{"id":20745,"date":"2025-12-12T09:09:30","date_gmt":"2025-12-12T01:09:30","guid":{"rendered":"https:\/\/viox.com\/?p=20745"},"modified":"2025-12-12T09:09:32","modified_gmt":"2025-12-12T01:09:32","slug":"mcb-ambient-temperature-ratings-and-derating-factors","status":"publish","type":"post","link":"https:\/\/test.viox.com\/vi\/mcb-ambient-temperature-ratings-and-derating-factors\/","title":{"rendered":"\u0110\u00e1nh gi\u00e1 nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng v\u00e0 h\u1ec7 s\u1ed1 suy gi\u1ea3m c\u1ee7a MCB"},"content":{"rendered":"<div class=\"product-intro\">\n<h2>Gi\u1edbi thi\u1ec7u<\/h2>\n<p>Khi l\u1ef1a ch\u1ecdn m\u1ed9t <a href=\"https:\/\/test.viox.com\/vi\/mcb\/\">b\u1ed9 ng\u1eaft m\u1ea1ch thu nh\u1ecf (MCB)<\/a> \u0111\u1ed1i v\u1edbi m\u1ed9t h\u1ec7 th\u1ed1ng \u0111i\u1ec7n, h\u1ea7u h\u1ebft c\u00e1c k\u1ef9 s\u01b0 t\u1eadp trung v\u00e0o d\u00f2ng \u0111i\u1ec7n \u0111\u1ecbnh m\u1ee9c\u2014nh\u01b0ng c\u00f3 m\u1ed9t bi\u1ebfn s\u1ed1 quan tr\u1ecdng c\u00f3 th\u1ec3 \u1ea3nh h\u01b0\u1edfng l\u1edbn \u0111\u1ebfn hi\u1ec7u su\u1ea5t: nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng. M\u1ed9t MCB \u0111\u1ecbnh m\u1ee9c 32A kh\u00f4ng nh\u1ea5t thi\u1ebft ph\u1ea3i t\u1ea3i 32A m\u1ed9t c\u00e1ch an to\u00e0n trong m\u1ecdi m\u00f4i tr\u01b0\u1eddng. Tr\u00ean th\u1ef1c t\u1ebf, \u1edf nhi\u1ec7t \u0111\u1ed9 cao, MCB \u0111\u00f3 c\u00f3 th\u1ec3 ng\u1eaft \u1edf m\u1ee9c ch\u1ec9 28A ho\u1eb7c th\u1ea5p h\u01a1n, d\u1eabn \u0111\u1ebfn t\u1eaft m\u00e1y \u0111\u1ed9t ng\u1ed9t v\u00e0 l\u1ed7i h\u1ec7 th\u1ed1ng.<\/p>\n<p>Hi\u1ec3u c\u00e1c \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng MCB v\u00e0 c\u00e1c h\u1ec7 s\u1ed1 suy gi\u1ea3m l\u00e0 \u0111i\u1ec1u c\u1ea7n thi\u1ebft cho c\u00e1c chuy\u00ean gia \u0111i\u1ec7n, nh\u1eefng ng\u01b0\u1eddi c\u1ea7n \u0111\u1ea3m b\u1ea3o b\u1ea3o v\u1ec7 \u0111\u00e1ng tin c\u1eady trong c\u00e1c \u0111i\u1ec1u ki\u1ec7n v\u1eadn h\u00e0nh kh\u00e1c nhau. Cho d\u00f9 b\u1ea1n \u0111ang thi\u1ebft k\u1ebf b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n cho kh\u00ed h\u1eadu sa m\u1ea1c, ch\u1ec9 \u0111\u1ecbnh b\u1ed9 ng\u1eaft m\u1ea1ch cho t\u1ee7 m\u00e1y m\u00f3c k\u00edn hay kh\u1eafc ph\u1ee5c s\u1ef1 c\u1ed1 ng\u1eaft m\u1ea1ch phi\u1ec1n to\u00e1i, th\u00ec c\u00e1c c\u00e2n nh\u1eafc v\u1ec1 nhi\u1ec7t \u0111\u1ed9 \u0111\u00f3ng m\u1ed9t vai tr\u00f2 quy\u1ebft \u0111\u1ecbnh.<\/p>\n<p>H\u01b0\u1edbng d\u1eabn to\u00e0n di\u1ec7n n\u00e0y xem x\u00e9t nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn hi\u1ec7u su\u1ea5t MCB nh\u01b0 th\u1ebf n\u00e0o, gi\u1ea3i th\u00edch ph\u01b0\u01a1ng ph\u00e1p t\u00ednh to\u00e1n suy gi\u1ea3m v\u00e0 cung c\u1ea5p h\u01b0\u1edbng d\u1eabn th\u1ef1c t\u1ebf cho c\u00e1c c\u00e0i \u0111\u1eb7t th\u1ef1c t\u1ebf. \u0110\u1ebfn cu\u1ed1i, b\u1ea1n s\u1ebd hi\u1ec3u c\u00e1ch ch\u1ecdn v\u00e0 \u00e1p d\u1ee5ng MCB \u0111\u00fang c\u00e1ch trong c\u00e1c m\u00f4i tr\u01b0\u1eddng nhi\u1ec7t kh\u00e1c nhau, \u0111\u1ea3m b\u1ea3o c\u1ea3 an to\u00e0n v\u00e0 \u0111\u1ed9 tin c\u1eady khi v\u1eadn h\u00e0nh.<\/p>\n<h2>T\u00ecm hi\u1ec3u v\u1ec1 \u0110\u1ecbnh m\u1ee9c Nhi\u1ec7t \u0111\u1ed9 MCB<\/h2>\n<h3>Nhi\u1ec7t \u0111\u1ed9 Tham chi\u1ebfu Ti\u00eau chu\u1ea9n<\/h3>\n<p>M\u1ecdi MCB \u0111\u1ec1u \u0111\u01b0\u1ee3c hi\u1ec7u ch\u1ec9nh v\u00e0 ki\u1ec3m tra \u1edf nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng tham chi\u1ebfu c\u1ee5 th\u1ec3, \u0111\u00f3ng vai tr\u00f2 l\u00e0 \u0111\u01b0\u1eddng c\u01a1 s\u1edf cho \u0111\u1ecbnh m\u1ee9c d\u00f2ng \u0111i\u1ec7n danh \u0111\u1ecbnh c\u1ee7a n\u00f3. Theo <a href=\"https:\/\/test.viox.com\/vi\/iec-60898-1-vs-iec-60947-2\/\">IEC 60898-1<\/a>\u2014ti\u00eau chu\u1ea9n qu\u1ed1c t\u1ebf chi ph\u1ed1i MCB cho c\u00e1c h\u1ed9 gia \u0111\u00ecnh v\u00e0 c\u00e1c c\u00e0i \u0111\u1eb7t t\u01b0\u01a1ng t\u1ef1\u2014nhi\u1ec7t \u0111\u1ed9 tham chi\u1ebfu n\u00e0y l\u00e0 <strong>30\u00b0C (86\u00b0F)<\/strong>. \u1ede nhi\u1ec7t \u0111\u1ed9 ch\u00ednh x\u00e1c n\u00e0y, MCB s\u1ebd ho\u1ea1t \u0111\u1ed9ng theo \u0111\u1ecbnh m\u1ee9c tr\u00ean nh\u00e3n c\u1ee7a n\u00f3.