Load rooj rau cable ntoo khaub lig-section: xaiv, muab xam

Qhov tseeb xaiv ntawm tus ntoo khaub lig seem ntawm xov nyob rau hauv lub nplij siab thiab kev nyab xeeb ntawm tsev. Thaum overloading overheated neeg xyuas pib thiab rwb thaiv tsev tej zaum yuav oplavitsya, uas ua rau ib tug tua hluav taws los yog ib tug luv luv Circuit Court. Tab sis tus ntoo khaub lig-seem ntawm ntau tshaj li tsim nyog coj unprofitable, raws li tus nqi ntawm lub cable qab.

Feem ntau, nws nyob ntawm lub xov tooj ntawm cov neeg muas zaub, los ntawm thawj kev txiav txim hwj huam tas nrho siv tiaj tus, thiab ces txawj tshwm sim los ntawm 0.75. Lub EMP rooj yog thov loads dua tus ntoo khaub lig seem ntawm lub cable. Raws li nws yuav muab tau yooj yim txiav txim xyuas pib txoj kab uas hla, uas yog nyob rau hauv cov ntaub ntawv thiab dhau tus tam sim no. Feem ntau, tooj liab nyob ntawm tej los.

Tus ntoo khaub lig-seem ntawm lub cable conductors yuav tsum phim raws nraim xam - nyob rau hauv cov kev taw qhia uas ua tus qauv loj ntau yam. Cov feem ntau txaus ntshai thaum nws yog heev tsawg. Ces tus neeg xyuas pib lossi overheated, thiab kev rho tawm sai sai tsis. Thiab yog hais tias koj nruab ib lub uas tsim nyog Circuit Court breaker, ces nws yuav tsum yog ib tug heev lag luam.

Thaum Inflating seem ntawm cov hlau, nws yuav raug nqi ntau dua. Txawm tias ib tug tej yam cia yog tsim nyog vim hais tias nyob rau hauv lub neej yav tom ntej, raws li ib tug txoj cai, nws yog tsim nyog mus cuag tus tshiab cov khoom siv. Nws yog ib advisable mus siv ib tug muaj kev ruaj ntseg tshaj ntawm 1.5.

Muab xam los ntawm tag nrho cov hwj chim

Tag nrho cov tswv yim hwj chim ntog ca rau cov ntsiab tswv yim uas nkag mus rau hauv lub switchboard, thiab tom qab nws yog branched rau hauv ib tug kab:

• teeb pom kev zoo;
• qhov hluav taws xob pab pawg neeg;
• cais cov khoom siv loj.

Yog li ntawd, qhov loj tshaj plaws tus ntoo khaub lig-section ntawm lub hwj chim cable - nyob rau kev nkag. Nyob rau diverting kab yog txo, nyob ntawm seb lub load. Nyob rau hauv thawj qhov chaw, txiav txim los ntawm lub hwj huam tas nrho ntawm tag nrho cov loads. Nws yog tsis yooj yim, raws li lub corps ntawm lub tsev khoom siv thiab passports rau lawv nws yog xws.

Tag nrho cov chaw yuav ntxiv. suav thiab rau txhua Circuit Court zoo ua. Kws txawj hais kom muab lub sum los ntawm ib tug txo tau ntawm 0.75. Qhov no yog vim lub fact tias thaum tag nrho cov pab kiag li lawm nyob rau hauv lub network yog tsis tau sau. Lwm tus muaj ib qho seem ntawm ib tug loj loj. Raws li ib tug tshwm sim, ib tug kev rau lub tom ntej commissioning ntxiv fais pab kiag li lawm, uas yuav tsum tau yuav nyob rau hauv lub neej yav tom ntej. Nws yuav tsum tau muab sau tseg hais tias qhov no version ntawm lub xam ntawm lub cable yog ntau txhim khu kev qha.

Yuav ua li cas los mus txiav txim cov hlau me me?

Nyob rau hauv tag nrho cov suav featured seem ntawm lub cable. Nyob rau hauv txoj kab uas hla mus txhais nws yooj yim Yog hais tias koj siv cov mis:

• S = π D² / 4;
• D = √ (4 × S / π).

Qhov twg π = 3,14.

Cov tub ntxhais hlau yog thawj tsim nyog los xam qhov kev ncua npaum li cas (N). Ces tus measured txoj kab uas hla (D) ntawm ib tug ntawm lawv, tom qab uas lub sectional cheeb tsam no yog txiav txim:

S = N × D² / 1,27.

Tso tseg ntawm tej yog siv qhov twg yooj yog yuav tsum tau. Pheej yig dua cov khoom conductors siv nyob rau hauv ib tug nyob ruaj ruaj installation.

