{"id":799,"date":"2023-12-19T16:33:42","date_gmt":"2023-12-19T08:33:42","guid":{"rendered":"https:\/\/www.britecelectric.com\/?post_type=blog&p=799"},"modified":"2024-09-05T16:36:48","modified_gmt":"2024-09-05T08:36:48","slug":"799-2","status":"publish","type":"blog","link":"https:\/\/www.britecelectric.com\/fi\/blog\/799-2\/","title":{"rendered":"Ylij\u00e4nnitesuoja: mit\u00e4 tulee huomioida?"},"content":{"rendered":"Tehokas ylij\u00e4nnitesuoja ei ole yksinkertaisesti asennettu. Se on sovitettava yksil\u00f6llisesti \u2013 suojattavaan j\u00e4rjestelm\u00e4\u00e4n ja paikan p\u00e4\u00e4ll\u00e4 vallitseviin ymp\u00e4rist\u00f6olosuhteisiin. T\u00e4st\u00e4 syyst\u00e4 suunnittelun ja konseptin on oltava johdonmukaisia. T\u00e4m\u00e4 tarkoittaa, ett\u00e4 monet yksityiskohdat on otettava huomioon standardien ja m\u00e4\u00e4r\u00e4ysten tarkastelusta aina salamansuojavy\u00f6hykkeen mukaiseen luokitukseen asti.\r\n\r\nSalama- ja ylij\u00e4nnitesuojastandardit<\/strong>\r\n\r\nKansalliset ja kansainv\u00e4liset standardit antavat oppaan ukkos- ja ylij\u00e4nnitesuojakonseptin luomiseen sek\u00e4 yksitt\u00e4isten suojalaitteiden suunnitteluun.\r\n\r\nIEC 62305 mukainen ukkossuoja<\/strong>:<\/strong>\r\n\r\nPart 1: Characteristics of lightning strikes\r\n\r\nIn Part 1 of this standard [1], the characteristic properties of lightning strikes, the likelihood of occurrence, and the potential for hazard are taken into account.\r\n\r\nPart 2: Risk analysis\r\n\r\nThe risk analysis according to Part 2 of this standard [2] describes a process with which, first of all, the need for lightning protection for a physical system is analyzed. Various sources of damage, e.g., a direct lightning strike in the building, come into focus, as do the types of damage resulting from this:\r\n\r\n\u2022 Impact on health or loss of life\r\n\r\n\u2022 Loss of technical services for the public\r\n\r\n\u2022 Loss of irreplaceable objects of cultural significance\r\n\r\n\u2022 Financial losses\r\n\r\nThe financial benefits are determined as follows: how does the annual total cost for a lightning protection system compare to the costs of potential damage without a protection system? The cost evaluation is based on the outgoings for the planning, assembly, and maintenance of the lightning protection system.\r\n\r\nParts 3 and 4: Planning aids and specifications\r\n\r\nIf the risk assessment determines that lightning protection is required and cost-effective, then the type and scope of the specific measures for protection can be planned based on Parts 3 [3] and 4 [4] of this standard. The lightning protection level determined by risk management is decisive for determining the type and scope of the measures.\r\n\r\nFor physical structures that require an extremely high level of safety, almost all strikes must be captured and conducted away safely. For systems where a higher residual risk is acceptable, strikes with lower amplitudes are not captured.\r\n\r\nYlij\u00e4nnitesuoja standardin IEC 60364-4-44 mukaan<\/strong>\r\n\r\nThis standard [5] describes the conditions in which surge protective devices are to be used in low-voltage systems to protect the electrical installation against surge voltages. The area of application is thereby limited to surge voltages caused by atmospheric influences or as a consequence of switching procedures that are transmitted by the power supply system. Direct lightning strikes in a structural system are not considered, only strikes in or in the vicinity of supply lines.\r\n\r\nLikewise, structural systems with an explosion risk as well as structural applications that could cause damage to the environment (e.g., petrochemical systems or nuclear power plants) are not included in the application of the standard. For these processes, lightning strike standard IEC 62305 is to be used exclusively.