Energy and Power
Effective Resistance Of Busbars
The construction of busbar is usually carried out by putting together several flat bars in parallel for each phase. The spacing between the bars is made equal to their thickness for practical reasons, and this leads to skin and proximity effects. If one refers to… Read more
Jan 12, 2012 | By Edvard Csanyi
Energy Efficiency
Potential Energy Savings In Utility Buildings Using EIB
Flexibility, utilisation value and energy saving are the three main requirements for utility buildings (administration, office and public buildings, schools, hospitals, etc.). Apart from recouping investment costs, so-called life-cycle costs are also becoming increasingly important. These are made up of… Read more
Jan 11, 2012 | By Edvard Csanyi
Energy and Power
Operation Of Potentially Explosive Installations – The Directive 99/92/EC
In addition to the 94/9/EC Directive, which regulates how explosion protected equipment and protective systems are placed on the market and the design, construction and quality requirements to be met by them, the 99/92/EC Directive stating “Minimum requirements for improving the health and safety protection… Read more
Jan 09, 2012 | By Edvard Csanyi
Transformers
12 Main Classes Of Power Transformer
Transformers are used for a wide variety of purposes, with the complete range of voltage and power ratings as well as many special features for particular applications. The following covers the main types: Transformers for electronic circuits or for low-voltage… Read more
Jan 08, 2012 | By Edvard Csanyi
Electric Motor
How to select AC converter for VSD?
Altough manufacturers’ catalogues try to make it easy as possible, there are many variables associated with the selection and rating of the optimum electric motor and AC converter for a Variable Speed Drive (VSD) application. In many cases, it requires… Read more
Jan 06, 2012 | By Edvard Csanyi
Energy and Power
Voltage and Current Phase Relationships in an Inductive Circuit
Any change in current in a coil (either a rise or a fall) causes a corresponding change of the magnetic flux around the coil. Because the current changes at its maximum rate when it is going through its zero value… Read more
Jan 05, 2012 | By Edvard Csanyi
Renewable Energy
Photovoltaic End-Use Application Markets
Photovoltaic markets can be classified based on the end-use application of the technology. The most common PV projects are off-grid applications. Water pumping also represents an important application of PV, particularly in developing countries. The largest long-term market potential for… Read more
Jan 04, 2012 | By Edvard Csanyi
Medium Voltage
ABB MV Switchgear – Single Busbar Or Double Busbar?
Most switchgear installations used in industry with normal service conditions are based on single busbar arrangements. Compared to double busbar switchgear, single busbar switchgear is definitely easier to use, readily understood by operators, requires less space, and the total cost of installation… Read more
Jan 03, 2012 | By Edvard Csanyi
Energy and Power
The Need for Breaker Failure Protection
Circuit breakers are strategically located in power systems to connect circuits and electrical apparatus. Circuit breakers are commanded to open and close by protection and control systems that monitor conditions on the power system. Protection systems are coordinated so that… Read more
Jan 01, 2012 | By Edvard Csanyi
News
Thank you very much, wish you all the best in 2012!
Dear Friends of EEP, Over the past year EEP has reached many milestones. Among them: an expansion of our reach to audience of electrical engineers all over the world – with more than 10K members, 228,343 Visits, 162,090 unique Visitors… Read more
Dec 30, 2011 | By Edvard Csanyi
Electric Motor
NEC Code for Size of Cable for Motor
Size of Cable for Branch circuit which has Single Motor connection is 125% of Motor Full Load Current Capacity. What is the minimum rating in amperes for Cables supplying 1 No of 5 hp, 415-volt, 3-phase motor at 0.8 Power… Read more
Dec 30, 2011 | By Jignesh Parmar
Electric Motor
The Cage Induction Motor Explained In Details
This simplest form of AC induction motor or asynchronous motor is the basic, universal workhorse of industry. Its general construction is shown in Fig. 1. It is usually designed for fixed-speed operation, larger ratings having such features as deep rotor… Read more
Dec 29, 2011 | By Edvard Csanyi
Energy and Power
Using Core-Balance Current Transformer For Earth Fault Protection
The core-balance current transformer (or CBCT) is normally of the ring type, through the centre of which is passed cable that forms the primary winding. An earth fault relay, connected to the secondary winding, is energised only when there is… Read more
Dec 28, 2011 | By Edvard Csanyi
Industrial Automation
Ladder diagrams and the PLC for electrical engineers – beginners
The ladder diagram has and continues to be the traditional way of representing electrical sequences of operations. These diagrams represent the interconnection of field devices in such a way that the activation, or turning ON, of one device will turn… Read more
Dec 27, 2011 | By Edvard Csanyi
Protection
Transformer Protection – Abstract from NEC
According to NEC 450.4, “each transformer 600 volts, nominal, or less shall be protected by an individual overcurrent device installed in series with each ungrounded input conductor.” Such overcurrent device shall be rated or set at not more than 125%… Read more
Dec 26, 2011 | By Jignesh Parmar