<\/p>\n<p>\u0110\u1ed1i v\u1edbi c\u00e1c \u1ee9ng d\u1ee5ng c\u00f4ng nghi\u1ec7p \u0111\u00f2i h\u1ecfi b\u1ed9 ng\u1eaft m\u1ea1ch m\u1ea1nh m\u1ebd h\u01a1n, ch\u1eb3ng h\u1ea1n nh\u01b0 b\u1ed9 ng\u1eaft m\u1ea1ch v\u1ecf \u0111\u00fac (MCCB) \u0111\u01b0\u1ee3c \u0111i\u1ec1u ch\u1ec9nh b\u1edfi IEC 60947-2, nhi\u1ec7t \u0111\u1ed9 tham chi\u1ebfu ti\u00eau chu\u1ea9n th\u01b0\u1eddng l\u00e0 <strong>40\u00b0C (104\u00b0F)<\/strong>. \u0110\u01b0\u1eddng c\u01a1 s\u1edf cao h\u01a1n n\u00e0y ph\u1ea3n \u00e1nh m\u00f4i tr\u01b0\u1eddng nhi\u1ec7t kh\u1eaft khe h\u01a1n th\u01b0\u1eddng th\u1ea5y trong c\u00e1c c\u00e0i \u0111\u1eb7t c\u00f4ng nghi\u1ec7p.<\/p>\n<h3>C\u00e1ch MCB \u0110\u01b0\u1ee3c \u0110\u00e1nh Gi\u00e1<\/h3>\n<p>D\u00f2ng \u0111i\u1ec7n \u0111\u1ecbnh m\u1ee9c (In) \u0111\u01b0\u1ee3c \u0111\u00e1nh d\u1ea5u tr\u00ean MCB bi\u1ec3u th\u1ecb d\u00f2ng \u0111i\u1ec7n li\u00ean t\u1ee5c t\u1ed1i \u0111a m\u00e0 thi\u1ebft b\u1ecb c\u00f3 th\u1ec3 mang v\u00f4 th\u1eddi h\u1ea1n \u1edf nhi\u1ec7t \u0111\u1ed9 tham chi\u1ebfu m\u00e0 kh\u00f4ng b\u1ecb ng\u1eaft. \u0110\u1ecbnh m\u1ee9c n\u00e0y \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh th\u00f4ng qua th\u1eed nghi\u1ec7m nghi\u00eam ng\u1eb7t, trong \u0111\u00f3 ph\u1ea7n t\u1eed ng\u1eaft nhi\u1ec7t c\u1ee7a MCB\u2014th\u01b0\u1eddng l\u00e0 d\u1ea3i l\u01b0\u1ee1ng kim\u2014\u0111\u01b0\u1ee3c hi\u1ec7u ch\u1ec9nh \u0111\u1ec3 u\u1ed1n cong v\u00e0 k\u00edch ho\u1ea1t c\u01a1 ch\u1ebf ng\u1eaft \u1edf c\u00e1c ng\u01b0\u1ee1ng qu\u00e1 d\u00f2ng c\u1ee5 th\u1ec3.<\/p>\n<p>D\u1ea3i l\u01b0\u1ee1ng kim l\u00e0 tr\u00e1i tim c\u1ee7a b\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i MCB. N\u00f3 bao g\u1ed3m hai kim lo\u1ea1i kh\u00e1c nhau \u0111\u01b0\u1ee3c li\u00ean k\u1ebft v\u1edbi nhau, m\u1ed7i kim lo\u1ea1i c\u00f3 m\u1ed9t h\u1ec7 s\u1ed1 gi\u00e3n n\u1edf nhi\u1ec7t kh\u00e1c nhau. Khi d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u1ea3i, n\u00f3 t\u1ea1o ra nhi\u1ec7t. Khi nhi\u1ec7t \u0111\u1ed9 t\u0103ng l\u00ean, c\u00e1c kim lo\u1ea1i gi\u00e3n n\u1edf v\u1edbi t\u1ed1c \u0111\u1ed9 kh\u00e1c nhau, khi\u1ebfn d\u1ea3i b\u1ecb u\u1ed1n cong. Khi n\u00f3 u\u1ed1n cong \u0111\u1ee7, n\u00f3 s\u1ebd k\u00edch ho\u1ea1t c\u01a1 ch\u1ebf ng\u1eaft, ng\u1eaft m\u1ea1ch.<\/p>\n<p>H\u1ec7 th\u1ed1ng c\u01a1 nhi\u1ec7t thanh l\u1ecbch n\u00e0y ho\u1ea1t \u0111\u1ed9ng ch\u00ednh x\u00e1c \u1edf nhi\u1ec7t \u0111\u1ed9 tham chi\u1ebfu \u0111\u00e3 hi\u1ec7u ch\u1ec9nh. Tuy nhi\u00ean, n\u00f3 c\u0169ng v\u1ed1n nh\u1ea1y c\u1ea3m v\u1edbi nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng xung quanh MCB\u2014\u0111\u00f3 l\u00e0 l\u00fd do t\u1ea1i sao vi\u1ec7c suy gi\u1ea3m tr\u1edf n\u00ean quan tr\u1ecdng.<\/p>\n<h3>Gi\u1edbi h\u1ea1n Ph\u1ea1m vi Nhi\u1ec7t \u0111\u1ed9<\/h3>\n<p>M\u1eb7c d\u00f9 MCB th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u0111\u00e1nh gi\u00e1 \u0111\u1ec3 ho\u1ea1t \u0111\u1ed9ng trong ph\u1ea1m vi t\u1eeb -20\u00b0C \u0111\u1ebfn +70\u00b0C, nh\u01b0ng kh\u1ea3 n\u0103ng mang d\u00f2ng \u0111i\u1ec7n \u0111\u1ecbnh m\u1ee9c c\u1ee7a ch\u00fang gi\u1ea3m \u0111\u00e1ng k\u1ec3 khi nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng t\u0103ng l\u00ean v\u01b0\u1ee3t qu\u00e1 \u0111i\u1ec3m tham chi\u1ebfu. Ng\u01b0\u1ee3c l\u1ea1i, trong m\u00f4i tr\u01b0\u1eddng l\u1ea1nh h\u01a1n d\u01b0\u1edbi nhi\u1ec7t \u0111\u1ed9 tham chi\u1ebfu, MCB c\u00f3 th\u1ec3 cho ph\u00e9p d\u00f2ng \u0111i\u1ec7n cao h\u01a1n m\u1ed9t ch\u00fat tr\u01b0\u1edbc khi ng\u1eaft\u2014m\u1eb7c d\u00f9 \u0111\u00e2y hi\u1ebfm khi l\u00e0 m\u1ed9t c\u00e2n nh\u1eafc thi\u1ebft k\u1ebf v\u00ec c\u00e1c d\u00e2y c\u00e1p v\u00e0 thi\u1ebft b\u1ecb \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i c\u00f3 nh\u1eefng h\u1ea1n ch\u1ebf v\u1ec1 nhi\u1ec7t \u0111\u1ed9 ri\u00eang.