Electrical Lectures
4 Main Means For The Generation Of Reactive Power
The four main means for the generation of reactive power are: synchronous alternators, synchronous compensators (SC), static var compensators (SVC) and banks of static capacitors. Contents Synchronous alternators Synchronous compensators… Read more
Jun 29, 2015 | By Edvard
Testing and Commissioning
12 Transformer Factory Tests Briefly Explained
The remainder of the twelve factory tests are briefly summarized below. The details of the test set connections and formulas of some of the listed tests are already described in… Read more
Jun 29, 2015 | By Edvard
Energy and Power
Take into account these losses when purchasing power transformer
Losses and purchase price should be considered when deciding which transformer to purchase. The purpose of this technical article is to present a uniform approach that can be used to determine the dollar… Read more
Jun 26, 2015 | By Edvard
Energy and Power
Example for Coordination of Cascaded Circuit Breakers
A 440 V 60 Hz switchboard feeds a 4-wire distribution board for small loads such as socket outlets. The switchboard has a fault making capacity of 100kA rms. After applying… Read more
Jun 24, 2015 | By Edvard
Electric Motor
Calculation of motor starting time as first approximation
The problems connected to motor starting operations are fundamentally linked to the type of motor which a determined motor operational torque “CM” offers, to the starting modality and to the… Read more
Jun 22, 2015 | By Edvard
Testing and Commissioning
5 components of current drawn by the DC voltage testing of insulation
When DC voltage is applied to an insulation, the electric field stress gives rise to current conduction and electrical polarization. Consider an elementary circuit as shown in Figure 1 below,… Read more
Jun 19, 2015 | By Edvard
Energy and Power
5 copper busbar jointing methods you should know
Efficient joints in copper busbar conductors can be made very simply by: Bolting Clamping Riveting Soldering Welding Bolting and clamping are used extensively on-site. Shaped busbars may be prefabricated by… Read more
Jun 17, 2015 | By Edvard
Electric Motor
Basics of DC Motors For Electrical Engineers – Beginners
Separate field excitation DC motors are still sometimes used for driving machines at variable speed. These motors are very easy to miniaturize, and essential for very low powers and low… Read more
Jun 15, 2015 | By Edvard
Testing and Commissioning
Procedure for transformer lightning impulse test
The purpose of the impulse voltage test is to secure that the transformer insultations withstand the lightning overvoltages which may occur in service. Where: C1 – Impulse capacitor Rc – Charging… Read more
Jun 12, 2015 | By Edvard
Energy and Power
When To Use a Solidly Grounded System?
As is evident from the name, a solidly grounded system is one where the neutral of the system is directly connected to ground without introducing any intentional resistance in the… Read more
Jun 10, 2015 | By Edvard
Energy and Power
How to achieve selective coordination of circuit breakers
Selective coordination is often referred to simply as coordination. Coordination is defined in NEC® 240.2 as: “The proper localization of a fault condition to restrict outages to the equipment affected,… Read more
Jun 08, 2015 | By Edvard
Energy and Power
What Is The Poor Power Quality?
Most electrical and electronic equipment is designed to operate from a power supply with a particular specification that usually defines the minimum and maximum limits for RMS (root mean-square) voltage… Read more
Jun 05, 2015 | By Edvard
Energy and Power
Understanding Transfer Switch Transition Types
Transfer switches are used for quickly and safely transitioning all electrical power consumed by the circuit, equipment, or systems connected to the transfer switch output between those normal and emergency power… Read more
Jun 03, 2015 | By Edvard
