{"id":797,"date":"2023-12-19T16:31:05","date_gmt":"2023-12-19T08:31:05","guid":{"rendered":"https:\/\/www.britecelectric.com\/?post_type=blog&p=797"},"modified":"2024-09-05T16:36:33","modified_gmt":"2024-09-05T08:36:33","slug":"surge-protector-faq","status":"publish","type":"blog","link":"https:\/\/www.britecelectric.com\/fi\/blog\/surge-protector-faq\/","title":{"rendered":"Ylij\u00e4nnitesuojan UKK"},"content":{"rendered":"Kest\u00e4v\u00e4tk\u00f6 ylij\u00e4nnitesuojat ikuisesti?<\/strong>\r\n\r\nEi, he eiv\u00e4t. Joka kerta kun ylij\u00e4nnitesuoja ohjaa virtapiikin pois kytketyst\u00e4 laitteesta, suojan sis\u00e4inen rakenne vaurioituu hieman. Ajan my\u00f6t\u00e4 ylij\u00e4nnitesuojan osat, jotka pit\u00e4v\u00e4t liitetyn laitteen turvassa, lakkaavat toimimasta. Kuinka kauan t\u00e4m\u00e4 kest\u00e4\u00e4, riippuu virtapiikin taajuudesta ja voimakkuudesta.\r\n\r\nEiv\u00e4tk\u00f6 nykyiset suojat, kuten MCB, ELCB jne., riit\u00e4 suojaamaan ylij\u00e4nnitett\u00e4 vastaan?<\/strong>\r\n\r\nAll the existing protecting devices like MCB, ELCB etc. are current sensitive devices. They get activated based on a fault current. These devices are triggered when the fault current persists for duration of more than 3 to 20 milliseconds. However, the surge typically lasts for a few micro seconds only during which time it causes all the damage.\r\n\r\nHence the conventional devices like MCB, ELCB fuses etc. are not effective in protection against surges. In view of the above, special equipment called surge protection device which has a response time of two nanoseconds is required to be installed to protect against the surges.\r\n\r\nMik\u00e4 on virtapiike?<\/strong>\r\n\r\nVirtapiikki on piikki talosi johtojen l\u00e4pi kulkevassa s\u00e4hk\u00f6virrassa. Ne voivat vahingoittaa yleisi\u00e4 laitteita, herkk\u00e4\u00e4 AV-elektroniikkaa ja tietokonelaitteita.\r\n\r\nMit\u00e4 eri tekniikoita k\u00e4ytet\u00e4\u00e4n yhten\u00e4isasiakirjoissa?<\/strong>\r\n\r\nJotkut SPD:iss\u00e4 k\u00e4ytetyist\u00e4 suosituista teknologioista ovat seuraavat:\r\n
    \r\n \t
  1. i) Kaasupurkausputket<\/li>\r\n \t
  2. ii) Metallioksidivaristorit<\/li>\r\n<\/ol>\r\niii) Kipin\u00e4v\u00e4li\r\n
      \r\n \t
    1. iv) Zener-diodi<\/li>\r\n \t
    2. v) Silicon Avalanche -diodit<\/li>\r\n<\/ol>\r\nN\u00e4ist\u00e4 kaasupurkausputket, metallioksidivaristorit ja kipin\u00e4v\u00e4li ovat suosituimpia ylij\u00e4nnitesuojatyyppej\u00e4.\r\n\r\nMik\u00e4 aiheuttaa virtapiikin?<\/strong>\r\n\r\nSuurin osa virtapiikeist\u00e4 tulee kotisi sis\u00e4lt\u00e4. Virtapiikit johtuvat monista eri tekij\u00f6ist\u00e4, mukaan lukien ankarat s\u00e4\u00e4olosuhteet, vialliset tai vaurioituneet s\u00e4hk\u00f6johdot tai suuritehoisen s\u00e4hk\u00f6laitteen, kuten ilmastointilaitteen tai suuren s\u00e4hk\u00f6moottorin, \u00e4killinen k\u00e4ynnistyminen ja sammuminen.\r\n\r\nValitaanko SPD-luokitukset linjavirran mukaan?<\/strong>\r\n\r\nYleens\u00e4 s\u00e4hk\u00f6virtapiiriin asennetut SPD:t on kytketty rinnan ja ovat siten riippumattomia kuormitusvirrasta (linjavirrasta).\r\n\r\nMiksi murehtia virtapiikkej\u00e4?<\/strong>\r\n\r\nVoimakkaat virtapiikit voivat pyyhki\u00e4 kodin laitteet hetkess\u00e4. Myrskyjen aiheuttamien aaltojen lis\u00e4ksi keskim\u00e4\u00e4r\u00e4inen koti voi kokea useita \u201cpiilotettuja\u201d aaltoja p\u00e4iv\u00e4ss\u00e4 muista eri l\u00e4hteist\u00e4. N\u00e4m\u00e4 pienemm\u00e4t j\u00e4nnitteet aiheuttavat kumulatiivisia vaurioita elektroniikkaan, lyhent\u00e4en niiden k\u00e4ytt\u00f6ik\u00e4\u00e4 ja lopulta aiheuttaen niiden ep\u00e4onnistumisen.\r\n\r\nKuinka m\u00e4\u00e4ritt\u00e4\u00e4, mink\u00e4 tyyppiset SPD:t asennetaan tiettyyn paikkaan?<\/strong>\r\n\r\nSPD:n valinta tietyss\u00e4 paikassa riippuu:\r\n
        \r\n \t
      1. a) Sijainnin topografia salamaniskujen perusteella.<\/li>\r\n \t
      2. b) Alttius kytkent\u00e4piikeille suurten kuormien l\u00e4heisyydess\u00e4 \/ kytketty maaseutusy\u00f6tt\u00f6\u00f6n jne.<\/li>\r\n \t
