{"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\/fr\/blog\/low-voltage-power-supply-systems\/","title":{"rendered":"Syst\u00e8mes d'alimentation basse tension"},"content":{"rendered":"Terminologie CEI<\/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 de r\u00e9seaux TN<\/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-S<\/strong>\r\n\r\nPE et N sont des conducteurs s\u00e9par\u00e9s qui sont connect\u00e9s ensemble uniquement \u00e0 proximit\u00e9 de la source d'alimentation.\r\n\r\n\"\"\r\n\r\nTN\u2212C<\/strong>\r\n\r\nUn conducteur PEN combin\u00e9 remplit les fonctions \u00e0 la fois de conducteur PE et de conducteur N. (Sur les syst\u00e8mes 230\/400 V normalement utilis\u00e9s uniquement pour les r\u00e9seaux de distribution)\r\n\r\n\"\"\r\n\r\nTN\u2212C\u2212S<\/strong>\r\n\r\nUne partie du syst\u00e8me utilise un conducteur PEN combin\u00e9, qui est \u00e0 un moment donn\u00e9 divis\u00e9 en lignes PE et N distinctes. Le conducteur PEN combin\u00e9 se trouve g\u00e9n\u00e9ralement entre la sous-station et le point d'entr\u00e9e dans le b\u00e2timent, et la terre et le neutre sont s\u00e9par\u00e9s dans la t\u00eate de service. Au Royaume-Uni, ce syst\u00e8me est \u00e9galement connu sous le nom de mise \u00e0 la terre multiple de protection (PME), en raison de la pratique consistant \u00e0 connecter le conducteur combin\u00e9 neutre et terre via le chemin le plus court possible aux piquets de terre locaux \u00e0 la source.et \u00e0 intervalles r\u00e9guliers le long des r\u00e9seaux de distribution jusqu'\u00e0 chaque local, pour assurer \u00e0 la fois la mise \u00e0 la terre du syst\u00e8me et la mise \u00e0 la terre des \u00e9quipements \u00e0 chacun de ces emplacements. Des syst\u00e8mes similaires en Australie et en Nouvelle-Z\u00e9lande sont d\u00e9sign\u00e9s comme neutre \u00e0 plusieurs mises \u00e0 la terre (MEN) et, en Am\u00e9rique du Nord, comme neutre \u00e0 plusieurs mises \u00e0 la terre (MGN).\r\n\r\n\"\"\r\n\r\nR\u00e9seau TT<\/strong>\r\n\r\nDans un syst\u00e8me de mise \u00e0 la terre TT, la connexion \u00e0 la terre de protection pour le consommateur est assur\u00e9e par une prise de terre locale, et une autre est install\u00e9e ind\u00e9pendamment au niveau du g\u00e9n\u00e9rateur. Il n\u2019y a pas de \u2018 fil de terre \u2019 entre les deux. L'imp\u00e9dance de la boucle de d\u00e9faut est plus \u00e9lev\u00e9e et, \u00e0 moins que l'imp\u00e9dance de l'\u00e9lectrode ne soit effectivement tr\u00e8s faible, une installation TT devrait toujours avoir un RCD (GFCI) comme premier isolateur.\r\n\r\n\"\"\r\n\r\nR\u00e9seau informatique<\/strong>\r\n\r\nDans un r\u00e9seau informatique, le syst\u00e8me de distribution \u00e9lectrique n'a aucune connexion \u00e0 la terre ou seulement une connexion \u00e0 haute imp\u00e9dance.\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\/fr\/wp-json\/wp\/v2\/blog\/758","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.britecelectric.com\/fr\/wp-json\/wp\/v2\/blog"}],"about":[{"href":"https:\/\/www.britecelectric.com\/fr\/wp-json\/wp\/v2\/types\/blog"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.britecelectric.com\/fr\/wp-json\/wp\/v2\/media\/780"}],"wp:attachment":[{"href":"https:\/\/www.britecelectric.com\/fr\/wp-json\/wp\/v2\/media?parent=758"}],"wp:term":[{"taxonomy":"blog_category","embeddable":true,"href":"https:\/\/www.britecelectric.com\/fr\/wp-json\/wp\/v2\/blog_category?post=758"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}