Juriya na ɗan gajeren lokaci (Icw): iyawar amai jujjuyawadon jure 0.05, 0.1, 0.25, 0.5 ko 1s ba tare da faɗuwa ba a wani ƙarfin lantarki da aka bayar, gajeriyar kewayawa, ko yanayin wuta.
Ƙididdigar ɗan gajeren lokaci jure halin yanzu, kuma aka sani da thermal barga halin yanzu, shine ingantaccen halin yanzu wanda na'ura mai karyawa ko wata na'ura za ta iya jurewa na ƙayyadadden lokaci.Girman sa yana daidai da ƙididdiga na gajeren zangon halin yanzu kuma lokacin yawanci shine 3 ko 4 seconds.
Icw shine ma'aunin kimanta daidaiton wutar lantarki da kwanciyar hankali mai zafi na mai watsewar kewayawa a cikin ɗan gajeren tafiyar jinkiri.Yana da na'urar kewayawa ajin B.Yawancin lokaci, mafi ƙarancin VALUE na Icw shine:
Lokacin A cikin ≤2500A, shine 12In ko 5kA,
Lokacin A> 2500A, shine 30kA
(DOMIN YUW1_2000, Icw shine 400V, 50kA; na DW45_3200, Icw shine 400V, 65kA).
Icw rated gajeren lokaci jure halin yanzu:Mai sana'anta yayi iƙirarin cewa RMS mai jurewa na ɗan gajeren lokaci da aka ayyana ta halin yanzu da lokaci ana iya ɗaukarsa azaman RMS mai jurewa ga samfur na ɗan lokaci, ƙarƙashin yanayin da ya dace, don cikakken saitin kayan aiki da kayan lantarki.Amma yanayin samfuran daban-daban ba iri ɗaya ba ne, ma'anar ƙimar haƙuri na ɗan gajeren lokaci ba zai zama iri ɗaya ba, ainihin sa shine galibin abubuwan da ke gaba:
- Tabbatar da amincin tsarin samar da wutar lantarki;
- Dangane da tabbatar da amincin tsarin samar da wutar lantarki, tsaro na samfurin da kansa
Don tsarin rarraba ƙananan ƙarancin wutar lantarki, ƙimar da aka ƙididdige shi an ƙaddara ta hanyar gajeren lokaci wanda zai iya faruwa a cikin tsarin a wurin shigarwa da kuma lokacin da samfurin kanta da sauran samfurori a cikin tsarin zasu iya jure wa halin yanzu.
Iec60364-4-43 misali don gajeriyar kariyar tsarin rarraba wutar lantarki ya bayyana a sarari: a kowane lokaci a cikin madauki saboda gajeriyar da'irar da ke haifar da duk abin da ke yanzu, bai kamata ya wuce na yanzu ba, a cikin jagorar tsarin bai wuce madaidaicin iyakar zafin jiki ba. na lokacin karyawa.
Don gajeriyar da'irar da ba ta wuce daƙiƙa 5 ba, lokacin (t) don jagorar ya tashi daga yanayin da ya dace da shi na yau da kullun zuwa matsakaicin zafin da aka yarda da shi ana iya ƙididdige shi ta hanyar dabara mai zuwa:
T = (k * S/I) 2K kayan haɗin gwiwa, yanki mai jagora S, I short-circuit darajar halin yanzu.
A sama, zaɓi kayan aiki mai ƙarancin ƙarfi wanda aka ƙididdige ƙimar juriya na ɗan gajeren lokaci na yanzu, daga wurin shigarwa na matsakaicin matsakaicin ɗan gajeren lokaci, jagora ko wasu kayan aiki a cikin tsarin daga hawan zafin jiki zuwa zafin jiki na iya jure iyakokin lokaci, wannan bangarorin biyu. don yin la'akari, a cikin ƙayyade matsakaicin matsakaicin matsakaicin matsakaicin wurin shigarwa na yanzu kuma tsarin zai iya jure wa matsakaicin matsakaicin matsakaicin lokaci, Hakanan yana ƙayyade juriya na ɗan gajeren lokaci na ƙananan kayan aiki a wurin shigarwa.
Saboda tsari da amfani da kayan aikin lantarki daban-daban sun bambanta, akwai wasu buƙatu na musamman don ƙimar ɗan gajeren lokaci na halin yanzu bisa tushen gamsar da amincin tsarin:
- Don kayan aikin lantarki irin su sandunan bas, ƙananan kabad ɗin rarraba wutar lantarki, da masu kashe haɗin kai, ƙimar gajeriyar kewayawa bai kamata ta kasance ƙasa da ƙimar da ake tsammani na ɗan gajeren lokaci ba a wurin shigarwa, kuma ya kamata ƙayyadadden lokacin ƙayyadaddun lokaci na yanzu ya kamata. Kada ku kasance ya fi guntu lokacin aiki na kayan aikin kariya a cikin tsarin.
- Don masu watsewar da'ira ta amfani da aji B, ƙimar haƙuri na ɗan gajeren lokaci ba za ta zama ƙasa da ƙimar da ake tsammani na ɗan gajeren lokaci ba a wurin shigarwa, kuma ƙarancin juriya na ɗan lokaci na yanzu ba zai zama ƙasa da lokacin aiki na tsarin ƙasa ba. -matakin na'urorin kariya, da tabbatar da zaɓi tare da ƙananan na'urori masu kariya.
Yanzu, da tsarin samar da wutar lantarki load da sa ran short-kewaye halin yanzu karuwa, rarraba bas tsarin yawa karuwa, low-ƙarfin lantarki lantarki kayan aiki miniaturization, idan kawai bin gajeren lokaci haƙuri halin yanzu a karkashin dogon lokaci iyaka na high darajar, a gaskiya,. babu wani babban amfani mai amfani.
Don haka bisa ga yuwuwar matsakaicin matsakaicin wuraren shigarwa na gajeriyar kewayawa na yanzu da sauran na'urori a cikin tsarin na iya jure matsakaicin matsakaicin gajeren lokaci na lokacin, zaɓi mai dacewa na kayan aikin lantarki a cikin aminci ƙarƙashin ƙayyadaddun ƙimar juriya na ɗan gajeren lokaci, a cikin daidai da ƙimar 0.5s Icw don jarrabawa da alama sun sami damar biyan buƙatun tsaro na tsarin da mafi girman inganci.