What is exciting current?

Exciting current, when used in connection with transformers, is the current or amperes required for excitation. The exciting current on most fighting and power transformers varies from approximately 10% on small sizes of about 1 KVA and smaller to approximately .5% to 4% on larger sizes of 750 KVA. The exciting current is made up of two components, one of which is a real component and is in the form of losses or referred to as no load watts; the other is in the form of reactive power and is referred to as KVAR.

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Definition of Friction and Brake

Friction is main bad effect of a motor. Friction reduce a motor efficiency. Friction mainly create in a motor for it’s corrosion or speed ratio on spin. In a motor flywheel adjusted in drive wheel. In a gear ratio it mainly depends on gear and flywheel transfer energy on drive wheel. In a car or heavy load carrier vehicle used spring for reduce vibration and friction reduce generally use oil especially used in lubrication. For friction reduce one should firstly should select a metal which is help to reduce corrosion that’s means high resistance corrosion. Brake is also more important issue for a vehicle for it speed is slow down. There are three types of brake such as electromagnetic, disc and drum brake. Kinetic energy change to heat energy a vehicle speed reduce. Most of the car and vehicle use hydraulic brake which based in 6 steps and depends on 6 parts. These six parts are valve, road wheel, pedal, cylinder and boost. Electromagnetic brake is more popular for it’s more fa...

Mechanism of Solar Collector for Flat Plate

Solar collector main theme is collect radiation from sun and it transfer to heat energy or electricity to other storage such as a battery. One can use various types of solar collector such as a disk, flat and tube in thermally. In solar collector radiation absorb but the amount of supply heat is greater than absorb of heat. Radiation is mainly depends on environment, place, temperature, sunlight and air. For running a turbine solar collector used for initially running. If a collector any one compare concentrating solar and non concentrating solar collector there have basic difference such as concentrating solar has more benefits because it received radiation in whole area. In 1950 two person whore they Hottel & Whillier give a new theme to us for flat plate solar collector which has more benefit. A flat plate solar collector has some gradient such as i...

Why Coal is limited for world people?

Coal is a natural source of energy. But has limitation in earth. Coal is made from based on carbon. And other metals also contain such as H (hydrogen), S (Sulfur), N (nitrogen), O(oxygen). Coal is harder than any other metal. Coal mainly found in Soil, By using coal and give high pressure people can produce high temperature which is used by people in various ways such as produce electricity. Coal is largest natural energy in world anthropogenic. By using coal there have create much amount of CO 2 (carbon die oxide) which more bad for our environment and polluted our air. By using the amount of pollution is more than using natural gas in produce of electricity. When produce 1 MH (Mega watt hour) produce electricity carbon die oxide produce about two thousands pounds by using coal. And when also same amount of electricity produce by using natural gas carbon die oxide produce one thousand pounds. For reducing the emission of CO ...

How to Calculate Heat Rate of Generator Engine?

Types of Power Plant (Technology) Natural Gas Based power plant technology Diesel power plant technology Heat Rate of Engine= Fuel Flow or Fuel burned * Fuel Heating Value / Power Output 1 Liter Diesel = 0.85 Kg Example: Heat Rate of Diesel Generator at 100% Load Engine Model- 2506A-E15TAG2 Engine Capacity=400 eKW Fuel Consumption=84 L = 71.4 Kg Electrical Energy Output = 400 KW Heating Value of Diesel = 42.5 MJ/Kg Heat Rate of Engine= Fuel Flow or Fuel burned * Fuel Heating Value / Power Output Heat Rate of Engine = 71.4 Kg * 42.5 MJ/Kg /400KW Heat Rate of Engine =7.58 MJ/KWH Heat Rate of Gas Generator at 100% Load Engine Model- VHP5904LTD Engine Capacity= 900 eKW Fuel Consumption= 271 Nm 3 Electrical Energy Output= 900 KW Fuel Consumption= 0.28 Nm3/KWH Heating Value of Natural Gas= 35.22 MJ/ Nm 3 Heat Rate of Engine= Fuel Flow or Fuel burned * Fue...