\r\n\r\nSurge protective devices should be used if transient overvoltage could have effects on the following:\r\n\r\n\u2022 Human lives, e.g., safety systems, hospitals\r\n\r\n\u2022 Public and cultural institutions, e.g., loss of public services, IT centers, museums\r\n\r\n\u2022 Industrial or business activities, e.g., hotels, banks, production systems, farms.\r\n\r\nPerussuojatoimenpiteet ja -varusteet<\/strong>\r\n\r\nIn order to consistently protect a structural system from lightning strikes and surge voltages, various protective measures or equipment that are tailored to one another are required. A broad division can be made as follows:\r\n\r\n\u2022 External lightning protection\r\n\r\n\u2022 Internal lightning protection\r\n\r\n\u2022 Grounding and equipotential bonding\r\n\r\n\u2022 Coordinated SPD system\r\n\r\nUlkoinen ukkossuojaus<\/strong>\r\n\r\nUlkoinen salamasuojaus (kuva 15) pyrkii ohjaamaan suojattavan kohteen l\u00e4helle tulevat iskut ja v\u00e4litt\u00e4m\u00e4\u00e4n salamavirran osumiskohdasta maahan. N\u00e4in ollen l\u00e4mp\u00f6-, magneetti- tai s\u00e4hk\u00f6vaikutus ei voi aiheuttaa vahinkoa. Ulkoinen ukkossuojaus on systemaattista: se koostuu ilmap\u00e4\u00e4tteest\u00e4, sulkimista ja maadoitusj\u00e4rjestelm\u00e4st\u00e4.\r\n\r\n\"10\"<\/strong>\r\n\r\nSis\u00e4inen ukkossuojaus<\/strong>\r\n\r\nThe internal lightning protection system should prevent dangerous spark formation inside the system. Sparks can be caused by lightning current in the external lightning protection system or in other conductive parts of the structural system.\r\n\r\nThe internal lightning protection system consists of equipotential bonding and the electrical insulation of external lightning protection systems.\r\n\r\nLightning protection equipotential bonding is a combination of measures that prevent potential differences. They mainly connect the lightning protection system to metal installations, internal systems, as well as electrical and electronic systems within the system.\u00a0This occurs by means of equipotential bonding lines, surge protective devices or isolating spark gaps.\r\n\r\nMaadoitus ja potentiaalintasaus<\/strong>\r\n\r\nMaadoitusj\u00e4rjestelm\u00e4n tarkoituksena on jakaa ja purkaa siepattu salamavirta maahan. T\u00e4ss\u00e4 maadoitusj\u00e4rjestelm\u00e4n tyyppi on t\u00e4rke\u00e4mpi kuin maadoitusvastus. Salamavirta on hyvin lyhyt pulssi, joka k\u00e4ytt\u00e4ytyy kuin korkeataajuinen virta. Tehokas potentiaalintasaus on my\u00f6s t\u00e4rke\u00e4\u00e4. Potentiaalin tasaus yhdist\u00e4\u00e4 kaikki s\u00e4hk\u00f6\u00e4 johtavat osat toisiinsa johtimien kautta \u2013 aktiiviset johtimet on suojattu ylij\u00e4nnitesuojalla. N\u00e4in tekem\u00e4ll\u00e4 sesuojaa kaikenlaisilta kytkimilt\u00e4.\r\n\r\nKoordinoitu SPD-j\u00e4rjestelm\u00e4<\/strong>\r\n\r\nA coordinated SPD system is understood to be a multi-level system of surge protective devices that are coordinated with each other.\r\n\r\nThe following steps are recommended in order to achieve a high-performance SPD system.\r\n\r\n\u2022\u00a0Divide the structural system into lightning protection zones\r\n\r\n\u2022 Incorporate all lines that cross between different zones into the local equipotential bonding using suitable SPDs\r\n\r\n\u2022 Coordinate different types of SPDs: the devices must address each other selectively in order to prevent individual components from overloading\r\n\r\n\u2022 Use short supply lines for the parallel connection of SPDs between active conductors and the equipotential bonding\r\n\r\n\u2022 Lay protected and unprotected lines separately\r\n\r\n\u2022 Only ground equipment via the respective SPD (recommended)\r\n\r\nSalamansuojavy\u00f6hykkeet<\/strong>\r\n\r\nDeciding where to install surge protective devices within a structural system is based on the lightning protection zone concept explained in Part 4 of the lightning protection standard IEC 62305 [4].