good working order at all times and maintenance schedule of the system should be drawn up by the maintenance unit and circulated to all the concerned for proper monitoring and execution. Fire safety officer shall be responsible for proper monitoring of the fire detection and fire fighting system and...
Fire Fighting
Published on September 1, 2013
As per IS 2190:2010, for all practical purposes, the basic types of fires can be grouped into following four classes: Class A fires, Class B fires, Class C fires and Class D fires. Class A fires are fires involving solid combustible material of organic nature such as wood, paper, rubber, plastics etc, where cooling effect of water is essential for extinguishment...
Fire Detection and Alarm System
Published on August 25, 2013
Prompt detection of an out-break of fire in its incipient stage and generation of alarm for quick and correct application of fire fighting media minimizes the loss from fire to a great extent. The purpose of a fire detection and alarm system is to detect a fire or its likelihood and generate audible and visual alarm to alert the building occupants...
Energy Audit
Published on August 18, 2013
Energy Conservation Act, 2001, defines Energy Audit as: “The verification, monitoring and analysis of use of energy including submission of technical report containing recommendations for improving energy efficiency with cost benefit analysis and an action plan to reduce energy...
Energy from Biomass
Published on August 11, 2013
Biomass is renewable, widely available, carbon-neutral and has the potential to provide significant productive employment in rural areas. Biomass is derived from numerous sources including by-product from sugar and wood industry, agricultural crops, forests etc. Biomass is an important source of energy and the most important fuel worldwide after coal, oil and natural gas...
Energy from Biogas
Published on August 4, 2013
Biogas is generated mainly from organic wastes such as cattle manure and other bio-degradable organic wastes through anaerobic digestion. The estimated potential of household biogas based plants based on animal wastes is 12 million...
Renewable Energy in India
Published on July 28, 2013
Renewable energy, is obtained from sources that are continuously replenished by natural processes. For example, solar energy, wind energy, bio-energy, hydropower...
Small Hydro Power
Published on July 21, 2013
Hydro power is one of the largest renewable energy resources being used for generation of electricity. SHP projects are classified based on capacity as follows...
Energy Recovery from Waste
Published on July 14, 2013
Increasing urbanization, industrialization and development activities result in generation of enourmous quantities of wastes in the urban and industrial areas. In India, each year about 30 Mt of municipal solid waste and about 4 400 million cubic meter of liquid waste are generated. Most wastes that are generated find their way into land and water bodies without proper treatment...
Wind Energy
Published on July 7, 2013
Wind energy has been in use in sailing and grinding and other mechanical applications for centuries. It has emerged as a viable renewable energy option with application in electricity generation, water pumping and battery charging. Generation of electricity has emerged as most...
Capacitors
Published on June 30, 2013
The All PP (APP) capacitors have been developed recently to overcome the limitations of metallized PP (MPP) capacitors. APP capacitors are already working very well in high voltage systems. These capacitors could not be introduced...
Power Factor Improvement
Published on June 23, 2013
Power factor is the ratio of the real power to apparent power and is either less than or equal to unity. In an AC circuit, current can either lag behind or lead to the voltage depending on the circuit elements and accordingly the power factor is termed as lagging or leading. Various causes can be attributed for low power factor...
Cables
Published on June 16, 2013
Selection of cable is based on the following factors: Current carrying capacity, Voltage drop...
Components of EA Set
Published on June 9, 2013
In telephone exchanges, the EA set is used for power requirement of essential loads like exchange load, pumps, lift, corridor and staircase lighting, FD and FF appliances and few essential lights on each floor. The main component of EA set are as follow...
Installation of Air Conditioning Plant
Published on June 2, 2013
A detailed programme for installation should be made and if the firm for carrying out the work is fixed, it should be discussed with him and targets finalized. This programme should at least decide dates for following events...
Factor Affecting Air Conditioning Plant Capacity
Published on May 26, 2013
Air conditioning is the simultaneous control of the temperature, humidity and pollution level within a limit of tolerance in a confined space. Such inside conditions may require to be maintained either for human comfort or for maintenance of equipment. The air conditioning load as such can be defined as that amount of heat which is instantaneously added or removed by the equipment. Heat flows from a hot medium to a colder medium and as such it is imperative that...
