{"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\/ar\/blog\/low-voltage-power-supply-systems\/","title":{"rendered":"\u0623\u0646\u0638\u0645\u0629 \u0625\u0645\u062f\u0627\u062f \u0627\u0644\u0637\u0627\u0642\u0629 \u0630\u0627\u062a \u0627\u0644\u062c\u0647\u062f \u0627\u0644\u0645\u0646\u062e\u0641\u0636"},"content":{"rendered":"\u0645\u0635\u0637\u0644\u062d\u0627\u062a \u0627\u0644\u0644\u062c\u0646\u0629 \u0627\u0644\u0627\u0646\u062a\u062e\u0627\u0628\u064a\u0629 \u0627\u0644\u0645\u0633\u062a\u0642\u0644\u0629<\/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\n\u0623\u0646\u0648\u0627\u0639 \u0634\u0628\u0643\u0627\u062a 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\u2212S<\/strong>\r\n\r\nPE \u0648N \u0639\u0628\u0627\u0631\u0629 \u0639\u0646 \u0645\u0648\u0635\u0644\u0627\u062a \u0645\u0646\u0641\u0635\u0644\u0629 \u0645\u062a\u0635\u0644\u0629 \u0628\u0628\u0639\u0636\u0647\u0627 \u0627\u0644\u0628\u0639\u0636 \u0641\u0642\u0637 \u0628\u0627\u0644\u0642\u0631\u0628 \u0645\u0646 \u0645\u0635\u062f\u0631 \u0627\u0644\u0637\u0627\u0642\u0629.\r\n\r\n\"\"\r\n\r\nTN\u2212C<\/strong>\r\n\r\n\u064a\u0624\u062f\u064a \u0645\u0648\u0635\u0644 PEN \u0627\u0644\u0645\u062f\u0645\u062c \u0648\u0638\u0627\u0626\u0641 \u0643\u0644 \u0645\u0646 \u0645\u0648\u0635\u0644 PE \u0648N. (\u0641\u064a \u0623\u0646\u0638\u0645\u0629 230\/400 \u0641\u0648\u0644\u062a \u062a\u0633\u062a\u062e\u062f\u0645 \u0639\u0627\u062f\u0629 \u0644\u0634\u0628\u0643\u0627\u062a \u0627\u0644\u062a\u0648\u0632\u064a\u0639 \u0641\u0642\u0637)\r\n\r\n\"\"\r\n\r\nTN\u2212C\u2212S<\/strong>\r\n\r\n\u064a\u0633\u062a\u062e\u062f\u0645 \u062c\u0632\u0621 \u0645\u0646 \u0627\u0644\u0646\u0638\u0627\u0645 \u0645\u0648\u0635\u0644 PEN \u0645\u062f\u0645\u062c\u064b\u0627\u060c \u0648\u0627\u0644\u0630\u064a \u064a\u062a\u0645 \u062a\u0642\u0633\u064a\u0645\u0647 \u0641\u064a \u0645\u0631\u062d\u0644\u0629 \u0645\u0627 \u0625\u0644\u0649 \u062e\u0637\u0648\u0637 PE \u0648N \u0645\u0646\u0641\u0635\u0644\u0629. \u064a\u062d\u062f\u062b \u0645\u0648\u0635\u0644 PEN \u0627\u0644\u0645\u062f\u0645\u062c \u0639\u0627\u062f\u0629 \u0628\u064a\u0646 \u0627\u0644\u0645\u062d\u0637\u0629 \u0627\u0644\u0641\u0631\u0639\u064a\u0629 \u0648\u0646\u0642\u0637\u0629 \u0627\u0644\u062f\u062e\u0648\u0644 \u0625\u0644\u0649 \u0627\u0644\u0645\u0628\u0646\u0649\u060c \u0648\u064a\u062a\u0645 \u0641\u0635\u0644 \u0627\u0644\u0623\u0631\u0636 \u0648\u0627\u0644\u0645\u062d\u0627\u064a\u062f \u0641\u064a \u0631\u0623\u0633 \u0627\u0644\u062e\u062f\u0645\u0629. \u0641\u064a \u0627\u0644\u0645\u0645\u0644\u0643\u0629 \u0627\u0644\u0645\u062a\u062d\u062f\u0629\u060c \u064a\u064f\u0639\u0631\u0641 \u0647\u0630\u0627 \u0627\u0644\u0646\u0638\u0627\u0645 \u0623\u064a\u0636\u064b\u0627 \u0628\u0627\u0633\u0645 \u0627\u0644\u062a\u0623\u0631\u064a\u0636 \u0627\u0644\u0648\u0642\u0627\u0626\u064a \u0627\u0644\u0645\u062a\u0639\u062f\u062f (PME)\u060c \u0646\u0638\u0631\u064b\u0627 \u0644\u0645\u0645\u0627\u0631\u0633\u0629 \u062a\u0648\u0635\u064a\u0644 \u0627\u0644\u0645\u0648\u0635\u0644 \u0627\u0644\u0645\u062d\u0627\u064a\u062f \u0648\u0627\u0644\u0623\u0631\u0636\u064a \u0627\u0644\u0645\u062f\u0645\u062c \u0639\u0628\u0631 \u0623\u0642\u0635\u0631 \u0637\u0631\u064a\u0642 \u0639\u0645\u0644\u064a \u0625\u0644\u0649 \u0642\u0636\u0628\u0627\u0646 \u0627\u0644\u0623\u0631\u0636 \u0627\u0644\u0645\u062d\u0644\u064a\u0629 \u0639\u0646\u062f \u0627\u0644\u0645\u0635\u062f\u0631\u0648\u0639\u0644\u0649 \u0641\u062a\u0631\u0627\u062a \u0639\u0644\u0649 \u0637\u0648\u0644 \u0634\u0628\u0643\u0627\u062a \u0627\u0644\u062a\u0648\u0632\u064a\u0639 \u0644\u0643\u0644 \u0645\u0628\u0646\u0649\u060c \u0644\u062a\u0648\u0641\u064a\u0631 \u0643\u0644 \u0645\u0646 \u062a\u0623\u0631\u064a\u0636 \u0627\u0644\u0646\u0638\u0627\u0645 \u0648\u062a\u0623\u0631\u064a\u0636 \u0627\u0644\u0645\u0639\u062f\u0627\u062a \u0641\u064a \u0643\u0644 \u0645\u0648\u0642\u0639 \u0645\u0646 \u0647\u0630\u0647 \u0627\u0644\u0645\u0648\u0627\u0642\u0639. \u062a\u0645 \u062a\u0635\u0646\u064a\u0641 \u0627\u0644\u0623\u0646\u0638\u0645\u0629 \u0627\u0644\u0645\u0645\u0627\u062b\u0644\u0629 \u0641\u064a \u0623\u0633\u062a\u0631\u0627\u0644\u064a\u0627 \u0648\u0646\u064a\u0648\u0632\u064a\u0644\u0646\u062f\u0627 \u0639\u0644\u0649 \u0623\u0646\u0647\u0627 \u0645\u062d\u0627\u064a\u062f\u0629 \u0645\u062a\u0639\u062f\u062f\u0629 \u0627\u0644\u062a\u0623\u0631\u064a\u0636 (MEN)\u060c \u0648\u0641\u064a \u0623\u0645\u0631\u064a\u0643\u0627 \u0627\u0644\u0634\u0645\u0627\u0644\u064a\u0629\u060c \u0639\u0644\u0649 \u0623\u0646\u0647\u0627 \u0645\u062d\u0627\u064a\u062f\u0629 \u0645\u062a\u0639\u062f\u062f\u0629 \u0627\u0644\u062a\u0623\u0631\u064a\u0636 (MGN).\r\n\r\n\"\"\r\n\r\n\u0634\u0628\u0643\u0629 \u062a\u064a \u062a\u064a<\/strong>\r\n\r\n\u0641\u064a \u0646\u0638\u0627\u0645 \u0627\u0644\u062a\u0623\u0631\u064a\u0636 TT\u060c \u064a\u062a\u0645 \u062a\u0648\u0641\u064a\u0631 \u0627\u0644\u062a\u0648\u0635\u064a\u0644 \u0627\u0644\u0623\u0631\u0636\u064a \u0627\u0644\u0648\u0642\u0627\u0626\u064a \u0644\u0644\u0645\u0633\u062a\u0647\u0644\u0643 \u0628\u0648\u0627\u0633\u0637\u0629 \u0642\u0637\u0628 \u0643\u0647\u0631\u0628\u0627\u0626\u064a \u0623\u0631\u0636\u064a \u0645\u062d\u0644\u064a\u060c \u0648\u064a\u0648\u062c\u062f \u0622\u062e\u0631 \u0645\u062b\u0628\u062a \u0628\u0634\u0643\u0644 \u0645\u0633\u062a\u0642\u0644 \u0641\u064a \u0627\u0644\u0645\u0648\u0644\u062f. \u0644\u0627 \u064a\u0648\u062c\u062f \u2018\u0633\u0644\u0643 \u0623\u0631\u0636\u064a\u2019 \u0628\u064a\u0646 \u0627\u0644\u0627\u062b\u0646\u064a\u0646. \u062a\u0643\u0648\u0646 \u0645\u0642\u0627\u0648\u0645\u0629 \u062d\u0644\u0642\u0629 \u0627\u0644\u0635\u062f\u0639 \u0623\u0639\u0644\u0649\u060c \u0648\u0645\u0627 \u0644\u0645 \u062a\u0643\u0646 \u0645\u0642\u0627\u0648\u0645\u0629 \u0627\u0644\u0642\u0637\u0628 \u0627\u0644\u0643\u0647\u0631\u0628\u0627\u0626\u064a \u0645\u0646\u062e\u0641\u0636\u0629 \u062c\u062f\u064b\u0627 \u0628\u0627\u0644\u0641\u0639\u0644\u060c \u0641\u064a\u062c\u0628 \u0623\u0646 \u064a\u062d\u062a\u0648\u064a \u062a\u0631\u0643\u064a\u0628 TT \u062f\u0627\u0626\u0645\u064b\u0627 \u0639\u0644\u0649 RCD (GFCI) \u0643\u0639\u0627\u0632\u0644 \u0623\u0648\u0644.\r\n\r\n\"\"\r\n\r\n\u0634\u0628\u0643\u0629 \u062a\u0643\u0646\u0648\u0644\u0648\u062c\u064a\u0627 \u0627\u0644\u0645\u0639\u0644\u0648\u0645\u0627\u062a<\/strong>\r\n\r\n\u0641\u064a \u0634\u0628\u0643\u0629 \u062a\u0643\u0646\u0648\u0644\u0648\u062c\u064a\u0627 \u0627\u0644\u0645\u0639\u0644\u0648\u0645\u0627\u062a\u060c \u0644\u0627 \u064a\u0643\u0648\u0646 \u0644\u0646\u0638\u0627\u0645 \u0627\u0644\u062a\u0648\u0632\u064a\u0639 \u0627\u0644\u0643\u0647\u0631\u0628\u0627\u0626\u064a \u0623\u064a \u0627\u062a\u0635\u0627\u0644 \u0628\u0627\u0644\u0623\u0631\u0636 \u0639\u0644\u0649 \u0627\u0644\u0625\u0637\u0644\u0627\u0642\u060c \u0623\u0648 \u0623\u0646\u0647 \u064a\u062d\u062a\u0648\u064a \u0641\u0642\u0637 \u0639\u0644\u0649 \u0627\u062a\u0635\u0627\u0644 \u0639\u0627\u0644\u064a \u0627\u0644\u0645\u0642\u0627\u0648\u0645\u0629.\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\/ar\/wp-json\/wp\/v2\/blog\/758","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.britecelectric.com\/ar\/wp-json\/wp\/v2\/blog"}],"about":[{"href":"https:\/\/www.britecelectric.com\/ar\/wp-json\/wp\/v2\/types\/blog"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.britecelectric.com\/ar\/wp-json\/wp\/v2\/media\/780"}],"wp:attachment":[{"href":"https:\/\/www.britecelectric.com\/ar\/wp-json\/wp\/v2\/media?parent=758"}],"wp:term":[{"taxonomy":"blog_category","embeddable":true,"href":"https:\/\/www.britecelectric.com\/ar\/wp-json\/wp\/v2\/blog_category?post=758"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}