\r\n\r\nIt divides structural systems into lightning protection zones (LPZ), and does so from outside to inside with decreasing lightning protection levels. In external zones only resistant equipment can be used. However, in internal zones, sensitive equipment can also be used. The individual zones are characterized and named as follows:\r\n\r\nLPZ 0A<\/strong>\r\n\r\nSuojaamaton alue rakennuksen ulkopuolella, jossa salama iskee suoraan, on mahdollista. Salamavirtojen suora kytkent\u00e4 linjoissa, salamaniskun vaimentamaton magneettikentt\u00e4\r\n\r\nLPZ 0B<\/strong>\r\n\r\nRakennuksen ulkopuolella oleva alue, joka on suojattu suorilta salamaniskuilta ilmap\u00e4\u00e4tteell\u00e4. Salaman iskun vaimentamaton magneettikentt\u00e4 aiheutti vain ylij\u00e4nnitevirtoja linjoille.\r\n\r\nLPZ 1<\/strong>\r\n\r\nRakennuksen sis\u00e4ll\u00e4 oleva alue, joka voi silti olla alttiina suurienergisille ylij\u00e4nnitteille tai aaltovirroille ja voimakkaille s\u00e4hk\u00f6magneettisille kentille\r\n\r\nLPZ 2<\/strong>\r\n\r\nRakennuksen sis\u00e4ll\u00e4 oleva alue, joka voi edelleen olla alttiina ylij\u00e4nnitteille tai ylij\u00e4nnitevirroille ja s\u00e4hk\u00f6magneettisille kentille, jotka ovat jo merkitt\u00e4v\u00e4sti heikentyneet.\r\n\r\nLPZ 3<\/strong>\r\n\r\nArea inside the building which may only be subjected to extremely low or hardly any surge voltages or surge currents and very weak or non-existent electromagnetic fields.\r\n\r\nAll lines that cross between zones must use coordinated surge protective devices. Their power values are based on the protection class to be achieved, which is determined according to legal specifications or by means of the risk analysis. When it comes to selecting surge protective devices, use the standard as a basis, assuming that 50% of the lightning current will be discharged to ground. The other 50% of the lightning current is directed to the electrical installation via the main equipotential bonding and from there must be conducted away from the SPD system.","protected":false},"featured_media":800,"parent":0,"menu_order":175,"template":"","meta":{"_acf_changed":false},"blog_category":[8],"class_list":["post-799","blog","type-blog","status-publish","has-post-thumbnail","hentry","blog_category-company-news"],"acf":{"des":"Effective surge protection is not just simply installed. It has to be individually coordinated \u2013 to the system that is to be protected and the ambient conditions that are prevalent on site.","txt":"Effective surge protection is not just simply installed. It has to be individually coordinated \u2013 to the system that is to be protected and the ambient conditions that are prevalent on site. For this reason, the design and concept must be consistent. This means many details must be taken into account, from considering the standards and stipulations right through to classification according to lightning protection zone.\r\n\r\nLightning and surge protection standards<\/strong>\r\n\r\nNational and international standards provide a guide to establishing a lightning and surge protection concept as well as the design of the individual protective devices.\r\n\r\nLightning protection according to IEC 62305<\/strong>:<\/strong>\r\n\r\nPart 1: Characteristics of lightning strikes\r\n\r\nIn Part 1 of this standard [1], the characteristic properties of lightning strikes, the likelihood of occurrence, and the potential for hazard are taken into account.\r\n\r\nPart 2: Risk analysis\r\n\r\nThe risk analysis according to Part 2 of this standard [2] describes a process with which, first of all, the need for lightning protection for a physical system is analyzed. Various sources of damage, e.g., a direct lightning strike in the building, come into focus, as do the types of damage resulting from this:\r\n\r\n\u2022 Impact on health or loss of life\r\n\r\n\u2022 Loss of technical services for the public\r\n\r\n\u2022 Loss of irreplaceable objects of cultural significance\r\n\r\n\u2022 Financial losses\r\n\r\nThe financial benefits are determined as follows: how does the annual total cost for a lightning protection system compare to the costs of potential damage without a protection system? The cost evaluation is based on the outgoings for the planning, assembly, and maintenance of the lightning protection system.