Air Conditioning Systems
Published on May 19, 2013
Air conditioning means the maintenaning the desired air conditions inside a confined space irrespective of outside atmospheric conditions. Air conditioning is basically provided to...
Servo Controlled Voltage Stabiliser
Published on May 12, 2013
The IE Rules 1956 stipulated that the supplier shall supply voltage at the commencement of supply limiting the variation to 6 % of the declared voltage in case of LV / MV distribution system and +6 % / -9 % in case of HV distribution system. But generally it is observed that very low voltage during the day & normal voltage during night in residential area and very low voltage during day and very high voltage during night in industrial areas. As most of the equipment are designed to operate for a voltage variation of...
IE Rules
Published on May 5, 2013
The Indian Electricity Rules, 1956 was made under section 37 of the Indian Electricity Act, 1910 (now repealed after enactment of the Electricity Act, 2003, but these rules themselves has been allowed to be in force till rules under section 53 of new Act are made). These Rules mainly deal with...
Stepper Motors
Published on January 13, 2013
Stepper motors operates on reluctance motor principle. The construction of these motors is quite simple. The stator has slotted structure equipped with two or more individual coils and rotor has salient projections but no coils. The rotor is designed with or without permanent magnet attached to its shaft and stepper motor is classified accordingly. If rotor has permanent magnet attached to its shaft, the motor is called permanent magnet stepper motor; otherwise it is called reluctance type stepper motor.
The input to the stator is in the form of pulses and on each pulse the rotor rotates in step by the desired angle. The angular shift per input pulse depends on the number of stator and rotor poles / projections. The train of pulses is generally...
Printed D.C. Motor
Published on January 6, 2013
Air gap is axial in such motors and the magnetic circuit completes through the ferromagnetic block at one end which also serves as the case of the ...
Tacho-generators
Published on December 30, 2012
Tacho-generators are used for measurement of angular velocity and give output voltage proportional to rotational speed. There are mainly two types of tacho-generators based on output voltage—d.c. tacho-generator and ...
Shaded Pole Induction Motors
Published on December 23, 2012
The shaded-pole induction motor usually has salient poles with one portion of each pole surrounded by a short-circuited turn of copper called a shading coil. Induced currents in the shading coil cause the flux in the shaded portion of the pole to lag the flux in other portion. The result is similiar to a rotating field moving in the direction from the unshaded to shaded portion of the pole causing induction of current in squirrel-cage rotor and a low starting torque is ...
Reluctance Motors
Published on December 16, 2012
The salient pole synchronous machine without any field or extiting winding runs at synchronous speed due to the reluctance torque and is termed Reluctance Motor. These motors find application in automatic control systems, telemetering devices and systems, signalisation circuits, sound film systems etc. requiring synchronised or simultaneous movements. Simplicity of construction is the main attraction of such motors. They are generally required in fractional kW sizes having ratings from a few watts to several hundreds of watts...
Rotating Amplifiers
Published on December 9, 2012
Power amplification may differ in magnitude with the variations in the value of ...
Servomotors
Published on December 2, 2012
In all servomechanisms, error signal is fed to an error-correcting device. This device then positions the output (valve, antenna, recorder pen etc.) so that it corresponds to the input. In order to do so, error-correcting device must be able to respond very quickly and have the ability to reverse direction. The most common device used in an error-correcting device is a servomotor. Servomotors can be either a.c. or d.c. While a.c. servomotors are used frequently, some applications require the use of d.c. servomotor
Selection of Pumps
Published on November 25, 2012
For selecting a pumping system, preliminary data should be carefully collected future increase in consumption of at least for next few years may also be considered. The following procedure is followed for selection of a pump...
Air Conditioning Load Estimation
Published on November 18, 2012
The actual instantaneous peak load requirement; type of control is determined by the condition to be maintained during peak and partial load. To estimate capacity of plant, an accurate survey of the load component of the space...
