Electrical Design Project of a Three Bed Room House (1)
Electrical design is not an easy task. It requires a lot of expertise. Detailed study is needed prior to installation work. The engineer must consider quality and any specific requirements… Read more
Mar 21, 2014 | By Sufi Shah Hamid Jalali
Electrical Thumb Rules You MUST Follow (8)
Accuracy Class of Metering CT Accuracy Class Letter of CT Accuracy Class of Protection CT Continued from part 7: Electrical Thumb Rules You MUST Follow (Part 7) Metering Class CT… Read more
Mar 10, 2014 | By jiguparmar
The Risk Of Deadly Lightning Current and Few Things You Should Know
Lightning currents are load-independent currents, i.e. a lightning discharge can be considered an almost ideal current source. If a load-independent active electric current flows through conductive components, the amplitude of the current,… Read more
Mar 05, 2014 | By Edvard Csanyi
Total Losses in Power Distribution and Transmission Lines (2)
Continued from first part: Total Losses in Power Distribution & Transmission Lines (1) There are two types of transmission and distribution losses: Technical losses (explained in previous part) Non-technical losses… Read more
Mar 03, 2014 | By jiguparmar
Practices for grounding and bonding of cable trays
Cable tray may be used as the Equipment Grounding Conductor (EGC) in any installation where qualified persons will service the installed cable tray system. There is no restriction as to… Read more
Feb 26, 2014 | By Edvard Csanyi
Effect of utility-induced surges in a steel mill with variable speed drives
A steel mill with variable speed drives (VSDs) had problems of frequent tripping of the VSDs with the indication overvoltage in AC line. Each tripping caused severe production disruption and… Read more
Feb 12, 2014 | By Edvard Csanyi
What is the short-circuit switching (making / breaking) capacity?
The switching capacity is the r.m.s value of a current at a given power factor cos φ as well as a given rated voltage at which a switchgear or a… Read more
Feb 10, 2014 | By Edvard Csanyi
Electrical Preventive Maintenance of Air Circuit Breakers
Remove and clean interphase barriers. Clean all insulating materials with vacuum and/or clean lint free rags. If it is necessary to use cleaning solvents, use only solvents recommended by the… Read more
Feb 07, 2014 | By Edvard Csanyi
Purposes and Examples of Safety Interlocking Devices
Most switchboards and motor control centres are fitted with a variety of electrical and mechanical safety interlocking devices. Their purposes are to protect against for example: Withdrawing the switching device while… Read more
Feb 05, 2014 | By Edvard Csanyi
Conceptual Model of Smart Grid Framework by IEC
From a communication point of view, each system plays the role of either supplier or consumer of information, or more typically both. In addition to this intersystem communication, these systems… Read more
Feb 03, 2014 | By Edvard Csanyi
MV Circuit Breaker Or Vacuum Contactor? (2)
Continued from first part: MV Circuit Breaker Or Vacuum Contactor? (Part 1) When applied properly, both medium-voltage circuit breakers and medium-voltage fused contactors should provide decades of reliable service. Applied incorrectly,… Read more
Jan 31, 2014 | By Mohan Krishnasamy
MV Circuit Breaker Or Vacuum Contactor? (1)
To compare the application of medium-voltage circuit breakers and of fused contactors, we must understand the basic characteristics of each switching technology. Comparison presented here shows the major characteristics of… Read more
Jan 29, 2014 | By Mohan Krishnasamy
Dimensioning of Power Distribution Systems (2)
Continued from the first part: Dimensioning of Power Distribution Systems (1) Dimensioning of cable routes and devices follows the maximum load currents to be expected at this distribution level. As… Read more
Jan 24, 2014 | By Edvard Csanyi
Dimensioning of Power Distribution Systems (1)
When the basic supply concept for the electricity supply system has been established, it is necessary to dimension the electrical power system. Dimensioning means the sizing rating of all equipment… Read more
Jan 20, 2014 | By Edvard Csanyi
Calculating the short-circuit current across the terminals of a synchronous generator
Calculating the short-circuit current across the terminals of a synchronous generator is very complicated because the internal impedance of the latter varies according to time. When the power gradually increases, the… Read more
Jan 13, 2014 | By Edvard Csanyi