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Showing posts from May, 2014

What is the cheapest source of renewable energy ? - Biomass

The conventional energy sources are rapidly depleting because of their excessive use in the modern world. And that's why energy or power generation sectors are very much interested in the utilization of renewable energy sources. The conventional energy source includes Natural Gas, Coal, Nuclear Energy, Crude oil etc. The price of these non-renewable fuels is almost touching the sky and getting

Transformer On load Tap changer

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ON Load Tap Changer There is always requirement of variation of voltage at secondary side even when load is connected then on load tap changer is used for the same. In case of on load tap changer tapping’s on the winding are brought out through a terminal board to separate oil filled compartment in which the on-load tap changer switch is housed. This tap changer is in the form of switch with motorized control. Handle is also provided in case of emergency. The essential feature of an on-load tap changing gear is the maintenance of circuit continuity throughout the tap changing operation. The circuit must not be broken otherwise there will be discontinuity of supply to load. Selector switch must not break current an additional separate oil filled compartment is used to house the diverter switch which breaks the load current by an interrupted arc. During that process carbon will be formed therefore oil in the diverter switch compartment must be prevented from mixing with oil in the main

Window A.C. and Split Air conditioner Working Principle and Circuits

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Air conditioner as name suggests is an electrically operated equipment which perform following functions:- 1. Temperature 2. Humidity 3. Quality of Air Air conditioners are becoming an integrated part of every household and Shops. An air conditioner makes your home cooler. It performs the function of cooling by drawing heat out of house/Shop and transferred the same hear to outdoor unit of AC and replaces the the air in house or shop by colder air. Inside a split Air conditioner there are following parts:- 1. Compressor 2. Condenser 3. Evaporator 4. Refrigerant  Compressor function is to circulate refrigerant through outdoor unit and converts the same from gas to liquid. The liquid is then forced through the indoor evaporator coil or cooling compartment.  The indoor unit’s fan circulates the inside air to pass across the evaporator fins. The evaporator’s metal fins exchange the thermal energy with the air around it.  In Evaporator the refrigerant turns from liquid into vapor, removing

Earthing as Per Indian Standard IS 3043:1987

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Earthing is very important part in every electrical system below are earthing pits design which are self explanatory:- Earthing with copper plate:- GI earthing system:- Pipe earthing:- Above Pics describe how to design earthing pits in electrical systems as per Indian Standard IS 3043:1987

Transformer Cooling Methods

Cooling of Transformer:- Due transformer operation i.e. conversion of energy at one voltage level to another voltage level there are losses occur in the winding and core of the transformer. These losses appear as heat which must be dissipated to the surroundings.  There are following coolants used for transformer cooling:- 1.     Air 2.     Oil Transformers which are using air as a coolant are known as Dry type transformers. On the other hand transformers which uses Oil as a coolant are called as oil immersed transformers. In Dry Type transformers heat generated is dissipated to surroundings through convection. In case of oil immersed transformers the heat generated inside the core and the windings is conducted across them to their surfaces. This heat is transferred by the oil to the walls of tank through convection. Finally the heat is transferred to surroundings by radiation and convection. Methods of cooling in Transformer:- There is large no. of methods used for cooling of transfor

Condenser Classification – De-aeration of Condenser

What is Condenser ? The primary purpose of the condenser is to condense the exhaust steam from the turbine and thus recover the high-quality feedwater for reuse in the cycle. In order for a steam power station to operate an efficient-closed cycle, the condensing plant, cooling water (CW) system, and associated pumps must extract the maximum quantity of heat from the exhaust steam of the

Jet Turbine working Priciple

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There are various designs are available in the market for working of Jet turbine but they all works on the same principle.   The most typical type nowadays may be the centrifugal flow turbine , instead of the more time axial flow turbine . A centrifugal turbine mostly differs within the stage of compression - air entering the turbine is tossed outwards because it passes within the spinning impeller. The environment hits against within the can and thus is compressed greatly, before passing in to the combustion chamber. This intense compression boosts the temperature from the air, along with the pressure. The fuel, that is usually oil , is introduced in to the combustion chamber like a very fine spray, and thus mixes easily using the now very compressed air. This fuel/air mixture will be captivated with a small glow plug, much identical to the one available on a couple or 4 cycle model plane engine. Because the fuel/air mixture ignites and explodes inside the chamber, it's fo

Understanding Ohm's law

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Every electrical engineer knows ohm's law:- Now what is Ohm's law? Ohm law is relationship between Voltage, Current and resistance. This law states that Potential difference across an ideal conductor is proportional to current through it. i.e. Voltage = IR where R is known as Proportionality constant and also know as Resistance to current flow across conductor. This is linear law. But very useful for solving simple circuits. Basic Electrical rule that follows Ohm law is shown in pic by very interesting means:- You will love to see how electrical basics can been represented in such an interesting manner. By Ohms law Voltage= Current X Resistance Voltage in Volts Current in Amp And Resistance in Ohm From above pic it is very clear that more the potential difference more will be current . Resistance always restricts flow of current. As Per Ohm's Law current flow through a conductor is directly proportional to voltage or Potential difference across two points and inversely pro

Rotating Machines temperature measurement methods; Motors temperature

In every machine it becomes always very important to measure temperature of machines as we know what is ambient temperature on which machine runs and running temperature of machine, machine breakdowns can be reduced. If we know that machine temperature is rising then we can easily understand from that there is some abnormality with the machine. So it becomes prime importance to know and monitor the temperature of machines irrespective of their design. In this article we will study about various methods of temperature measurement. Method of measurement of Temperature rise in Machines:- In machines there is very difficult to measure temperature as there is complex heat flow through materials having different conductivities and heat transfer co-efficient. There are following methods for temperature measurement in machines:- 1.     Thermometer method 2.     Resistance method 3.     Temperature detector 1.     Thermometer Method:- Thermometer is usually applied at surface of machine. There

Effect of Environment on Induction Motor

Effect of Environmental factors on Rating of Machines:- Every machine is designed to operate under some designed environmental aspects if there are variations in these conditions then machine performance parameters will change accordingly. There are so many examples for the same below is example for the same:- Effect of Temperature:- A 100 KW motor of intermittent rating might able to deliver 200 KW if continuously operated at the north pole where ambient temperature is -80 degree Celsius, as heat generated during motor running is not sufficient to overheat the motor under these ambient conditions. Similarly when motors are operated under high temperature condition motors rating will get reduced. Effect of altitudes:- At high altitudes air density is low and which will decrease the cooling effect of motor. This limit is negligible for elevations less than 1000 m above sea level. For heights greater than 1000m the rating of machine should be reduced accordingly as per table shown below

Transformer Off-Load Tap changer

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There are two types of Tap changers in Transformers depending upon the rating of transformer. Off-load Tap changer On-Load Tap changer If a tap-changer is designed to operate with the transformer out of circuit the it is called off-load tap changer. In that Transformer line should be disconnected completely before changing the tap. If a Tap changer is designed to operate with the transformer in circuit then it is called as On-Load tap changer i.e. tap can be changed even when transformer will remains in line. Read about about why and where tap changer required in Transformer:- Read here Let’s discuss here about off –load or No load Tap changer:- No Load Tap Changer:- This type of Tap changer is used for seasonal voltage variations as in Summers load on HT increases leads to drop in HT voltage so O/P can be increased by using Transformer Tap changer and in Winters when load get reduced HT voltage restores to normal levels then tap changer position can be done according to value of HT V