Electrical Lectures
DC Motor Drive Explained In Few Words
In a DC motor, the magnetic field is created by the current through the field winding in the stator. This field is always at right angles to the field created by the armature winding. This condition, known as field orientation,… Read more
Jun 23, 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
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
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
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
Electrical Lectures
Inspection Of Voltage Drop In Conductors
It is part of the inspection process to ensure that installed conductors have been correctly selected for current carrying capacity and voltage drop. To check the suitability of the current carrying capacity it is simply a matter of looking at… Read more
Apr 15, 2012 | By Edvard Csanyi
Electrical Lectures
What is incident energy caused by arc flash?
Incident energy is the energy per unit area received on a surface located a working distance away from the arc flash location. The working distance is the distance from where the worker to the flash location. This is basically an… Read more
Apr 13, 2012 | By Edvard Csanyi
Electric Motor
Star-delta motor starter explained in details
Where is Star-Delta motor starter used? Well, the majority of induction motors are started directly on line (DOL), but when very big motors are started in this manner, the large starting current surges produce a disruption in the voltage on… Read more
Apr 10, 2012 | By Jignesh Parmar
Electrical Lectures
Short review of resistance, reactance and impedance
Resistance is essentially friction against the motion of electrons. It is present in all conductors to some extent (except superconductors!), most notably in resistors. When alternating current goes through a resistance, a voltage drop is produced that is in-phase with… Read more
Apr 08, 2012 | By Edvard Csanyi
Electrical Lectures
Capacitor Banks In Power System (part four)
Let us consider that there is a captive diesel generator (DG) the rating of which is specified as 1000kVA and PF 0.85. Rating in kVA specifies the maximum current the alternator can deliver at the system voltage. In the previous… Read more
Mar 27, 2012 | By Asif Eqbal
Electrical Lectures
Capacitor Banks In Power System (part three)
Continued from part two – Capacitor Banks In Power System (part two) Capacitor units shall be suitable for continuous operation at an RMS current of 1.30 times the current that occurs at rated sinusoidal voltage and rated frequency, excluding transients…. Read more
Mar 03, 2012 | By Asif Eqbal
Electrical Lectures
Capacitor Banks In Power System (part two)
Continued from part one – Capacitor Banks In Power System (part one) It should be noted that in an inductance the current lags the voltage by 90 degrees and in a capacitor the current leads the voltage by 90 degrees…. Read more
Mar 01, 2012 | By Asif Eqbal
Electrical Lectures
Capacitor banks in power system (part 1)
When a charge is delivered to a conductor its potential is raised in proportion to the quantity of charge given to it. At a particular potential a conductor can hold a given amount of charge. Capacitance is the term to… Read more
Feb 27, 2012 | By Asif Eqbal
Electrical Lectures
How to explain your kids, what is the electricity?
It’s really not an easy task to explain kids what is the electricity and what is really happening in the wires while lamp is powered, or what are the magnets, magnetism and how all this stuff works. Most important of… Read more
Feb 26, 2012 | By Edvard Csanyi
Electrical Lectures
Types of neutral earthing in power distribution (part 2)
Resistance grounding has been used in three-phase industrial applications for many years and it resolves many of the problems associated with solidly grounded and ungrounded systems. Resistance Grounding Systems limits the phase-to-ground fault currents. Continued from Types of neutral earthing… Read more
Feb 09, 2012 | By Jignesh Parmar
