{"id":758,"date":"2023-12-19T20:49:46","date_gmt":"2023-12-19T12:49:46","guid":{"rendered":"https:\/\/www.britecelectric.com\/?post_type=blog&p=758"},"modified":"2024-09-05T16:35:18","modified_gmt":"2024-09-05T08:35:18","slug":"low-voltage-power-supply-systems","status":"publish","type":"blog","link":"https:\/\/www.britecelectric.com\/hu\/blog\/low-voltage-power-supply-systems\/","title":{"rendered":"Kisfesz\u00fclts\u00e9g\u0171 t\u00e1pegys\u00e9gek"},"content":{"rendered":"IEC terminol\u00f3gia<\/strong>\r\n\r\nInternational standard IEC 60364 distinguishes three families of earthing arrangements, using the two-letter codes TN, TT, and IT.\r\n\r\nThe first letter indicates the connection between earth and the power-supply equipment (generator or transformer):\r\n\r\n\u201cT\u201d \u2014 Direct connection of a point with earth\r\n\r\n\u201cI\u201d \u2014 No point is connected with earth, except perhaps via high impedance.\r\n\r\nThe second letter indicates the connection between earth or network and the electrical device being supplied:\r\n\r\n\u201cT\u201d \u2014 Earth connection is by a local direct connection to earth, usually via a ground rod.\r\n\r\n\u201cN\u201d \u2014 the earth connection is supplied by the electricity supply network, either separately to the neutral conductor (TN-S), combined with the neutral conductor (TN-C), or both (TN-C-S). These are discussed below.\r\n\r\nA TN h\u00e1l\u00f3zatok t\u00edpusai<\/strong>\r\n\r\nIn a TN earthing system, one of the points in the generator or transformer is connected with earth, usually the star point in a three-phase system. The body of the electrical device is connected with earth via this earth connection at the transformer. This arrangement is a current standard for residential and industrial electric systems particularly in Europe.\r\n\r\nThe conductor that connects the exposed metallic parts of the consumer\u2019s electrical installation is called protective earth (PE; see also: Ground). The conductor that connects to the star point in a three-phase system, or that carries the return current in a single-phase system, is called neutral (N). Three variants of TN systems are distinguished:\r\n\r\nTN\u2212S<\/strong>\r\n\r\nA PE \u00e9s N k\u00fcl\u00f6n\u00e1ll\u00f3 vezet\u00e9kek, amelyek csak az \u00e1ramforr\u00e1s k\u00f6zel\u00e9ben vannak \u00f6sszek\u00f6tve.\r\n\r\n\"\"\r\n\r\nTN-C<\/strong>\r\n\r\nA kombin\u00e1lt PEN-vezet\u0151 mind a PE, mind az N vezet\u0151 funkci\u00f3j\u00e1t ell\u00e1tja. (230\/400 V-os rendszereken, amelyeket \u00e1ltal\u00e1ban csak eloszt\u00f3 h\u00e1l\u00f3zatokhoz haszn\u00e1lnak)\r\n\r\n\"\"\r\n\r\nTN\u2212C\u2212S<\/strong>\r\n\r\nA rendszer egy r\u00e9sze kombin\u00e1lt PEN vezet\u00e9ket haszn\u00e1l, amely bizonyos pontokon k\u00fcl\u00f6n PE \u00e9s N vezet\u00e9kekre van felosztva. A kombin\u00e1lt PEN vezet\u00e9k jellemz\u0151en az al\u00e1llom\u00e1s \u00e9s az \u00e9p\u00fcletbe val\u00f3 bel\u00e9p\u00e9si pont k\u00f6z\u00f6tt tal\u00e1lhat\u00f3, a kiszolg\u00e1l\u00f3fejben pedig a f\u00f6ld \u00e9s a nulla van elv\u00e1lasztva. Az Egyes\u00fclt Kir\u00e1lys\u00e1gban ezt a rendszert t\u00f6bbsz\u00f6r\u00f6s v\u00e9d\u0151f\u00f6ldel\u00e9snek (PME) is ismerik, mivel a kombin\u00e1lt nulla-f\u00f6ldelvezet\u0151t a lehet\u0151 legr\u00f6videbb \u00faton k\u00f6tik a forr\u00e1sn\u00e1l l\u00e9v\u0151 helyi f\u00f6ldel\u0151 rudakhoz.\u00e9s id\u0151k\u00f6z\u00f6nk\u00e9nt az eloszt\u00f3h\u00e1l\u00f3zatok ment\u00e9n minden helyis\u00e9gbe, hogy biztos\u00edts\u00e1k mind a rendszer f\u00f6ldel\u00e9s\u00e9t, mind a berendez\u00e9sek f\u00f6ldel\u00e9s\u00e9t ezeken a helyeken. Ausztr\u00e1li\u00e1ban \u00e9s \u00daj-Z\u00e9landon hasonl\u00f3 rendszereket t\u00f6bbsz\u00f6r\u00f6s f\u00f6ldelt semlegesnek (MEN), \u00c9szak-Amerik\u00e1ban pedig t\u00f6bb f\u00f6ldelt semlegesnek (MGN) jel\u00f6lnek.\r\n\r\n\"\"\r\n\r\nTT h\u00e1l\u00f3zat<\/strong>\r\n\r\nA TT f\u00f6ldel\u0151rendszerben a fogyaszt\u00f3 v\u00e9d\u0151f\u00f6ldel\u00e9si csatlakoz\u00e1s\u00e1t helyi f\u00f6ldel\u0151 elektr\u00f3da biztos\u00edtja, a gener\u00e1torn\u00e1l pedig egy m\u00e1sik \u00f6n\u00e1ll\u00f3an van felszerelve. A kett\u0151 k\u00f6z\u00f6tt nincs \u2018f\u00f6ldvezet\u00e9k\u2019. A hibahurok impedanci\u00e1ja magasabb, \u00e9s hacsak az elektr\u00f3da impedanci\u00e1ja nem nagyon alacsony, a TT-rendszerben mindig RCD-nek (GFCI) kell lennie az els\u0151 lev\u00e1laszt\u00f3nak.\r\n\r\n\"\"\r\n\r\ninformatikai h\u00e1l\u00f3zat<\/strong>\r\n\r\nInformatikai h\u00e1l\u00f3zatban az elektromos eloszt\u00f3 rendszernek egy\u00e1ltal\u00e1n nincs f\u00f6ldel\u00e9si kapcsolata, vagy csak nagy impedanci\u00e1j\u00fa kapcsolata van.