<\/p>\n<figure style=\"margin: 20px 0; text-align: center;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/technical-illustration-showing-mcb-temperature-rating-concept-with-cross-section-view-of-bimetallic-strip-mechanism-30c-reference-temperature-indicator.webp\" alt=\"Technical illustration showing MCB temperature rating concept with cross-section view of bimetallic strip mechanism, 30\u00b0C reference temperature indicator, and VIOX branding\" \/><figcaption style=\"font-style: italic; font-size: 0.9em; color: #666; margin-top: 8px;\">H\u00ecnh minh h\u1ecda k\u1ef9 thu\u1eadt cho th\u1ea5y kh\u00e1i ni\u1ec7m \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t \u0111\u1ed9 MCB v\u1edbi ch\u1ebf \u0111\u1ed9 xem m\u1eb7t c\u1eaft c\u1ee7a c\u01a1 ch\u1ebf d\u1ea3i l\u01b0\u1ee1ng kim, ch\u1ec9 b\u00e1o nhi\u1ec7t \u0111\u1ed9 tham chi\u1ebfu 30\u00b0C<\/figcaption><\/figure>\n<h2>Nhi\u1ec7t \u0111\u1ed9 M\u00f4i tr\u01b0\u1eddng \u1ea2nh H\u01b0\u1edfng \u0110\u1ebfn Hi\u1ec7u Su\u1ea5t MCB Nh\u01b0 Th\u1ebf N\u00e0o<\/h2>\n<h3>V\u1eadt l\u00fd c\u1ee7a Ng\u1eaft Nhi\u1ec7t<\/h3>\n<p>M\u1ed1i quan h\u1ec7 gi\u1eefa nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng v\u00e0 hi\u1ec7u su\u1ea5t MCB b\u1eaft ngu\u1ed3n t\u1eeb v\u1eadt l\u00fd nhi\u1ec7t c\u01a1 b\u1ea3n. D\u1ea3i l\u01b0\u1ee1ng kim b\u00ean trong MCB ph\u1ea3i \u0111\u1ea1t \u0111\u1ebfn m\u1ed9t nhi\u1ec7t \u0111\u1ed9 c\u1ee5 th\u1ec3 \u0111\u1ec3 ng\u1eaft. Nhi\u1ec7t \u0111\u1ed9 n\u00e0y \u0111\u1ea1t \u0111\u01b0\u1ee3c th\u00f4ng qua hai ngu\u1ed3n nhi\u1ec7t: nhi\u1ec7t do d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua d\u1ea3i (gia nhi\u1ec7t I\u00b2R) v\u00e0 nhi\u1ec7t t\u1eeb m\u00f4i tr\u01b0\u1eddng xung quanh (nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng).<\/p>\n<p>Khi nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng t\u0103ng l\u00ean, d\u1ea3i l\u01b0\u1ee1ng kim b\u1eaft \u0111\u1ea7u t\u1eeb nhi\u1ec7t \u0111\u1ed9 c\u01a1 s\u1edf cao h\u01a1n. Do \u0111\u00f3, n\u00f3 c\u1ea7n \u00edt nhi\u1ec7t b\u1ed5 sung h\u01a1n t\u1eeb d\u00f2ng \u0111i\u1ec7n \u0111\u1ec3 \u0111\u1ea1t \u0111\u1ebfn \u0111i\u1ec3m ng\u1eaft c\u1ee7a n\u00f3. V\u1ec1 m\u1eb7t th\u1ef1c t\u1ebf, \u0111i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 MCB s\u1ebd ng\u1eaft \u1edf d\u00f2ng \u0111i\u1ec7n th\u1ea5p h\u01a1n gi\u00e1 tr\u1ecb \u0111\u1ecbnh m\u1ee9c c\u1ee7a n\u00f3.<\/p>\n<p>H\u00e3y xem x\u00e9t m\u1ed9t MCB \u0111\u01b0\u1ee3c \u0111\u1ecbnh m\u1ee9c \u1edf 32A \u1edf 30\u00b0C. N\u1ebfu c\u00f9ng m\u1ed9t MCB \u0111\u00f3 ho\u1ea1t \u0111\u1ed9ng trong m\u00f4i tr\u01b0\u1eddng 50\u00b0C, d\u1ea3i l\u01b0\u1ee1ng kim b\u1eaft \u0111\u1ea7u n\u00f3ng h\u01a1n 20\u00b0C so v\u1edbi \u0111\u01b0\u1eddng c\u01a1 s\u1edf hi\u1ec7u chu\u1ea9n. \u0110\u1ec3 \u0111\u1ea1t \u0111\u1ebfn nhi\u1ec7t \u0111\u1ed9 ng\u1eaft, n\u00f3 c\u1ea7n \u00edt nhi\u1ec7t do d\u00f2ng \u0111i\u1ec7n g\u00e2y ra h\u01a1n\u2014c\u00f3 l\u1ebd ng\u1eaft \u1edf m\u1ee9c ch\u1ec9 29A ho\u1eb7c 30A thay v\u00ec 32A \u0111\u1ecbnh m\u1ee9c.