Xam Qhov Siab Tshaj Plaws ntawm Kev Teeb tsa
Kev xam qhov siab tshaj plaws ntawm kev teeb tsa hluav taws xob yog ib kauj ruam tseem ceeb kom ntseeg tau tias lub kaw lus ua haujlwm zoo, muaj txiaj ntsig, thiab tsis muaj teeb meem xws li kev ua haujlwm ntau zaus ntawm cov hluav taws xob Circuit Breakers (MCBs), cov xov hlau kub dhau sai, thiab txawm tias muaj kev phom sij hluav taws. Kev xam no tsis yog qhov tsim nyog thaum tsim cov kev teeb tsa tshiab xwb tab sis kuj thaum ntxiv cov khoom siv hluav taws xob rau hauv tsev, chaw ua haujlwm, khw muag khoom, lossis cov chaw lag luam. Kev nkag siab txog yuav ua li cas txiav txim siab qhov siab tshaj plaws tso cai rau peb xaiv qhov loj me ntawm cov xov hlau, MCB, thiab lwm yam khoom siv tiv thaiv.
1. Lub ntsiab lus ntawm qhov siab tshaj plaws yog dab tsi?
Qhov siab tshaj plaws ntawm lub zog hluav taws xob yog lub zog hluav taws xob loj tshaj plaws uas siv tau tib lub sijhawm hauv kev teeb tsa. Lub zog no feem ntau yog qhia hauv watts (W) lossis kilowatts (kW). Hauv lub kaw lus hluav taws xob, lub zog siab tshaj plaws yog cuam tshuam ncaj qha rau qhov tam sim no (amperes/A) ntws los ntawm cov conductors. Yog tias qhov tam sim no tshaj qhov peev xwm ntawm lub cable lossis kev tiv thaiv, overheating, voltage poob, thiab kev puas tsuaj tuaj yeem tshwm sim.
Nws yog ib qho tseem ceeb kom paub qhov txawv ntawm:
- Qhov thauj khoom uas tau teeb tsa: tag nrho lub zog ntawm txhua yam khoom siv txuas nrog, tsis hais seb lawv puas siv tib lub sijhawm lossis tsis siv.
- Qhov siab tshaj plaws / qhov siab tshaj plaws: lub zog loj tshaj plaws siv tib lub sijhawm (muaj tseeb).
- Qhov xav tau: kev sib piv ntawm qhov siab tshaj plaws thauj khoom rau cov khoom siv ntsia kom kwv yees kev siv tib lub sijhawm.
2. Vim li cas kev suav qhov siab tshaj plaws thiaj li tseem ceeb?
Muaj ntau yam tseem ceeb:
1. Kev nyab xeeb ntawm kev teeb tsa: cov xov hlau thiab cov kev sib txuas uas muaj ntau dhau tuaj yeem ua rau kub thiab ua rau muaj hluav taws.
2. Kev tiv thaiv kom haum: MCB/fuse yuav tsum tau xaiv los tiv thaiv lub cable, tsis yog tsuas yog ua raws li tag nrho lub zog ntawm cov khoom siv.
3. Kev ua haujlwm zoo thiab kev ntseeg siab: kev teeb tsa kom zoo txo qhov kev pheej hmoo ntawm kev poob hluav taws xob thiab cov khoom siv tsis ua haujlwm zoo.
4. Kev npaj fais fab ntawm daim ntawv cog lus: rau cov neeg siv hluav taws xob, kev xam cov khoom siv pab txiav txim siab PLN cov kev xav tau fais fab kom lawv tsis txaus lossis ntau dhau.
5. Yooj yim ntawm kev nthuav dav: los ntawm kev paub qhov peev xwm ntawm qhov muaj peev xwm, kev ntxiv cov khoom thauj yav tom ntej tuaj yeem npaj tau.
