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
Time relays setting ranges explained in details
Time relays are used in control switching operations involving time delay. Most of these time relays have multiple time setting ranges and most of them are explained below. Time relays perform either on-delay or off-delay timing. An arrow is used… Read more
Apr 30, 2012 | By Edvard Csanyi
Electric Motor
Direct On Line (DOL) Motor Starter
Different starting methods are employed for starting induction motors because Induction Motor draws more starting current during starting. We use a variety of starters in order to protect the windings from being damaged by the high current flow that is… Read more
Apr 22, 2012 | By Jignesh Parmar
Electric Motor
5 steps to choose the best motor for your application
For line-operated motors, loads fall into three general categories: constant torque, torque that changes abruptly, and torque that change gradually over time. Bulk material conveyors, extruders, positive displacement pumps, and compressors without air unloaders run at relatively steady levels of… Read more
Dec 03, 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
Electrical Lectures
What is the difference between MCB, MCCB, ELCB, and RCCB
This technical article briefly describes the most common breaker-related protection devices in low-voltage applications: MCB, MCCB, ELCB, and RCCB. We’ll describe their main characteristics and limitations and try to solve some misunderstandings and differences that many young engineers mix up…. Read more
Oct 25, 2011 | By Jignesh Parmar
Low Voltage
How Low-Voltage Air Circuit Breaker Works?
A low-voltage circuit breaker is one which is suited for circuits rated at 600 volts or lower. One of the most commonly used low-voltage air circuit breakers is the molded case circuit breaker (picture above). A circuit can be connected… Read more
Oct 23, 2011 | By Edvard Csanyi
Energy and Power
Aluminium or copper busbar trunking? Myth busted!
Following years of copper being the material of choice for high power busbar trunking in the UK, yet aluminium reigning supreme in the rest of the world, Schneider Electric takes a look at the case for aluminium over copper busbar… Read more
Oct 19, 2011 | By Edvard Csanyi
Low Voltage
Types Of Electrical Power Distribution Systems You Should Know About
Electrical power is distribution either three wires or four wires (3 wire for phases and 1 wire for Neutral). Voltage between phase to phase called Line Voltage and voltage between phase and neutral is called Phase Voltage. This forth wire… Read more
Sep 19, 2011 | By Jignesh Parmar
Energy and Power
Fuses – Principles of design and operation
A fuse consists of a replaceable part (the fuselink) and a fuse holder. Examples of fuse holders are shown in Fig. 1. The simplest fuselink is a length of wire. It is mounted by screw connections in a holder which… Read more
Jul 09, 2011 | By Edvard Csanyi
Electronics
Designing Raw DC Power Supplies
Every type of electrical or electronic apparatus needs a source of electrical energy to function. The source of electrical energy is called the power supply. The two main classifications of power supplies are line-operated power supplies (operated from a standard… Read more
Jul 03, 2011 | By Sa'ad Eddin
Energy Efficiency
Setting circuit breaker tripping with MS Excel spreadsheet
The protective unit of circuit breaker MUST fulfill: Instantaneous trip setting Im < Iscmin for a circuit-breaker Fusion current Ia < Iscmin for a fuse The protective unit (or device) must satisfy the two conditions: Its fault-current breaking rating must… Read more
Jul 02, 2011 | By Edvard Csanyi
Low Voltage
How residual current device (RCD) works?
The residual current device (rcd) is used to detect earth fault currents and to interrupt supply if an earth current flows. The main application is to prevent electrocution but RCDs can also be used to protect equipment, especially against fire…. Read more
Jun 11, 2011 | By Edvard Csanyi
Energy and Power
How contactor controls an electric motor?
When a relay is used to switch a large amount of electrical power through its contacts, it is designated by a special name: contactor. Contactors typically have multiple contacts, and those contacts are usually (but not always) normally-open, so that… Read more
Jun 01, 2011 | By Edvard Csanyi
