{"id":21474,"date":"2026-01-28T18:23:42","date_gmt":"2026-01-28T10:23:42","guid":{"rendered":"https:\/\/viox.com\/?p=21474"},"modified":"2026-01-28T18:23:46","modified_gmt":"2026-01-28T10:23:46","slug":"mccb-short-time-delay-icw-rating-explained","status":"publish","type":"post","link":"https:\/\/test.viox.com\/cs\/mccb-short-time-delay-icw-rating-explained\/","title":{"rendered":"Pro\u010d MCCB nab\u00edzej\u00ed ochranu se zpo\u017ed\u011bn\u00edm proti zkratu bez jmenovit\u00e9ho kr\u00e1tkodob\u00e9ho v\u00fddr\u017en\u00e9ho proudu (I<sub>cw<\/sub>)"},"content":{"rendered":"<div class=\"product-intro\">\n<figure style=\"text-align: center; margin: 20px 0;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/MCCB-electronic-trip-unit-in-industrial-panel-showing-400A-rating-and-current-display.webp\" alt=\"MCCB electronic trip unit in industrial panel showing 400A rating and current display - VIOX Electric\" \/><figcaption style=\"font-style: italic; color: #555; margin-top: 8px;\">Elektronick\u00e1 spou\u0161\u0165 MCCB v pr\u016fmyslov\u00e9m panelu zobrazuj\u00edc\u00ed jmenovit\u00fd proud 400 A a zobrazen\u00ed proudu \u2013 VIOX Electric<\/figcaption><\/figure>\n<h2>P\u0159\u00edm\u00e1 odpov\u011b\u010f<\/h2>\n<p><strong><a href=\"https:\/\/test.viox.com\/cs\/mccb\/\">Jisti\u010de s lisovanou sk\u0159\u00edn\u00ed (MCCB)<\/a> m\u016f\u017ee poskytnout ochranu proti zpo\u017ed\u011bn\u00e9mu zkratu bez jmenovit\u00e9ho kr\u00e1tkodob\u00e9ho v\u00fddr\u017en\u00e9ho proudu (I<sub>cw<\/sub>), proto\u017ee pat\u0159\u00ed do kategorie A podle normy IEC 60947-2, kde je selektivita dosa\u017eena technologi\u00ed omezov\u00e1n\u00ed proudu sp\u00ed\u0161e ne\u017e z\u00e1m\u011brn\u00fdm \u010dasov\u00fdm zpo\u017ed\u011bn\u00edm.<\/strong> Na rozd\u00edl od vzduchov\u00fdch jisti\u010d\u016f (ACB) kategorie B, kter\u00e9 \u201cvy\u010dk\u00e1vaj\u00ed\u201d poruchov\u00e9 proudy s pou\u017eit\u00edm vysok\u00fdch I<sub>cw<\/sub> , MCCB pou\u017e\u00edvaj\u00ed elektromagnetick\u00e9 odpuzov\u00e1n\u00ed kontakt\u016f a ultra rychl\u00e9 p\u0159eru\u0161en\u00ed oblouku k omezen\u00ed poruchov\u00e9 energie \u2013 chr\u00e1n\u00ed se a z\u00e1rove\u0148 koordinuj\u00ed s navazuj\u00edc\u00edmi za\u0159\u00edzen\u00edmi prost\u0159ednictv\u00edm sv\u00fdch inherentn\u00edch charakteristik kr\u00e1tk\u00e9ho zpo\u017ed\u011bn\u00ed (typicky 10-12\u00d7 I<sub>n<\/sub>) pod prahovou hodnotou okam\u017eit\u00e9ho vypnut\u00ed.<\/p>\n<hr \/>\n<h2>Kl\u00ed\u010dov\u00e9 poznatky<\/h2>\n<ul>\n<li>\u2705 <strong>Kategorie A vs. B<\/strong>: MCCB (kategorie A) postr\u00e1daj\u00ed deklarovan\u00e9 I<sub>cw<\/sub> , ale maj\u00ed inherentn\u00ed kr\u00e1tkodobou v\u00fddr\u017enou schopnost pod prahovou hodnotou odpuzov\u00e1n\u00ed kontakt\u016f (typicky &gt;12-14\u00d7 I<sub>n<\/sub>)<\/li>\n<li>\u2705 <strong>Fyzika omezov\u00e1n\u00ed proudu<\/strong>: Tlak pru\u017einy kontaktu je v MCCB z\u00e1m\u011brn\u011b n\u00edzk\u00fd, aby se umo\u017enilo rychl\u00e9 elektromagnetick\u00e9 odpuzov\u00e1n\u00ed p\u0159i vysok\u00fdch poruchov\u00fdch proudech (&gt;25\u00d7 I<sub>n<\/sub>), \u010d\u00edm\u017e se zabr\u00e1n\u00ed po\u0161kozen\u00ed rychl\u00fdm p\u0159eru\u0161en\u00edm sp\u00ed\u0161e ne\u017e prodlou\u017eenou v\u00fddr\u017e\u00ed<\/li>\n<li>\u2705 <strong>Realita kr\u00e1tk\u00e9ho zpo\u017ed\u011bn\u00ed<\/strong>: Nastaven\u00ed kr\u00e1tk\u00e9ho zpo\u017ed\u011bn\u00ed MCCB (nap\u0159. 10\u00d7 I<sub>n<\/sub>, 0,4 s) funguj\u00ed pouze tehdy, kdy\u017e poruchov\u00fd proud z\u016fstane pod prahovou hodnotou okam\u017eit\u00e9ho vypnut\u00ed \u2013 p\u0159ekro\u010den\u00ed t\u00e9to hodnoty spust\u00ed okam\u017eitou akci prost\u0159ednictv\u00edm magnetick\u00e9ho vypnut\u00ed nebo mechanism\u016f zalo\u017een\u00fdch na energii<\/li>\n<li>\u2705 <strong>Omezen\u00ed selektivity<\/strong>: Pln\u00e1 selektivita mezi MCCB vy\u017eaduje pe\u010dliv\u00e9 koordina\u010dn\u00ed tabulky; kask\u00e1dy ACB-to-MCCB dosahuj\u00ed lep\u0161\u00edch v\u00fdsledk\u016f, proto\u017ee ACB mohou skute\u010dn\u011b zpozdit (I<sub>cw<\/sub> = I<sub>Icu vs Ics<\/sub> schopnost), zat\u00edmco MCCB \u0159e\u0161\u00ed poruchy v navazuj\u00edc\u00edch obvodech<\/li>\n<li>\u2705 <strong>Bezpe\u010dnostn\u00ed p\u0159eps\u00e1n\u00ed<\/strong>: Pokro\u010dil\u00e9 MCCB s deaktivovateln\u00fdmi okam\u017eit\u00fdmi vypnut\u00edmi (nap\u0159. Schneider NSX) obsahuj\u00ed funkce \u201cenergetick\u00e9ho vypnut\u00ed\u201d nebo \u201cokam\u017eit\u00e9ho p\u0159eps\u00e1n\u00ed\u201d \u2013 pokud poruchov\u00fd proud p\u0159ekro\u010d\u00ed ~25\u00d7 I<sub>n<\/sub>, mechanismy ovl\u00e1dan\u00e9 plynem vynut\u00ed okam\u017eit\u00e9 vypnut\u00ed bez ohledu na nastaven\u00ed<\/li>\n<\/ul>\n<hr \/>\n<h2>Pochopen\u00ed kategori\u00ed selektivity podle IEC 60947-2<\/h2>\n<figure style=\"text-align: center; margin: 20px 0;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/Size-and-construction-comparison-between-ACB-with-Icw-rating-and-compact-MCCB-Category-A-breaker.webp\" alt=\"Size and construction comparison between ACB with Icw rating and compact MCCB Category A breaker - VIOX Electric\" \/><figcaption style=\"font-style: italic; color: #555; margin-top: 