By Stefan Fassbinder / Published on Mon, 2009-08-17 14:10
It may be normal that in a church an earthing electrode, if any, is directed to the sky, like this one found in Jena / Germany beneath the altar, and not linked to anything "earthly", but under "normal" conditions and from an electro-technical point of view, if there is any sort of electrical installation contained in any building at all, it should also be earthed!
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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 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 11:05
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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By Stefan Fassbinder / Published on Thu, 2008-03-13 13:34
Occasional reason for complaints: Conflicting statements on the same thing in different standards
Different standards often make divergent statements on the same part or component of an installation. This is because, firstly, one standard deals with electrical safety (e. g. IEC 60364-5-54), another one with functionality and EMC (e. g. IEC 60364-4-44) and possibly yet another with lightning protection (e. g. IEC 62305).
In many cases, the limits given in standards are mere estimates, so the respective bodies, since they all consist of technical experts, will always come to similar, but not necessarily the same limit values! Because standardisation, especially at an international level, is a very complex task, there is often a lack of communication between any two (or even more) bodies dealing with the same object from different perspectives. This is how the conflicting statements come about.
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