By Sergio Ferreira / Published on Tue, 2010-02-16 16:20
This Application Note provides an overview of available measures for energy efficiency improvement in the food and beverage processing industry. It is based on examples from theory and practice.
This study is not intended to be an exhaustive description of every operation in the sector, but rather tries to describe the most significant process-specific energy efficiency measures and reinforce these with practical case-studies.
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By Sergio Ferreira / Published on Tue, 2009-12-22 16:04
This Application Note is aimed at describing the use of energy and the potential energy savings in the school sector, on the basis of theory and practical case studies.
Schools represent some 6% of the total energy consumption in the tertiary sector. Before going into detail on the energy consumption of a school, the first paragraphs will briefly introduce the energy use of the utility sector and the part schools play in it.
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By Sergio Ferreira / Published on Mon, 2009-12-21 18:04
This application guide is aimed at describing the use of energy and the potential energy savings in the offices sector, on the basis of theory and practical case studies.
Before going into detail on the energy consumption of an office building, the first paragraphs will briefly introduce the energy use of such buildings.
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By Isabelle Heriakian / Published on Thu, 2009-10-29 16:09
This guide presents a methodology based on standard PN-IEC 60354 to check overloading capacity of transformers. Main changes versus standard PN-71/E-81000 are discussed and step by step examples are given. An essential advantage of the recommended methods of verification of overloading capacity of transformers is that the size and cooling modes of transformers are considered.
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By Isabelle Heriakian / Published on Tue, 2009-08-04 09:03
Industrial facilities are source of major disturbances to power system due to more and more large power loads being installed that, apart of their good functional properties, are characterised by negative impact on the quality of power.
The adverse impact of non-linear loads on a power system can be mitigated by means of compensation equipment like fixed capacitor (FC), thyristor controlled reactor (TCR) - FC/TCR.
The purpose of FC/TCR compensator is compensation of the fundamental component reactive power and filtering selected current harmonics.
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By Isabelle Heriakian / Published on Thu, 2009-01-29 10:19
In this guide, a design engineer works on a converter drive design and determines the voltage change coefficient during the drive start, compares it to permissible levels and suggests solutions to have it satisfying the limit.
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By Rob Van Heur / Published on Tue, 2009-01-20 15:57
This Application Note describes the energy consumption and opportunities for making energy savings in the plastics industry based on examples from both theory and practice.
Two hundred and thirty million tons of plastic are produced annually worldwide. Europe, including Switzerland and Norway, accounts for 25 per cent of total production, this being approximately equal to the production of North America.
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By Bryony Samuel / Published on Tue, 2008-12-09 10:50
It has been estimated that the cost of power quality problems to industry and commerce in the EU amounts to about 150 billion Euro per annum. Simple preventative measures, careful equipment selection, good design and effective maintenance could prevent most of this loss.
The Cost of Poor Power Quality introduces the cost implications of typical PQ problems.
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By Bryony Samuel / Published on Tue, 2008-12-09 10:45
Electrical power is an important raw material for all commercial operations and, like any other raw material, the quality of supply is very important. Any interruption, however short, can cause a production line to stop or data processing operations to fail. This Application Note discusses the potential cost of poor PQ to industry and commerce and outlines the common PQ problems that can cause serious financial loss.
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By Hans De Keulenaer / Published on Mon, 2008-12-08 13:32
Electrical safety of low voltage supply systems is the subject of many national and international standards. Installation rules providing electromagnetic compatibility were introduced during the last decade, but still are not well known to installers and system designers.
From the perspective of electromagnetic compatibility, there must be no operating currents, not even stray currents (as defined in IEC 60364-5-54) flowing through the earth wire and earthing and equipotential bonding system.
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By Bryony Samuel / Published on Wed, 2008-12-03 14:20
The presence of harmonic voltages and currents in the supply network cause many common power quality (PQ) problems.
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By jan.desmet@howest.be / Published on Wed, 2008-12-03 14:14
This Application Note discusses the effects of harmonic currents on power transformers. The main consequence is an increase in losses, mainly in the windings. Higher losses mean that more heat is generated in the transformer so that the operating temperature increases, leading to deterioration of the insulation and a potential reduction in lifetime. As a result, it is necessary to reduce the maximum power load on the transformer, a practice referred to as de-rating, or to take extra care in the design of the transformer to reduce these losses.
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By Bryony Samuel / Published on Wed, 2008-12-03 14:12
This Application Note discusses the sizing of neutral conductors in the presence of ‘triple-N’ harmonics– that is, currents with a harmonic order that is a multiple of three. This issue is particularly important in low voltage systems where harmonic pollution by single phase loads is an increasingly serious problem. Triple-N harmonic currents add arithmetically with the result that neutral currents that are often significantly higher than the phase currents.
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By Bryony Samuel / Published on Wed, 2008-12-03 14:10
This application note discusses the compatibility, with respect to harmonic voltage levels, of load devices with the electricity supply system. Consumers' equipment operating on the network causes disturbances which affect the proper operation of other equipment on the network.
To ensure compatibility it is necessary both to control the maximum level of disturbance that may be present at any point on the network and to establish a level of disturbance to which every item of equipment will be immune.
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By Bryony Samuel / Published on Wed, 2008-12-03 12:52
This Application Note discusses the use of active filters to reduce harmonic currents in installations. Active filters work by providing the harmonic current required by the load instead of it being drawn from the supply.
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By Bryony Samuel / Published on Wed, 2008-12-03 12:47
Nuisance tripping of circuit breakers is a common problem in many commercial and industrial installations. This Application Note explains the need to use ‘True rms’ measurement instrument when troubleshooting and analysing the performance of a power system.
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By Bryony Samuel / Published on Wed, 2008-12-03 11:13
This Application Note discusses practical design of earthing electrodes, including the calculation of earthing resistance for various electrode configurations, the materials used for electrodes and their corrosion performance. Equations are given for many common electrode geometries, including horizontal strips, rods, meshes, cable screens and foundations.
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By Bryony Samuel / Published on Wed, 2008-12-03 11:10
Electromagnetic interference, EMI, has become very important in the last few decades as the amount of electronic equipment in use has increased enormously. This has led to an increase in the sources of interference, e.g. digital equipment and switching power supplies, and an increase in the sensitivity of equipment to interference, due to higher data rates.
This development demands high quality electrical installations in all buildings where electromagnetic non-compatibility leads to either higher costs or to an unacceptable decrease in safety standards.
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By Bryony Samuel / Published on Wed, 2008-12-03 11:07
This application note proposes a systems approach to the design of the earthing system. It has to perform three functions: conducting lightning and short circuit currents to earth, preventing the dangerous touch and step voltages and providing the low impedance, equipotential environment required for electronic and communication equipment. These functions are apparently contradictory but can be achieved by careful design.
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By Bryony Samuel / Published on Wed, 2008-12-03 11:05
Earthing of electrical systems is very important. Its primary purpose is to ensure safety by providing protection for buildings and occupants against direct damage and electrical shock due to lightning or short circuit events. Its secondary purpose is to provide a noise free equipotential environment to enable electrical and electronic equipment to function correctly and reliably.
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