Electric Motor
Basics of 3-phase Induction Motor (part 2)
Continued from first part – Basics of 3-phase Induction Motor (part 1) For the purpose of standardization, the preferred rated voltages of three phase induction motor shall be in accordance with IS 12360: 1988. The voltages for three phases, 50… Read more
Aug 02, 2012 | By Asif Eqbal
Energy and Power
Overvoltages in the IT system
Electrical networks can be subject to overvoltages of varying origins. Some overvoltages, such as differential mode ones (between live conductors) affect all the earthing systems. This section is particularly concerned with common mode overvoltages, which mainly affect the IT system… Read more
Jul 26, 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
Electrical Lectures
Voltage vs. Current in a Resistor, Capacitor or Inductor
Elements in an electrical system behave differently if they are exposed to direct current as compared to alternating current. For ease of explanation, the devices have often been compared to similar every day items. Resistors in electrical systems are similar… Read more
Jul 03, 2012 | By Edvard Csanyi
Energy and Power
Autotransformer Connection Explained
An ordinary transformer consists of two windings called primary winding and secondary winding. These two windings are magnetically coupled and electrically isolated. But the transformer in which a part of windings is common to both primary and secondary is called… Read more
Jul 02, 2012 | By Jignesh Parmar
Energy and Power
Commissioning of Electrical Equipment
To verify system condition after has been energized with rated system (service) voltage for which it is designed. Also to ensure the protection, metering system for correct directionality. Multimeter Phase angle meter Phase sequence meter Communication software (if required) Before… Read more
Jun 25, 2012 | By Edvard Csanyi
Electric Motor
Soft Starter In Industrial Applications
An induction motor connected directly to the power supply draws a constant magnetizing current at full speed, no matter what the load is. At anything less than full load, power factor of the induction motor is less than its rated… Read more
Jun 16, 2012 | By Edvard Csanyi
Electrical Lectures
Dielectric Strength Of Insulator Materials
The atoms in insulating materials have very tightly-bound electrons, resisting free electron flow very well. However, insulators cannot resist indefinite amounts of voltage. With enough voltage applied, any insulating material will eventually succumb to the electrical ”pressure” and electron flow… Read more
Jun 14, 2012 | By Edvard Csanyi
Electrical Lectures
Understanding Vector Group of Transformer (Part 1)
Three phase transformer consists of three sets of primary windings, one for each phase, and three sets of secondary windings wound on the same iron core. The vector group of the transformer is determined by the connection between the windings… Read more
Jun 03, 2012 | By Jignesh Parmar
Energy Efficiency
Electric Power Quality and Lighting (part 1)
Concerns about the effects of lighting products on power distribution systems have focused attention on power quality. Poor power quality can waste energy and the capacity of an electrical system; it can harm both the electrical distribution system and devices… Read more
May 26, 2012 | By Sufi Shah Hamid Jalali
Cables
Sizing of power cables for circuit breaker controlled feeders (part 3)
Continued from article Sizing of power cables for circuit breaker controlled feeders (part 2) This criterion is applied so that the cross sectional area of the cable is sufficient to keep the voltage drop (due to impedance of cable conductor)… Read more
May 17, 2012 | By Asif Eqbal
Electrical Lectures
Power Measurement In AC Circuits
Power measurement in AC circuits can be quite a bit more complex than with DC circuits for the simple reason that phase shift complicates the matter beyond multiplying voltage by current figures obtained with meters. What is needed is an instrument… Read more
May 15, 2012 | By Edvard Csanyi
Electric Motor
Measurement of insulation resistance (IR) – Part 2
This article goes into details of insulation resistance values measured by Megger tester on many different kinds of equipment, such as switchgear, electrical wires & cables, electric motors, transmission & distribution lines, and other power system equipment. An insulation tester… Read more
Apr 29, 2012 | By Jignesh Parmar
Energy and Power
Single-Phase Power vs Three-Phase Power
The principal elements of an electric power system are the generating stations, the transmission lines, the substations, and the distribution networks. The generators produce the electricity, the transmission lines move it to regions where it is consumed, and the substations… Read more
Apr 01, 2012 | By Edvard Csanyi
Electronics
Difference between step-up transformer and voltage amplifier
A step up transformer basically increases the magnitude of primary applied voltage that is increases the amplitude of voltage wave form. A voltage amplifier does exactly the same. Than a very strange but thinkable question comes what is the difference… Read more
Mar 17, 2012 | By Asif Eqbal
