Intambo cross-kwesigaba sokubala. Uluhlu yokubala intambo cross-icandelo

Ukuze ubomi inkonzo ende kunye oluthembekileyo intambo kuyimfuneko ukukhetha nokubala. kweentambo zombane kokufaka ikakhulu ekhethiweyo icandelo umnqamlezo, ezisekelwe ubukhulu becala kumava. Ngamanye amaxesha oku kukhokelela iimpazamo. Ukubalwa intambo cross-candelo kuyimfuneko, kuqala kwiinto zonke, ngokwemiqathango ukhuseleko lombane. Bekuya kuba yinto ephosakeleyo, ukuba ucingo ubukhulu incinane okanye ezinkulu kuno oyifunayo.

Intambo cross-kwicandelo elisezantsi kakhulu

Eli tyala eyingozi kakhulu, ukususela nobushushu ye izinikezeli eliphezulu ingxinano ekhoyo ngoku, lo gama ukugcina ubushushu linyibilike kunye short circuit kwenzeka. Kusenokwenzeka kwakhona kuyaphula imililo zombane kwenzeka, kunye nabasebenzi ungafumana phantsi kwempixano. Ukuba intambo ukufaka ungumgqithi wesiphaluka, ivame kakhulu imisebenzi eza kudala ezinye kabi.

Icandelo umnqamlezo intambo ungaphezu ezifunwayo

Apha igqi- - lowo kwezoqoqosho. Ubukhulu umnqamlezo-candelo ucingo, kokukhona ebiza kakhulu kuyo. Ukuba wenza iintambo kulo lonke igumbi esima enkulu, kunokubiza isixa esikhulu. Ngamanye amaxesha kuyacetyiswa ukwenza ungeno engundoqo amakhulu cross-candelo, ukuba umthwalo kulindeleke ukuba lande kakhulu kwi Inetweki yekhaya.

Ukuba le ntambo ukubeka umatshini afanelekileyo isindwe alandelayo xa nayiphi na kubo kusebenza ndingumgqithi wesiphaluka.

Indlela ukubala intambo cross-icandelo?

Ngaphambi kokufakwa, kucetyiswa ukuba wenze ubalo lwe intambo cross-candelo umthwalo. umqhubi ngalinye amandla ethile, leyo kufuneka ibe ngaphantsi kwe kwiplagi yombane.

amandla yokubala

Indlela elula ukubala umthwalo iyonke phezu phambili. Intambo umthwalo ubalo cross-section azezi nokuzimisela kwamandla zizonke abathengi. Ngamnye kubo ixabiso layo njengoko kubonisiwe kwi umzimba okanye nencwadana leyo yokundwendwela. Emva koko, amandla iyonke yande ngokuphindwe 0.75. Oku kungenxa yokuba zonke izixhobo ayikwazi uvulwe ngaxeshanye. Kuba yokugqibela ubungakanani ekufuneka etafileni isetyenziselwa yokubala icandelo intambo.

Ukubalwa kwicandelo yangoku intambo

A indlela echanileyo ngakumbi na ukubalwa umthwalo yangoku. Intambo cross-kwesigaba sokubala senziwa ngokujonga ngokusweleka yangoku ngawo. formula olusetyenziswa womnatha ezi-:

I _Calc. = P / (U _nom ∙ cosφ),

apho P - umthwalo amandla, U _N. --mbane ombane (220 V).

Ukuba imveliso iyonke wolayisho esebenzayo yendlu yi-10 kW, i yangoku kuqikelelwa I _Calc. = 10000/220 ≈ 46 A. Xa ubalo kwenziwa intambo cross-icandelo ngoku, ukulungiswa kwi intambo ngokubekwa iimeko (echazwe kwezinye izintlu ezizodwa), kwakunye sindisa xa malunga phezulu nge-5 A. Ngenxa yoko umbane, I _Calc. = 46 + 5 = 51 A.

Ukutyeba uzimisele phantsi weefayili waphila. Intambo cross-icandelo ubalo usebenzisa spreadsheets yenza kube lula ukufumana ubukhulu elifanelekileyo ngoku kuvumelekile ixesha elide. Kuba iintambo ezingundoqo ezintathu-endlwini emoyeni, kuyimfuneko ukuba ukhethe inani kwicala elikhulu umnqamlezo-candelo umgangatho. Kuyinto 10 mm ^2. Ukuchaneka wokubala kuba self-ngetshekhi, usebenzisa i sokubala intanethi - yokubala intambo cross-candelo, apho zifumaneka kwezinye iindawo.