\r\n\r\nParts 3 and 4: Planning aids and specifications\r\n\r\nIf the risk assessment determines that lightning protection is required and cost-effective, then the type and scope of the specific measures for protection can be planned based on Parts 3 [3] and 4 [4] of this standard. The lightning protection level determined by risk management is decisive for determining the type and scope of the measures.\r\n\r\nFor physical structures that require an extremely high level of safety, almost all strikes must be captured and conducted away safely. For systems where a higher residual risk is acceptable, strikes with lower amplitudes are not captured.\r\n\r\nSurge protection according to IEC 60364-4-44<\/strong>\r\n\r\nThis standard [5] describes the conditions in which surge protective devices are to be used in low-voltage systems to protect the electrical installation against surge voltages. The area of application is thereby limited to surge voltages caused by atmospheric influences or as a consequence of switching procedures that are transmitted by the power supply system. Direct lightning strikes in a structural system are not considered, only strikes in or in the vicinity of supply lines.\r\n\r\nLikewise, structural systems with an explosion risk as well as structural applications that could cause damage to the environment (e.g., petrochemical systems or nuclear power plants) are not included in the application of the standard. For these processes, lightning strike standard IEC 62305 is to be used exclusively.\r\n\r\nSurge protective devices should be used if transient overvoltage could have effects on the following:\r\n\r\n\u2022 Human lives, e.g., safety systems, hospitals\r\n\r\n\u2022 Public and cultural institutions, e.g., loss of public services, IT centers, museums\r\n\r\n\u2022 Industrial or business activities, e.g., hotels, banks, production systems, farms.\r\n\r\nBasic protective measures and equipment<\/strong>\r\n\r\nIn order to consistently protect a structural system from lightning strikes and surge voltages, various protective measures or equipment that are tailored to one another are required. A broad division can be made as follows:\r\n\r\n\u2022 External lightning protection\r\n\r\n\u2022 Internal lightning protection\r\n\r\n\u2022 Grounding and equipotential bonding\r\n\r\n\u2022 Coordinated SPD system\r\n\r\nExternal lightning protection<\/strong>\r\n\r\nExternal lightning protection (Fig. 15) aims to divert strikes which come near to the object to be protected and to transmit the lightning current from the point where it hits to ground. As such, no damage can be caused by means of thermal, magnetic or electrical effects. External lightning protection is systematic: it consists of the air-terminal, the arresters, and the grounding system.\r\n\r\n\"10\"<\/strong>\r\n\r\nInternal lightning protection<\/strong>\r\n\r\nThe internal lightning protection system should prevent dangerous spark formation inside the system. Sparks can be caused by lightning current in the external lightning protection system or in other conductive parts of the structural system.\r\n\r\nThe internal lightning protection system consists of equipotential bonding and the electrical insulation of external lightning protection systems.\r\n\r\nLightning protection equipotential bonding is a combination of measures that prevent potential differences. They mainly connect the lightning protection system to metal installations, internal systems, as well as electrical and electronic systems within the system.\u00a0This occurs by means of equipotential bonding lines, surge protective devices or isolating spark gaps.\r\n\r\nGrounding and equipotential bonding<\/strong>\r\n\r\nThe grounding system aims to distribute and discharge the captured lightning current to ground. Here, the type of grounding system is more important than the grounding resistance. The lightning current is a very short pulse that behaves like a high-frequency current. Effective equipotential bonding is also important. Equipotential bonding connects all electrically conductive parts with each other via conductors \u2013 active conductors are protected by surge protective devices. By doing so, it protects against all types of couplings.