8px;\">Porovn\u00e1n\u00ed velikosti a konstrukce mezi ACB s jmenovitou hodnotou Icw a kompaktn\u00edm jisti\u010dem MCCB kategorie A \u2013 VIOX Electric<\/figcaption><\/figure>\n<h3>Kategorie B: ACB s deklarovan\u00fdm I<sub>cw<\/sub><\/h3>\n<p>Vzduchov\u00e9 jisti\u010de (ACB) jsou navr\u017eeny pro <strong>Kategorie B<\/strong> aplikace, kde je selektivita dosa\u017eena z\u00e1m\u011brn\u00fdm kr\u00e1tkodob\u00fdm zpo\u017ed\u011bn\u00edm. Podle normy IEC 60947-2 mus\u00ed tato za\u0159\u00edzen\u00ed deklarovat jmenovit\u00fd kr\u00e1tkodob\u00fd v\u00fddr\u017en\u00fd proud (I<sub>cw<\/sub>) \u2013 maxim\u00e1ln\u00ed poruchov\u00fd proud, kter\u00fd m\u016f\u017ee jisti\u010d v\u00e9st v sepnut\u00e9m stavu po stanovenou dobu (0,05 s, 0,1 s, 0,25 s, 0,5 s nebo 1,0 s) bez po\u0161kozen\u00ed.<\/p>\n<p><strong>Kl\u00ed\u010dov\u00e9 vlastnosti jisti\u010d\u016f kategorie B:<\/strong><\/p>\n<table style=\"border-collapse: collapse; width: 100%; margin: 20px 0;\" border=\"1\" cellpadding=\"10\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>Parametr<\/th>\n<th>Specifikace<\/th>\n<th>\u00da\u010del<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>I<sub>cw<\/sub> Hodnocen\u00ed<\/strong><\/td>\n<td>Minim\u00e1ln\u011b 12\u00d7 I<sub>n<\/sub> nebo 5 kA (r\u00e1my \u22642500 A)<br \/>\nMinim\u00e1ln\u011b 30 kA (r\u00e1my &gt;2500 A)<\/td>\n<td>Umo\u017e\u0148uje z\u00e1m\u011brn\u00e9 zpo\u017ed\u011bn\u00ed b\u011bhem poruch<\/td>\n<\/tr>\n<tr>\n<td><strong>Kontaktn\u00ed design<\/strong><\/td>\n<td>Vysok\u00fd tlak pru\u017einy<\/td>\n<td>Zabra\u0148uje odpuzov\u00e1n\u00ed kontakt\u016f b\u011bhem doby zpo\u017ed\u011bn\u00ed<\/td>\n<\/tr>\n<tr>\n<td><strong>Mo\u017enost odlo\u017een\u00ed vypnut\u00ed<\/strong><\/td>\n<td>Okam\u017eit\u00e9 vypnut\u00ed lze deaktivovat<\/td>\n<td>Umo\u017e\u0148uje \u010dist\u011b \u010dasovou koordinaci<\/td>\n<\/tr>\n<tr>\n<td><strong>Typical Application<\/strong><\/td>\n<td>Hlavn\u00ed p\u0159\u00edvody, distribu\u010dn\u00ed v\u00fdvody<\/td>\n<td>Koordinuje se s navazuj\u00edc\u00edmi MCCB<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Nap\u0159\u00edklad ACB 800 A s I<sub>cw<\/sub> = 85 kA\/1 s vydr\u017e\u00ed poruchov\u00fd proud 85 kA a\u017e 1 sekundu, zat\u00edmco rel\u00e9 kr\u00e1tkodob\u00e9ho zpo\u017ed\u011bn\u00ed \u201c\u010dek\u00e1\u201d, a\u017e navazuj\u00edc\u00ed za\u0159\u00edzen\u00ed odstran\u00ed poruchu. Tato schopnost vy\u017eaduje robustn\u00ed mechanickou konstrukci \u2013 zes\u00edlen\u00e1 ramena kontakt\u016f, vysok\u00fd tlak kontaktu (zabra\u0148uj\u00edc\u00ed elektromagnetick\u00e9mu odpuzov\u00e1n\u00ed) a tepelnou hmotu pro absorpci I<sup>2<\/sup>t energie.<\/p>\n<h3>Kategorie A: MCCB bez deklarovan\u00e9ho I<sub>cw<\/sub><\/h3>\n<p>Lisovan\u00e9 jisti\u010de (MCCB) obvykle spadaj\u00ed pod <strong>Kategorie A<\/strong>\u2013 za\u0159\u00edzen\u00ed \u201ckter\u00e1 nejsou specificky ur\u010dena pro selektivitu za podm\u00ednek zkratu\u201d podle normy IEC 60947-2. Tyto jisti\u010de nedeklaruj\u00ed I<sub>cw<\/sub> hodnoty, proto\u017ee jejich konstruk\u010dn\u00ed filozofie up\u0159ednost\u0148uje <strong>rychl\u00e9 p\u0159eru\u0161en\u00ed poruchy<\/strong> p\u0159ed prodlou\u017eenou v\u00fddr\u017e\u00ed poruchy.<\/p>\n<p><strong>Pro\u010d MCCB nedeklaruj\u00ed I<sub>cw<\/sub>:<\/strong><\/p>\n<ol>\n<li><strong>Konstrukce omezuj\u00edc\u00ed proud<\/strong>: Tlak pru\u017einy kontaktu je z\u00e1m\u011brn\u011b n\u00edzk\u00fd, aby se usnadnilo rychl\u00e9 elektromagnetick\u00e9 odpuzov\u00e1n\u00ed, kdy\u017e poruchov\u00fd proud p\u0159ekro\u010d\u00ed ~10-14\u00d7 I<sub>n<\/sub><\/li>\n<li><strong>Povinnost okam\u017eit\u00e9ho vypnut\u00ed<\/strong>: V\u011bt\u0161ina MCCB nem\u016f\u017ee deaktivovat okam\u017eitou ochranu \u2013 jak\u00e1koli porucha p\u0159ekra\u010duj\u00edc\u00ed okam\u017eitou prahovou hodnotu spust\u00ed okam\u017eit\u00e9 vypnut\u00ed<\/li>\n<li><strong>Tepeln\u00e1 omezen\u00ed<\/strong>: Kompaktn\u00ed lisovan\u00e1 konstrukce nem\u016f\u017ee rozpt\u00fdlit tepelnou energii (I<sup>2<\/sup>t) spojenou s prodlou\u017eenou v\u00fddr\u017e\u00ed vysok\u00e9ho proudu<\/li>\n<\/ol>\n<p>Nicm\u00e9n\u011b to neznamen\u00e1 <strong>ne<\/strong> , \u017ee MCCB zcela postr\u00e1daj\u00ed kr\u00e1tkodobou v\u00fddr\u017enou schopnost \u2013 maj\u00ed inherentn\u00ed, nedeklarovanou prahovou hodnotu, pod kterou kontakty z\u016fst\u00e1vaj\u00ed sepnut\u00e9.<\/p>\n<hr \/>\n<h2>Fyzika odpuzov\u00e1n\u00ed kontakt\u016f MCCB<\/h2>\n<figure style=\"text-align: center; margin: 20px 0;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/MCCB-electromagnetic-contact-repulsion-mechanism-diagram-showing-force-balance-and-current-thresholds.webp\" alt=\"MCCB electromagnetic contact repulsion mechanism diagram showing force balance and current thresholds - VIOX Electric\" \/><figcaption style=\"font-style: italic; color: #555; margin-top: 8px;\">Diagram mechanismu elektromagnetick\u00e9ho odpuzov\u00e1n\u00ed kontakt\u016f MCCB zobrazuj\u00edc\u00ed rovnov\u00e1hu sil a proudov\u00e9 prahov\u00e9 hodnoty \u2013 VIOX Electric<\/figcaption><\/figure>\n<h3>Prahov\u00e1 hodnota elektromagnetick\u00e9ho odpuzov\u00e1n\u00ed<\/h3>\n<p>Kdy\u017e poruchov\u00fd proud prot\u00e9k\u00e1 paraleln\u00edmi cestami kontakt\u016f v MCCB, generuje protilehl\u00e1 magnetick\u00e1 pole, kter\u00e1 vytv\u00e1\u0159ej\u00ed <strong>elektrodynamick\u00e9 odpudiv\u00e9 s\u00edly<\/strong> (Lorentzova s\u00edla). Kontaktn\u00ed pru\u017eina mus\u00ed p\u016fsobit proti t\u00e9to s\u00edle, aby udr\u017eela kontakty zav\u0159en\u00e9.