Caixa combinadora fotovoltaica<\/a> Dimensionamento e fus\u00e3o de cordas CC<\/h3>\n\n\n\nAp\u00f3s determinar a classifica\u00e7\u00e3o de tens\u00e3o, a pr\u00f3xima etapa \u00e9 dimensionar os dispositivos de prote\u00e7\u00e3o contra sobrecorrente (OCPDs), que normalmente s\u00e3o fus\u00edveis. O objetivo principal dos fus\u00edveis de string \u00e9 proteger contra a corrente reversa. Uma falha em um string pode fazer com que outros strings sejam realimentados por ele, criando uma condi\u00e7\u00e3o perigosa de sobrecorrente.<\/p>\n\n\n\n
De acordo com a norma NEC 690.9, a fus\u00edvel de n\u00edvel de fio \u00e9 necess\u00e1ria sempre que voc\u00ea tiver tr\u00eas ou mais cadeias de caracteres em paralelo<\/strong>. With only two strings, the reverse current potential is not high enough to exceed the module’s fuse rating, so fuses are not required by code (though they are still sometimes used as a disconnecting means).<\/p>\n\n\n\nComo dimensionar fus\u00edveis de cordas:<\/strong><\/p>\n\n\n\nThe NEC requires that the fuse be rated to handle continuous duty and potential irradiance spikes. This is accomplished by multiplying the module’s Short-Circuit Current (Isc) by a factor of 1.56.<\/p>\n\n\n\n
\n1,25 fator<\/strong> para carga cont\u00ednua (circuitos que podem operar por mais de 3 horas).<\/li>\n\n\n\n1,25 fator<\/strong> for potential “irradiance enhancement” where sun exposure can exceed the standard 1000 W\/m\u00b2.<\/li>\n\n\n\n1.25 \u00d7 1.25 = 1.56<\/code><\/li>\n<\/ul>\n\n\n\nF\u00f3rmula de classifica\u00e7\u00e3o do fus\u00edvel:<\/strong> Classifica\u00e7\u00e3o m\u00ednima do fus\u00edvel \u2265 Isc do m\u00f3dulo \u00d7 1,56<\/code><\/p>\n\n\n\nAp\u00f3s calcular esse m\u00ednimo, voc\u00ea seleciona o pr\u00f3ximo tamanho de fus\u00edvel padr\u00e3o acima.<\/p>\n\n\n\n
Limita\u00e7\u00e3o crucial: Classifica\u00e7\u00e3o m\u00e1xima do fus\u00edvel em s\u00e9rie<\/strong>\\O tamanho calculado do fus\u00edvel n\u00e3o deve exceder essa classifica\u00e7\u00e3o.<\/strong> Se isso acontecer, o projeto do seu sistema est\u00e1 com defeito, o que normalmente significa que o m\u00f3dulo escolhido n\u00e3o pode ser usado com esse n\u00famero de strings em paralelo.<\/p>\n\n\n\nExemplo:<\/strong><\/p>\n\n\n\n\nIsc do m\u00f3dulo: 10.5A<\/li>\n\n\n\n Classifica\u00e7\u00e3o m\u00e1xima de fus\u00edveis da s\u00e9rie do m\u00f3dulo: 20A<\/li>\n\n\n\n Classifica\u00e7\u00e3o m\u00ednima do fus\u00edvel = 10.5A \u00d7 1.56<\/code> = 16.38A<\/strong><\/li>\n<\/ul>\n\n\n\nCom base nesse c\u00e1lculo, voc\u00ea escolheria o pr\u00f3ximo tamanho padr\u00e3o acima, que \u00e9 um 20A<\/strong> fuse. Since 20A is equal to the module’s maximum series fuse rating, this is a valid selection. If the calculation had resulted in 21A, you would not be able to use a 25A fuse, and the design would need to be re-evaluated.<\/p>\n\n\n\nParte 3: Coordena\u00e7\u00e3o da prote\u00e7\u00e3o contra sobrecorrente<\/h3>\n\n\n\n A coordena\u00e7\u00e3o da prote\u00e7\u00e3o garante que, no caso de uma falha, o OCPD correto abra primeiro. No caso de uma falha em um \u00fanico string, o fus\u00edvel individual do string deve queimar, isolando apenas esse string sem colocar todo o array off-line. O OCPD principal na sa\u00edda da caixa combinadora s\u00f3 deve disparar se houver uma falha grave nos condutores principais que levam ao inversor.<\/p>\n\n\n\n