<\/p>\n<h3>Gi\u1ea3m C\u00f4ng su\u1ea5t D\u00f2ng \u0111i\u1ec7n<\/h3>\n<p>Theo quy t\u1eafc chung, \u0111\u1ed1i v\u1edbi MCB t\u1eeb nhi\u1ec7t, c\u00f4ng su\u1ea5t mang d\u00f2ng \u0111i\u1ec7n gi\u1ea3m kho\u1ea3ng <strong>6-10% cho m\u1ed7i l\u1ea7n t\u0103ng 10\u00b0C<\/strong> tr\u00ean nhi\u1ec7t \u0111\u1ed9 tham chi\u1ebfu. \u0110\u00e2y kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t m\u1ed1i quan h\u1ec7 tuy\u1ebfn t\u00ednh tr\u00ean t\u1ea5t c\u1ea3 c\u00e1c ph\u1ea1m vi nhi\u1ec7t \u0111\u1ed9 v\u00e0 n\u00f3 kh\u00e1c nhau t\u00f9y theo nh\u00e0 s\u1ea3n xu\u1ea5t v\u00e0 d\u00f2ng s\u1ea3n ph\u1ea9m, nh\u01b0ng n\u00f3 cung c\u1ea5p m\u1ed9t khung \u01b0\u1edbc t\u00ednh h\u1eefu \u00edch.<\/p>\n<p>V\u00ed d\u1ee5:<\/p>\n<ul>\n<li>M\u1ed9t MCB \u1edf 40\u00b0C (cao h\u01a1n 10\u00b0C so v\u1edbi tham chi\u1ebfu 30\u00b0C) c\u00f3 th\u1ec3 ho\u1ea1t \u0111\u1ed9ng \u1edf kho\u1ea3ng 94% c\u00f4ng su\u1ea5t \u0111\u1ecbnh m\u1ee9c c\u1ee7a n\u00f3<\/li>\n<li>\u1ede 50\u00b0C (cao h\u01a1n 20\u00b0C so v\u1edbi tham chi\u1ebfu), c\u00f4ng su\u1ea5t gi\u1ea3m xu\u1ed1ng kho\u1ea3ng 88-90%<\/li>\n<li>\u1ede 60\u00b0C (cao h\u01a1n 30\u00b0C so v\u1edbi tham chi\u1ebfu), c\u00f4ng su\u1ea5t c\u00f3 th\u1ec3 gi\u1ea3m xu\u1ed1ng 80-85%<\/li>\n<\/ul>\n<h3>C\u00e1c Ch\u1ebf \u0110\u1ed9 H\u1ecfng H\u00f3c Do Suy Gi\u1ea3m Kh\u00f4ng \u0110\u1ea7y \u0110\u1ee7<\/h3>\n<p>Khi MCB ho\u1ea1t \u0111\u1ed9ng \u1edf nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng cao h\u01a1n m\u00e0 kh\u00f4ng xem x\u00e9t \u0111\u1ebfn vi\u1ec7c suy gi\u1ea3m th\u00edch h\u1ee3p, hai ch\u1ebf \u0111\u1ed9 h\u1ecfng h\u00f3c ch\u00ednh s\u1ebd xu\u1ea5t hi\u1ec7n:<\/p>\n<p><strong>Phi\u1ec1n To\u00e1i V\u1ea5p Ng\u00e3<\/strong>: MCB ng\u1eaft trong qu\u00e1 tr\u00ecnh ho\u1ea1t \u0111\u1ed9ng b\u00ecnh th\u01b0\u1eddng v\u00ec d\u00f2ng \u0111i\u1ec7n th\u1ef1c t\u1ebf, trong khi n\u1eb1m trong \u0111\u1ecbnh m\u1ee9c tr\u00ean nh\u00e3n, v\u01b0\u1ee3t qu\u00e1 c\u00f4ng su\u1ea5t \u0111\u00e3 \u0111i\u1ec1u ch\u1ec9nh theo nhi\u1ec7t \u0111\u1ed9. \u0110i\u1ec1u n\u00e0y d\u1eabn \u0111\u1ebfn th\u1eddi gian ng\u1eebng ho\u1ea1t \u0111\u1ed9ng b\u1ea5t ng\u1edd, t\u1ed5n th\u1ea5t n\u0103ng su\u1ea5t v\u00e0 s\u1ef1 th\u1ea5t v\u1ecdng cho c\u00e1c nh\u00e0 khai th\u00e1c, nh\u1eefng ng\u01b0\u1eddi kh\u00f4ng th\u1ea5y qu\u00e1 t\u1ea3i r\u00f5 r\u00e0ng.<\/p>\n<p><strong>L\u00e3o H\u00f3a S\u1edbm<\/strong>: N\u1ebfu MCB li\u00ean t\u1ee5c ho\u1ea1t \u0111\u1ed9ng g\u1ea7n gi\u1edbi h\u1ea1n suy gi\u1ea3m nhi\u1ec7t \u0111\u1ed9 c\u1ee7a n\u00f3 trong m\u00f4i tr\u01b0\u1eddng n\u00f3ng, c\u00e1c th\u00e0nh ph\u1ea7n b\u00ean trong s\u1ebd tr\u1ea3i qua \u1ee9ng su\u1ea5t nhi\u1ec7t t\u0103ng t\u1ed1c. \u0110i\u1ec1u n\u00e0y l\u00e0m gi\u1ea3m hi\u1ec7u chu\u1ea9n d\u1ea3i l\u01b0\u1ee1ng kim theo th\u1eddi gian, l\u00e0m gi\u1ea3m tu\u1ed5i th\u1ecd c\u1ee7a thi\u1ebft b\u1ecb v\u00e0 c\u00f3 kh\u1ea3 n\u0103ng l\u00e0m t\u1ed5n h\u1ea1i \u0111\u1ebfn \u0111\u1ed9 tin c\u1eady c\u1ee7a b\u1ea3o v\u1ec7.<\/p>\n<p>C\u1ea3 hai k\u1ecbch b\u1ea3n \u0111\u1ec1u l\u00e0m suy y\u1ebfu m\u1ee5c \u0111\u00edch c\u01a1 b\u1ea3n c\u1ee7a MCB: b\u1ea3o v\u1ec7 m\u1ea1ch \u0111\u00e1ng tin c\u1eady, c\u00f3 th\u1ec3 d\u1ef1 \u0111o\u00e1n \u0111\u01b0\u1ee3c.<\/p>\n<figure style=\"margin: 20px 0; text-align: center;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/professional-graph-showing-mcb-temperature-derating-curve-with-declining-current-capacity-from-30c-to-70c-ambient-temperature.webp\" alt=\"Professional graph showing MCB temperature derating curve with declining current capacity from 30\u00b0C to 70\u00b0C ambient temperature, featuring VIOX logo\" \/><figcaption style=\"font-style: italic; font-size: 0.9em; color: #666; margin-top: 8px;\">\u0110\u1ed3 th\u1ecb chuy\u00ean nghi\u1ec7p hi\u1ec3n th\u1ecb \u0111\u01b0\u1eddng cong suy gi\u1ea3m nhi\u1ec7t \u0111\u1ed9 MCB v\u1edbi c\u00f4ng su\u1ea5t d\u00f2ng \u0111i\u1ec7n gi\u1ea3m t\u1eeb nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng 30\u00b0C \u0111\u1ebfn 70\u00b0C, c\u00f3 logo VIOX<\/figcaption><\/figure>\n<h2>C\u00e1c Y\u1ebfu T\u1ed1 Suy Gi\u1ea3m \u0110\u01b0\u1ee3c Gi\u1ea3i Th\u00edch<\/h2>\n<h3>Y\u1ebfu T\u1ed1 Suy Gi\u1ea3m L\u00e0 G\u00ec?