Energy and Power
Discrimination between residual current circuit breakers (RCCBs)
The operating principle of the residual current release is basically the detection of an earth fault current, by means of a toroid transformer which embraces all the live conductors, included the neutral if distributed. In absence of an earth fault,… Read more
Jan 11, 2013 | By Edvard Csanyi
Energy and Power
Lighting Circuits Connections for Interior Electrical Installations (3)
Continued from 2nd part: Lighting Circuits Connections for Interior Electrical Installations (2) The main reason for installing an emergency lighting system is to enable the building to meet fire safety legislation in a way that is visually acceptable and meets… Read more
Jan 02, 2013 | By Emmanouil Angeladas
Energy and Power
Flexibility and Reliability of Numerical Protection Relay
The first protection devices based on microprocessors were employed in 1985. The widespread acceptance of numerical technology by the customer and the experiences of the user helped in developing the second generation numerical relays in 1990. Conventional electromechanical and static… Read more
Dec 27, 2012 | By Jignesh Parmar
Energy and Power
Few Words About Digital Protection Relay
Around 1980s the digital relay entered the market. Compared to the Solid State Relay, the digital relay takes the advantages of the development of microprocessors and microcontrollers. Instead of using analog signals, the digital relay converts all measured analog quantities… Read more
Dec 24, 2012 | By Jignesh Parmar
Energy and Power
Inspection and Test Procedures for Metal-Enclosed Busways
Visual and Mechanical Inspection Electrical Tests Test Values Test Values – Visual and Mechanical Test Values – Electrical Tables: TABLE 100.12 – US Standard Fasteners Bolt-Torque Values for Electrical Connections TABLE 100.1 – Insulation Resistance Test Values Electrical Apparatus and… Read more
Dec 22, 2012 | By Edvard Csanyi
Energy and Power
Short-Circuit Switching Capacity Definition
The switching capacity is the r.m.s value of a current at a given power factor cosφ as well as a given rated voltage at which a switchgear or a fuse can still shut-off under specified conditions in an operationally safe… Read more
Dec 20, 2012 | By Edvard Csanyi
Energy and Power
The Solid State Relay (Static Relay) Overview
The static relay is the next generation relay after electromechanical type.The Solid Static relays was first introduced in 1960’s. The term ‘static’ implies that the relay has no moving mechanical parts in it. Compared to the Electromechanical Relay, the Solid… Read more
Dec 19, 2012 | By Jignesh Parmar
Energy and Power
The Good Old Electromechanical Protective Relay
This is the first generation oldest relaying system and they have been in use for many years. They have earned a well-deserved reputation for accuracy, dependability, and reliability. There are two basic types of operating mechanisms: Electromagnetic-attraction relay and Electromagnetic-induction… Read more
Dec 18, 2012 | By Jignesh Parmar
Energy and Power
Using Protective Relay For Fighting Against Faults
Introduction to Protective Relay Working Principle of Protective Scheme What is Relay? Functions of Protective Relay Desirable qualities of protective relaying Terminology of protective relay History of Protective Relay Types of Relays Types of Relay based on Relay Operation Mechanism… Read more
Dec 17, 2012 | By Jignesh Parmar
Energy and Power
Rogowski Coil Construction
Figure 1 shows the construction of a Rogowski coil, an air-core current transformer that is especially well suited to measuring ripple currents in the presence of a DC component or measuring pulsed currents. The raw output is proportional to the… Read more
Dec 13, 2012 | By Edvard Csanyi
Energy and Power
21 Safety Rules for Working with Electrical Equipment
A safe work environment is not always enough to control all potential electrical hazards. You must be very cautious and work safely. Safety rules help you control your and others risk of injury or death from workplace hazards. The good… Read more
Dec 12, 2012 | By Edvard Csanyi
Energy and Power
The Role of Fuse in Low Voltage Systems
A fuse is the very important protective device used to automatically disconnect a live circuit when a predetermined value of current & or time of predetermined current is exceeded. To simplify, fuse is actually the wire designed to melt, and thereby… Read more
Dec 11, 2012 | By Edvard Csanyi
Energy and Power
What Is The Basic Insulation Level (BIL)
Insulation levels are designed to withstand surge voltages, rather than only normal operating voltages. Since the transmission & distribution lines and substation equipment are protected by surge arresters draining the surges rapidly before the insulation is damaged, the arrester must… Read more
Dec 03, 2012 | By Edvard Csanyi
Energy and Power
Arrangements of LV Utility Distribution Networks (2)
Continued from the previous part: Arrangements of LV Utility Distribution Networks (1) In the past, an underground cable service or the wall-mounted insulated conductors from an overhead line service, invariably terminated inside the consumer’s premises, where the cable-end sealing box, the utility… Read more
Dec 01, 2012 | By Edvard Csanyi
Energy and Power
Arrangements of LV Utility Distribution Networks
In European countries the standard 3-phase 4-wire distribution voltage level is 230/400 V. Many countries are currently converting their LV systems to the latest IEC standard of 230/400 V nominal (IEC 60038). Medium to large-sized towns and cities have underground… Read more
Nov 30, 2012 | By Edvard Csanyi