<\/p>\n<p><strong>Rovnice silov\u00e9 rovnov\u00e1hy:<\/strong><\/p>\n<p style=\"text-align: center; background-color: #f9f9f9; padding: 10px; border-radius: 4px;\">F<sub>pru\u017eina<\/sub> &gt; F<sub>odpuzov\u00e1n\u00ed<\/sub> = k \u00b7 I<sup>2<\/sup><\/p>\n<p>Kde:<\/p>\n<ul>\n<li>F<sub>pru\u017eina<\/sub> = S\u00edla stla\u010den\u00ed kontaktn\u00ed pru\u017einy<\/li>\n<li>F<sub>odpuzov\u00e1n\u00ed<\/sub> = Elektromagnetick\u00e1 odpudiv\u00e1 s\u00edla (\u00fam\u011brn\u00e1 I<sup>2<\/sup>)<\/li>\n<li>k = Geometrick\u00e1 konstanta (rozte\u010d kontakt\u016f, konfigurace vodi\u010d\u016f)<\/li>\n<\/ul>\n<table style=\"border-collapse: collapse; width: 100%; margin: 20px 0;\" border=\"1\" cellpadding=\"10\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>Parametr n\u00e1vrhu MCCB<\/th>\n<th>Kategorie A (MCCB)<\/th>\n<th>Kategorie B (ACB)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>Tlak kontaktn\u00ed pru\u017einy<\/strong><\/td>\n<td>N\u00edzk\u00fd (2-5 N\/mm)<\/td>\n<td>Vysok\u00fd (10-20 N\/mm)<\/td>\n<\/tr>\n<tr>\n<td><strong>Pr\u00e1h odpuzov\u00e1n\u00ed<\/strong><\/td>\n<td>12-14\u00d7 I<sub>n<\/sub><\/td>\n<td>&gt;50\u00d7 I<sub>n<\/sub><\/td>\n<\/tr>\n<tr>\n<td><strong>Rychlost otev\u00edr\u00e1n\u00ed kontakt\u016f<\/strong><\/td>\n<td>3-7 ms (ultra rychl\u00e9)<\/td>\n<td>20-50 ms (\u0159\u00edzen\u00e9)<\/td>\n<\/tr>\n<tr>\n<td><strong>Zhas\u00edn\u00e1n\u00ed oblouku<\/strong><\/td>\n<td>Omezen\u00ed poruchov\u00e9 energie (I<sup>2<\/sup>t)<\/td>\n<td>Odolnost proti poruchov\u00e9mu trv\u00e1n\u00ed<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u00davahy o spou\u0161t\u011bn\u00ed motoru<\/h3>\n<p>V\u00fdzkum \u0160anghajsk\u00e9ho elektrotechnick\u00e9ho v\u00fdzkumn\u00e9ho \u00fastavu na 52 vzorc\u00edch motor\u016f odhalil, \u017ee spou\u0161t\u011bn\u00ed nap\u0159\u00edmo (DOL) produkuje prvn\u00ed \u0161pi\u010dkov\u00e9 z\u00e1b\u011brov\u00e9 proudy o velikosti <strong>8-12\u00d7 I<sub>n<\/sub><\/strong> pro v\u011bt\u0161inu motor\u016f, p\u0159i\u010dem\u017e odlehl\u00e9 hodnoty dosahuj\u00ed 13\u00d7 I<sub>n<\/sub>.<\/p>\n<p><strong>Tato data ur\u010duj\u00ed konstruk\u010dn\u00ed omezen\u00ed MCCB:<\/strong><\/p>\n<ul>\n<li><strong>Distribu\u010dn\u00ed MCCB<\/strong>: Okam\u017eit\u00e1 spou\u0161\u0165 nastavena na 10-12\u00d7 I<sub>n<\/sub> (nesm\u00ed vypnout p\u0159i z\u00e1b\u011brov\u00e9m proudu kondenz\u00e1toru nebo p\u0159i zapnut\u00ed transform\u00e1toru)<\/li>\n<li><strong>MCCB jmenovit\u00e9 pro motory<\/strong>: Okam\u017eit\u00e1 spou\u0161\u0165 nastavena na 13-14\u00d7 I<sub>n<\/sub> (mus\u00ed vydr\u017eet spou\u0161t\u011bn\u00ed DOL)<\/li>\n<li><strong>Pr\u00e1h odpuzov\u00e1n\u00ed kontakt\u016f<\/strong>: Mus\u00ed p\u0159ekro\u010dit nastaven\u00ed okam\u017eit\u00e9 spou\u0161t\u011b o 15-20 % rezervy, aby se zabr\u00e1nilo ru\u0161iv\u00e9mu otev\u00edr\u00e1n\u00ed kontakt\u016f b\u011bhem spou\u0161t\u011bc\u00edch p\u0159echodov\u00fdch jev\u016f<\/li>\n<\/ul>\n<p><strong>P\u0159\u00edklad v\u00fdpo\u010dtu pro MCCB jmenovit\u00fd pro motor 100A:<\/strong><\/p>\n<div style=\"background-color: #f5f5f5; padding: 15px; border-radius: 5px; margin: 15px 0; font-family: monospace;\">Nastaven\u00ed okam\u017eit\u00e9 spou\u0161t\u011b: 13 \u00d7 100A = 1 300A<br \/>\nPr\u00e1h odpuzov\u00e1n\u00ed kontakt\u016f: 1 300A \u00d7 1,2 = 1 560A (c\u00edlov\u00e1 hodnota n\u00e1vrhu)<br \/>\nNedeclarovan\u00e1 schopnost \u201cIcw\u201d: ~1 500A (pod prahem odpuzov\u00e1n\u00ed)<\/div>\n<p>Tato prahov\u00e1 hodnota 1 500A p\u0159edstavuje inherentn\u00ed kr\u00e1tkodobou v\u00fddr\u017e MCCB \u2013 dostate\u010dnou pro koordinaci s navazuj\u00edc\u00edmi za\u0159\u00edzen\u00edmi v rozsahu poruchy 1 000\u20131 500A, ale hluboko pod deklarovan\u00fdmi I<sub>cw<\/sub> hodnotami ACB (typicky 30-85kA).<\/p>\n<hr \/>\n<h2>Jak vlastn\u011b funguje kr\u00e1tkodob\u00e9 zpo\u017ed\u011bn\u00ed MCCB<\/h2>\n<figure style=\"text-align: center; margin: 20px 0;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/Technical-infographic-clean-202601280514.webp\" alt=\"MCCB three-zone protection logic diagram showing overload, short-time delay, and instantaneous trip thresholds - VIOX Electric\" \/><figcaption style=\"font-style: italic; color: #555; margin-top: 8px;\">Logick\u00e9 sch\u00e9ma ochrany t\u0159\u00ed z\u00f3n MCCB zobrazuj\u00edc\u00ed p\u0159et\u00ed\u017een\u00ed, kr\u00e1tkodob\u00e9 zpo\u017ed\u011bn\u00ed a prahov\u00e9 hodnoty okam\u017eit\u00e9ho vypnut\u00ed \u2013 VIOX Electric<\/figcaption><\/figure>\n<h3>T\u0159i provozn\u00ed z\u00f3ny<\/h3>\n<p>Modern\u00ed MCCB s elektronickou spou\u0161t\u00ed maj\u00ed t\u0159i ochrann\u00e9 z\u00f3ny, ale jejich interakce se z\u00e1sadn\u011b li\u0161\u00ed od ACB:<\/p>\n<table style=\"border-collapse: collapse; width: 100%; margin: 20px 