Energy and Power
Application of Circuit Breakers in IT Networks
IT supplies are used to prevent that a ground fault leads to immediate disconnection of the affected circuit like in a grounded system. Although a first ground fault results in a displacement of the potential of the entire supply, continued… Read more
Nov 03, 2012 | By Edvard Csanyi
Electric Motor
Motors for Hazardous Areas
Electrical drives/motors that are operated in hazardous areas must be built and engineered so that they cannot become an ignition source. This applies not only to normal operating and starting, but also in case of faults, for example at stalled rotor. The… Read more
Nov 02, 2012 | By Edvard Csanyi
Protection
Transformer Differential Protection Principles
Similar to bus protections, transformers are protected by differential relays. Inter-winding faults (short circuits) and ground faults within power transformers can be detected by this protection scheme. Failure to detect these faults and quickly isolate the transformer may cause serious… Read more
Nov 01, 2012 | By Edvard Csanyi
Energy and Power
Application of 4-pole Switchgear Devices
The majority of low-voltage switchgear is equipped with three contacts in the main circuit, which switch three-phase loads in all poles. In some applications switchgear with four main poles is required, either for safety reasons or for an optimum solution… Read more
Oct 31, 2012 | By Edvard Csanyi
Energy and Power
Smart and safe protective shutdown of LV system with selectivity
From the point of view of the operational safety and reliability of an entire low-voltage installation, it is usually desirable to specifically isolate the part of a system affected by a short-circuit in order to prevent spreading of the fault. Selectivity… Read more
Oct 30, 2012 | By Edvard Csanyi
Transformers
Transformers Are Never Silent
Yes, we all know that transformers are never silent. This is actually quite impossible, but in an environmentally aware, highly regulated world, the issue is not the level of noise, but its nature – and it’s very important. Transformers emit… Read more
Oct 29, 2012 | By Edvard Csanyi
Cables
Short Overview of LV Cable Terminations
A termination is the electrical and physical connection of a cable end to a piece of equipment or another cable. A splice is the electrical connection of a cable end to another cable with the same cable number. Cable terminations (splices) are… Read more
Oct 27, 2012 | By Edvard Csanyi
Electric Motor
Industrial Applications of Brushless Servomotor
A synchronous machine with permanent magnets on the rotor is the heart of the modern brushless servomotor drive. The motor stays in synchronism with the frequency of supply, though there is a limit to the maximum torque which can be… Read more
Oct 26, 2012 | By Edvard Csanyi
Cables
Corrosion Types Encountered With Power Cables
Introduction Anodic Corrosion (Stray DC Currents) Cathodic Corrosion Galvanic Corrosion Chemical Corrosion AC Corrosion Local Cell Corrosion Other Forms of Corrosion There are numerous types of corrosion, but the ones that are discussed here are the ones that are most… Read more
Oct 25, 2012 | By Edvard Csanyi
Energy and Power
Safety Clearance Recommendations for Transformer
Clearance from Outdoor Liquid Insulated Transformers to Buildings (NEC) Clearance between Two Outdoor Liquid Insulated Transformers (NEC) Dry Type Transformer in Indoor Installation (NES 420.21) Dry Type Transformer in Outdoor Installation (NES 420.22) Non Flammable Liquid-Insulated Transformer in Indoor Installation… Read more
Oct 24, 2012 | By Jignesh Parmar
Cables
The Good, The Bad and The Ugly Cable Insulation
The fundamental understanding of cable insulation properties forms the foundation for assessment of cable operability. These same fundamentals provide the basis for evaluating whether various electrical and physical tests and measurements are meaningful, cost-effective, and warranted. They are a basis… Read more
Oct 23, 2012 | By Edvard Csanyi
Cables
Cable engineering in substations and power plants
Is it true that single core cable should be unarmored because eddy currents are induced in armor of single core cable which will cause additional losses? If true then why not three core cables also unarmored and why single core… Read more
Oct 22, 2012 | By Asif Eqbal
Electric Motor
Few Words About Three-Phase Alternator
The three-phase alternator, as the name implies, has three single-phase windings spaced such that the voltage induced in any one phase is displaced by 120º from the other two. A schematic diagram of a three-phase stator showing all the coils… Read more
Oct 20, 2012 | By Edvard Csanyi
Energy and Power
Testing and Commissioning of Current Transformer
This technical article is prepared to help the commissioning personnel effectively perform and carry out the testing and commissioning tasks on current transformers before taking the equipment to service condition. General testing procedures for the current transformers (CTs) described in… Read more
Oct 19, 2012 | By Edvard Csanyi
Transformers
Definitions of Voltage Transformer Parameters
Rated voltage factor Rated primary voltage (Up) Rated secondary voltage Accuracy power Accuracy class Voltage ratio error Phase or phase displacement error Rated thermal limiting output The voltage transformer must comply with the network specifications, this is essential. As with… Read more
Oct 18, 2012 | By Edvard Csanyi
