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Showing posts from December, 2012

Transformer

A transformer is an electrical device that takes electricity of one voltage and changes it into another voltage. Types of transformer: Ø   Step up Ø   Step down Ø   Isolating Ø   Variable etc. In Ashuganj power station, step up transformers are used to up the voltage and minimize transmission loss. Step up transformer:             The transformer in which voltage is increased is called step up transformer. Here the secondary has more turns than the primary winding.                                                                                       Figure: Transformer Main parts of transformer:                          Ø   Transformer shell Ø   Inner core Ø   Oil reservoir Ø   Cooling system Ø   Bushing Transformer shell: It is a shell generally made of cast iron or steel. It holds all the equipments inside of shell. In this sense it is an outer casing of transformer. Inner core:      Inner core means the main core of para

Basic Electrical Equipments

Generator: In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. The source of mechanical energy may be a reciprocating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion engine, a wind turbine, a hand crank, compressed air or any other source of mechanical energy.                                                                                   Figure: Electric generator.             Working principle: Electromagnetic induction is the production of voltage across a conductor moving through a magnetic field. So to get voltage, induction is very necessary. There are three conditions of proper induction. 1.       Conductor 2.       Magnetic fields and 3.       Relative motion between them.                                                       Figure : Electromagnetic induction A metallic wire is warped around a met

Thermal insulation

The pipe carrying the fluids at a high temperature should be properly insulated to avoid heat loss to the surroundings. The insulation material should have low co-efficient of thermal conductivity. It should not damage the pipe material and should be able to resist the temperature to which it is subjected. Generally “Rock wool” is used for thermal insulation inpower plant.                                                                                      Figure: Rock wool Lath Lord. Use of insulation: Serial No:                     Name of insulation                      Use 1 Magnesia: Magnesia contains 85% carbonate of magnesium and 15% of binder It is used for temperature up to 325 0 C 2 Asbestos fiber It is used for temperature up to 500 0 C 3 Mineral wool It is used for temperature up to 875 0 C 4 Expanded mica, hair felt an