PAC Maintenance
Published on November 11, 2012
TROUBLE ANALYSIS FOR PACKAGE A.C. UNITS...
Window AC - Operation & Maintenance
Published on November 4, 2012
A typical refrigeration cycle for room air conditioners is shown in figure-I. Compressor takes in refrigerant vapour from the low pressure side, compresses it, and delivers it to the high pressure side of the system at higher temperature. In the condenser, discharged refrigerant...
Psychrometry
Published on October 28, 2012
Atmospheric air contains mostly a mixture of dry air and water vapour with some amount of other gases. Psychrometry deals with determination of thermodynamic properties of moist air and utilisation of these properties in analysis of conditions and processes...
Refrigerants
Published on October 21, 2012
A refrigerant should have low boiling point, its normal boiling point should be less than temp of refrigerant...
Scroll Compressors
Published on October 14, 2012
Scroll compressors offer high reliability, 100 % volumetric efficiency, low sound levels...
SMPS Power Plant
Published on October 7, 2012
The salient features & specification for SMPS based power plants are given in the table below. The figure of high frequency switched mode power supply is shown below...
Electrical Accidents
Published on September 30, 2012
The electrical equpments shall be installed such that they not only operate satisfactorily, but safely also. Every possible step should be taken to ensure safety and prevent accidents. The electrical accidents can be avoided...
Bus Bar
Published on September 23, 2012
Type of bus bars are open type and enclosed type. They are used...
Selection of Switchgear
Published on September 16, 2012
For selecting switchgears, in addition to normal factors current, voltage and frequency, the fault withstanding capacity is of prime importance. The allowable fault current depends on the capacity of supply company as well as the load and nature of fault. The fault level withstand capacity is known as rupturing capacity...
Constant Voltage Transformer
Published on September 9, 2012
These are basically servo stabilizers except for certain design aspects like very fast speed of correction and good normal and common mode noise suppression. Also they takes care of small dropout in the power for a few tens of milliseconds. They can be used for sophisticated electronic and electrical equipment like data processing equipments, elecro-medical equipments, electronic typewriters, telecom, VCR’s, PA systems, R&D labs etc. The typical specification for a CVT are given below...
Maintenance of Substation Equipment
Published on September 2, 2012
The switchgear and protective relaying system should be always alert to operate against an unexpectedly fault. Switchgear which was in quiescent state has to operate immediately. For such an operation, regular and detailed maintenance is necessary. The lack of maintenance may result in failure in operation...
Conductor Materials
Published on August 26, 2012
Specific gravity is the ratio of mass of any material to that of the same volume of water at 4oC. Density is the unit mass of material to that of volume at some reference temperature, usually 20oC. The numerical values, for all practical purposes, when density is expressed...
Instrument Transformers
Published on August 19, 2012
A transformer intended to supply measuring instruments, meters, relays and other similar apparatus is called an instrument transformer. These are, according to the quantity measured / monitored, further classified as...
Isolation Transformer
Published on August 12, 2012
Line transients and spikes are the main factors causing the wrong operation, erratic performance and inaccurate recording of the sensitive and sophisticated systems. Some of the effects of harmonics are...
Fire Protective Design of Buildings and Services
Published on August 5, 2012
State governments have enacted bylaws like Delhi Fire bylaws which are to be adhered to when constructing a high rise building. These bylaws have a statutory force. Designer must obtain and study the fire bylaws applicable to the particular area while planning. For the purpose of these regulations all buildings with height more than 15m are considered high rise buildings...
EA Maintenance
Published on July 29, 2012
Engine and alternator maintenance...
EA Capacity Selection
Published on July 22, 2012
For capacity calculation following procedure is applied...
Selection of Generating Sets
Published on July 15, 2012
Selection of generating set has to be done either by weight, by speed or by operating cycle...