<\/h3>\n<p>Y\u1ebfu t\u1ed1 suy gi\u1ea3m (c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 h\u1ec7 s\u1ed1 hi\u1ec7u ch\u1ec9nh nhi\u1ec7t \u0111\u1ed9 ho\u1eb7c h\u1ec7 s\u1ed1 hi\u1ec7u ch\u1ec9nh nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng) l\u00e0 m\u1ed9t h\u1ec7 s\u1ed1 nh\u00e2n \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng cho \u0111\u1ecbnh m\u1ee9c danh \u0111\u1ecbnh c\u1ee7a MCB \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh c\u00f4ng su\u1ea5t mang d\u00f2ng \u0111i\u1ec7n hi\u1ec7u qu\u1ea3 c\u1ee7a n\u00f3 \u1edf m\u1ed9t nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng c\u1ee5 th\u1ec3. Y\u1ebfu t\u1ed1 n\u00e0y lu\u00f4n nh\u1ecf h\u01a1n ho\u1eb7c b\u1eb1ng 1,0 \u0111\u1ed1i v\u1edbi nhi\u1ec7t \u0111\u1ed9 b\u1eb1ng ho\u1eb7c cao h\u01a1n nhi\u1ec7t \u0111\u1ed9 tham chi\u1ebfu.<\/p>\n<p>M\u1ed1i quan h\u1ec7 to\u00e1n h\u1ecdc r\u1ea5t \u0111\u01a1n gi\u1ea3n:<\/p>\n<p><strong>C\u00f4ng Su\u1ea5t D\u00f2ng \u0110i\u1ec7n Hi\u1ec7u Qu\u1ea3 = D\u00f2ng \u0110i\u1ec7n \u0110\u1ecbnh M\u1ee9c \u00d7 Y\u1ebfu T\u1ed1 Suy Gi\u1ea3m<\/strong><\/p>\n<p>V\u00ed d\u1ee5: n\u1ebfu MCB 25A c\u00f3 h\u1ec7 s\u1ed1 suy gi\u1ea3m l\u00e0 0,88 \u1edf 50\u00b0C:<\/p>\n<ul>\n<li>C\u00f4ng su\u1ea5t hi\u1ec7u qu\u1ea3 = 25A \u00d7 0,88 = 22A<\/li>\n<\/ul>\n<p>\u0110i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 trong m\u00f4i tr\u01b0\u1eddng 50\u00b0C, MCB kh\u00f4ng \u0111\u01b0\u1ee3c t\u1ea3i qu\u00e1 22A \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o ho\u1ea1t \u0111\u1ed9ng \u0111\u00e1ng tin c\u1eady m\u00e0 kh\u00f4ng b\u1ecb ng\u1eaft m\u1ea1ch phi\u1ec1n to\u00e1i.<\/p>\n<h3>C\u00e1c Y\u1ebfu T\u1ed1 Suy Gi\u1ea3m \u0110\u01b0\u1ee3c X\u00e1c \u0110\u1ecbnh Nh\u01b0 Th\u1ebf N\u00e0o<\/h3>\n<p>C\u00e1c y\u1ebfu t\u1ed1 suy gi\u1ea3m kh\u00f4ng ph\u1ea3i l\u00e0 c\u00e1c t\u00ednh to\u00e1n l\u00fd thuy\u1ebft\u2014ch\u00fang \u0111\u01b0\u1ee3c r\u00fat ra m\u1ed9t c\u00e1ch th\u1ef1c nghi\u1ec7m th\u00f4ng qua th\u1eed nghi\u1ec7m r\u1ed9ng r\u00e3i c\u1ee7a c\u00e1c nh\u00e0 s\u1ea3n xu\u1ea5t. M\u1ed7i d\u00f2ng s\u1ea3n ph\u1ea9m MCB tr\u1ea3i qua th\u1eed nghi\u1ec7m nhi\u1ec7t tr\u00ean m\u1ed9t lo\u1ea1t c\u00e1c nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng \u0111\u1ec3 \u0111o c\u00e1c \u0111\u1eb7c t\u00ednh ng\u1eaft th\u1ef1c t\u1ebf. C\u00e1c k\u1ebft qu\u1ea3 \u0111\u01b0\u1ee3c bi\u00ean so\u1ea1n th\u00e0nh c\u00e1c b\u1ea3ng ho\u1eb7c \u0111\u01b0\u1eddng cong suy gi\u1ea3m c\u1ee5 th\u1ec3 cho d\u00f2ng s\u1ea3n ph\u1ea9m \u0111\u00f3.<\/p>\n<p>\u0110\u00e2y l\u00e0 l\u00fd do t\u1ea1i sao \u0111i\u1ec1u quan tr\u1ecdng l\u00e0 ph\u1ea3i tham kh\u1ea3o t\u00e0i li\u1ec7u k\u1ef9 thu\u1eadt c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t thay v\u00ec ch\u1ec9 d\u1ef1a v\u00e0o c\u00e1c quy t\u1eafc chung c\u1ee7a ng\u00e0nh. C\u00e1c thi\u1ebft k\u1ebf MCB kh\u00e1c nhau, b\u1ed1 tr\u00ed th\u00e0nh ph\u1ea7n b\u00ean trong v\u00e0 c\u00e1c t\u00ednh n\u0103ng qu\u1ea3n l\u00fd nhi\u1ec7t c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn c\u00e1c \u0111\u1eb7c t\u00ednh suy gi\u1ea3m kh\u00e1c nhau ngay c\u1ea3 \u0111\u1ed1i v\u1edbi c\u00e1c b\u1ed9 ng\u1eaft m\u1ea1ch c\u00f3 c\u00f9ng \u0111\u1ecbnh m\u1ee9c danh \u0111\u1ecbnh.