Air Break Switch

Definition: The switch whose contacts open in the air and quenching of an arc achieves by compressed air, such type of switch is called an air break switch.The air acts as a dielectric medium for the air-break switch. It is more effective and reliable as compared to another switch.The air break switch is operated manually…

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On-Load Tap-Changing Transformer

Definition: The transformer which is not disconnected from the main supply when the tap setting is to be changed such type of transformer in known as on-load tap changing transformer. The tap setting arrangement is mainly used for changing the turn ratio of the transformer to regulate the system voltage while the transformer is delivering…

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Protection Zone in Power System

Definition: Protection zone is defined as the part of the power system which is protected by a certain protective scheme. It is established around each power system equipment. When the fault occurs on any of the protection zones then only the circuit breakers within that zone will be opened. Thus, only the faulty element will…

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Metal Oxide Surge Arrester

Definition: The arrester which uses zinc oxide semiconductor as a resistor material, such type of arrester is known as a metal oxide surge arrester or ZnO Diverter. This arrester provides protection against all types of AC and DC over voltages. It is mainly used for overvoltage protection at all voltage levels in a power system.…

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Overhead Ground Wire or Earth Wire

Definition: The overhead earth wire or ground wire is the form of lightning protection using a conductor or conductors. It is attached from support to support above the transmission line and well grounded at regular interval. The earth wire intercepts the direct lightning strikes, which would strike the phase conductors. The ground wire has no effect…

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Switchgear

Definition: The apparatus used for controlling, regulating and switching on or off the electrical circuit in the electrical power system is known as switchgear.The switches, fuses, circuit breaker, isolator, relays, current and potential transformer, indicating instrument, lightning arresters and control panels are examples of the switchgear devices. The switchgear system is directly linked to the supply…

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Electrical Substation

Definition: The electrical substation is the part of a power system in which the voltage is transformed from high to low or low to high for transmission, distribution, transformation and switching. The power transformer, circuit breaker, bus-bar, insulator, lightning arrester are the main components of an electrical substation. Single Line Diagram of an Electrical Substation…

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Induction Voltage Regulators

Definition: The induction voltage regulator is a type of an electrical machine in which the output voltage may be varied from zero to a certain maximum value depending upon the ratio of turns in the primary and secondary windings.The primary winding is connected to the circuit which is to be regulated, and secondary is connected…

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Motor Protection Scheme

The various types of the protective relays are available for protecting the motor from faults. These relays sense the abnormal operating condition and make the circuit breaker to trip. The motors provide protection against faults in windings and associated circuits, excessive overload and short circuits, under voltages, phase unbalances and single phasing, phase reversal and…

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Induction Motor Protection System

The circuit diagram of the three-phase induction motors is shown in the figure below. Magnetic contactor starter essentially consists of a set of start and stop push buttons with associated contacts, overload and underload protective devices.The start push button is a momentary contact switch that is held normally open by a spring. The stop push…

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