Using High-Speed Grounding Switches
Automatic high-speed grounding switches are applied for protection of power transformers when the cost of supplying other protective equipment is deemed unjustifiable and the amount of system disturbance that the high-speed grounding switch creates is judged acceptable. The switches are… Read more
Feb 15, 2013 | By Edvard Csanyi
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
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
How Do We Define Hazardous Areas?
The first requirement is to know what a hazardous area is. The principal factors relevant to the classifications of a hazardous area are the nature of the gases or dust present in the potentially explosive atmosphere and the likelihood of… Read more
Feb 09, 2013 | By Edvard Csanyi
How Motor Really Works?
The basic working of a motor is based on the fact that when ‘a current carrying conductor is placed in a magnetic field, it experiences a force’. If you take a simple DC motor, it has a current-carrying coil supported… Read more
Feb 08, 2013 | By Edvard Csanyi
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
How to Monitor Wind Speed?
When considering wind power, most people ask what the average annual wind speed is and how to get that number. The usual response is that you must monitor the wind speed at your site for at least 12 months, preferably… Read more
Feb 04, 2013 | By Edvard Csanyi
Connections Of Overcurrent Relay
This technical article is continued from first part: Types and Applications Of Overcurrent Relay It’s used for: 3-phase faults the overcurrent relays in all the 3-phases act. Phase to phase faults the relays in only the affected phases operate. Single… Read more
Feb 02, 2013 | By Jignesh Parmar
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
What is transformer rating based on?
In the U.S., transformers are rated based on the power output they are capable of delivering continuously at a specified rated voltage and frequency under “usual” operating conditions without exceeding prescribed internal temperature limitations. Insulation is known to deteriorate with… Read more
Jan 30, 2013 | By Edvard Csanyi
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
High Voltage Substations Overview (part 2)
Continued from first part: High Voltage Substations Overview (part 1) Transformers are used for the transformation of high and medium voltage to low voltage, flanked by specific protective devices and control systems, which constitute the low voltage distribution substations. A… Read more
Jan 26, 2013 | By Emmanouil Angeladas
High voltage substations overview (part 1)
High voltage substations are interconnection points within the power transmission and distribution systems between regions and countries. Different applications of substations lead to HV substations with and without power transformers: Step up from a generator voltage level to a high voltage… Read more
Jan 25, 2013 | By Emmanouil Angeladas
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
Differences Between Earthed and Unearthed Cables
In HT electrical distribution, the system can be earthed or unearthed. The selection of unearthed or earthed cable depends on distribution system. If such system is earthed, then we have to use cable which is manufactured for earthed system. (which… Read more
Jan 21, 2013 | By Jignesh Parmar
