Energy and Power
Harmonic distortion and high frequency applications
The presence of harmonic frequencies in addition to the fundamental 50Hz, bring about distortion of the fundamental sine wave. Considerable problems may arise dependant upon the level of this distortion. Sources of harmonic distortion can be: Variable Speed Drives UPS… Read more
Jul 07, 2014 | By Edvard Csanyi
Electric Motor
How to measure insulation resistance of a motor
If the motor is not put into operation immediately upon arrival, it is important to protect it against external factors like moisture, high temperature and impurities in order to avoid damage to the insulation. Before the motor is put into… Read more
Jun 09, 2014 | By Edvard Csanyi
Energy Efficiency
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 1 shows automatic transfer between two low-voltage utility supplies. Utility… Read more
Jan 15, 2014 | By Edvard Csanyi
Low Voltage
Example of MV/LV network structure with dual fed main MV switchboard
Connected to article: Example of standard MV/LV network structure MV consumer substation; The main MV switchboard can be backed up by a generator set and it feeds two MV/LV transformers; MV switchboard can be GIS or AIS and consist of… Read more
Jan 06, 2014 | By Edvard Csanyi
Energy and Power
Switching contactor and effect of long control lines
In accordance with IEC 60947-4-1 and IEC 60947-5-1, the normal control voltage range of power and control contactors lies between 85 … 110 % of the rated control voltage. Within these limits contactors pull-in perfectly. Frequently contactors are offered with… Read more
May 15, 2013 | By Edvard Csanyi
Energy and Power
Using AC switchgear in DC applications
Switchgear designed for alternating current can carry at least the same rated continuous operational DC current. With direct current the skin effect in the circuits disappears and none of the specific effects associated with alternating currents such as hysteresis or… Read more
Apr 19, 2013 | By Edvard Csanyi
Low Voltage
Defining Size and Location of Capacitor in Electrical System (2)
Continued from part 1: Defining Size and Location of Capacitor in Electrical System (2) Size of circuit breaker (CB), fuse and conductor of capacitor bank: A. Thermal and magnetic setting of a circuit breaker B. Fuse selection C. Size of… Read more
Mar 11, 2013 | By Jignesh Parmar
Cables
Differences Between Earthed and Unearthed Cables
In HT electrical distribution, the system can be earthed or unearthed. The selection of unearthed or earthed cable depends on distribution system. If such system is earthed, then we have to use cable which is manufactured for earthed system. (which… Read more
Jan 21, 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
Lighting
Lighting Circuits Connections for Interior Electrical Installations (2)
Continued from first part: Lighting Circuits Connections for Interior Electrical Installations In modern internal electrical installations, domestic and professional, there is a need for lighting installations in staircases and installation of emergency lighting that will operate in the event of interruption… Read more
Dec 31, 2012 | By Emmanouil Angeladas
Energy and Power
21 Safety Rules for Working with Electrical Equipment
A safe work environment is not always enough to control all potential electrical hazards. You must be very cautious and work safely. Safety rules help you control your and others risk of injury or death from workplace hazards. The good… Read more
Dec 12, 2012 | By Edvard Csanyi
Lighting
Lighting Circuits Connections for Interior Electrical Installations
Electrical lines which include lighting circuits begin from the main distribution panel of the installation and each line contains three conductors: phase, neutral and ground. All three conductors reach to the terminal point of each luminaire and if it has… Read more
Dec 07, 2012 | By Emmanouil Angeladas
Energy and Power
Arrangements of LV Utility Distribution Networks (2)
Continued from the previous part: Arrangements of LV Utility Distribution Networks (1) In the past, an underground cable service or the wall-mounted insulated conductors from an overhead line service, invariably terminated inside the consumer’s premises, where the cable-end sealing box, the utility… Read more
Dec 01, 2012 | By Edvard Csanyi
Energy and Power
Arrangements of LV Utility Distribution Networks
In European countries the standard 3-phase 4-wire distribution voltage level is 230/400 V. Many countries are currently converting their LV systems to the latest IEC standard of 230/400 V nominal (IEC 60038). Medium to large-sized towns and cities have underground… Read more
Nov 30, 2012 | By Edvard Csanyi
Energy and Power
Purpose of Miniature Circuit Breakers (MCBs)
Miniature circuit breakers (MCB) are primarily designed to protect cables and lines against overload (thermal) and short-circuit (electromagnetic). They thus care for protecting this electrical equipment against excessive temperature rises and destruction in the event of a short-circuit. They meet the requirements… Read more
Nov 24, 2012 | By Edvard Csanyi
