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
Energy and Power
Anti Pumping And Lockout Relays
What is ANSI code for Antipumping relay? ANSI codes 94 or even 52 can be used. Relays can be divided into six functional categories shown below: Detect defective lines, defective apparatus, or other dangerous or intolerable conditions. These relays generally… Read more
Jan 23, 2012 | By Asif Eqbal
Medium Voltage
ABB MV Switchgear – Single Busbar Or Double Busbar?
Most switchgear installations used in industry with normal service conditions are based on single busbar arrangements. Compared to double busbar switchgear, single busbar switchgear is definitely easier to use, readily understood by operators, requires less space, and the total cost of installation… Read more
Jan 03, 2012 | By Edvard Csanyi
Medium Voltage
Internal arc testing of MV switchgear – IEC 62271-200 (part three)
Continued from: Internal arc testing of MV switchgear – IEC 62271-200 (part two) The following chapter describes the development of a new gas-insulated switchgear generation GHA [4] for primary distribution for internal arc testing according to IEC 62271-200. All tests… Read more
Dec 16, 2011 | By Edvard Csanyi
Energy and Power
Medium voltage circuit breaker operating sequence
Rated switching sequence according to IEC, O – t – CO – t’ – CO. (cf. opposite diagram): O – Represents opening operation CO – Represents closing operation followed immediately by an opening operation Slow: O – 3 min –… Read more
Nov 10, 2011 | By Edvard Csanyi
Energy and Power
Working Principle of Earth Leakage Circuit Breaker (ELCB) and Residual Current Device (RCD)
The operation of an earth leakage circuit breaker (or shorten ELCB) is based on the fact that the algebraic sum of the currents in any healthy single phase, three phase and three phase and neutral system is zero. This simply… Read more
Nov 07, 2011 | By Jignesh Parmar