3. Cov ntaub ntawv uas yuav tsum tau sau
Ua ntej xam, sau cov ntaub ntawv hauv qab no:
– Daim ntawv teev cov khoom siv hluav taws xob (teeb, cua txias, twj tso kua mis, tshuab, khoos phis tawj, thiab lwm yam)
- Lub zog ntawm txhua yam khoom siv (W lossis VA) los ntawm daim ntawv lo / daim ntawv lo
- Qhov hluav taws xob ntawm lub cev (feem ntau 220 V 1 theem lossis 380/400 V 3 theem)
- Hom thauj khoom (resistive, inductive, motor, electronic)
- Kev kwv yees siv tib lub sijhawm los ntawm qhov xav tau
Yog tias lub zog ntawm daim ntawv lo yog sau ua VA (Volt-Ampere), nws txhais tau tias lub zog pom tseeb. Rau qee qhov kev thauj khoom xws li cov motors lossis cov khoom siv uas muaj lub zog tsawg, VA tuaj yeem loj dua W. Txawm li cas los xij, rau kev xam tam sim no thiab lub peev xwm tiv thaiv, VA feem ntau yog siv los ua qhov kev kwv yees zoo.
4. Cov Qauv Xam Xam Yooj Yim
a) 1 theem system (220 V)
Rau ib qho yooj yim resistive load:
– P (W) = V (V) × Kuv (A)
- Ces kuv (A) = P / V
Yog tias peb xav txog qhov fais fab (cos φ) ntawm ib qho kev thauj khoom:
– P = V × I × cos φ
- Ces kuv = P / (V × cos φ)
b) 3-theem system (380/400 V)
Rau 3-theem loads:
– P = √3 × V × Kuv × cos φ
– Ces kuv = P / (√3 × V × cos φ)
Hauv kev teeb tsa tiag tiag, tus nqi ntawm cos φ (lub zog fais fab) feem ntau yog nyob rau hauv qhov ntau ntawm 0,8–1, nyob ntawm hom kev thauj khoom.
5. Cov Kauj Ruam Los Xam Qhov Siab Tshaj Plaws
Kauj Ruam 1: Xam qhov load uas tau teeb tsa
Ntxiv tag nrho lub zog ntawm txhua yam khoom siv:
Piv txwv yooj yim (lub tsev me me):
– Teeb: 10 cov ntsiab lus × 10 W = 100 W
– Lub tub yees: 150 W
– TV: 120 W
- Lub lauj kaub mov: 300 W
– Hlau: 350 W
- Twj tso dej: 250 W
– 1 Pob AC: 800 W
Tag nrho cov khoom thauj uas tau teeb tsa = 100 + 150 + 120 + 300 + 350 + 250 + 800 = 2.070 W
Kauj Ruam 2: Txheeb xyuas qhov xav tau
Tsis yog txhua yam khoom siv siv tib lub sijhawm. Piv txwv li, hauv tsev, qhov kev thov dav dav tuaj yeem yog 0,6–0,8, nyob ntawm cov qauv siv. Rau cov haujlwm tshaj lij, qhov kev thov yog hais txog cov qauv lossis kev paub dhau los hauv thaj chaw.
Piv txwv li, siv qhov kev thov kom muaj 0,7:
Qhov siab tshaj plaws = 2.070 W × 0,7 = 1.449 W
Kauj Ruam 3: Hloov mus rau tam sim no
Rau 1 theem 220 V:
Kuv = P / V = 1.449 / 220 ≈ 6,59 A
Kauj Ruam 4: Txheeb xyuas qhov kev nyab xeeb ntawm qhov chaw
Yuav kom tiv thaiv tau qhov kev teeb tsa kom tsis txhob ua haujlwm ntawm qhov txwv siab tshaj plaws tas mus li, feem ntau yuav muab qhov sib txawv ntawm 20-30% rau kev siv mus sij hawm ntev.
Tsim tam sim no = 6,59 A × 1,25 ≈ 8,24 A
Hauv qhov no, 10 A MCB tuaj yeem raug txiav txim siab, muab tias qhov seem ntawm cable kuj tsim nyog.
6. Tej yam tseem ceeb uas feem ntau tsis quav ntsej
a) Pib tam sim no
Cov tshuab hluav taws xob xws li cov twj tso dej thiab cov cua txias muaj cov hluav taws xob pib ntau zaus dua li qub. Lub MCB me me tuaj yeem dhia thaum lub sijhawm pib. Rau cov khoom siv lub cev muaj zog, kev xaiv MCB thiab cov xov hlau yuav tsum xav txog cov yam ntxwv pib thiab hom MCB (cov nkhaus B, C, D).
b) Kev faib khoom ib lub voj voog
Qhov siab tshaj plaws ntawm tag nrho cov khoom thauj tsis tas txhais tau tias tag nrho cov khoom thauj nyob rau ntawm ib kab. Kev teeb tsa zoo faib lub voj voog ua ntau lub voj voog: teeb pom kev zoo, qhov hluav taws xob dav dav, cua txias, twj tso kua mis, chav ua noj, thiab lwm yam. Kev faib no txo qhov kev pheej hmoo ntawm kev thauj khoom ntau dhau ib kab thiab ua kom yooj yim rau kev tswj hwm qhov txhaum.
