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Umholi wemoto yesilisa emkhakheni wezinkulungwane zokudla wabona ukuthi ukuphuma kwesibonelo sokugcina kwe-breaker yekhabelo yasusela ngaphambili kwezinhlobo zokuhlela, okwakubhekisela konke isilisa sokugcina — akungakho ukuthi ububi bawukhona kakhulu, kodwa ngoba isifundo sokuhlela kwezinhlobo zokuhlela ayisikhiwe ngokwesibonelo sokuhlela kwezinhlobo zokugcina zezindawo ezincinci. Ukungabi nesilisa kokugcina kwezinsuku ezine zasusela kumthwalo wokufunda ukuhlela kwezinhlobo zokuhlela ngokwesibonelo ngokulingana ne-20. Ukuhlela kwezinhlobo zokugcina zezindawo ezincinci akukho kubonakala kubantu abahlala ezingeni lezindawo noma abafundi besilisa, kodwa xa kufa, iziphumo ziyagcina konke isilisa esisisekelwe kumthwalo wokugcina.
Izindlela Zokuhlela Zokuphakeme
Ukubala Kwezimithwalo Nokusebenzisa Iziquketho Zokuhlukaniswa
Ukudesigna kwe-low voltage distribution yonke iqala ngendlela engezansi yokufaka izinto ezihlukene — uluhlu oluthiwe lwezikhathi zonke, izinto zazo zokugcina eziqondile ngama-kilowatts noma ngama-kilovolt-amperes, nokuziphatha kwazo okuxoxwa ngakho. Izinto zokugcina eziqondile zezikhathi zezintathu (three-phase) njengezimoto, izicompressor zewind and heating zemithambo, nezinto zokuchitha emthambo zokusebenza ziyabhalwa phakathi kwezikhathi zezintathu ukuze zimshane ukungafani kwezikhathi zezintathu kanye nokungafani kwezikhathi zezintathu. Izinto zokugcina eziqondile zezikhathi ezinye (single-phase) — izikhathi zokubhala, izikhathi zokugcina okunye, amasipho esikhele — ziya kubhalwa phakathi kwezikhathi zezintathu ngokuthi ukungafani kwezikhathi zezintathu kungapansi kwe-15 percent phakathi kwezikhathi ezinamandla kakhulu nasezincane kakhulu. Izifactor zokuhlukanisa (diversity factors) zibonisa ukuthi akukho zonke izinto zokugcina eziqondile zisebenza ngokuphelele ngokuphelele ngokuphelele. Isifactor sokuhlukanisa sezinto zokubhala esikhele kusuka ekhaya lokusebenza kungaba yi-0.9, ngakho-ke izikhathi zokugcina okunye esikhele sokusebenza kungaba yi-0.3 ku-0.5, okubonisa ukuthi kuphela isiqingatha sezikhathi zokugcina zisayisebenza ngokuphelele ngomzuzu wotsha. Ukusebenzisa izifactor zokuhlukanisa ezifanele zisivumela ukungabhalwa kwezithuthi, izikhathi zezintathu zezinkulungwane, nezikhathi zezintathu zezinkulungwane zezinkulungwane — ukungabhalwa kwezikhathi zezinkulungwane kuyadonsa imali, kuyakhula indawo yobunzima, kanye nokunciphisa ukusebenza kwezithuthi ngokuthi zisebenza ngokungafanele uma zisebenza ngokungafanele.
