Protection
Overcurrent protection of transformer (NEC 450.3)
The overcurrent protection required for transformers is consider for Protection of Transformer only. Such overcurrent protection will not necessarily protect the primary or secondary conductors or equipment connected on the secondary side of the transformer. Introduction Overcurrent protection of transformers… Read more
Oct 08, 2012 | By Jignesh Parmar
Power Substation
Designing of HV Power Substation and Layout
Introduction Earthing and Bonding Substation Earthing Calculation Methodology (Earthing Materials) Layout of Substation Different Layouts for Substations (single busbar, mesh, 1 1/2 cb) Principle of Substation Layouts (spatial separation, maintenance zones) Components of a Substation (cbs, cts, isolators, insulation, transformers etc.) Substations are the… Read more
Oct 01, 2012 | By sprabakar22
Protection
Delayed Auto-Reclosing On EHV Systems
On highly interconnected transmission systems, where the loss of a single line is unlikely to cause two sections of the system to drift apart significantly and lose synchronism, delayed auto-reclosing can be employed. Dead times of the order of 5s-60s are commonly used…. Read more
Aug 11, 2012 | By Edvard Csanyi
Energy and Power
The major components of an Air Circuit Breaker and the Arc Interruption
The basic characteristics for air magnetic circuit breakers are maximum rationalization and constructional simplicity. The major components of such breakers are: the poles, the arc chutes, the base frame, the operating mechanism. The operating mechanism construction and parts are similar to that of… Read more
Jul 25, 2012 | By Edvard Csanyi
Medium Voltage
Field Inspection of New Medium-Voltage Switchgear
Step Description of what you should do 1.1 Check switchgear assembly for alignment, levelness, and tightness of all bolting. 1.2 Check all equipment for the removal of blocking, supports, temporary ties, and temporary jumper wires. 1.3 Check control power transformer… Read more
Jul 16, 2012 | By Edvard Csanyi
Energy and Power
Definitions from the Standard UL 489 (MCCB)
The requirements of this standard cover molded-case circuit breakers (MCCB), circuit breaker and ground-fault circuit-interrupters, fused circuit breakers, and accessory high-fault protectors. These circuit breakers are specifically intended to provide service entrance, feeder, and branch circuit protection in accordance with… Read more
Jul 12, 2012 | By Edvard Csanyi
Energy and Power
The Role of Circuit Breakers in LV/MV Power Systems
A circuit breaker is protective device which is designed to automatically open an electrical circuit thus preventing harm and damages to equipment and personnel. The damages are due to over load, short circuits and sometimes earth faults. Circuit breakers are made… Read more
Jul 09, 2012 | By Edvard Csanyi
Low Voltage
Assemblies of switchgear and control panels (3)
Continued from 2nd part of article: Assemblies of switchgear and control panels (part 2) Now coverage of distribution panels and switchboards will be presented including molded case circuit breakers (MCCB), safety switches, panelboards, multimetering equipment, ground fault circuit interrupters. Most of the… Read more
Jun 30, 2012 | By Edvard Csanyi
Energy and Power
Substation Switching Schemes
This technical article is intended to provide description and comparison of single line options for a DESN substation. The goal is to provide an analytical comparison for all options so that one can select the optimum solution considering cost, reliability,… Read more
Jun 26, 2012 | By Edvard Csanyi
Energy and Power
Circuit breakers classified by interrupting medium
A circuit breaker is defined as “a mechanical switching device capable of making, carrying and breaking currents under normal circuit conditions and also making, carrying and breaking for a specified time, and breaking currents under specified abnormal circuit conditions such… Read more
Jun 20, 2012 | By Edvard Csanyi
Energy and Power
MCB – Miniature Circuit Breaker Construction
The miniature circuit breaker (MCB) plays an important role in providing overcurrent protection and a disconnect means in electrical networks. Recent advancements in circuit breaker technology has increased breaker performance and protection. A breaker is a device designed to isolate a circuit… Read more
Jun 07, 2012 | By Edvard Csanyi
Electrical Lectures
Fundamental Characteristics of Circuit Breaker
The fundamental characteristics of a circuit breaker are: Its rated voltage Ue Its rated current In Its tripping current level adjustment ranges for overload protection (Ir or Irth) and for short circuit protection (Im) Current-level setting values which refer to the… Read more
Jun 05, 2012 | By Edvard Csanyi
Cables
Sizing of power cables for circuit breaker controlled feeders (part 1)
The following three criteria apply for the sizing of cables for circuit breaker controlled feeders: [fancy_header]I. Short circuit current withstand capacity[/fancy_header] This criteria is applied to determine the minimum cross section area of the cable, so that cable can withstand… Read more
May 10, 2012 | By Asif Eqbal
Energy and Power
Types of Residual Current Devices (RCD)
For domestic applications only the first five of the below listed residual current devices (RCD) need to be considered. For industrial and commercial buildings all of the classifications need to be considered. Table below aims to identify where each type… Read more
May 03, 2012 | By Edvard Csanyi
Energy and Power
Glossary of Medium Voltage Switchgear Terms
This glossary was published originally by Schneider Electric and it is intended to cover the meaning of many common words and phrases used in association with medium voltage switchgear. Many terms will also be applicable to low voltage switchgear as… Read more
Jan 25, 2012 | By Edvard Csanyi
