Technical Information Power And Control Cables Power Appendixes Guide to the Wiring Regulations Earthing arrangements (Schematics) Page Earthing arrangements (Schematics)
| Earthing arrangements (Schematics) | |
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| TN-C System earthing | TN-S System earthing |
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| TN-C-S System earthing with PME | TN-C-S System earthing with PNB |
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| TT System earthing | IT System earthing |
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Cost : TN networks save the cost of a low-impedance earth connection at the site of each consumer. Such a connection (a buried metal structure) is required to provide protective earth in IT and TT systems. TN-C networks save the cost of an additional conductor needed for separate N and PE connections. However, to mitigate the risk of broken neutrals, special cable types and lots of connections to earth are needed. |
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Application examples : * Most of modern homes in Europe have a TN-C-S earthing system . * Laboratory rooms, medical facilities, construction sites, repair workshops, mobile electrical installations, and other environments that are supplied via engine-generators where there is an increased risk of insulation faults, often use an IT earthing arrangement supplied from isolation transformers . * In remote areas, where the cost of an additional PE conductor outweighs the cost of a local earth connection, TT networks are commonly used in some countries |
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