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 | 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 | Mohan Krishnasamy

6 Simple Rules to Ensure Substation Safety

Another extremely important substation engineering aspect is associated with safety protection. It is fair to say that safety is always a No. 1 priority in substation design, operation and maintenance…. Read more

Jan 27, 2014 | Edvard

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 | Edvard

Power Transformer Capacitance and Dissipation Factor Test

The capacitance and dissipation factor test is an AC low voltage maintenance test and is very similar to the power factor test. While the transformer preparation is identical to the… Read more

Jan 22, 2014 | Edvard

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 | Edvard

How to perform a power transformer turns ratio test

Power transformer turns ratio test is an AC low voltage test which determines the ratio of the high voltage winding to all other windings at no-load. The turns ratio test… Read more

Jan 17, 2014 | Edvard

Automatic transfer switch (ATS) between two low-voltage utility supplies

Multiple utility services may be used as an emergency or standby source of power. Required is an additional utility service from a separate source and the required switching equipment. Figure… Read more

Jan 15, 2014 | Edvard

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 | Edvard

8 main disadvantages of HVDC transmission

Few weeks back I posted an article about advantages of HVDC over HVAC transmission systems. Advantages of HVDC are numerous and very well recognized, but like everything on this earth… Read more

Jan 10, 2014 | Edvard