\r\n\r\n\"\"","protected":false},"featured_media":780,"parent":0,"menu_order":183,"template":"","meta":{"_acf_changed":false},"blog_category":[8],"class_list":["post-758","blog","type-blog","status-publish","has-post-thumbnail","hentry","blog_category-company-news"],"acf":{"des":"International standard IEC 60364 distinguishes three families of earthing arrangements, using the two-letter codes TN, TT, and IT.","txt":"IEC terminology<\/strong>\r\n\r\nInternational standard IEC 60364 distinguishes three families of earthing arrangements, using the two-letter codes TN, TT, and IT.\r\n\r\nThe first letter indicates the connection between earth and the power-supply equipment (generator or transformer):\r\n\r\n\u201cT\u201d \u2014 Direct connection of a point with earth\r\n\r\n\u201cI\u201d \u2014 No point is connected with earth, except perhaps via high impedance.\r\n\r\nThe second letter indicates the connection between earth or network and the electrical device being supplied:\r\n\r\n\u201cT\u201d \u2014 Earth connection is by a local direct connection to earth, usually via a ground rod.\r\n\r\n\u201cN\u201d \u2014 the earth connection is supplied by the electricity supply network, either separately to the neutral conductor (TN-S), combined with the neutral conductor (TN-C), or both (TN-C-S). These are discussed below.\r\n\r\nTypes of TN networks<\/strong>\r\n\r\nIn a TN earthing system, one of the points in the generator or transformer is connected with earth, usually the star point in a three-phase system. The body of the electrical device is connected with earth via this earth connection at the transformer. This arrangement is a current standard for residential and industrial electric systems particularly in Europe.\r\n\r\nThe conductor that connects the exposed metallic parts of the consumer\u2019s electrical installation is called protective earth (PE; see also: Ground). The conductor that connects to the star point in a three-phase system, or that carries the return current in a single-phase system, is called neutral (N). Three variants of TN systems are distinguished:\r\n\r\nTN\u2212S<\/strong>\r\n\r\nPE and N are separate conductors that are connected together only near the power source.\r\n\r\n\"\"\r\n\r\nTN\u2212C<\/strong>\r\n\r\nA combined PEN conductor fulfills the functions of both a PE and an N conductor. (On 230\/400 V systems normally only used for distribution networks)\r\n\r\n\"\"\r\n\r\nTN\u2212C\u2212S<\/strong>\r\n\r\nPart of the system uses a combined PEN conductor, which is at some point split up into separate PE and N lines. The combined PEN conductor typically occurs between the substation and the entry point into the building, and earth and neutral are separated in the service head. In the UK, this system is also known as protective multiple earthing (PME), because of the practice of connecting the combined neutral-and-earth conductor via the shortest practicable route to local earth rods at the source and at intervals along the distribution networks to each premises, to provide both system earthing and equipment earthing at each of these locations. Similar systems in Australia and New Zealand are designated as multiple earthed neutral (MEN) and, in North America, as multi-grounded neutral (MGN).\r\n\r\n\"\"\r\n\r\nTT network<\/strong>\r\n\r\nIn a TT earthing system, the protective earth connection for the consumer is provided by a local earth electrode, and there is another independently installed at the generator. There is no \u2018earth wire\u2019 between the two. The fault loop impedance is higher, and unless the electrode impedance is very low indeed, a TT installation should always have an RCD (GFCI) as its first isolator.\r\n\r\n\"\"\r\n\r\nIT network<\/strong>\r\n\r\nIn an IT network, the electrical distribution system has no connection to earth at all, or it has only a high-impedance connection.\r\n\r\n\"\""},"_links":{"self":[{"href":"https:\/\/www.britecelectric.com\/hu\/wp-json\/wp\/v2\/blog\/758","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.britecelectric.com\/hu\/wp-json\/wp\/v2\/blog"}],"about":[{"href":"https:\/\/www.britecelectric.com\/hu\/wp-json\/wp\/v2\/types\/blog"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.britecelectric.com\/hu\/wp-json\/wp\/v2\/media\/780"}],"wp:attachment":[{"href":"https:\/\/www.britecelectric.com\/hu\/wp-json\/wp\/v2\/media?parent=758"}],"wp:term":[{"taxonomy":"blog_category","embeddable":true,"href":"https:\/\/www.britecelectric.com\/hu\/wp-json\/wp\/v2\/blog_category?post=758"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}