0;\" border=\"1\" cellpadding=\"10\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>Ochrann\u00e1 z\u00f3na<\/th>\n<th>Rozsah nastaven\u00ed<\/th>\n<th>Skute\u010dn\u00e9 chov\u00e1n\u00ed<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>Dlouhodob\u00e9 (p\u0159et\u00ed\u017een\u00ed)<\/strong><\/td>\n<td>0,4-1,0\u00d7 I<sub>n<\/sub>, 3-30s<\/td>\n<td>Tepeln\u00e1 ochrana pomoc\u00ed v\u00fdpo\u010dtu I<sup>2<\/sup>t<\/td>\n<\/tr>\n<tr>\n<td><strong>Kr\u00e1tkodob\u00e9 zpo\u017ed\u011bn\u00ed<\/strong><\/td>\n<td>2-12\u00d7 I<sub>n<\/sub>, 0,1-0,5s<\/td>\n<td><strong>Aktivn\u00ed pouze pod prahem okam\u017eit\u00e9ho vypnut\u00ed<\/strong><\/td>\n<\/tr>\n<tr>\n<td><strong>Okam\u017eit\u00e9<\/strong><\/td>\n<td>10-14\u00d7 I<sub>n<\/sub> (pevn\u00e9 nebo nastaviteln\u00e9)<\/td>\n<td><strong>Ve v\u011bt\u0161in\u011b MCCB nelze deaktivovat<\/strong><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>Sc\u00e9n\u00e1\u0159 1: Poruchov\u00fd proud pod prahem okam\u017eit\u00e9ho vypnut\u00ed<\/h3>\n<p><strong>Podm\u00ednky<\/strong>: Poruchov\u00fd proud = 8\u00d7 I<sub>n<\/sub> (800A pro jisti\u010d 100A)<\/p>\n<ol>\n<li>Proud p\u0159ekro\u010d\u00ed z\u00f3nu dlouhodob\u00e9ho zpo\u017ed\u011bn\u00ed \u2192 Aktivuje se zpo\u017ed\u011bn\u00ed v kr\u00e1tk\u00e9m \u010dase<\/li>\n<li>Elektronick\u00e1 spou\u0161\u0165 za\u010dne odpo\u010d\u00edt\u00e1vat (nap\u0159. 0,4 s)<\/li>\n<li>Pokud porucha p\u0159etrv\u00e1v\u00e1, spou\u0161t\u011bc\u00ed c\u00edvka se po zpo\u017ed\u011bn\u00ed aktivuje<\/li>\n<li>Kontakty se otev\u0159ou pomoc\u00ed mechanismu s akumulovanou energi\u00ed (doba otev\u0159en\u00ed ~20-30 ms)<\/li>\n<\/ol>\n<p><strong>V\u00fdsledek<\/strong>: Skute\u010dn\u00e1 \u010dasov\u011b zpo\u017ed\u011bn\u00e1 koordinace s pod\u0159\u00edzen\u00fdmi za\u0159\u00edzen\u00edmi<\/p>\n<h3>Sc\u00e9n\u00e1\u0159 2: Poruchov\u00fd proud nad okam\u017eitou prahovou hodnotou<\/h3>\n<p><strong>Podm\u00ednky<\/strong>: Poruchov\u00fd proud = 15\u00d7 I<sub>n<\/sub> (1 500 A pro jisti\u010d 100 A)<\/p>\n<ol>\n<li>Proud p\u0159ekro\u010d\u00ed okam\u017eitou prahovou hodnotu \u2192 Magnetick\u00e1 spou\u0161\u0165 se okam\u017eit\u011b aktivuje<\/li>\n<li>Nastaven\u00ed zpo\u017ed\u011bn\u00ed v kr\u00e1tk\u00e9m \u010dase je <strong>vynech\u00e1no<\/strong><\/li>\n<li>Spou\u0161t\u011bc\u00ed c\u00edvka se aktivuje b\u011bhem 5-10 ms<\/li>\n<li>Kontakty se otev\u0159ou, ale poruchov\u00fd proud ji\u017e mohl zp\u016fsobit elektromagnetick\u00e9 odpuzov\u00e1n\u00ed<\/li>\n<\/ol>\n<p><strong>V\u00fdsledek<\/strong>: \u017d\u00e1dn\u00e9 z\u00e1m\u011brn\u00e9 zpo\u017ed\u011bn\u00ed \u2013 MCCB vypne tak rychle, jak je to mo\u017en\u00e9<\/p>\n<h3>Sc\u00e9n\u00e1\u0159 3: Poruchov\u00fd proud v\u00fdrazn\u011b p\u0159ekra\u010duje prahovou hodnotu odpuzov\u00e1n\u00ed<\/h3>\n<p><strong>Podm\u00ednky<\/strong>: Poruchov\u00fd proud = 50\u00d7 I<sub>n<\/sub> (5 000 A pro jisti\u010d 100 A, bl\u00ed\u017e\u00edc\u00ed se I<sub>Icu vs Ics<\/sub>)<\/p>\n<ol>\n<li>S\u00edla elektromagnetick\u00e9ho odpuzov\u00e1n\u00ed p\u0159ekra\u010duje tlak pru\u017einy<\/li>\n<li>Kontakty se rozlet\u00ed b\u011bhem 3-7 ms (rychleji ne\u017e spou\u0161t\u011bc\u00ed mechanismus)<\/li>\n<li>Nap\u011bt\u00ed oblouku rychle stoup\u00e1, omezuje \u0161pi\u010dkov\u00fd proud (proudov\u00e9 omezen\u00ed)<\/li>\n<li>Energie oblouku m\u016f\u017ee spustit spou\u0161t\u011bc\u00ed mechanismus, nebo se jisti\u010d spol\u00e9h\u00e1 pouze na zh\u00e1\u0161en\u00ed oblouku<\/li>\n<\/ol>\n<p><strong>V\u00fdsledek<\/strong>: Ultra rychl\u00e9 omezen\u00ed proudu \u2013 \u017e\u00e1dn\u00e1 koordinace, ale ochrana za\u0159\u00edzen\u00ed pomoc\u00ed I<sup>2<\/sup>t redukce<\/p>\n<hr \/>\n<h2>Zvl\u00e1\u0161tn\u00ed p\u0159\u00edpad: MCCB s deaktivovatelnou okam\u017eitou spou\u0161t\u00ed<\/h2>\n<h3>Mechanismus \u201cEnergy Trip\u201d Schneider NSX<\/h3>\n<p>N\u011bkter\u00e9 \u0161pi\u010dkov\u00e9 MCCB (nap\u0159. Schneider Electric NSX s vyp\u00ednac\u00edmi jednotkami Micrologic) umo\u017e\u0148uj\u00ed deaktivovat okam\u017eitou ochranu pro zlep\u0161en\u00ed selektivity. Tato za\u0159\u00edzen\u00ed v\u0161ak obsahuj\u00ed <strong>povinn\u00e9 bezpe\u010dnostn\u00ed p\u0159eps\u00e1n\u00ed<\/strong> naz\u00fdvan\u00e9 \u201cenergy trip\u201d nebo \u201cinstantaneous override\u201d.\u201d<\/p>\n<p><strong>Jak to funguje:<\/strong><\/p>\n<ol>\n<li>U\u017eivatel deaktivuje okam\u017eitou spou\u0161\u0165, povol\u00ed zpo\u017ed\u011bn\u00ed v kr\u00e1tk\u00e9m \u010dase (nap\u0159. 