<\/p>\n<h3>\u0110\u01b0\u1eddng Cong Suy Gi\u1ea3m<\/h3>\n<p>C\u00e1c nh\u00e0 s\u1ea3n xu\u1ea5t th\u01b0\u1eddng tr\u00ecnh b\u00e0y th\u00f4ng tin suy gi\u1ea3m \u1edf hai \u0111\u1ecbnh d\u1ea1ng: d\u1eef li\u1ec7u d\u1ea1ng b\u1ea3ng v\u00e0 \u0111\u01b0\u1eddng cong \u0111\u1ed3 h\u1ecda. \u0110\u01b0\u1eddng cong suy gi\u1ea3m v\u1ebd nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng tr\u00ean tr\u1ee5c X so v\u1edbi h\u1ec7 s\u1ed1 suy gi\u1ea3m ho\u1eb7c c\u00f4ng su\u1ea5t d\u00f2ng \u0111i\u1ec7n hi\u1ec7u qu\u1ea3 tr\u00ean tr\u1ee5c Y.<\/p>\n<p>C\u00e1c \u0111\u01b0\u1eddng cong n\u00e0y ti\u1ebft l\u1ed9 c\u00e1c \u0111\u1eb7c \u0111i\u1ec3m quan tr\u1ecdng:<\/p>\n<ul>\n<li>M\u1ed1i quan h\u1ec7 th\u01b0\u1eddng l\u00e0 phi tuy\u1ebfn t\u00ednh, v\u1edbi s\u1ef1 gi\u1ea3m c\u00f4ng su\u1ea5t d\u1ed1c h\u01a1n \u1edf nhi\u1ec7t \u0111\u1ed9 cao h\u01a1n<\/li>\n<li>M\u1ed9t s\u1ed1 thi\u1ebft k\u1ebf MCB cho th\u1ea5y s\u1ef1 suy gi\u1ea3m d\u1ea7n d\u1ea7n h\u01a1n, trong khi nh\u1eefng thi\u1ebft k\u1ebf kh\u00e1c gi\u1ea3m m\u1ea1nh h\u01a1n<\/li>\n<li>C\u00e1c \u0111\u01b0\u1eddng cong c\u00f3 th\u1ec3 ph\u1eb3ng \u1edf nhi\u1ec7t \u0111\u1ed9 r\u1ea5t cao, ti\u1ebfn g\u1ea7n \u0111\u1ebfn gi\u1edbi h\u1ea1n ho\u1ea1t \u0111\u1ed9ng t\u1ed1i \u0111a tuy\u1ec7t \u0111\u1ed1i c\u1ee7a MCB<\/li>\n<\/ul>\n<h3>C\u00e1c V\u00ed D\u1ee5 T\u00ednh To\u00e1n Th\u1ef1c T\u1ebf<\/h3>\n<p><strong>V\u00ed d\u1ee5 1: Suy Gi\u1ea3m C\u01a1 B\u1ea3n<\/strong><\/p>\n<p>B\u1ea1n c\u1ea7n l\u1eafp \u0111\u1eb7t MCB trong b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n n\u01a1i nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng b\u00ean trong \u0111\u1ea1t 55\u00b0C. M\u1ea1ch y\u00eau c\u1ea7u b\u1ea3o v\u1ec7 li\u00ean t\u1ee5c cho t\u1ea3i 30A. D\u1eef li\u1ec7u c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t cho th\u1ea5y h\u1ec7 s\u1ed1 suy gi\u1ea3m l\u00e0 0,85 \u1edf 55\u00b0C.<\/p>\n<ul>\n<li>\u0110\u1ecbnh m\u1ee9c MCB c\u1ea7n thi\u1ebft = D\u00f2ng \u0110i\u1ec7n T\u1ea3i \u00f7 Y\u1ebfu T\u1ed1 Suy Gi\u1ea3m<\/li>\n<li>\u0110\u1ecbnh m\u1ee9c MCB c\u1ea7n thi\u1ebft = 30A \u00f7 0,85 = 35,3A<\/li>\n<li><strong>Ch\u1ecdn k\u00edch th\u01b0\u1edbc ti\u00eau chu\u1ea9n ti\u1ebfp theo: MCB 40A<\/strong><\/li>\n<\/ul>\n<p><strong>V\u00ed d\u1ee5 2: Ph\u01b0\u01a1ng Ph\u00e1p Ti\u1ebfp C\u1eadn X\u00e1c Minh<\/strong><\/p>\n<p>B\u1ea1n \u0111\u00e3 ch\u1ec9 \u0111\u1ecbnh MCB 63A cho m\u1ed9t \u1ee9ng d\u1ee5ng. Nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng d\u1ef1 ki\u1ebfn l\u00e0 60\u00b0C. B\u1ea3ng c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t cho th\u1ea5y MCB n\u00e0y c\u00f3 th\u1ec3 mang 54A \u1edf 60\u00b0C (h\u1ec7 s\u1ed1 suy gi\u1ea3m kho\u1ea3ng 0,86).<\/p>\n<p>N\u1ebfu t\u1ea3i th\u1ef1c t\u1ebf c\u1ee7a b\u1ea1n l\u00e0 58A:<\/p>\n<ul>\n<li>58A &gt; 54A (c\u00f4ng su\u1ea5t \u0111\u00e3 \u0111i\u1ec1u ch\u1ec9nh theo nhi\u1ec7t \u0111\u1ed9)<\/li>\n<li><strong>MCB 63A kh\u00f4ng \u0111\u1ee7 c\u00f4ng su\u1ea5t cho \u1ee9ng d\u1ee5ng n\u00e0y; n\u00e2ng c\u1ea5p l\u00ean 80A<\/strong><\/li>\n<\/ul>\n<p><strong>V\u00ed d\u1ee5 3: T\u00ednh to\u00e1n ng\u01b0\u1ee3c<\/strong><\/p>\n<p>M\u1ed9t h\u1ec7 th\u1ed1ng hi\u1ec7n t\u1ea1i s\u1eed d\u1ee5ng MCB 32A. Nhi\u1ec7t \u0111\u1ed9 m\u00f9a h\u00e8 b\u00ean trong t\u1ee7 \u0111i\u1ec7n \u0111\u1ea1t 65\u00b0C. S\u1eed d\u1ee5ng h\u1ec7 s\u1ed1 suy gi\u1ea3m c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t l\u00e0 0.78 \u1edf 65\u00b0C:<\/p>\n<ul>\n<li>C\u00f4ng su\u1ea5t hi\u1ec7u d\u1ee5ng = 32A \u00d7 0.78 = 25A<\/li>\n<li><strong>T\u1ea3i li\u00ean t\u1ee5c an to\u00e0n t\u1ed1i \u0111a: 25A<\/strong><\/li>\n<\/ul>\n<p>Nh\u1eefng v\u00ed d\u1ee5 n\u00e0y ch\u1ee9ng minh t\u1ea1i sao vi\u1ec7c gi\u1ea3m c\u00f4ng su\u1ea5t theo nhi\u1ec7t \u0111\u1ed9 ph\u1ea3i l\u00e0 m\u1ed9t ph\u1ea7n kh\u00f4ng th\u1ec3 thi\u1ebfu trong vi\u1ec7c l\u1ef1a ch\u1ecdn MCB, ch\u1ee9 kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t suy ngh\u0129 mu\u1ed9n m\u00e0ng.