Packing, Seals and Gaskets

Packing, seal and gasket resists the flow of fluid from machinery face, head, joint and machinery gap or clearance. Packing materials: Fiber, asbestos, cotton, synthetic materials, plastic, Teflon, graphite etc. Packing structure: Twisted, Braided and Consolidated. Gasket: A gasket is a mechanical seal that fills the space between two mating surfaces, generally to prevent leakage from or into the joined objects while under compression. Gaskets allow " less-than-perfect " mating surfaces on machine parts where they can fill irregularities. Gaskets are commonly produced by cutting from sheet materials, such as gasket paper, rubber, silicone, metal, cork, felt, neoprene, nitrile rubber, fiberglass, or a plastic polymer (such as polychlorotrifluoroethylene) ...

what is the difference between long shunt and short shunt dc generator?

How do they differ from normal generator? Draw their V-I characteristics and explain them? In short shunt connection the shunt field is connected directly across the armature terminals and the armature connection equals the sum of the shunt field current plus the load current . In this instance the load current flow s through the series field winding so that the load current and series field current are one and same. In long shunt connection the voltage across the shunt field is the same as the terminal voltage of the generator and current in the armature will be the current in the series field. The armature current equals the shunt field current plus the load current. A shunt generator has the field circuit connected directly across the armature. As more devices connected in parallel the load on the generator increases that the generator current increases which...

Why a dc generator fails to build up voltage?

How can the problem be remedied : No residual magnetism, reversed field connection and high resistance of field circuit are responsible for the failure of build up process of a dc generator. The factors are explained below: No residual magnetism: For the starting build up process requires some residual magnetism in the magnetic circuit then no voltage will be generated that can produce current flow through field circuit. Reversed field connection: The voltage induced inside the coil of field circuit due to residual magnetism that can permit the flow of current. For the following direction of this flux will be created and the direction of this flux will be same direction as the residual flux. If the field connections are reversed the lines of flux produced by current flow will oppose the residual flux, as a result generate voltage will decrease rather than increase. So voltage build up process failed. Field circuit resistance ...

Therbligs and Basic 17 motion name of therblig

Therbligs : A graphical representation of the co-ordinated activities of an operators body members. These activities ar described in terms of basic or fundamental motions known as therbligs. At the time Frank Gilbreth was doing his work in the field of motion study, he also concluded that any manual activity could be described in terms of 17 fundamental motions. This comparable to our being able to describe every word in the English language in terms of some of the 26 letters of the alphabet. Each of these fundamental motions is called a Therblig. Basic 17 motion name of Therblig : Name of Therblig Letter abbreviation Search Select Grasp Transport empty Transport loaded ...

Which type of Battery connection Series or Parallel Connection is used for Diesel Generator?

Diesel Generator Battery Connection Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To remove the possibility of arching, remove the negative battery cable is first and attach the negative battery last. When using jumper cables to start the engine make sure to connect the cables in parallel Positive to positive and negative to negative. When using external electrical source to start the engine, turn the disconnect switch to the OFF position. Remove the key before attaching the jumper cables. To avoid damage to engine parts do not connect jumper starting or battery charging cable to any fuel system or electronic component. Battery Parallel Connection: The accompanying illustration shows a typical parallel battery connection. This arrangement doubles the cranking amperage. Battery Series Connection: This illustration sh...

Various Methods of Drawing Flow Nets

1. Hydraulic models: a. Streamlines can be traced by injecting a dye in a seepage model or Heleshaw apparatus. b. They by drawing equipotential lines the flow net is completed. 2. Analytical Method: a. It is only applied to problems with simple and ideal boundaries conditions. b. The equation corresponding curve ǿ and Ѱ are first obtained and the same are plotted to give the flow net pattern for the flow of fluid between the given boundary shape. 3. Electrical Analogy Method: This method based on the fact that the flow of fluids and flow of electricity through a conductor are analogus. These two systems are similar in the respect that electric potential is analogus to the velocity potential. The electric current is analogus to...

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