Le zokubasa cable xa yangoku ugeleza

Xa umthwalo luqalisile intambo ivelisa ubushushu:

Q = I ² YE W / cm

apho I - ngoku, R - zombane resistivity, n - inani macingo.

Ukusuka yokukhuluma kulandela ukuba imali amandla ngokomlinganiselo isikweri wire onqamlezwa nomsinga.

Ukubalwa kuvumelekile yangoku Umqhubi lobushushu zokufudumeza

Intambo ayikwazi ngokungenammiselo kuba shushu, ekubeni ubushushu dissipated kokusingqongileyo. Ekugqibeleni lizama lusekiwe kwaye nezinikezeli lobushushu rhoqo.

Ukuze inkqubo-karhulumente ngcembe lo ngokunxulumene ilandelayo ubamba:

P = Δt / ΣS = (t _x - t _CP) / (ΣS),

apho Δt = t _f -t _cp - umahluko phakathi lobushushu eliphakathi ngemithambo, ΣS - ukuxhathisa lobushushu.

Kuvumelekile yangoku eqhubekayo ayahamba intambo, ukususela athi:

I _Dop = √ ((t _ext - t _CP) / (RnΣS)),

apho ut _ext - lobushushu okuvunyelwe zokufudumeza iingcingo (ixhomekeke kuhlobo cable kunye nokufakwa USB). Ngokuqhelekileyo, akukho degrees 70 kwimo yesiqhelo kunye 80 - in likaxakeka.

Iimeko yobushushu wokuzibhubhisa ukusebenza, intambo

Xa intambo iyafakwa nayiphi medium, ubushushu kumiselwa yakheke nokufuma. Ibalwa resistivity umhlaba ukuthathwa ilingana 120 ohms ∙ ° C / W (udongwe ngesanti kwi ukufuma ka-12-14%). Ukucacisa imfuneko ukwazi ukwakhiwa engqongileyo, ngoko ke unako ukufumana kweelana izinto phezu kwetafile. Ukwandisa conductivity wobushushu ye esemseleni wawakhotha izele nodongwe. Abavumelekanga ukuba babe ku doti yakhe yokwakha kunye namatye.

transfer ubushushu intambo emoyeni iphantsi kakhulu. Oku mandundu ngakumbi xa ebekwe kwi-channel cable apho kukho layers umoya olongezelelweyo. Apha, umthwalo yangoku kufuneka incitshiswe kuthelekiswa ixabiso abaliweyo. Ezona mpawu zobuchwepheshe iintambo kunye ngcingo elikhokelayo lobushushu elifutshane yesekethe kuvumelekile ka-120 ° C for PVC usambathisa. ukumelana umhla- 70% yetotali kwaye ephambili izibalo. Ekuhambeni kwexesha, lo ukunyuka yokugquma conductivity ngenxa omiswe yayo. Oku kufuneka kuqwalaselwe izibalo.

Ukuhla ombane kule ntambo

Ngenxa yokuba izinikezeli ibe nokumelana zombane, kwamandla ngaphandle inxenye kwi zokufudumeza zabo, kwaye kufikwa zabathengi ngaphantsi kunokuba kwakunjalo ekuqaleni kumgca. Ngenxa yoko, ubude wire ilahlekileyo enokubakho ngenxa ufudumele.

Intambo kufuneka kuphela khetha icandelo umnqamlezo, ukuba ukuqinisekisa ukusebenza kwayo, kodwa kwakhona ukuthatha ingqalelo umgama apho amandla asuka elangeni. ukwanda umthwalo kukhokelela ekwandeni ezikhoyo nombhexeshi. Kulo mzekelo, ilahleko kwanda.

On spotlight ombane amancinci isicelo. Ukuba yehliswe kancinane, oko kwangoko azikaqapheleki. Ukuba ukhetha i ngcingo engalunganga ebekwe akude umbane ibhalbhu khangela buthuntu. Le ombane yehliswe kakhulu kwi Icandelo ngalinye, yaye oku ibonakala ngokukhanya. Ngoko kuyimfuneko cable cross-icandelo kubude ukubala.