Yuav ua li cas xaiv ib tug cable ntawm lub hwj chim?

Nyob rau hauv thiaj li yuav khaws cov xov, thov load rooj rau cable ntoo khaub lig-section:

• Yog hais tias txoj kab yog qhib-energized 220, thiab cov hwj huam tas nrho yog 4 kW, yog coj tooj liab xyuas pib seem ntawm 1.5 mm². Qhov no loj yog feem ntau siv rau xov teeb pom kev zoo.
• Nrog lub hwj chim ntawm 6 kW yuav tsum tau xyuas pib ntoo khaub lig-section loj - 2.5 mm². Cov hlau no yog siv rau cov nyob, uas txuas cov khoom siv.
• 10 kW yuav tsum tau xov mus rau 6 lub mm². Feem ntau, nws yog tsim los rau cov chav ua noj, nyob qhov twg lub kev cob cog rua hluav taws xob qhov cub. Nce xws li ib tug load yog ua los ntawm ib tug nyias muaj nyias ib txoj kab.

Uas cable yog zoo dua?

Electricians zoo-paub German hom cable num rau chaw ua hauj lwm thiab chaw qhov chaw. Nyob rau hauv Russia, lub hom tso cables uas yog tus yam ntxwv hauv qab no, txawm tias lawv yuav muaj tib lub npe. Lawv yuav tsum tau txawv los ntawm streaks ntawm lub compound nyob rau hauv qhov chaw ntawm lub conductors los yog tsis muaj thereof.

Cov hlau thiab multiwire monolithic tawm. Txhua tus tub ntxhais li zoo li tag nrho cov twisted insulated PVC sab nraum, nyob rau lub muab tub lim yog tsim therebetween nonflammable:

• Yog li, lub num cable yog siv hauv tsev raws li rwb thaiv tsev rau hauv txoj kev yog muab los ntawm tshav ntuj.
• Thiab raws li lub sab hauv thiab sab nraud hluav taws xob thaiv yog dav siv VVG qib cable. Nws yog pheej yig thiab txhim khu kev qha txaus. Rau tso nyob rau hauv lub hauv av nws yog tsis pom zoo.
• VVG hom hlau yog ua ca thiab puag ncig. Muab tub lim ntawm cores yog tsis muaj feem xyuam.
• Cable VVGng-P-LS ua nrog lub plhaub uas tsis txhawb combustion. Lub cores no yog ua los puag ncig mus rau seem 16 mm² thiab saum toj no - sector.
• Hom cables PVS thiab ua SHVVP tso tseg thiab no mas siv tau los txuas lub tsev khoom siv. Nws yog feem ntau siv raws li ib lub tsev hluav taws xob thaiv. Tawm sab nraud tso tseg conductors yog tsis pom zoo vim corrosion. Ntxiv mus, lub rwb thaiv tsev thaum lub sij hawm dabtsi yog khoov tej kab nrib pleb ntawm tsawg kub.
• Nyob rau hauv txoj kev hauv qab no av paving thiab armored cables yog resistant rau dej thiab AVBShv VBShv. Armor ua los ntawm ob tug steel menyuam, uas tsub kom lub ntseeg ntawm lub cable thiab ua rau nws resistant rau cov neeg kho tshuab kev nyuaj siab.

Kev txiav txim ntawm load tam sim no

Ib tug ntau yog tshwm sim yog muab cable ntoo khaub lig seem xam lub hwj chim thiab tam sim no, nyob rau lub geometric tsis txuam nrog qhov hluav taws xob.

Rau tsev neeg thaiv nws yuav tsum coj mus rau hauv tus account tsis tau tsuas yog lub resistive load, tab sis kuj reactive. Tus tam sim no siv yog txiav txim los ntawm cov mis:

I = P / (U ∙ cosφ ).

Tsim reactive load fluorescent teeb thiab motors ntawm hluav taws xob khoom siv (tub yees, lub tshuab nqus tsev, lub hwj chim cov cuab yeej thiab lwm tus neeg.).

Piv txwv li ntawm xam lub cable ntoo khaub lig-section ntawm tam sim no

Cia peb kawm saib yuav ua li cas ua tau, yog hais tias nws yog tsim nyog los txiav txim seb tus ntoo khaub lig-seem ntawm tooj liab cable los txuas rau lub tsev khoom siv nrog tag nrho muaj peev xwm ntawm 25 kW thiab peb-theem tshuab mus rau 10 kW. Qhov no kev twb kev txuas yog ua tsib-core cables pw nyob rau hauv lub hauv av. Noj mov ua tom tsev los ntawm ib tug peb-theem network.

