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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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) ...

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...

Maintenance Schedule for Clarke Fire Pump Engine

Maintenance Schedule for Clarke Fire Pump Engine Clarke Fire Pump Engine Daily Maintenance: · Battery check · Lube oil check · Radiator water check · Cleanliness · Fuel Check Clarke Fire Pump Engine Weekly Maintenance: · Air cleaner check · Battery check · Belts check · Coolant Hoses check · Coolant leaks check · Coolant levels and conditions check · Coolin...

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 ...

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 ...

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...

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...

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...

Boiler

Boiler Boiler: A steam boiler is usually a closed vessel made of steel. Its function is to transfer the heat produced by the combustion of fuel to water and ultimately to generate steam. Types of boiler: 1. Fire tube or smoke tube boiler 2. Water tube boiler Figure: Boiler...

“Equalizer connection is needed in lap winding armature but not in wave winding “ why ?

The equivalent circuit of a four point – pole dynamo with a simplex winding. The voltage induced in each path is assumed to both to be same and should be if the reluctance of each magnetic path is the same, so that the lines of flux cut by each inductor of each path are the same. However wear of the bearings or deflection of the armature shaft may cause the armature to be closer to some poles and farther from others, thus changing the length of the air gap, and therefore the reluctance of the magnetic circuits of the poles is not identical. This factors cause the voltage in the materials making up the magnetic circuit. These factors cause the voltage in each parallel path differ, and the unequal voltages in turn cause flow of a circulating current through the windings and brushes , undue heating of the armature and waste the power. To reduce the circulating current, points on the winding which should be at the same potentials are brought to the same potentials by c...

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