10\u00d7 I<sub>n<\/sub>, 0,4 s)<\/li>\n<li>Poruchov\u00fd proud dos\u00e1hne 30\u00d7 I<sub>n<\/sub> (3 000 A pro jisti\u010d 100 A)<\/li>\n<li>Kontakty se odpuzuj\u00ed, tvo\u0159\u00ed se oblouk<\/li>\n<li>Energie oblouku ionizuje materi\u00e1l generuj\u00edc\u00ed plyn v obloukov\u00e9 komo\u0159e<\/li>\n<li>N\u00e1r\u016fst tlaku aktivuje pneumatick\u00fd spou\u0161t\u011bc\u00ed mechanismus b\u011bhem 10-15 ms<\/li>\n<li>Jisti\u010d vypne <strong>bez ohledu na nastaven\u00ed elektronick\u00e9 spou\u0161t\u011b<\/strong><\/li>\n<\/ol>\n<table style=\"border-collapse: collapse; width: 100%; margin: 20px 0;\" border=\"1\" cellpadding=\"10\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>\u00darove\u0148 poruchov\u00e9ho proudu<\/th>\n<th>Odezva NSX<\/th>\n<th>Standardn\u00ed odezva MCCB<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>8\u00d7 I<sub>n<\/sub><\/strong><\/td>\n<td>Zpo\u017ed\u011bn\u00ed v kr\u00e1tk\u00e9m \u010dase funguje norm\u00e1ln\u011b<\/td>\n<td>Funkce zpo\u017ed\u011bn\u00ed v kr\u00e1tk\u00e9m \u010dase<\/td>\n<\/tr>\n<tr>\n<td><strong>15\u00d7 I<sub>n<\/sub><\/strong><\/td>\n<td>Funkce zpo\u017ed\u011bn\u00ed v kr\u00e1tk\u00e9m \u010dase (okam\u017eit\u00e9 vypnut\u00ed deaktivov\u00e1no)<\/td>\n<td>Okam\u017eit\u00e1 spou\u0161\u0165 (nelze deaktivovat)<\/td>\n<\/tr>\n<tr>\n<td><strong>&gt;25\u00d7 I<sub>n<\/sub><\/strong><\/td>\n<td>Energy trip p\u0159eb\u00edr\u00e1 zpo\u017ed\u011bn\u00ed<\/td>\n<td>Odpuzov\u00e1n\u00ed kontakt\u016f + okam\u017eit\u00e1 spou\u0161\u0165<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Tato konstrukce zabra\u0148uje katastrofick\u00e9mu selh\u00e1n\u00ed, kdy\u017e u\u017eivatel\u00e9 nespr\u00e1vn\u011b nakonfiguruj\u00ed nastaven\u00ed ochrany \u2013 MCCB se v\u017edy sama ochr\u00e1n\u00ed p\u0159i extr\u00e9mn\u00edch \u00farovn\u00edch poruchy, i kdy\u017e to ohroz\u00ed selektivitu.<\/p>\n<hr \/>\n<h2>Praktick\u00e9 strategie koordinace<\/h2>\n<figure style=\"text-align: center; margin: 20px 0;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/Time-current-coordination-diagram-showing-ACB-and-MCCB-selectivity-zones-with-fault-scenario-analysis.webp\" alt=\"Time-current coordination diagram showing ACB and MCCB selectivity zones with fault scenario analysis - VIOX Electric\" \/><figcaption style=\"font-style: italic; color: #555; margin-top: 8px;\">\u010casov\u011b-proudov\u00fd koordina\u010dn\u00ed diagram zobrazuj\u00edc\u00ed selektivn\u00ed z\u00f3ny ACB a MCCB s anal\u00fdzou sc\u00e9n\u00e1\u0159\u016f poruch \u2013 VIOX Electric<\/figcaption><\/figure>\n<h3>Strategie 1: Kask\u00e1da ACB-to-MCCB (doporu\u010deno)<\/h3>\n<p><strong>Konfigurace:<\/strong><\/p>\n<ul>\n<li><strong>Na stran\u011b zdroje<\/strong>: 1600A ACB, I<sub>cw<\/sub> = 65kA\/0,5s, zpo\u017ed\u011bn\u00ed v kr\u00e1tk\u00e9m \u010dase = 0,4s<\/li>\n<li><strong>Na stran\u011b z\u00e1t\u011b\u017ee<\/strong>: 400A MCCB, I<sub>Icu vs Ics<\/sub> = 50kA, okam\u017eit\u00e9 = 5 000 A (12,5\u00d7 I<sub>n<\/sub>)<\/li>\n<\/ul>\n<p><strong>Anal\u00fdza koordinace:<\/strong><\/p>\n<table style=\"border-collapse: collapse; width: 100%; margin: 20px 0;\" border=\"1\" cellpadding=\"10\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>Um\u00edst\u011bn\u00ed poruchy<\/th>\n<th>Poruchov\u00fd proud<\/th>\n<th>Akce nad\u0159azen\u00e9ho ACB<\/th>\n<th>Akce pod\u0159\u00edzen\u00e9ho MCCB<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>Pod\u0159\u00edzen\u00fd p\u0159\u00edvod<\/strong><\/td>\n<td>8 kA<\/td>\n<td>\u010cek\u00e1 0,4 s (v r\u00e1mci I<sub>cw<\/sub>)<\/td>\n<td>Vyp\u00edn\u00e1 okam\u017eit\u011b (&gt;12,5\u00d7 I<sub>n<\/sub>)<\/td>\n<\/tr>\n<tr>\n<td><strong>Pod\u0159\u00edzen\u00fd p\u0159\u00edvod<\/strong><\/td>\n<td>45 kA<\/td>\n<td>\u010cek\u00e1 0,4 s (v r\u00e1mci I<sub>cw<\/sub>)<\/td>\n<td>Vyp\u00edn\u00e1 okam\u017eit\u011b (omezuj\u00edc\u00ed proud)<\/td>\n<\/tr>\n<tr>\n<td><strong>Hlavn\u00ed p\u0159\u00edpojnice<\/strong><\/td>\n<td>60 kA<\/td>\n<td>Vyp\u00edn\u00e1 po 0,4 s<\/td>\n<td>Neovlivn\u011bno<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>V\u00fdsledek<\/strong>: Pln\u00e1 selektivita do 50 kA (MCCB I<sub>Icu vs Ics<\/sub> limit)<\/p>\n<h3>Strategie 2: Koordinace MCCB-MCCB (omezen\u00e1)<\/h3>\n<p><strong>Konfigurace:<\/strong><\/p>\n<ul>\n<li><strong>Na stran\u011b zdroje<\/strong>: 400A MCCB, okam\u017eit\u00e1 = 5 000 A (12,5\u00d7 I<sub>n<\/sub>)<\/li>\n<li><strong>Na stran\u011b z\u00e1t\u011b\u017ee<\/strong>: 100A MCCB, okam\u017eit\u00e1 = 1 300 A (13\u00d7 I<sub>n<\/sub>)<\/li>\n<\/ul>\n<p><strong>Anal\u00fdza koordinace:<\/strong><\/p>\n<table style=\"border-collapse: collapse; width: 100%; margin: 20px 0;\" border=\"1\" cellpadding=\"10\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>Poruchov\u00fd proud<\/th>\n<th>Nad\u0159azen\u00fd MCCB<\/th>\n<th>Pod\u0159azen\u00fd MCCB<\/th>\n<th>Selektivita?<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>1 500 A<\/strong><\/td>\n<td>Zpo\u017ed\u011bn\u00e9 zkratov\u00e9 (0,3 s)<\/td>\n<td>Okam\u017eit\u00fd v\u00fdlet<\/td>\n<td>\u2705 Ano<\/td>\n<\/tr>\n<tr>\n<td><strong>4 000 A<\/strong><\/td>\n<td>Zpo\u017ed\u011bn\u00e9 zkratov\u00e9 (0,3 s)<\/td>\n<td>Okam\u017eit\u00fd v\u00fdlet<\/td>\n<td>\u2705 Ano<\/td>\n<\/tr>\n<tr>\n<td><strong>6 000 A<\/strong><\/td>\n<td><strong>Okam\u017eit\u00fd v\u00fdlet<\/strong><\/td>\n<td>Okam\u017eit\u00fd v\u00fdlet<\/td>\n<td>\u274c Ne (vypnou oba)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>Hranice selektivity<\/strong>: ~4 500 A (90% nastaven\u00ed okam\u017eit\u00e9ho nad\u0159azen\u00e9ho jisti\u010de)<\/p>\n<p><strong>Zlep\u0161en\u00ed<\/strong>: Pro ov\u011b\u0159en\u00ed skute\u010dn\u00e9 propu\u0161t\u011bn\u00e9 energie pou\u017eijte koordina\u010dn\u00ed tabulky v\u00fdrobce \u2013 proudov\u011b omezuj\u00edc\u00ed MCCB mohou st\u00e1le dos\u00e1hnout selektivity p\u0159i vy\u0161\u0161\u00edch poruchov\u00fdch \u00farovn\u00edch prost\u0159ednictv\u00edm I<sup>2<\/sup>t diskriminace.