Iiparamitha ze-low voltage breaker circuit: ixesha elifutshane lokumelana nangoku (Icw), isetyenziselwa ntoni le parameter?

Ukumelana nexesha elifutshane (Icw):Ubuchule beumephuli wojikelezoukumelana no-0.05, 0.1, 0.25, 0.5 okanye 1s ngaphandle kokukhubeka kumbane onikiweyo, i-short-circuit current, okanye i-power factor.
Ilinganiswe ngexesha elifutshane lokumelana nombane, okwabizwa ngokuba yi-thermal stable current, ngumbane osebenzayo onokuthi i-breaker circuit okanye esinye isixhobo singakwazi ukumelana nexesha elifutshane elichaziweyo.Ubungakanani bayo bulingana nokulinganisa i-short-circuit current kwaye ixesha lidla ngokuba yi-3 okanye i-4 imizuzwana.

I-Icw yisalathiso sokuvavanya ukuzinza kombane kunye nokuzinza kwe-thermal ye-breaker circuit kuhambo olufutshane lokulibaziseka.Yeyokuqhelisa isekethe yeklasi B.Ngesiqhelo, ubuncinci VALUE be-Icw bu:

Xa ku-≤2500A, yi-12In okanye i-5kA,

Xa Kwi>2500A, yi-30kA

(KWE-YUW1_2000, i-Icw yi-400V, 50kA; ye-DW45_3200, i-Icw yi-400V, 65kA).

I-Icw ithelwe ngexesha elifutshane ukumelana nangoku:Umenzi uthi i-RMS iyanyamezeleka ixesha elifutshane elichazwe ngoku kunye nexesha linokuthi lithathwe njenge-RMS enyamezelekayo kwimveliso yexesha eliqingqiweyo, phantsi kweemeko ezifanelekileyo, kwisethi epheleleyo yezixhobo kunye nezixhobo zombane.Kodwa ubume beemveliso ezahlukeneyo azifani, inkcazo yokulinganiswa kwexesha elifutshane lokunyamezela ixabiso langoku aliyi kufana ngokupheleleyo, ingundoqo yalo manqaku alandelayo:

• Ukuqinisekisa ukuthembeka konikezelo lwamandla enkqubo;

• Ngesiseko sokuqinisekisa ukuthembeka kwenkqubo yokunikezelwa kwamandla, ukhuseleko lwemveliso ngokwayo

Kwinkqubo yokusabalalisa i-low-voltage, umlinganiselo we-short-circuit current unqunywe ngumbane omfutshane onokuthi wenzeke kwinkqubo kwindawo yokufakela kunye nexesha apho imveliso ngokwayo kunye nezinye iimveliso kwinkqubo inokumelana nombane.

I-Iec60364-4-43 umgangatho wokukhusela isiphaluka esifutshane senkqubo yokuhambisa amandla ichazwe ngokucacileyo: nakweyiphi na indawo kwi-loop ngenxa yesiphaluka esifutshane esibangelwa yiyo yonke yangoku, akufanele idlule ngoku, kwi-conductor yenkqubo ayidluli ubushushu obuvumelekileyo bomda. ixesha lokuqhawula.

Kwiisekethe ezimfutshane ezihlala imizuzwana emi-5, ixesha (t) lokuba umqhubi anyuke ukusuka kubushushu obuqhelekileyo obuvumelekileyo bokusebenza ukuya kubushushu obuphezulu obuvumelekileyo bunokubalwa ngokuqikelelwa ngolu hlobo lulandelayo:

T = (k * S/I) I-2K ye-coefficient yezinto, indawo yomqhubi we-S, i-short-circuit current value.

Ngaphezulu, khetha isixhobo soxinzelelo oluphantsi olulinganiswe ixesha elifutshane lokumelana nexabiso langoku, ukusuka kwindawo yofakelo lobuninzi be-short-circuit yangoku, umqhubi okanye ezinye izixhobo kwinkqubo ukusuka ekunyukeni kweqondo lokushisa ukuya kwiqondo lokushisa kunokumelana nomda wexesha, le miba mibini. ukuqwalasela, ekumiseleni indawo yokufakela i-short-circuit yangoku kunye nenkqubo inokumelana neyona ndlela iphezulu ye-short-circuit yangoku yexesha, Ikwamisela ukunyamezela kwexesha elifutshane lexesha langoku lezixhobo eziphantsi kwe-voltage kwindawo yofakelo.

Ngenxa yokuba ulwakhiwo kunye nokusetyenziswa kwezixhobo zombane ezahlukeneyo zahlukile, kukho iimfuno ezikhethekileyo zexabiso lexesha elifutshane lexeshana ngokwesiseko sokwanelisa ukhuseleko lwenkqubo:

• Kwizixhobo zombane ezinjengeebhasi, iikhabhathi zokuhambisa umbane ophantsi-voltage, kunye nokuqhawula uqhagamshelo, ixabiso langoku lee-short-circuit akufuneki libe ngaphantsi kwexabiso elilindelekileyo le-short-circuit yangoku kwindawo yofakelo, kunye nexesha elimiselweyo lexesha elimiselweyo ingabi mfutshane kunexesha lokusebenza kwezixhobo ezikhuselayo kwinkqubo.

• Kwizaphuli zesekethe zisebenzisa iklasi B, ixabiso langoku lonyamezelo olufutshane aliyi kuba ngaphantsi kwexabiso elilindelekileyo le-short-circuit yangoku kwindawo yofakelo, kwaye ixesha lomda wokunyamezela okufutshane aliyi kuba ngaphantsi kwexesha lokusebenza kwenkqubo esezantsi. -izixhobo zokukhusela ezisemgangathweni, kwaye uqinisekise ukukhethwa kunye nezixhobo zokukhusela ezisezantsi.

Ngoku, inkqubo umthamo unikezelo lwamandla kunye nokulindeleka elifutshane-yesekethe ukwanda ngoku, yokusasazwa inkqubo yebhasi ukwanda ingxinano, low-voltage izixhobo zombane miniaturization, ukuba kuphela ukusukelwa unyamezelo lwexeshana langoku phantsi komda ixesha elide ixabiso eliphezulu, enyanisweni. akukho kubaluleka okukhulu okusebenzayo.

Ngoko ke ngokokunokwenzeka ubuninzi beengongoma zofakelo lwesekethe yangoku kunye nezinye izixhobo ezikwinkqubo ziyakwazi ukumelana nobuninzi bexesha elifutshane lexesha, ukhetho olufanelekileyo lwezixhobo zombane kwindawo ekhuselekileyo phantsi komda wexesha elifutshane lokumelana nexabiso langoku, ngokungqinelana ne-0.5 s I-Icw values ​​ukuya kwiimviwo ibonakala ikwazile ukuhlangabezana neemfuno zokhuseleko lwesistim kunye nokusebenza ngempumelelo okukhulu.