Icandelo ibalulekileyo intambo yabathengi imi phezu kwezinye. Iilahleko zithathwa ikakhulu ngenxa umthwalo.

Xa isayithi L le ombane drop umqhubi iya kuba:

ΔU = (IMizekeliso + Qx) L / U _n,

apho P kunye Q- esebenzayo kunye namandla lovukelo, r kunye x - isahlulo esebenzayo kunye L reactance, kunye U _n - ixabiso amandla ombane apho umthwalo lisebenza ngokuqhelekileyo.

ΔU amukeleka nga kombane ngamagalelo eziphambili musa ngaphezulu ± 5% ukukhanyisa Izakhiwo zokuhlala kunye neziphaluka namandla. Oluvela kwigalelo ukuya ilahleko umthwalo akufunekanga ibe ngaphezulu kwe-4%. Ngokuba imigca emide kufuneka athathe ingqalelo uxhathiso ezenza ye intambo, leyo ixhomekeke umgama phakathi kwezinikezeli ezikufutshane.

Uqhagamsheleko Consumer

Imithwalo bangathungelana ngeendlela ezahlukeneyo. Ezi ndlela zilandelayo common kakhulu:

• ekupheleni uthungelwano;
• Abasebenzisi zisasazwa ngokufanayo ngaphaya komgca;
• nokukhuliswa isabelo umgca oludityaniswe umthwalo ngokufanayo ezisasaziweyo.

UMZEKELO 1

Amandla ombane 4 kW. Ubude cable 20 m, i ρ resistivity = 0,0175 ∙ Ohm ^mm2.

Ngoku uzimisele ukusuka ngokunxulumene: I = P / U _nom = 4 ∙ 1000/220 = 18.2 A.

Ke ithatha itafile yokubala intambo cross-candelo, uze ukhethe ubukhulu efanelekileyo. Kuba ucingo lobhedu, oko kuya kuba S = 1,5 mm ^2.

Ifomula yokubala icandelo cable: S = 2ρl / R. Ngenxa kunokwenzeka ukumisela uxhathiso yombane intambo: R = 2 ∙ 0,0175 ∙ 20 / 1.5 = 0.46 ohms.

Ngokwexabiso ezaziwayo R icaciswa ΔU = IR / U ∙ 100% * 100 = 18.2 ∙ 0,46 / 220 ∙ 100 = 3.8%.

Isiphumo ekubaleni i ngaphantsi kwe-5%, ngoko ke ilahleko iya kwamkeleka. Kwimeko ilahleko ezinkulu kufuneka kwandiswe icandelo umnqamlezo intambo yi inani osecaleni, ngaphezulu uluhlu oluqhelekileyo - 2.5 mm ^2.

UMZEKELO 2

Ezintathu yesekethe umbani sinxulumene ngaxeshanye kunye namanye kwi kwisigaba esinye ezinezigaba ezithathu-line, bathwele, kuqulethe-wire ezine USB 70 mm ² ukuya kuma-50 m ubude yaye conductive zangoku 150 A. Ngokuba ubude ngamnye kumgca yokucacisa 20 m idlula zangoku 20 A.

ilahleko Interfacial wokuwalayisha emele ziquka: ΔU = 150 ∙ _izigaba 0, 05 ∙ 0,55 = 4,1 V. Ngoku kufuneka amisele ilahleko phakathi cala kunye sigaba, ekubeni zokukhanya elidityaniswe kuyo 220 V: ΔU _{f n} = 4 1 / √3 = 2,36 V.

Ngomhla enye ezidityanisiweyo Izibane yesekethe ombane Jackson mali ku: ΔU = 18 ∙ 20 ∙ 0,02 = 7,2 V. Le ilahleko zizonke zigqitywa isixa U _esesi = (2.4 + 7.2) / 230 = 4.2 100 ∙ %. Ixabiso ubalelwa ngezantsi ilahleko kuvumelekile, nto leyo 6%.

isiphelo

Ukukhusela abaqhubi ukuba nobushushu ngexesha elide-aphilileyo umthwalo kunye neetafile ezenziwe intambo cross-icandelo ubalo obuvumelekileyo yangoku oluqhubekayo. Ukongeza, ukuba kuyimfuneko ukubala kwala macingo ngezinto ukuhla ombane kuzo ayengasekho eqhelekileyo. Ngaloo kubo ushwankathelwa ilahleko kwisekethe yonikezelo.