Remote Operation of EA Set
Published on July 8, 2012
The digitisation of information technology allows vast amount of data to share the same communication channel and thus remote monitoring of various electrical installation can be done from a distant station by digitizing the parameters and communicating them. This can result in a lot of savings as any major breakdown can be averted and also maintenance ond operator costs...
Space Requirement for EA set
Published on July 1, 2012
The various accessories and equipment associated with an EA set for which space is required are: EA set, control panel, batteries and exhaust pipe...
Noise Control for EA Set
Published on June 24, 2012
With the down trend in the construction of departmental bulidings and going for private accomodation that too in load centres the need for saving in space requirement and noise and poluution control has increased. Also there is increased awareness of noise and pollution and these are to be kept under...
Generating Set Ventilation
Published on June 17, 2012
Air flow requirement of generating sets
Protection of Buildings against Lightning
Published on June 10, 2012
Protection of special structures, such as those exceeding 30 m in height, structures with roofs of high inflammability, buildings with explosive or highly inflammable contents, fences, trees and structures near the trees, structures supporting overhead electricity supply, telephone and other lines, structures with radio and television aerials, tents, metal scaffoldings and similar structures, tall metal masts, tower cranes and revolving and travelling structures, farm buildings in area of high lightning incidence, sports stadium, raised motorways, bridges, dwelling houses etc is done...
Lightning Mechanism
Published on June 3, 2012
Storm fronts are caused by the rising masses of warm air which expands at attitudes of upto 15 000 meters. At the centre, at about 6 000 meters, there is a powerful up draught, leading to the separation of charges. The presence of ice crystals and supercooled water droplets is closely associated with this formation of electric fields by separation of charges. Studies has demnstrated that hailstones bear negative charges and ice crystals bear positive charges. Being lighter, the ice crystals are carried by the up draught into the upper region of the cloud, whilst the hailstones fall into central regions of the cloud. So by this process, positive charges gets accumulated in the upper part and negative charges in the lower part...
Surges
Published on May 27, 2012
AC equipments are subjected to occasional lightning surges, switching surges and power frequency overvoltages. Upto voltage levels of 345 kV lightning surges are more dangerous and after that switching surges which are consided to be 2.7 p.u. wheareas lightning level is around 900 kV. Each equipment has certain assigned withstand levels as...
Lightning Arrester
Published on May 20, 2012
Requirements of a protective device: It should take no current during normal power frequency condition. The breakdown strength should be above the normal power frequency voltages and permissible over voltages (normally 5 to 10 %). Transient over voltages of value more than insulation flash over should be diverted...
Motors and their Protection
Published on May 13, 2012
The performance of a motors with various ratings vary as follows: slip varies directly as the output; starting torque and starting current vary inversely with the output. Frequent starting, reversing or heavy starting conditions may necessiate selection of a motor with an output rating higher than that normally required for continuous duty. The normal design criterion is that the motor shall be capable of two starts in succession at rated load torque, inertia and temperature, followed by a cooling period of 30 minutes before attempting a further starting sequence. At rated voltage, the motor can withstand 1.25 to 1.5 times the rated current for two minutes without suffering damage or permanent deformations...
Power Transmission by Vee Belt drives
Published on May 6, 2012
The polyster cords are replacing the conventional rayon cords as reinforcement members of industrial V-belt drives due to their higher power transmission capacity, lower belt stretch and higher dimensional stability. Another development in V-belt technology is the polychloropre (Neoprene, Bayprene etc) covering given to the base rubber belt. This jacket offers improved oil, heat and water resistance. The following is the typical data about polyster cord reinforced V-belts...
Power Transmission by Flexible Coupling
Published on April 29, 2012
The flexible couplings allow certain amount of parallel and angular misalignments and absorbs shock forces and hence they are preferred for many direct drives. The resilient tyre flexible coupling finds wide acceptance due to their desirable features of easy installation and maintenance. The details required for selection of coupling are...
Lift Operation
Published on April 22, 2012
The various controls like governing, starting, stopping, direction of motion, acceleration, speed and retardation are specified in IS 1860 : 1968. The generally used controls are given below...