Isso \u00e9 feito garantindo que o dispositivo downstream tenha uma classifica\u00e7\u00e3o mais baixa do que o dispositivo upstream.<\/p>\n\n\n\nComponente<\/strong><\/th>Finalidade<\/strong><\/th>Regra geral de dimensionamento<\/strong><\/th>Refer\u00eancia NEC<\/strong><\/th><\/tr><\/thead>Fus\u00edvel de corda<\/strong><\/td>Protege strings individuais de falhas de corrente reversa de outras strings.<\/td> Isc \u00d7 1,56<\/code> (e deve ser \u2264 a classifica\u00e7\u00e3o m\u00e1xima do fus\u00edvel do m\u00f3dulo)<\/td>690.9(A)<\/code><\/td><\/tr>Combinador principal OCPD<\/strong><\/td>Protege o fio de sa\u00edda principal da caixa combinadora para o inversor.<\/td> Soma de todas as classifica\u00e7\u00f5es de fus\u00edveis de string, arredondada para o tamanho de disjuntor padr\u00e3o mais pr\u00f3ximo. Ou (Isc total \u00d7 1,25)<\/code> e selecione o pr\u00f3ximo tamanho padr\u00e3o de OCPD acima.<\/td>690.9(A)<\/code> & 240.4<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\nPerguntas frequentes (FAQ)<\/h3>\n\n\n\n Preciso de fus\u00edveis para apenas duas cadeias de caracteres paralelas?<\/strong>\\Posso usar fus\u00edveis ou disjuntores com classifica\u00e7\u00e3o CA para circuitos CC?<\/strong>\\O que acontece se eu instalar o fus\u00edvel de tamanho errado?<\/strong><\/p>\n\n\n\n\nMuito pequeno:<\/strong> The fuse will be subject to “nuisance tripping,” blowing under normal operating conditions (e.g., on a cool, very sunny day), causing unnecessary system downtime.<\/li>\n\n\n\nMuito grande:<\/strong> A fuse that is too large (especially one exceeding the module’s Maximum Series Fuse Rating) will not protect the module from damaging reverse currents. This can lead to module failure and creates a fire risk.<\/li>\n<\/ul>\n\n\n\nPor que o multiplicador de 1,56 \u00e9 usado para dimensionamento?<\/strong>\\Qual \u00e9 a \u201cClassifica\u00e7\u00e3o m\u00e1xima de fus\u00edveis em s\u00e9rie\u201d de um m\u00f3dulo?<\/strong>\\Conclus\u00e3o<\/h3>\n\n\n\n Matching a PV combiner box’s current and voltage ratings is a systematic process guided by engineering principles and the strict safety standards of the NEC. The core takeaways are:<\/p>\n\n\n\n
\nTens\u00e3o em primeiro lugar:<\/strong> Sempre determine a tens\u00e3o m\u00e1xima do sistema usando a temperatura mais baixa esperada para seu local. Todos os componentes devem ser classificados para essa tens\u00e3o.<\/li>\n\n\n\nSegundo atual:<\/strong> Size string fuses based on the module’s Isc and the 1.56x multiplier, but never exceed the module’s Maximum Series Fuse Rating.<\/li>\n\n\n\nO c\u00f3digo \u00e9 fundamental:<\/strong> When in doubt, defer to NEC Article 690 and the manufacturer’s datasheets for all components.<\/li>\n<\/ol>\n\n\n\nBy following these guidelines, you can ensure your solar array’s combiner box is sized safely, reliably, and professionally, forming a robust foundation for your entire PV system.<\/p>","protected":false},"excerpt":{"rendered":"
In a solar photovoltaic (PV) system, the combiner box plays a central role in consolidating power and ensuring safety. It’s a junction box where the output of multiple solar strings are connected in parallel, combining their current before sending it to the inverter. More importantly, it houses the critical overcurrent protection devices (fuses or circuit […]<\/p>","protected":false},"author":4,"featured_media":2285,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[],"class_list":["post-2279","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/posts\/2279","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/comments?post=2279"}],"version-history":[{"count":1,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/posts\/2279\/revisions"}],"predecessor-version":[{"id":2283,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/posts\/2279\/revisions\/2283"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/media\/2285"}],"wp:attachment":[{"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/media?parent=2279"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/categories?post=2279"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cnkuangya.com\/pt\/wp-json\/wp\/v2\/tags?post=2279"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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