Energy and Power
Installation of Distribution-to-Utilization Voltage Transformers
Aerial transformer installations may utilize a three-phase unit or banked single-phase units. Transformers, either singly or in banks, having an individual unit or combined capacity greater than 300 kVA will not be mounted on single wood poles. Special structural considerations… Read more
Nov 11, 2011 | By Edvard Csanyi
Energy and Power
Medium voltage circuit breaker operating sequence
Rated switching sequence according to IEC, O – t – CO – t’ – CO. (cf. opposite diagram): O – Represents opening operation CO – Represents closing operation followed immediately by an opening operation Slow: O – 3 min –… Read more
Nov 10, 2011 | By Edvard Csanyi
Transformers
Sources of Sound in Transformers
Unlike cooling-fan or pump noise, the sound radiated from a transformer is tonal in nature, consisting of even harmonics of the power frequency. It is generally recognized that the predominant source of transformer noise is the core. The low frequency,… Read more
Nov 09, 2011 | By Edvard Csanyi
Energy and Power
Working Principle of Earth Leakage Circuit Breaker (ELCB) and Residual Current Device (RCD)
The operation of an earth leakage circuit breaker (or shorten ELCB) is based on the fact that the algebraic sum of the currents in any healthy single phase, three phase and three phase and neutral system is zero. This simply… Read more
Nov 07, 2011 | By Jignesh Parmar
Electric Motor
DC motor and generator – design, application and operation
History will recognize the vital role played by DC motors in the development of industrial power transmission systems, the dc machine being the first practical device to convert electrical power into mechanical power. Inherently straight forward operating characteristics, flexible performance… Read more
Nov 06, 2011 | By Edvard Csanyi
Biomass Energy
Biodiesel – Myths and Facts
Few facts you most probably know already, but never the less to mention: A clean burning alternative fuel, produced from domestic, renewable resources such as plant oils, animal fats, used cooking oil and even new sources such as algae. Contains… Read more
Nov 05, 2011 | By Bipul Raman
Lighting
Basic parameters used in lighting you should know
Abbreviation: φ phi Unit: lm lumen The luminous flux describes the quantity of light emitted by a light source. The luminous efficiency is the ratio of the luminous flux to the electrical power consumed (lm/W). It is a measure of… Read more
Nov 03, 2011 | By Edvard Csanyi
Protection
Transformer Winding Faults
A fault on a transformer winding is controlled in magnitude by the following factors: Source impedance Neutral earthing impedance Transformer leakage reactance Fault voltage Winding connection Several distinct cases arise and are examined below. The winding earth fault current depends… Read more
Nov 02, 2011 | By Edvard Csanyi
