Electrical Lectures
The Rheostat In Few Simple Words
A variable resistor can be made from a wirewound element, rather than a solid strip of material. This is called a rheostat. A rheostat can have either a rotary control or a sliding control. This depends on whether the nichrome… Read more
Mar 20, 2013 | By Edvard Csanyi
Energy and Power
Sources and Contributors To Short Circuit Current
Every electrical system confines electric current flow to selected paths by surrounding the conductors with insulators of various types. Short circuit current is the flow of electrical energy that results when the insulation barrier fails and allows current to flow… Read more
Mar 15, 2013 | By Edvard Csanyi
Energy and Power
Working principle of thermal motor protection relay
Thermal motor protection relays contain three bimetal strips together with a trip mechanism in a housing made of insulating material. The bimetal strips are heated by the motor current, causing them to bend and activating the trip mechanism after a… Read more
Mar 09, 2013 | By Edvard Csanyi
Energy and Power
An Overview Of Short Circuit Current (part 3)
Fault calculations are carried out to find the magnitude of fault current at various voltage levels of electrical system. One of the key components in the calculation process is to determine the total impedance of the circuit from the utility /… Read more
Mar 08, 2013 | By Asif Eqbal
Electronics
Super Capacitors – Different Than Others (part 2)
Continued from first part: Super Capacitors – Different Then Others (part 1) Equivalent circuit How to measure the capacitance? Charge Method Discharge Method Measure Capacitance Capacitor types Advantages of the supercapacitors Super capacitors can be illustrated similarly to conventional film,… Read more
Mar 01, 2013 | By sravankumarpadala
Energy and Power
An Overview Of Short Circuit Current (part 2)
Continued from previous technical article: An Overview Of Short Circuit Current (part 1) Sub transient reactance Xd” is the apparent reactance of the stator winding at the instant short circuit occurs, and it determines the current flow during the first… Read more
Feb 27, 2013 | By Asif Eqbal
Energy and Power
An Overview Of Short Circuit Current (part 1)
There are essentially four types of faults: three-phase, single line-to-ground, double line-to-ground, and line-to-line. Each of these types of faults can result in different magnitudes of fault current. In all types, however, there is a common element: an abnormally low-impedance… Read more
Feb 25, 2013 | By Asif Eqbal
Energy and Power
And Now Something We All Use – The Socket Outlets
A socket outlet is a female socket connected to the power wiring in the building and will accept the male plug attached at the end of the flexible cord of an appliance such as a vacuum cleaner, electric fire or… Read more
Feb 22, 2013 | By Edvard Csanyi
Energy and Power
Medium Voltage Switchgear (2) – Selection of Switching Devices
Continued from first part: Medium Voltage Switchgear (1) – Basics of Switching Devices Switching devices are selected both according to their ratings and according to the switching duties to be performed, which also includes the switching rates. Selection according to… Read more
Feb 13, 2013 | By Emmanouil Angeladas
Energy and Power
The Basics of Switching Devices In Medium Voltage Switchgear (Part 1)
According to international rules, there are only two voltage levels: Low voltage: up to and including 1kV AC (or 1,500V DC) and High voltage: above 1kV AC (or 1,500V DC). Most electrical appliances used in household, commercial and industrial applications work with low… Read more
Feb 11, 2013 | By Emmanouil Angeladas
Energy and Power
Did Tesla Discover the Secrets of Antigravity?
Nikola Tesla has been credited for the creation of much of the technology that we take for granted today. Without the genius of Tesla we would not have: Radio, Television, AC electricity, Tesla coil, Flourescent lighting, Neon lighting, Radio control… Read more
Feb 06, 2013 | By Edvard Csanyi
Energy and Power
Types and Applications Of Overcurrent Relay
Distribution systems are susceptible to overcurrent flow within its components. Overcurrent may arise from abnormal system conditions, including overloads and short-circuit failures, or from typical system conditions, such as transformer inrush current and motor initiation. Consequently, under typical system conditions,… Read more
Feb 01, 2013 | By Jignesh Parmar
Energy and Power
How to manipulate energized conductors with hot stick
Hot sticks are poles made of an insulating material. They have tools and/or fittings on the ends which allow workers to manipulate energized conductors and equipment from a safe distance. Hot sticks vary in length depending on the voltage level… Read more
Jan 28, 2013 | By Edvard Csanyi
Energy and Power
Comparison of Protection Relay Types
This comparison summarize characteristics of all protection relay types described in previously published technical articles: Using Protective Relay For Fighting Against Faults The Good Old Electromechanical Protective Relay The Solid State Relay (Static Relay) Overview Few Words About Digital Protection… Read more
Jan 23, 2013 | By Jignesh Parmar
Energy and Power
Power measurement in a three-phase system
Electrical power is measured with a wattmeter. A wattmeter consists of a current coil connected in series with load, while the other potential coil is connected parallel with load. Depending on the strength of each magnetic field movement, the pointer… Read more
Jan 19, 2013 | By Edvard Csanyi