<\/p>\n<hr \/>\n<h2>Srovn\u00e1vac\u00ed tabulka: Charakteristiky kr\u00e1tkodob\u00e9ho zpo\u017ed\u011bn\u00ed ACB vs. MCCB<\/h2>\n<table style=\"border-collapse: collapse; width: 100%; margin: 20px 0;\" border=\"1\" cellpadding=\"10\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>Funkce<\/th>\n<th>ACB (kategorie B)<\/th>\n<th>MCCB (kategorie A)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td><strong>I<sub>cw<\/sub> Prohl\u00e1\u0161en\u00ed<\/strong><\/td>\n<td>\u2705 Ano (30\u201385 kA, 0,05\u20131,0 s)<\/td>\n<td>\u274c Ne (nedeklarov\u00e1no)<\/td>\n<\/tr>\n<tr>\n<td><strong>Vlastn\u00ed odolnost<\/strong><\/td>\n<td>Velmi vysok\u00e1 (&gt;50\u00d7 I<sub>n<\/sub>)<\/td>\n<td>Omezen\u00e1 (12\u201314\u00d7 I<sub>n<\/sub>)<\/td>\n<\/tr>\n<tr>\n<td><strong>Tlak kontaktn\u00ed pru\u017einy<\/strong><\/td>\n<td>Vysok\u00e1 (zabra\u0148uje odpuzov\u00e1n\u00ed)<\/td>\n<td>N\u00edzk\u00e1 (umo\u017e\u0148uje omezen\u00ed proudu)<\/td>\n<\/tr>\n<tr>\n<td><strong>Okam\u017eit\u00e9 vypnut\u00ed<\/strong><\/td>\n<td>Lze deaktivovat<\/td>\n<td>Obvykle pevn\u00e9 (nelze deaktivovat)<\/td>\n<\/tr>\n<tr>\n<td><strong>Rozsah kr\u00e1tkodob\u00e9ho zpo\u017ed\u011bn\u00ed<\/strong><\/td>\n<td>0,05\u20131,0 s (nastaviteln\u00e9)<\/td>\n<td>0,1\u20130,5 s (pouze pod prahem okam\u017eit\u00e9ho vypnut\u00ed)<\/td>\n<\/tr>\n<tr>\n<td><strong>Metoda koordinace<\/strong><\/td>\n<td>Zalo\u017eeno na \u010dase (skute\u010dn\u00e9 zpo\u017ed\u011bn\u00ed)<\/td>\n<td>Zalo\u017eeno na proudu (omezen\u00ed + zpo\u017ed\u011bn\u00ed)<\/td>\n<\/tr>\n<tr>\n<td><strong>Typical Application<\/strong><\/td>\n<td>Hlavn\u00ed p\u0159\u00edvod (1000\u20136300 A)<\/td>\n<td>Ochrana v\u00fdvodu (16\u20131600 A)<\/td>\n<\/tr>\n<tr>\n<td><strong>Selektivita s pod\u0159azen\u00fdm jisti\u010dem<\/strong><\/td>\n<td>Pln\u00e1 (a\u017e do I<sub>cw<\/sub>)<\/td>\n<td>\u010c\u00e1ste\u010dn\u00e1 (a\u017e do prahu okam\u017eit\u00e9ho vypnut\u00ed)<\/td>\n<\/tr>\n<tr>\n<td><strong>Mechanismus vlastn\u00ed ochrany<\/strong><\/td>\n<td>Tepeln\u00e1 hmota + mechanick\u00e1 pevnost<\/td>\n<td>Odpuzov\u00e1n\u00ed kontakt\u016f + omezen\u00ed oblouku<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<hr \/>\n<h2>Pro\u010d na tom z\u00e1le\u017e\u00ed pro n\u00e1vrh syst\u00e9mu<\/h2>\n<h3>Myln\u00e1 p\u0159edstava 1: \u201cKr\u00e1tkodob\u00e9 zpo\u017ed\u011bn\u00ed MCCB = Kr\u00e1tkodob\u00e9 zpo\u017ed\u011bn\u00ed ACB\u201d<\/h3>\n<p><strong>Realita<\/strong>: Kr\u00e1tkodob\u00e9 zpo\u017ed\u011bn\u00ed MCCB funguje pouze v \u00fazk\u00e9m proudov\u00e9m okn\u011b (mezi dlouhodob\u00fdm a okam\u017eit\u00fdm prahem). P\u0159i poruch\u00e1ch p\u0159ekra\u010duj\u00edc\u00edch okam\u017eit\u00e9 nastaven\u00ed MCCB vyp\u00ednaj\u00ed okam\u017eit\u011b \u2013 nedoch\u00e1z\u00ed k \u017e\u00e1dn\u00e9mu zpo\u017ed\u011bn\u00ed.<\/p>\n<p><strong>Dopad na n\u00e1vrh<\/strong>: P\u0159i specifikaci ochrany MCCB v\u017edy ov\u011b\u0159te:<\/p>\n<ol>\n<li>Nastaven\u00ed okam\u017eit\u00e9ho vypnut\u00ed pod\u0159azen\u00e9ho za\u0159\u00edzen\u00ed<\/li>\n<li>Maxim\u00e1ln\u00ed poruchov\u00fd proud v koordina\u010dn\u00edm bod\u011b<\/li>\n<li>Zda poruchov\u00fd proud p\u0159ekro\u010d\u00ed pr\u00e1h okam\u017eit\u00e9ho vypnut\u00ed nad\u0159azen\u00e9ho MCCB<\/li>\n<\/ol>\n<h3>Myln\u00e1 p\u0159edstava 2: \u201c\u017d\u00e1dn\u00e9 I<sub>cw<\/sub> Rating = \u017d\u00e1dn\u00e1 schopnost kr\u00e1tkodob\u00e9 odolnosti\u201d<\/h3>\n<p><strong>Realita<\/strong>: MCCB maj\u00ed inherentn\u00ed kr\u00e1tkodobou odolnost a\u017e do prahu odpuzov\u00e1n\u00ed kontakt\u016f (~12\u201314\u00d7 I<sub>n<\/sub>). Tato schopnost umo\u017e\u0148uje omezenou koordinaci s pod\u0159azen\u00fdmi za\u0159\u00edzen\u00edmi, i kdy\u017e ne v rozsahu ACB.<\/p>\n<p><strong>Dopad na n\u00e1vrh<\/strong>: Koordinace MCCB-MCCB je mo\u017en\u00e1, ale vy\u017eaduje:<\/p>\n<ul>\n<li>Pe\u010dliv\u00e9 odd\u011blen\u00ed nastaven\u00ed okam\u017eit\u00e9ho vypnut\u00ed (minim\u00e1ln\u00ed pom\u011br 1,5:1)<\/li>\n<li>Tabulky selektivity poskytnut\u00e9 v\u00fdrobcem<\/li>\n<li>Zohledn\u011bn\u00ed \u00fa\u010dink\u016f omezen\u00ed proudu na propu\u0161t\u011bnou energii<\/li>\n<\/ul>\n<h3>Myln\u00e1 p\u0159edstava \u010d. 3: \u201cDeaktivace okam\u017eit\u00e9ho vypnut\u00ed \u010din\u00ed z MCCB = ACB\u201d<\/h3>\n<p><strong>Realita<\/strong>: I MCCB s deaktivovateln\u00fdm okam\u017eit\u00fdm vyp\u00edn\u00e1n\u00edm (nap\u0159. NSX) obsahuj\u00ed mechanismy potla\u010den\u00ed zalo\u017een\u00e9 na energii, kter\u00e9 vynut\u00ed vypnut\u00ed p\u0159i extr\u00e9mn\u00edch \u00farovn\u00edch poruchy (&gt;25\u00d7 I<sub>n<\/sub>). Nemohou \u201cvy\u010dk\u00e1vat\u201d vysok\u00e9 poruchov\u00e9 proudy jako ACB.