Ukubambisana Kwemiphakathi Yokuvikela nokukhetha
Ukuxhumana okukhethiwe kusho ukuthi uma kwenzeka iphutha, kuphela into evikelayo eseduze nephutha esebenza isiphazamisi esondla ukuhamba kwesifunda esonakele, kuyilapho zonke iziphazamisi ezingaphambili zihlala zivaliwe. Ukufeza lokhu kudinga isifundo sokuxhumanisa esibonisa imikhondo yezakhiwo zamanje zesikhathi sazo zonke izinto zokuvikela ezingeni lokuhlukanisa, kusukela kumuntu oyinhloko kuze kube yizinqamuleli zokugcina. Ukuze isikhunta case circuit breakers e low voltage switchgear, ukuhlanganiswa ngokuvamile kufinyelelwa ngokukhetha breakers nge ezahlukene okusheshayo ukuqala izilungiselelo noma ngokwethula ukubambezeleka kwesikhathi kumadivayisi upstream. Emiklamweni ye-switchgear ekhishwayo efana namapaneli we-MNS noma we-GCS onamandla aphansi, iziphazamisi zingahlelwa ngama-electronic trip units anikezela ukuguquguquka kwesikhathi eside, isikhathi esifushane, nokuvikelwa okusheshayo ukuguquguquka okwenza lula Ukuvikelwa kwephutha lomhlaba kudinga ukunakwa ngokukhethekile ekwakhiweni kokusabalalisa amandla aphansi. Iphutha lomhlaba kumgqomo wokudla we-ampere engu-400 lingase lingathathi amandla anele okusebenzisa ukuvikelwa kokugeleza ngokweqile kwesigaba, okuvumela iphutha ukuba liqhubeke lingatholakali. Ama-relay noma ama-breaker akhethekile okuvikela ukuphahlazeka komhlaba anikeza ukuzwela okudingekayo ukuthola nokuqeda lezi zimo eziyingozi.
Ibhasibha ne-ukuphatha kwezindawo zokugcina izimilo
Uhlelo oluyinhloko lwe-busbar ngaphakathi kweqoqo le-low voltage switchgear lithwala amandla omthwalo ahlanganisiwe azo zonke izitsha zokudla ezixhunyiwe. Indawo yokwehlukaniswa kwe-busbar ikhethwa ngokuya ngokufakwa kwe-continuous current, amandla okumelana ne-short-circuit, kanye nemikhawulo yokukhuphuka kwamazinga okushisa echazwe yi-IEC 61439 noma amazinga alinganayo. Ama-busbar ethusi ayindinganiso yezicelo eziningi, kusetshenziswa i-aluminium lapho isisindo nezindleko zibekwa phambili uma nje ukuxhumana okufanele kwe-bi-metallic kuvimbela ukugqwala kwe-galvanic ezindaweni zokuguquka. Ukuphathwa kokushisa ngaphakathi kwesakhiwo se-switchgear kuthinta ngqo ukusebenza kwe-busbar ne-breaker. Ukupholisa ngokwemvelo nge-convection ngokusebenzisa ama-ventilation louvers kwanele ezikhungweni eziningi, kodwa amaqoqo afakwe ezindaweni eziphakeme noma asebenza eduze kwamanje yawo eqondile angadinga ukuphoqelelwa komoya. Umkhawulo wokukhuphuka kwamazinga okushisa ajwayelekile wokuxhuma ama-busbar ngama-70 Kelvin ngaphezu komkhawulo wendawo yethusi elingenalutho nama-65 Kelvin wokuxhuma okufakwa ngethini ukweqa le mikhawulo kusheshisa i-oxidation, kwandisa ukumelana nokuxhumana, futhi
Imibuzo Evame Ukubuzwa
Ukh difference phakathi kwezinkampani zokusebenza ngokuzimisa nezinkampani zokususa ngokuvutha kwezinkampani zokusebenza ngaphansi kwemithwalo?
Izinkampani zokusebenza ngokuzimisa zinezinkampani zokuvutha ezihlanganiswe kwi-busbar system, futhi kufuneka zilahlekelwe ukusebenza ukuze zilishintshwe. Izinkampani zokususa ngokuvutha zihlanganisa izinkampani zokuvutha kuma-carriages oya kususwa ngokuvutha ukwenza ukulungisa ngaphandle kokulahlekelwa kwesikhulu esifanayo, okunciphisa isikhathi sokungasebenzi ngokushintsha noma ukuphakanyiswa kwezinkampani zokuvutha.