\r\n\r\nCoordinated SPD system<\/strong>\r\n\r\nA coordinated SPD system is understood to be a multi-level system of surge protective devices that are coordinated with each other.\r\n\r\nThe following steps are recommended in order to achieve a high-performance SPD system.\r\n\r\n\u2022\u00a0Divide the structural system into lightning protection zones\r\n\r\n\u2022 Incorporate all lines that cross between different zones into the local equipotential bonding using suitable SPDs\r\n\r\n\u2022 Coordinate different types of SPDs: the devices must address each other selectively in order to prevent individual components from overloading\r\n\r\n\u2022 Use short supply lines for the parallel connection of SPDs between active conductors and the equipotential bonding\r\n\r\n\u2022 Lay protected and unprotected lines separately\r\n\r\n\u2022 Only ground equipment via the respective SPD (recommended)\r\n\r\nLightning protection zones<\/strong>\r\n\r\nDeciding where to install surge protective devices within a structural system is based on the lightning protection zone concept explained in Part 4 of the lightning protection standard IEC 62305 [4].\r\n\r\nIt divides structural systems into lightning protection zones (LPZ), and does so from outside to inside with decreasing lightning protection levels. In external zones only resistant equipment can be used. However, in internal zones, sensitive equipment can also be used. The individual zones are characterized and named as follows:\r\n\r\nLPZ 0A<\/strong>\r\n\r\nUnprotected area outside a building in which direct lightning strikes\u00a0is\u00a0a possibility. Direct coupling of lightning currents in lines, unattenuated magnetic field of the lightning strike\r\n\r\nLPZ 0B<\/strong>\r\n\r\nArea outside the building that is protected from direct lightning strikes by means of an air-terminal. Unattenuated magnetic field of the lightning strike only induced surge currents on lines.\r\n\r\nLPZ 1<\/strong>\r\n\r\nArea inside the building which may still be subjected to high-energy surge voltages or surge currents and strong electromagnetic fields\r\n\r\nLPZ 2<\/strong>\r\n\r\nArea inside a building which may still be subjected to surge voltages or surge currents and electromagnetic fields that have already been significantly weakened.\r\n\r\nLPZ 3<\/strong>\r\n\r\nArea inside the building which may only be subjected to extremely low or hardly any surge voltages or surge currents and very weak or non-existent electromagnetic fields.\r\n\r\nAll lines that cross between zones must use coordinated surge protective devices. Their power values are based on the protection class to be achieved, which is determined according to legal specifications or by means of the risk analysis. When it comes to selecting surge protective devices, use the standard as a basis, assuming that 50% of the lightning current will be discharged to ground. The other 50% of the lightning current is directed to the electrical installation via the main equipotential bonding and from there must be conducted away from the SPD system."},"_links":{"self":[{"href":"https:\/\/www.britecelectric.com\/fi\/wp-json\/wp\/v2\/blog\/799","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.britecelectric.com\/fi\/wp-json\/wp\/v2\/blog"}],"about":[{"href":"https:\/\/www.britecelectric.com\/fi\/wp-json\/wp\/v2\/types\/blog"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.britecelectric.com\/fi\/wp-json\/wp\/v2\/media\/800"}],"wp:attachment":[{"href":"https:\/\/www.britecelectric.com\/fi\/wp-json\/wp\/v2\/media?parent=799"}],"wp:term":[{"taxonomy":"blog_category","embeddable":true,"href":"https:\/\/www.britecelectric.com\/fi\/wp-json\/wp\/v2\/blog_category?post=799"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}