<\/p>\n<p><strong>Dopad na n\u00e1vrh<\/strong>: P\u0159i pou\u017eit\u00ed MCCB s nastaviteln\u00fdm okam\u017eit\u00fdm vyp\u00edn\u00e1n\u00edm:<\/p>\n<ul>\n<li>Ov\u011b\u0159te si u v\u00fdrobce pr\u00e1h vypnut\u00ed na z\u00e1klad\u011b energie<\/li>\n<li>Nep\u0159edpokl\u00e1dejte chov\u00e1n\u00ed podobn\u00e9 ACB p\u0159i poruchov\u00fdch proudech bl\u00ed\u017e\u00edc\u00edch se I<sub>Icu vs Ics<\/sub><\/li>\n<li>Zva\u017ete dopady energie obloukov\u00e9ho v\u00fdboje na zpo\u017ed\u011bn\u00e9 vypnut\u00ed<\/li>\n<\/ul>\n<hr \/>\n<h2>Intern\u00ed odkazy a souvisej\u00edc\u00ed zdroje<\/h2>\n<p>Pro hlub\u0161\u00ed pochopen\u00ed souvisej\u00edc\u00edch koncept\u016f ochrany prozkoumejte tyto technick\u00e9 p\u0159\u00edru\u010dky VIOX:<\/p>\n<ul>\n<li><a href=\"https:\/\/test.viox.com\/cs\/electrical-derating-temperature-altitude-grouping-factors\/\"><strong>Elektrick\u00e9 sn\u00ed\u017een\u00ed v\u00fdkonu: Teplota, nadmo\u0159sk\u00e1 v\u00fd\u0161ka a faktory seskupov\u00e1n\u00ed<\/strong><\/a> \u2013 Zjist\u011bte, jak environment\u00e1ln\u00ed faktory ovliv\u0148uj\u00ed jmenovit\u00e9 proudy jisti\u010d\u016f a koordinaci<\/li>\n<li><a href=\"https:\/\/test.viox.com\/cs\/ats-circuit-breaker-coordination-guide-icw-selectivity\/\"><strong>Pr\u016fvodce koordinac\u00ed ATS a jisti\u010d\u016f: I<sub>cw<\/sub> &amp; Vysv\u011btlen\u00ed selektivity<\/strong><\/a> \u2013 Podrobn\u00e1 anal\u00fdza koordinace kategorie A vs. B v aplikac\u00edch automatick\u00e9ho p\u0159ep\u00edn\u00e1n\u00ed<\/li>\n<li><a href=\"https:\/\/test.viox.com\/cs\/current-limiting-circuit-breaker-guide\/\"><strong>Pr\u016fvodce proudov\u011b omezen\u00fdm jisti\u010dem: Ochrana a specifikace<\/strong><\/a> \u2013 Hloubkov\u00fd ponor do fyziky elektromagnetick\u00e9ho odpuzov\u00e1n\u00ed a I<sup>2<\/sup>omezen\u00ed t<\/li>\n<li><a href=\"https:\/\/test.viox.com\/cs\/types-of-circuit-breakers\/\"><strong>Typy jisti\u010d\u016f: Kompletn\u00ed pr\u016fvodce klasifikac\u00ed<\/strong><\/a> \u2013 Komplexn\u00ed p\u0159ehled rozd\u00edl\u016f a aplikac\u00ed ACB, MCCB, MCB<\/li>\n<li><a href=\"https:\/\/test.viox.com\/cs\/commercial-ev-charging-protection-guide-acb-mccb-rcbo\/\"><strong>Pr\u016fvodce ochranou komer\u010dn\u00edho nab\u00edjen\u00ed EV: ACB, MCCB a RCBO typu B<\/strong><\/a> \u2013 P\u0159\u00edklad koordinace v re\u00e1ln\u00e9m sv\u011bt\u011b s v\u00fdpo\u010dty zat\u00ed\u017een\u00ed<\/li>\n<\/ul>\n<hr \/>\n<h2>FAQ: Ochrana MCCB proti zkratu se zpo\u017ed\u011bn\u00edm<\/h2>\n<h3>Q1: Mohu pou\u017e\u00edt MCCB jako hlavn\u00ed p\u0159\u00edvod m\u00edsto ACB?<\/h3>\n<p><strong>A<\/strong>: Mo\u017en\u00e9, ale nedoporu\u010duje se pro syst\u00e9my vy\u017eaduj\u00edc\u00ed plnou selektivitu. MCCB postr\u00e1daj\u00ed deklarovan\u00e9 I<sub>cw<\/sub> hodnoty, tak\u017ee nemohou spolehliv\u011b zpozdit vypnut\u00ed pro koordinaci s navazuj\u00edc\u00edmi za\u0159\u00edzen\u00edmi p\u0159i vysok\u00fdch poruchov\u00fdch proudech (&gt;10\u00d7 I<sub>n<\/sub>). Pou\u017e\u00edvejte ACB pro hlavn\u00ed p\u0159\u00edvody v pr\u016fmyslov\u00fdch za\u0159\u00edzen\u00edch, kde je selektivita kritick\u00e1, nebo ov\u011b\u0159te limity koordinace pomoc\u00ed tabulek v\u00fdrobce pro komer\u010dn\u00ed aplikace.<\/p>\n<h3>Q2: Co se stane, kdy\u017e nastav\u00edm zpo\u017ed\u011bn\u00ed zkratu MCCB na 0,5 s, ale poruchov\u00fd proud je 20\u00d7 I<sub>n<\/sub>?<\/h3>\n<p><strong>A<\/strong>: Jisti\u010d vypne <strong>okam\u017eit\u011b<\/strong> pomoc\u00ed magnetick\u00e9 spou\u0161t\u011b, ignoruje nastaven\u00ed zpo\u017ed\u011bn\u00ed 0,5 s. Zpo\u017ed\u011bn\u00ed zkratu MCCB funguj\u00ed pouze tehdy, kdy\u017e poruchov\u00fd proud z\u016fstane mezi hodnotou sepnut\u00ed zkratu (nap\u0159. 2\u201310\u00d7 I<sub>n<\/sub>) a prahem okam\u017eit\u00e9ho vypnut\u00ed (nap\u0159. 12\u00d7 I<sub>n<\/sub>). Nad okam\u017eit\u00fdm vypnut\u00edm m\u00e1 magnetick\u00fd prvek p\u0159ednost p\u0159ed elektronick\u00fdm nastaven\u00edm.<\/p>\n<h3>Q3: Pou\u017e\u00edvaj\u00ed v\u0161echny MCCB technologii omezen\u00ed proudu?<\/h3>\n<p><strong>A<\/strong>: Ne. Termomagnetick\u00e9 MCCB (pevn\u00e9 vypnut\u00ed, bez nastavitelnosti) obvykle pou\u017e\u00edvaj\u00ed pomalej\u0161\u00ed bimetalov\u00e9 prvky p\u0159et\u00ed\u017een\u00ed a nemus\u00ed dos\u00e1hnout skute\u010dn\u00e9ho omezen\u00ed proudu. Elektronick\u00e9 MCCB s rychl\u00fdmi kontakty a optimalizovan\u00fdmi zh\u00e1\u0161ec\u00edmi komorami oblouku s v\u011bt\u0161\u00ed pravd\u011bpodobnost\u00ed omezuj\u00ed proud (ov\u011b\u0159te si u v\u00fdrobce pomoc\u00ed k\u0159ivek propu\u0161t\u011bn\u00e9ho proudu, kter\u00e9 ukazuj\u00ed I<sub>p<\/sub> a I<sup>2<\/sup>hodnoty t pod potenci\u00e1ln\u00edmi \u00farovn\u011bmi poruchy).<\/p>\n<h3>Q4: Jak ov\u011b\u0159\u00edm selektivitu mezi dv\u011bma MCCB?<\/h3>\n<p><strong>A<\/strong>: Pou\u017eijte koordina\u010dn\u00ed tabulky v\u00fdrobce (nejen \u010dasov\u011b-proudov\u00e9 k\u0159ivky). Tabulky zohled\u0148uj\u00ed:<\/p>\n<ul>\n<li>Propou\u0161t\u011bnou energii (I<sup>2<\/sup>t) navazuj\u00edc\u00edho jisti\u010de<\/li>\n<li>Pr\u00e1h energie nevypnut\u00ed p\u0159ed\u0159azen\u00e9ho jisti\u010de<\/li>\n<li>\u00da\u010dinky omezen\u00ed proudu p\u0159i r\u016fzn\u00fdch \u00farovn\u00edch poruchy<br \/>\nP\u0159\u00edklad: Schneider Electric poskytuje podrobn\u00e9 tabulky selektivity ve sv\u00fdch koordina\u010dn\u00edch p\u0159\u00edru\u010dk\u00e1ch, kter\u00e9 ukazuj\u00ed maxim\u00e1ln\u00ed limity selektivity (nap\u0159. \u201cSelektivn\u00ed a\u017e do 15 kA\u201d mezi specifick\u00fdmi modely MCCB).