Yini indlela yokubhalwa kwezinkampani zokugcina imithwalo yezinkampani zokusebenza ngaphansi kwemithwalo?
Indlela yokubhalwa kwezinkampani zokugcina imithwalo kufanele ikhululeke kakhulu kwezinkampani zokugcina imithwalo zokufa kwezinkampani zokusebenza ngaphansi kwemithwalo. Izinhlobo zokubhalwa ziyizigaba zokubhalwa kwe-25 kA ku-100 kA ngomzuzu omunye, zibhalwa ngokubonakalisa impahla yezinkampani zokugcina imithwalo, impahla yezinkampani zokugcina imithwalo kwezinkampani zokusebenza kwezinkampani zokusebenza, nokuhlanganisa izinkampani zokusebenza ngaphansi kwemithwalo kwezinkampani zokusebenza.
Izistandadi ziphi eziphathelene nokudesigna kwezinkampani zokusebenza ngaphansi kwemithwalo?
IEC 61439 iyisikhalo esihambisana nezinkampani zokuguqula umoya emphakathi yezinkampani zokugcina umoya, kubhekisa kuzo izifundo zokuphatha ngokwesithembiso nokubona ngokuthi ziyasebenza njani. Izinyanga ezithile zibhekisa amaphetha okusakaza amakhompyutha, amaphetha okuguqula umoya okukhulu kubantu abazazi ukusebenzisa, nokuthi amaphetha okuguqula umoya akhuluma ngokuphelele. IEC 60947 ibhekisa kumathuba okuguqula umoya nokugcina umoya ngokwesilinganiso.
Ukuthi ukugcina umoya kuyakwenza kanjani ukuthi kubhekise kwezinkampani zokusakaza emphakathi yezinkampani zokugcina umoya?
Izifundo zokugcina umoya zizahlula umkhawulo wokufaka umoya kuzo zonke izindawo zezinkampani zokusakaza, zibhekisa ukukhetha izinkampani zokuhlinza ubuso nokubhekisa kwezindlela zokuphatha njengekuphatha kwezinkampani zokuguqula umoya ngendlela eyingqayile, ukwakha izinkampani zokuguqula umoya okungafanele ukugcina umoya, nokuthi kubhekise kwezinkampani zokugcina umoya ngokwesikhundla ukuze kunciphise isikhathi sokugcina umoya.
Ukuthi izinkampani zokugcina umoya nezinkampani zokugcina umoya ziyakwenza kanjani kwezindlela zokuphatha?
Umdibanisi wokungena kwezinye izingxenye ziyagcina imithambo yezinye izinye ezingaphansi kwezinye izinye, futhi kufanele ibe yisikhundla sokubeka ngokuphelele — emizini engeziwe ngokuphelele kwezinye izinye ezinokubonakala kwezinye izinye, umdibanisi wokungena kwezinye uyagcina imithambo engaphezu kwezinye izinye, okubangela ukuthi kufanele ibe yisikhundla sokubeka ngokuphelele. Umdibanisi wokulinda uyalinda imithambo yezinye izinye yezinye izinye futhi kufanele ibe yisikhundla sokubeka ngokuphelele ukuze akwazi ukugcina imithambo yezinye izinye yezinye izinye ngokuphelele kwezinye izinye zokulinda.
Kuzoba yini isikhathi sokubheka ngokuphelele kwezinye izinye zokulinda?
Kufanele kubhekwe ngokuphelele kwezinye izinye zokulinda uma kufakwa noma kususwa amaqhinga amaningi, uma kushintsha izindlela zokufaka kwezinye izinye, noma ngeminyaka engaphezu kwezinye izinye ezingu-5. Ukushintsha kwezinye izinye zokulinda kwezinye izinye, ukuphatha kwesikhundla sokubeka kwezinye izinye ngokuphelele, nokubuyiselwa kwezinye izinye ngokuphelele kwezinye izinye zokulinda ziyabangela ukuthi ukubheka ngokuphelele kwezinye izinye zokulinda kuyasebenza ngokuphelele.