<\/p>\n<figure style=\"margin: 20px 0; text-align: center;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/infographic-demonstrating-mcb-derating-factor-calculation-with-step-by-step-visual-example-showing-32a-mcb-at-50c-with-0-88-factor-equals-28-2a-effective-capacity.webp\" alt=\"Infographic demonstrating MCB derating factor calculation with step-by-step visual example showing 32A MCB at 50\u00b0C with 0.88 factor equals 28.2A effective capacity, VIOX branded\" \/><figcaption style=\"font-style: italic; font-size: 0.9em; color: #666; margin-top: 8px;\">H\u00ecnh \u1ea3nh tr\u1ef1c quan minh h\u1ecda c\u00e1ch t\u00ednh h\u1ec7 s\u1ed1 suy gi\u1ea3m c\u00f4ng su\u1ea5t MCB v\u1edbi v\u00ed d\u1ee5 tr\u1ef1c quan t\u1eebng b\u01b0\u1edbc hi\u1ec3n th\u1ecb MCB 32A \u1edf 50\u00b0C v\u1edbi h\u1ec7 s\u1ed1 0.88 t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi c\u00f4ng su\u1ea5t hi\u1ec7u d\u1ee5ng 28.2A, th\u01b0\u01a1ng hi\u1ec7u VIOX<\/figcaption><\/figure>\n<h2>B\u1ea3ng &amp; H\u01b0\u1edbng d\u1eabn Suy gi\u1ea3m Ti\u00eau chu\u1ea9n<\/h2>\n<h3>Gi\u00e1 tr\u1ecb Suy gi\u1ea3m \u0110i\u1ec3n h\u00ecnh<\/h3>\n<p>M\u1eb7c d\u00f9 c\u00e1c h\u1ec7 s\u1ed1 suy gi\u1ea3m c\u1ee5 th\u1ec3 kh\u00e1c nhau t\u00f9y theo nh\u00e0 s\u1ea3n xu\u1ea5t v\u00e0 d\u00f2ng s\u1ea3n ph\u1ea9m, nh\u01b0ng d\u1eef li\u1ec7u ng\u00e0nh cho th\u1ea5y c\u00e1c m\u1eabu nh\u1ea5t qu\u00e1n. \u0110\u1ed1i v\u1edbi MCB nhi\u1ec7t t\u1eeb \u0111\u01b0\u1ee3c hi\u1ec7u chu\u1ea9n \u1edf 30\u00b0C (theo IEC 60898-1), c\u00e1c h\u1ec7 s\u1ed1 suy gi\u1ea3m \u0111i\u1ec3n h\u00ecnh l\u00e0:<\/p>\n<table style=\"width: 100%; border-collapse: collapse; margin: 20px 0;\" border=\"1\">\n<thead>\n<tr style=\"background-color: #f9f9f9;\">\n<th style=\"padding: 10px; text-align: left;\">Nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng<\/th>\n<th style=\"padding: 10px; text-align: left;\">H\u1ec7 s\u1ed1 Suy gi\u1ea3m \u0110i\u1ec3n h\u00ecnh<\/th>\n<th style=\"padding: 10px; text-align: left;\">V\u00ed d\u1ee5: C\u00f4ng su\u1ea5t Hi\u1ec7u d\u1ee5ng c\u1ee7a MCB 32A<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"padding: 10px;\">30\u00b0C (tham chi\u1ebfu)<\/td>\n<td style=\"padding: 10px;\">1.00<\/td>\n<td style=\"padding: 10px;\">32A<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px;\">40\u00b0C<\/td>\n<td style=\"padding: 10px;\">0.94 &#8211; 0.97<\/td>\n<td style=\"padding: 10px;\">30A \u2013 31A<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px;\">50\u00b0C<\/td>\n<td style=\"padding: 10px;\">0.88 &#8211; 0.95<\/td>\n<td style=\"padding: 10px;\">28A \u2013 30A<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px;\">60\u00b0C<\/td>\n<td style=\"padding: 10px;\">0.76 &#8211; 0.90<\/td>\n<td style=\"padding: 10px;\">24A \u2013 29A<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px;\">70\u00b0C<\/td>\n<td style=\"padding: 10px;\">0.64 &#8211; 0.85<\/td>\n<td style=\"padding: 10px;\">20A \u2013 27A<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u0110\u1ed1i v\u1edbi MCB v\u00e0 <a href=\"https:\/\/test.viox.com\/vi\/mccb\/\">MCCBs<\/a> \u0111\u01b0\u1ee3c hi\u1ec7u chu\u1ea9n \u1edf 40\u00b0C (theo IEC 60947-2), \u0111\u01b0\u1eddng c\u01a1 s\u1edf thay \u0111\u1ed5i t\u01b0\u01a1ng \u1ee9ng:<\/p>\n<table style=\"width: 100%; border-collapse: collapse; margin: 20px 0;\" border=\"1\">\n<thead>\n<tr style=\"background-color: #f9f9f9;\">\n<th style=\"padding: 10px; text-align: left;\">Nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng<\/th>\n<th style=\"padding: 10px; text-align: left;\">H\u1ec7 s\u1ed1 Suy