c) Qhov hluav taws xob poob qis
Cov xov hlau ntev uas muaj cov hluav taws xob ntau tuaj yeem ua rau lub zog hluav taws xob poob qis, uas tuaj yeem ua rau lub teeb tsaus ntuj thiab lub cev muaj zog kub dhau sai. Hauv kev tsim qauv, lub zog hluav taws xob poob qis raug khaws cia rau hauv qhov txwv tsim nyog (piv txwv li, 3% rau lub teeb thiab 5% rau tag nrho, nyob ntawm tus qauv siv).
d) Kev sib txuas zoo thiab qhov kub thiab txias
Cov xov hlau uas muaj kev sib txuas xoob lossis nyob rau hauv qhov chaw kub siab yuav kub sai dua. Lub peev xwm nqa tam sim no ntawm cov xov hlau raug cuam tshuam los ntawm txoj kev teeb tsa (hauv cov yeeb nkab, sab nraum zoov, faus, lossis hauv lub tais) thiab qhov kub thiab txias ib puag ncig.
7. Txheeb xyuas lub peev xwm hluav taws xob uas xav tau
Ntxiv rau kev xaiv MCB, kev xam qhov siab tshaj plaws ntawm qhov hnyav kuj pab tau rau kev txiav txim siab qhov xav tau ntawm lub zog ntawm daim ntawv cog lus. Hais yooj yim:
Lub zog xav tau (VA) ≈ Qhov siab tshaj plaws (W) / qhov fais fab
Yog tias qhov fais fab piv yog 0,85:
VA ≈ 1.449 / 0,85 ≈ 1.705 VA
Yog li ntawd, 2.200 VA ntawm lub zog yuav txaus rau lub tsev piv txwv, yog tias txhua yam khoom siv hnyav tsis tau qhib tib lub sijhawm.
8. Cov Yuam Kev Feem Ntau Hauv Kev Xam Qhov Siab Tshaj Plaws
1. Ntxiv tag nrho cov hwj chim thiab tom qab ntawd xaiv MCB loj tam sim ntawd yam tsis tau saib lub peev xwm ntawm cov xov hlau.
2. Tsis quav ntsej txog qhov xav tau ua rau kev xam suav tsis ruaj khov thiab cov nqi nce ntxiv.
3. Tsis xav txog qhov pib tam sim no ntawm lub cev muaj zog, ua rau MCB mus ncig ntau zaus.
4. Nyeem yuam kev txog lub zog ntawm lub cuab yeej (piv txwv li, xav tias 1 PK yeej ib txwm yog 736 W thaum qhov tseeb AC siv sib txawv).
5. Tsis quav ntsej txog kev ntxiv cov khoom thauj yav tom ntej, yog li ntawd kev teeb tsa sai sai "puv".
9. Xaus Lus
Kev xam qhov siab tshaj plaws ntawm kev teeb tsa yog lub hauv paus tseem ceeb rau kev npaj hluav taws xob kom muaj kev nyab xeeb thiab txhim khu kev qha. Qhov tseem ceeb, ua tib zoo ntsuas qhov hnyav, siv cov yam ntxwv xav tau los kwv yees kev siv tib lub sijhawm, hloov mus rau tam sim no, thiab tom qab ntawd xaiv cov khoom siv tiv thaiv thiab cov xov hlau uas muaj qhov ntev txaus. Nrog cov kauj ruam yooj yim tab sis muaj txheej txheem no, koj qhov kev teeb tsa hluav taws xob yuav tsis muaj kev thauj khoom ntau dhau, ruaj khov dua, thiab tuaj yeem ua raws li qhov xav tau hluav taws xob txhua hnub.
Yog tias koj xav tau, kuv tuaj yeem tsim ib qho piv txwv kev xam zauv tshwj xeeb dua (tsev ib theem, tsev khw, lossis chaw ua haujlwm 3 theem) ua tiav nrog cov lus qhia faib hluav taws xob, qhov loj ntawm MCB, thiab kev kwv yees ntawm qhov seem ntawm cov xov hlau raws li qhov xwm txheej thauj khoom uas koj muab.