      3. c) Piiriin kytketyn laitteen herkkyys.<\/li>\r\n<\/ol>\r\nNormally SPDs with Class-B & C are installed at the main panels and SPDs with Class-C rate are installed at the sub panels. The ratings for class-B, SPDs shall be a minimum of 12.5 KA Iimp.\r\n\r\nFor the Class-C (Imax. rating), it should be, a minimum of 40 kA at the sub panels.\r\n\r\nFor the Class-D SPDs which are installed near sensitive equipment, the criteria shall be the residual voltage or the protection level which should be lower than the temporary over voltage withstanding capacity of the protected equipment.\r\n\r\nMit\u00e4 ylij\u00e4nnitesuoja tekee?<\/strong>\r\n\r\nYlij\u00e4nnitesuoja suojaa elektroniikkaa ylij\u00e4nnitepiikkien ja j\u00e4nnitepiikkien haitallisilta vaikutuksilta. Ylij\u00e4nnitesuojat voivat absorboida ja haihduttaa ylij\u00e4nnitevirtaa niin, ett\u00e4 liitetyt laitteet ovat suojassa ylij\u00e4nnitteelt\u00e4.\r\n\r\nMist\u00e4 tiet\u00e4\u00e4, ett\u00e4 asennettu SPD toimii?<\/strong>\r\n\r\nKoska SPD:t on aina kytketty rinnan s\u00e4hk\u00f6piirin kanssa, ei normaalin kulkusuunnan aikana voida tiet\u00e4\u00e4, ovatko ne toimintakunnossa vai eiv\u00e4t. Siksi on v\u00e4ltt\u00e4m\u00e4t\u00f6nt\u00e4 saada paikallinen ja kauko-indikaatio s\u00e4hk\u00f6isen kosketuksen avulla, jotta voidaan tiet\u00e4\u00e4 ja seurata SPD:n terveytt\u00e4.\r\n\r\nOnko SPD:n erillinen maadoitus tarpeen?<\/strong>\r\n\r\nSPD:ille ei tarvitse olla erillist\u00e4 tai omistettua maadoitusta. SPD:t tulee aina kytke\u00e4 yleiseen maadoitusverkkoon.\r\n\r\nOnko hyv\u00e4 maadoitus v\u00e4ltt\u00e4m\u00e4t\u00f6n SPD:n tehokkaalle toiminnalle?<\/strong>\r\n\r\nKaikki SPD:t toimivat ohjaamalla ylim\u00e4\u00e4r\u00e4isen energian maahan. T\u00e4st\u00e4 syyst\u00e4 on v\u00e4ltt\u00e4m\u00e4t\u00f6nt\u00e4, ett\u00e4 SPD:hen kytketyn maadoitusj\u00e4rjestelm\u00e4n on oltava tehokkaassa toimintakunnossa, jotta aaltovirta voi kulkea maahan esteett\u00e4.\r\n\r\nOvatko SPD:t saatavilla muihin sovelluksiin kuin s\u00e4hk\u00f6piireihin, kuten puhelinlinjoihin, datalinjoihin jne.?<\/strong>\r\n\r\nSPD:t ovat varmasti saatavilla jokaiselle piirille, kuten puhelinlinjoille, datalinjoille, Ethernet-linjoille, signaalilinjoille jne. Kaikissa n\u00e4iss\u00e4 piireiss\u00e4 SPD:t on kytketty sarjaan.\r\n\r\nRiitt\u00e4\u00e4k\u00f6 ensisijaiset SPD:t yksin laitteiden suojaamiseen?<\/strong>\r\n\r\nEi, pienist\u00e4 tiloista suuriin tiloihin on yleens\u00e4 tarpeen omaksua per\u00e4kk\u00e4inen tai kerrostettu l\u00e4hestymistapa, jossa ensisijainen suojaus asennetaan palvelun sis\u00e4\u00e4nk\u00e4yntipaneeliin ja toissijainen suojaus haarapaneeleihin. Jokainen laitos vaatii yksil\u00f6llisen analyysin oikean suojan m\u00e4\u00e4ritt\u00e4miseksi k\u00e4ytett\u00e4v\u00e4n laitteiston tarpeisiin. Voi jopa olla tarpeen sis\u00e4llytt\u00e4\u00e4 lis\u00e4k\u00e4ytt\u00f6pisteen SPD:t, jos t\u00e4m\u00e4 laite sijaitsee jonkin matkan p\u00e4\u00e4ss\u00e4 sy\u00f6tt\u00f6paneelista. Kaskadimainen l\u00e4hestymistapaIEEE suosittelee, ja t\u00e4m\u00e4ntyyppinen l\u00e4hestymistapa tarjoaa tehokkaimman ylij\u00e4nnitesuojan koko laitoksessa. Jos haluat lis\u00e4tietoja SPD:n hakemisesta, valitse ymp\u00e4rist\u00f6tyyppi, josta olet kiinnostunut: teollisuus-, kaupallinen tai asuinalue.\r\n\r\nMiksi tarvitsen SPD:n, kun minulla on jo erotusmuuntaja?<\/strong>\r\n\r\nEristysmuuntajat tarjoavat eritt\u00e4in hyv\u00e4n yhteismuotoisen hylk\u00e4yksen, mutta ne eiv\u00e4t tarjoa hyv\u00e4\u00e4 differentiaalista (normaali) moodien hylk\u00e4\u00e4mist\u00e4. Toisin sanoen, ylij\u00e4nnite, joka on asetettu tasaisesti sek\u00e4 linjan (L) ett\u00e4 nollajohtimien (N) p\u00e4\u00e4lle, hylk\u00e4\u00e4 eristysmuuntajan, kun taas L- ja N-johtimien v\u00e4lill\u00e4 esiintyv\u00e4 ylij\u00e4nnite kulkee muuntajan l\u00e4pi. Muista my\u00f6s, ett\u00e4 suurin osa transienteista aiheutuu laitoksen kuormista, n\u00e4iden kuormituspuolella.muuntajat. N\u00e4iden