Category: Power Systems
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Air Circuit Breakers: Features, Operation & Applications
Air Circuit Breaker Features & Operation An air circuit breaker employs atmospheric air as its interrupting medium. The arc is drawn between its contacts and extended via arc runners on to an arc chute where it is presented with a large cooling surface of arc splitter plates. These break the arc into a number of…
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Residential Electrical Wiring: Key Safety Considerations
Residential Electrical Wiring Overview A residential electric power service typically consists of a three wire ac system supplied by the local power utility company. A distribution transformer with a primary and two secondaries formed with a center tap on the secondary side is shown below: The distribution transformer is located on the utility pole, from…
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Electric Wiring Testing & Inspection Instruments Requirements
In order to carry out the verification process proficiently, the person conducting the inspection and test must be in possession of suitable test instruments. In this article, we look at some of the key requirements for electric wiring testing and inspection instruments. The commonly used instruments for electric wiring testing and inspection include: Nowadays we…
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Protective Relays: Function, Features & Operation
A protective relay is basically an electrical device that detects a fault in a power system and initiates the operation of the circuit breaker to isolate the defective section or component from the rest of the system. In other words, the prime function of protective relays is the timely and discriminative clearance of system faults.…
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SF6 Circuit Breakers: Features, Operation & Applications
Introduction Many modern designs of circuit breakers for use at transmission voltages utilize sulphur hexafluoride (SF6) gas both as an arc-interrupting/arc-quenching and a dielectric medium. At distribution voltages SF6 designs of circuit breakers are also used, however vacuum and bulk-oil circuit breakers still find a wide use as alternatives. The SF6 is an electron-negative gas…
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5 Causes of High-Voltage Switchgear Failures
Switchgear is basically equipment used switch ON or OFF generators, transmission lines, distributors and other equipment under both normal and abnormal conditions. Switchgear consists of switching and protecting devices such as switches, fuses, circuit breakers, relays, and so forth. In other words switchgear can be defined as equipment used for switching, controlling and protecting the…
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Main Types of Earthing Systems
Introduction The process of connecting the metallic frame i.e. non-current part of electrical equipment or some electrical part of the system such as the neutral point of the secondary side of the distribution transformers or the star point in a star connected system to the earth is called grounding or earthing. The potential of the…
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DC Transmission and Distribution
In most cases, the dc power is obtained from large ac power systems by employing converting mechanisms like synchronous or rotary converters, solid-state converters and motor-generator sets and so forth. The reasons why power generation is done in ac form rather than dc are: How DC Power is Obtained from AC Power A general layout…
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Major Technologies for Smart Grid Implementation
Smart grid can enhance legacy electric systems (i.e. the traditional electricity infrastructure) by improving reliability and security; additional smart grid can offer economic benefits and cost savings, environmental improvement, and so forth. Generally smart grid represents the integration of digital technologies, sensors and other information and communication technologies to enable more efficient and reliable electricity…
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4 Common Arrangements of Distribution Substations
The general technique of supplying large quantity of power to factories or other complexes is by means of high-voltage (HV) supply, typically at 11 kV, occasionally at 6.6 kV. The installation consists of a main substation at the point of entry, with HV cables to supply subsidiary substations located near load centres. Where necessary, it…