<\/li>\n<\/ul>\n<h3>Q5: Pro\u010d maj\u00ed MCCB dimenzovan\u00e9 pro motory vy\u0161\u0161\u00ed nastaven\u00ed okam\u017eit\u00e9ho vypnut\u00ed (13\u201314\u00d7 I<sub>n<\/sub>)?<\/h3>\n<p><strong>A<\/strong>: Aby se zabr\u00e1nilo ru\u0161iv\u00e9mu vyp\u00edn\u00e1n\u00ed b\u011bhem spou\u0161t\u011bn\u00ed motoru p\u0159\u00edmo na s\u00ed\u0165 (DOL). V\u00fdzkum ukazuje, \u017ee z\u00e1b\u011brov\u00fd proud motoru m\u016f\u017ee dos\u00e1hnout 12\u201313\u00d7 I<sub>n<\/sub> pro prvn\u00ed \u0161pi\u010dku. MCCB dimenzovan\u00e9 pro motory maj\u00ed tak\u00e9 vy\u0161\u0161\u00ed prahov\u00e9 hodnoty odpuzov\u00e1n\u00ed kontakt\u016f (&gt;14\u00d7 I<sub>n<\/sub>), aby se zajistilo, \u017ee se kontakty b\u011bhem spou\u0161t\u011bc\u00edch p\u0159echodov\u00fdch jev\u016f neotev\u0159ou, co\u017e by zp\u016fsobilo zbyte\u010dn\u00e9 opot\u0159eben\u00ed a potenci\u00e1ln\u00ed sva\u0159ov\u00e1n\u00ed p\u0159i op\u011btovn\u00e9m sepnut\u00ed.<\/p>\n<hr \/>\n<h2>Z\u00e1v\u011br<\/h2>\n<p>Zjevn\u00fd paradox MCCB nab\u00edzej\u00edc\u00edch ochranu proti zkratu se zpo\u017ed\u011bn\u00edm bez jmenovit\u00fdch I<sub>cw<\/sub> hodnot pramen\u00ed ze z\u00e1sadn\u00edho rozd\u00edlu ve filozofii ochrany: <strong>ACB odol\u00e1vaj\u00ed poruch\u00e1m prost\u0159ednictv\u00edm mechanick\u00e9 pevnosti a tepeln\u00e9 hmoty, zat\u00edmco MCCB omezuj\u00ed poruchy prost\u0159ednictv\u00edm elektromagnetick\u00e9 fyziky a rychl\u00e9ho p\u0159eru\u0161en\u00ed oblouku.<\/strong><\/p>\n<p>Pochopen\u00ed tohoto rozd\u00edlu je z\u00e1sadn\u00ed pro elektroin\u017een\u00fdry navrhuj\u00edc\u00ed koordina\u010dn\u00ed sch\u00e9mata. MCCB mohou dos\u00e1hnout selektivn\u00ed koordinace s navazuj\u00edc\u00edmi za\u0159\u00edzen\u00edmi v r\u00e1mci sv\u00e9 inherentn\u00ed schopnosti odol\u00e1vat zkratu se zpo\u017ed\u011bn\u00edm (obvykle 12\u201314\u00d7 I<sub>n<\/sub>), ale nemohou replikovat chov\u00e1n\u00ed ACB p\u0159i vysok\u00fdch poruchov\u00fdch proudech bl\u00ed\u017e\u00edc\u00edch se jejich vyp\u00ednac\u00ed schopnosti. Pro aplikace vy\u017eaduj\u00edc\u00ed plnou selektivitu v cel\u00e9m rozsahu poruchov\u00e9ho proudu z\u016fst\u00e1vaj\u00ed hlavn\u00ed p\u0159\u00edvody ACB koordinovan\u00e9 s nap\u00e1je\u010di MCCB zlat\u00fdm standardem \u2013 vyu\u017e\u00edvaj\u00ed mo\u017enosti \u010dasov\u00e9ho zpo\u017ed\u011bn\u00ed kategorie B proti proudu a z\u00e1rove\u0148 vyu\u017e\u00edvaj\u00ed v\u00fdhody omezen\u00ed proudu kategorie A po proudu.<\/p>\n<p><strong>Kl\u00ed\u010dov\u00e1 z\u00e1sada n\u00e1vrhu<\/strong>: P\u0159izp\u016fsobte kategorii jisti\u010de aplikaci \u2013 pou\u017e\u00edvejte ACB tam, kde pot\u0159ebujete \u201cvy\u010dkat\u201d poruchy, pou\u017e\u00edvejte MCCB tam, kde pot\u0159ebujete \u201crychle zlikvidovat poruchy\u201d.\u201d<\/p>\n<hr \/>\n<p><strong>O spole\u010dnosti VIOX Electric<\/strong>: VIOX Electric je p\u0159edn\u00ed B2B v\u00fdrobce elektrick\u00fdch za\u0159\u00edzen\u00ed, specializuj\u00edc\u00ed se na lisovan\u00e9 jisti\u010de (MCCB), vzduchov\u00e9 jisti\u010de (ACB) a komplexn\u00ed \u0159e\u0161en\u00ed ochrany pro pr\u016fmyslov\u00e9 a komer\u010dn\u00ed aplikace. N\u00e1\u0161 in\u017een\u00fdrsk\u00fd t\u00fdm poskytuje technickou podporu pro slo\u017eit\u00e9 koordina\u010dn\u00ed studie a optimalizaci n\u00e1vrhu syst\u00e9mu. <a href=\"https:\/\/test.viox.com\/cs\/\">Kontaktujte n\u00e1s<\/a> pro aplika\u010dn\u011b specifick\u00e9 pokyny.<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>MCCB electronic trip unit in industrial panel showing 400A rating and current display &#8211; VIOX Electric Direct Answer Molded Case Circuit Breakers (MCCBs) can provide short-time delay protection without a rated short-time withstand current (Icw) because they belong to IEC 60947-2 Category A, where selectivity is achieved through current-limiting technology rather than intentional time delays. [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":21475,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"inline_featured_image":false,"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[1],"tags":[],"class_list":["post-21474","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/test.viox.com\/cs\/wp-json\/wp\/v2\/posts\/21474","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/test.viox.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/test.viox.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/test.viox.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/test.viox.com\/cs\/wp-json\/wp\/v2\/comments?post=21474"}],"version-history":[{"count":1,"href":"https:\/\/test.viox.com\/cs\/wp-json\/wp\/v2\/posts\/21474\/revisions"}],"predecessor-version":[{"id":21476,"href":"https:\/\/test.viox.com\/cs\/wp-json\/wp\/v2\/posts\/21474\/revisions\/21476"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/test.viox.com\/cs\/wp-json\/wp\/v2\/media\/21475"}],"wp:attachment":[{"href":"https:\/\/test.viox.com\/cs\/wp-json\/wp\/v2\/media?parent=21474"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/test.viox.com\/cs\/wp-json\/wp\/v2\/categories?post=21474"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/test.viox.com\/cs\/wp-json\/wp\/v2\/tags?post=21474"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}