Nyob rau hauv view ntawm lub reactive tivthaiv, lub hwj chim khoom vaj khoom tsev thiab cov khoom siv yuav tsum tau:

• P _{lub neej.} = 25 / 0,7 = 35,7 kW;
• P _Rev.. = 10 / 0.7 = 14.3 kW.

Txiav txim tam sim no nyob rau kev tawm tswv yim:

• Kuv _{lub neej.} = 35,7 × 1000/220 = 162 A;
• Kuv _Rev. = 14,3 × 1000/380 = 38 A.

Yog hais tias ib-theem loads faib evenly tshaj peb theem, ib tug yuav tau tham:

Kuv _Q = 162/3 = 54 A.

Txhua theem yuav yog tus tam sim no load:

Kuv _p = 54 + 38 = 92 A.

Tag nrho cov khoom nyob rau tib lub sij hawm yuav tsis ua hauj lwm. Xav paj tau paj rau txhua theem tam sim no muaj mus rau:

Kuv _f = 92 × 0,75 × 1,5 = 103,5 A.

Lub tsib neeg xyuas pib cables yog npaum li cas mus rau hauv tus account xwb lub theem conductors. Rau cable pw nyob rau hauv lub hauv av, yuav txiav txim rau qhov tam sim no 103,5 A ntoo khaub lig seem 16 mm² (Load rooj rau cable ntoo khaub lig-section).

Hloov kho xam amperage yam nyiaj vim hais tias nws yuav tsum tau ib tug me me ntoo khaub lig-section. Thaum ib tug ntxhib muab xam los ntawm lub hwj chim cable, neeg xyuas pib ntoo khaub lig-seem ntawm 25 mm², uas yuav raug nqi kim kim.

Lub voltage nco rau lub cable

Lub conductors muaj kuj, uas yuav tsum tau suav hais tias. Qhov no yog tshwj xeeb tshaj yog ib qho tseem ceeb rau cov loj cable ntev los yog nyob rau hauv nws me me ntoo khaub lig-section. PES tsim qauv uas cov voltage nco rau lub cable yuav tsum tsis pub tshaj 5%. Lub xam yog ua li cas nyob rau hauv cov nram qab no txoj kev.

1. Txiav txim siab xyuas pib kuj: R = 2 × (ρ × L) / S .
2. Yog lub voltage nco: U _ncoo. = Kuv × R. Nyob rau hauv kev sib raug zoo mus rau ib tug linear feem pua nws yuav tsum: _U% = (U _ncoo / U _{Lis ..)} × 100.

Nyob rau hauv cov qauv, cov cim:

• ρ - resistivity × Ohm mm² / m;
• S - tus ntoo khaub lig-sectional cheeb tsam mm².

Lub qhov zoo tshaj ntawm 2 ntawd hais tias tam sim no yog ntws nyob rau hauv ob strands.

Piv txwv li ntawm xam ntawm lub cable voltage nco

Piv txwv li, nws yog tsim nyog los mus laij lub voltage nco nyob tus neeg xyuas pib seem nqa ib tug 2.5 mm², ntev ntawm 20 m. Nws yog tsim nyog mus cuag lub Vuam transformer 7 kW.

• Hlau kuj yog: R = 2 (0,0175 × 20) / 2,5 = 0,28 ohms.
• Tus tam sim no siv nyob rau hauv ib tug neeg xyuas pib: I = 7000/220 = 31,8 A.
• Lub voltage nco rau lub Nqa: U _ncoo. = 31,8 × 0,28 = 8,9 V.
• Qhov feem pua ntawm cov voltage nco: _U% = (8,9 / 220) × 100 = 4.1%.

Nqa haum rau VUAM TSHUAB ntawm cov kev cai lag luam ntawm hluav taws xob uas yuav tsum tau raws li ib feem pua lub caij nplooj zeeg nyob rau hauv nws ib tug voltage yog nyob rau hauv ib txwm txwv. Txawm li cas los, nws cov nuj nqis nyob rau hauv lub mov lead yog loj, nws muaj peev xwm adversely cuam tshuam lub vuam txoj kev. Ntawm no nws yog tsim nyog los saib rau sab pub voltage txwv rau cov vuam siv lub tshuab.

xaus

Yuav kom nti tiv thaiv cov xov ntawm overheating thaum lub sij hawm heev lub sij hawm lub nyob tam sim no, cable ntoo khaub lig-section yog xam los ntawm cov permissible nruam currents. Lub xam yog yooj yim zog yog hais tias tus load daim ntawv thov nyob rau hauv lub cable ntoo khaub lig-section. Ib tug ntau yog tshwm sim yog tau yog hais tias lub xam yog ua los ntawm lub siab tshaj plaws tam sim no load. Thiab rau ib tug ruaj khov thiab ntev lub sij hawm kev lag luam ntawm lub Circuit Court breaker xov ntsia.