sis\u00e4isesti syntyvien transienttien vaikutusten minimoimiseksi laitteesta toiseen tulisi sijoittaa SPD.","protected":false},"featured_media":798,"parent":0,"menu_order":176,"template":"","meta":{"_acf_changed":false},"blog_category":[8],"class_list":["post-797","blog","type-blog","status-publish","has-post-thumbnail","hentry","blog_category-company-news"],"acf":{"des":"Do surge protectors last forever?No, they do not. Each time a surge protector reroutes a power surge away from your connected equipment, the internal structure of the protector takes a little bit of damage.","txt":"Do surge protectors last forever?<\/strong>\r\n\r\nNo, they do not. Each time a surge protector reroutes a power surge away from your connected equipment, the internal structure of the protector takes a little bit of damage. Over time the parts of the surge protector that keep your connected equipment safe simply stop working. How long this takes depends on the frequency and strength of power surges.\r\n\r\nAre the existing protections like MCB, ELCB etc. not sufficient to protect against surges?<\/strong>\r\n\r\nAll the existing protecting devices like MCB, ELCB etc. are current sensitive devices. They get activated based on a fault current. These devices are triggered when the fault current persists for duration of more than 3 to 20 milliseconds. However, the surge typically lasts for a few micro seconds only during which time it causes all the damage.\r\n\r\nHence the conventional devices like MCB, ELCB fuses etc. are not effective in protection against surges. In view of the above, special equipment called surge protection device which has a response time of two nanoseconds is required to be installed to protect against the surges.\r\n\r\nWhat is a power surge?<\/strong>\r\n\r\nA power surge is a spike in the electrical current flowing through the wires of your house. They can damage common appliances, sensitive AV electronics and computer equipment.\r\n\r\nWhat are the different technologies used in SPDs?<\/strong>\r\n\r\nSome of the popular technologies used in SPDs are the following:\r\n
          \r\n \t
        1. i) Gas discharge tubes<\/li>\r\n \t
        2. ii) Metal oxide varistors<\/li>\r\n<\/ol>\r\niii) Spark gap\r\n
            \r\n \t
          1. iv) Zener diode<\/li>\r\n \t
          2. v) Silicon Avalanche diodes<\/li>\r\n<\/ol>\r\nAmong these, gas discharge tubes, metal oxide varistors and spark gap are the most popular types of surge arresters.\r\n\r\nWhat causes a power surge?<\/strong>\r\n\r\nMost power surges stem from inside your home. Power surges are caused by many different factors, including severe weather, faulty or damaged electric wiring or the sudden turning on and off of a high power electrical device like an air conditioner or large electric motor.\r\n\r\nAre the SPDs ratings to be selected depending on the line current?<\/strong>\r\n\r\nGenerally, the SPDs installed on the electrical Power circuit are connected in parallel and hence will be independent of load (line) current.\r\n\r\nWhy worry about power surges?<\/strong>\r\n\r\nStrong power surges can wipe out your home equipment in an instant. In addition to surges caused by storms, the average home can experience multiple \u201chidden\u201d surges a day from other various sources. These smaller surges cause cumulative damage to electronics, shortening their life and eventually causing them to fail.\r\n\r\nHow to determine what types of SPDs are to be installed at a given location?<\/strong>\r\n\r\nThe selection of SPDs at a given location depends on:\r\n
              \r\n \t
            1. a) The topography of the location in terms of lightning strikes.<\/li>\r\n \t
            2. b) Susceptibility to switching surges in terms of proximity to large loads \/ connected to rural feeder etc.<\/li>\r\n \t
