Energy and Power
Surge protective categories defined by ANSI/IEEE C62.41
Three different surge protective classes or zones have been defined by ANSI/IEEE C62.41, Recommended Practice on Surge Voltages in Low Voltage Power Circuits. These classes are illustrated in the pictorial diagram Fig. 12-1. Category C (outdoors) is the region outside the… Read more
Jun 28, 2013 | By Edvard Csanyi
Energy and Power
Overvoltages Caused by Lightning
Overvoltages of atmospheric origin arise from uncontrollable sources and their severity for the load depends on many parameters that are determined according to where the lightning strikes and the structure of the electrical network. The impact of lightning on a… Read more
Apr 26, 2013 | By Edvard Csanyi
Energy and Power
An overview of GFCI – Ground-fault circuit interrupter
The NEC requires that Ground-Fault Circuit Interrupters (GFCIs) be installed in many different rooms and locations in both public and private buildings. They are now required in bathrooms, kitchens, appliance rooms or spaces, and garages. In addition, they are required… Read more
Apr 10, 2013 | By Edvard Csanyi
Power Substation
Responding to Cyber Intrusion in SCADA System
Continued from technical article: Detecting Cyber Intrusion in SCADA System The “three R’s” of the response to cyber intrusion are: Recording, Reporting, and Restoring. Theoretically, it would be desirable to record all data communications into and out of all substation… Read more
Apr 08, 2013 | By Edvard Csanyi
Power Substation
Active fire protection measures in power substation
Active fire protection measures are automatic fire protection measures that warn occupants of the existence of fire, and extinguish or control the fire. These measures are designed to automatically extinguish or control a fire at its earliest stage, without risking… Read more
Apr 01, 2013 | By Edvard Csanyi
Energy and Power
Preparing to synchronize a generator to the grid
Synchronizing the generator to the grid can be tricky if you don’t know what you’re doing. But let’s start from the beginning. A device that transforms mechanical power from a prime mover into AC electric power at a particular voltage… Read more
Mar 27, 2013 | By Edvard Csanyi
Energy and Power
Lightning Protection System – Germany Regulations
The purpose of a lightning protection system is to protect buildings from direct lightning strikes and possible fire, or from the consequences of the load-independent active lightning current (non-igniting flash of lightning). If national regulations, e.g. building regulations, special regulations… Read more
Mar 22, 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
Protection
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
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
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
Discrimination between residual current circuit breakers (RCCBs)
The operating principle of the residual current release is basically the detection of an earth fault current, by means of a toroid transformer which embraces all the live conductors, included the neutral if distributed. In absence of an earth fault,… Read more
Jan 11, 2013 | By Edvard Csanyi
Energy and Power
Flexibility and Reliability of Numerical Protection Relay
The first protection devices based on microprocessors were employed in 1985. The widespread acceptance of numerical technology by the customer and the experiences of the user helped in developing the second generation numerical relays in 1990. Conventional electromechanical and static… Read more
Dec 27, 2012 | By Jignesh Parmar
High Voltage
7 Golden Safety Rules for Working In HV Laboratory
Employees performing operations and testing work in high voltage laboratory are exposed to a greater hazard than most other employees. Safety rules MUST NOT be seen as a means of limiting our freedom, but should rather be looked upon as valuable… Read more
Dec 26, 2012 | By Edvard Csanyi
Energy and Power
Few Words About Digital Protection Relay
Around 1980s the digital relay entered the market. Compared to the Solid State Relay, the digital relay takes the advantages of the development of microprocessors and microcontrollers. Instead of using analog signals, the digital relay converts all measured analog quantities… Read more
Dec 24, 2012 | By Jignesh Parmar