Selection of Lift
Published on April 15, 2012
For selection of a passenger lift, following factors are considered: quality and quantity of service. Quantity of service is a measure of passenger carrying capacity during 5 minutes peak period of day and is also known as passenger handling capacity...
Installation of Lifts
Published on April 8, 2012
The important points which should be seen for satisfactory installation are: The working drawing showing the lift shaft and machine room details should be forwarded to the firm for the preparation of general arrangement drawing. The existing site dimensions of lift shaft, pit and machine room (if constructed ) should also be...
Features of Luminaires
Published on March 25, 2012
The quality of a finished product depends on the quality of raw materials used, workmanship and the manufacturing processes adopted. The main features of the luminaires should be: The luminaire should be efficient and be able to do its function of light distribution etc effectively, these properties depend upon the raw material used and the treatment and finishing done...
Uninterrupted Power Supply
Published on March 18, 2012
This is the era of information technology and so many sophisticated devices like PCs are used which are very sensitive to the supplies having spikes, power glitches, electrical noise, voltage sags and surges, waveform distortions, frequency variations and brown outs. The Computers needs clean and uninterrupted power. The most sensitive device of a computer is the disk drive which is driven by a motor whose speed depends upon the frequency. Thus frequency variation can cause reading errors, dropping or addition of a few bits...
Earthing
Published on March 11, 2012
Though electrical equipment are manufactured and installed to give trouble free service, failure of various components cannot be ruled out. Failure of electrical equipment or system happens due to: Insulation puncture, accidental contact between low & high voltage line, break-down of insulation between primary and secondary of a transformer and lightning strokes. These may cause...
EI Design
Published on March 4, 2012
The aspects for the design are energy conservation, flexibility, aesthetics and user friendliness. Appreciation of these factors will help in a systematic approach. Besides these items of general nature there are certain specific requirements also of a particular building / space which need to be taken into consideration while finalizing the design. Giving regard to general and specific requirements certain recommendations are made for each type of building and for each of the spaces constituting the building...
Aviation Obstruction Light
Published on February 26, 2012
High-rise buildings and structures such as chimneys, towers and smoke stacks are potential hazards to aircraft. As such mandatory provisions are in force for providing AOL's for hazard indication on structures above 6m in height...
Task Lighting
Published on February 19, 2012
When a general lighting proves inadequate for a specific task it is necessary to provide a licalised light in order to obtain the required type and degree of illumination. This can be grouped in four types...
Nuclear Energy
Published on February 12, 2012
France's 80 % of electricity is generated by 58 nuclear power plants. Nuclear production of electricity is steady and consistent while wind turbines (even at their best) generate power only 22 % of the time. Solar cells do not work in bad weather or darkness. Backup systems running on fossil fuels must keep running on standby so all the advantages of reduced emission are lost...
Estimation of Air Conditioning Work
Published on February 5, 2012
In order to procure and install package type air conditioning system, it is essential to have the details of various items of work involved and their quantities. To have the above information in consolidated form...
Design Conditions for Air Conditioning
Published on January 29, 2012
Design conditions to be maintained...
AC Ducting
Published on January 22, 2012
Factors affecting ducting: Shortest path to reduce power, material and space...
Synchros
Published on January 15, 2012
Synchros are a.c. electromagnetic devices that find wide application in servomechanism. However they can also be used as indicating instruments for registering mechanical displacements remotely.
There are four basic types of synchros—control transmitter (CX), control transformer (CT), control differential (CD), and control receiver (CR) ...
Magnetic Amplifiers
Published on January 8, 2012
Magnetic amplifiers utilize the concept of magnetic saturation. The heart of the magnetic amplifier is the saturated core reactor. When a saturated reactor is used in a circuit to amplify, the entire circuit becomes a magnetic amplifier...
Geothermal Energy
Published on January 1, 2012
Geothermal energy is an energy which is obtained from Earth. It is a pollution free source of energy and can be used continually. In the core of Earth, many radioactive materials like magma, uranium and thorium are found in abundance. As per the scientists, these can be sources...