            3. c) Sensitivity of the equipment connected to the circuit.<\/li>\r\n<\/ol>\r\nNormally SPDs with Class-B & C are installed at the main panels and SPDs with Class-C rate are installed at the sub panels. The ratings for class-B, SPDs shall be a minimum of 12.5 KA Iimp.\r\n\r\nFor the Class-C (Imax. rating), it should be, a minimum of 40 kA at the sub panels.\r\n\r\nFor the Class-D SPDs which are installed near sensitive equipment, the criteria shall be the residual voltage or the protection level which should be lower than the temporary over voltage withstanding capacity of the protected equipment.\r\n\r\nWhat does a surge protector do?<\/strong>\r\n\r\nA surge protector safeguards electronics from the harmful effects of power surges and voltage spikes. Surge protectors can absorb and dissipate the power of a surge so that connected equipment is shielded from the surge.\r\n\r\nHow does one know the SPD installed is working?<\/strong>\r\n\r\nSince the SPDs are always connected in parallel to the electrical circuit, during the normal course it is not possible to know whether they are in working condition or not. Hence it is necessary to have a local and remote indication using electrical contact in order to know and monitor the healthiness of the SPD.\r\n\r\nIs it necessary for having separate grounding for SPDs?<\/strong>\r\n\r\nIt is not necessary to have a separate or dedicated grounding for SPDs. The SPDs should always be connected to the general earth grid.\r\n\r\nIs a good earthing system necessary for efficient working of the SPD?<\/strong>\r\n\r\nAll SPDs work by diverting the excess energy to the ground. Hence it is imperative that the earthing system connected to the SPD must be in efficient working condition so that the surge current can flow to the earth without any hindrance.\r\n\r\nAre SPDs available for applications other than the electrical circuit like telephone lines, data lines etc.?<\/strong>\r\n\r\nSPDs are certainly available for every circuit like telephone lines, data lines, Ethernet lines, signal lines etc. In all these circuits SPDs are connected in series.\r\n\r\nAre primary SPDs alone sufficient for equipment protection?<\/strong>\r\n\r\nNo, from a small facility to a large facility, it is usually necessary to adopt a cascaded or layered approach where primary protection is installed at the service entrance panel, and secondary protection at branch panels. Each facility requires individual analysis to determine the right protection to meet the needs of the equipment being used. It can even be necessary to include additional point-of-use SPDs if this equipment is located some distance from the supplying panel. A cascaded approach is recommended by the IEEE and this type of approach will provide the most effective surge protection throughout a facility. For more information on where to apply SPDs, select the type of environment you\u2019re interested in: industrial, commercial, or residential.\r\n\r\nWhy do I need an SPD when I already have an isolation transformer?<\/strong>\r\n\r\nIsolation transformers provide very good common mode rejection but do not provide good differential (normal) mode rejection. In other words, a surge superimposed equally on both the line (L) and neutral (N) conductors will see rejection by the isolation transformer, while a surge appearing differentially between the L and N conductors will pass through the transformer. Also, keep in mind the majority of transients are being generated by the loads within the facility, on the load side of these transformers. To minimize the effects of these internally generated transients from one piece of equipment to another an SPD should be placed."},"_links":{"self":[{"href":"https:\/\/www.britecelectric.com\/fi\/wp-json\/wp\/v2\/blog\/797","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\/798"}],"wp:attachment":[{"href":"https:\/\/www.britecelectric.com\/fi\/wp-json\/wp\/v2\/media?parent=797"}],"wp:term":[{"taxonomy":"blog_category","embeddable":true,"href":"https:\/\/www.britecelectric.com\/fi\/wp-json\/wp\/v2\/blog_category?post=797"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}