gi\u1ea3m \u0110i\u1ec3n h\u00ecnh<\/th>\n<th style=\"padding: 10px; text-align: left;\">V\u00ed d\u1ee5: C\u00f4ng su\u1ea5t Hi\u1ec7u d\u1ee5ng c\u1ee7a MCCB 100A<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"padding: 10px;\">40\u00b0C (tham chi\u1ebfu)<\/td>\n<td style=\"padding: 10px;\">1.00<\/td>\n<td style=\"padding: 10px;\">100<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px;\">50\u00b0C<\/td>\n<td style=\"padding: 10px;\">0.90 &#8211; 0.94<\/td>\n<td style=\"padding: 10px;\">90A \u2013 94A<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px;\">60\u00b0C<\/td>\n<td style=\"padding: 10px;\">0.80 &#8211; 0.87<\/td>\n<td style=\"padding: 10px;\">80A \u2013 87A<\/td>\n<\/tr>\n<tr>\n<td style=\"padding: 10px;\">70\u00b0C<\/td>\n<td style=\"padding: 10px;\">0.70 &#8211; 0.80<\/td>\n<td style=\"padding: 10px;\">70A \u2013 80A<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>C\u00e1c ph\u1ea1m vi ph\u1ea3n \u00e1nh s\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa c\u00e1c thi\u1ebft k\u1ebf s\u1ea3n ph\u1ea9m c\u1ee7a c\u00e1c nh\u00e0 s\u1ea3n xu\u1ea5t kh\u00e1c nhau. D\u00f2ng MCB cao c\u1ea5p v\u1edbi kh\u1ea3 n\u0103ng qu\u1ea3n l\u00fd nhi\u1ec7t n\u00e2ng cao c\u00f3 th\u1ec3 cho th\u1ea5y hi\u1ec7u su\u1ea5t t\u1ed1t h\u01a1n \u1edf nhi\u1ec7t \u0111\u1ed9 cao.<\/p>\n<h3>D\u1eef li\u1ec7u C\u1ee5 th\u1ec3 c\u1ee7a Nh\u00e0 s\u1ea3n xu\u1ea5t<\/h3>\n<p>C\u00e1c nh\u00e0 s\u1ea3n xu\u1ea5t h\u00e0ng \u0111\u1ea7u cung c\u1ea5p th\u00f4ng tin chi ti\u1ebft v\u1ec1 vi\u1ec7c gi\u1ea3m c\u00f4ng su\u1ea5t trong danh m\u1ee5c k\u1ef9 thu\u1eadt c\u1ee7a h\u1ecd:<\/p>\n<p><strong>D\u00f2ng ABB S200 (tham chi\u1ebfu 30\u00b0C)<\/strong>: \u0110\u1ed1i v\u1edbi MCB 80A, d\u00f2ng \u0111i\u1ec7n ho\u1ea1t \u0111\u1ed9ng t\u1ed1i \u0111a \u1edf c\u00e1c nhi\u1ec7t \u0111\u1ed9 kh\u00e1c nhau x\u1ea5p x\u1ec9 77.6A \u1edf 50\u00b0C, 75.2A \u1edf 60\u00b0C v\u00e0 72.8A \u1edf 70\u00b0C.<\/p>\n<p><strong>D\u00f2ng Schneider Electric Acti9<\/strong>: M\u1ed9t b\u1ed9 ng\u1eaft nhi\u1ec7t t\u1eeb 160A \u0111\u01b0\u1ee3c hi\u1ec7u chu\u1ea9n \u1edf 40\u00b0C cho th\u1ea5y c\u00f4ng su\u1ea5t hi\u1ec7u d\u1ee5ng l\u00e0 150A \u1edf 50\u00b0C, 140A \u1edf 60\u00b0C v\u00e0 130A \u1edf 70\u00b0C\u2014th\u1ec3 hi\u1ec7n m\u1ee9c gi\u1ea3m kho\u1ea3ng 10A cho m\u1ed7i m\u1ee9c t\u0103ng 10\u00b0C.<\/p>\n<p><strong>Eaton v\u00e0 Siemens<\/strong>: C\u1ea3 hai nh\u00e0 s\u1ea3n xu\u1ea5t \u0111\u1ec1u nh\u1ea5n m\u1ea1nh t\u1ea7m quan tr\u1ecdng c\u1ee7a vi\u1ec7c tham kh\u1ea3o t\u00e0i li\u1ec7u c\u1ee5 th\u1ec3 c\u1ee7a s\u1ea3n ph\u1ea9m, v\u00ec \u0111\u1eb7c t\u00ednh gi\u1ea3m c\u00f4ng su\u1ea5t kh\u00e1c nhau \u0111\u00e1ng k\u1ec3 trong danh m\u1ee5c MCB m\u1edf r\u1ed9ng c\u1ee7a h\u1ecd.<\/p>\n<h3>H\u01b0\u1edbng d\u1eabn Ti\u00eau chu\u1ea9n IEC<\/h3>\n<p>IEC 60898-1 v\u00e0 IEC 60947-2 thi\u1ebft l\u1eadp c\u00e1c giao th\u1ee9c th\u1eed nghi\u1ec7m v\u00e0 nhi\u1ec7t \u0111\u1ed9 tham chi\u1ebfu nh\u01b0ng kh\u00f4ng b\u1eaft bu\u1ed9c c\u00e1c gi\u00e1 tr\u1ecb gi\u1ea3m c\u00f4ng su\u1ea5t c\u1ee5 th\u1ec3. Thay v\u00e0o \u0111\u00f3, c\u00e1c nh\u00e0 s\u1ea3n xu\u1ea5t ph\u1ea3i cung c\u1ea5p d\u1eef li\u1ec7u n\u00e0y d\u1ef1a tr\u00ean th\u1eed nghi\u1ec7m lo\u1ea1i s\u1ea3n ph\u1ea9m c\u1ee7a h\u1ecd. C\u00e1c ti\u00eau chu\u1ea9n y\u00eau c\u1ea7u MCB ho\u1ea1t \u0111\u1ed9ng an to\u00e0n trong ph\u1ea1m vi nhi\u1ec7t \u0111\u1ed9 quy \u0111\u1ecbnh c\u1ee7a ch\u00fang, nh\u01b0ng s\u1ef1 suy gi\u1ea3m hi\u1ec7u su\u1ea5t \u1edf nhi\u1ec7t \u0111\u1ed9 kh\u1eafc nghi\u1ec7t l\u00e0 \u0111i\u1ec1u \u0111\u01b0\u1ee3c d\u1ef1 ki\u1ebfn v\u00e0 ph\u1ea3i \u0111\u01b0\u1ee3c t\u00ednh \u0111\u1ebfn trong k\u1ef9 thu\u1eadt \u1ee9ng d\u1ee5ng.<\/p>\n<h3>Khi n\u00e0o n\u00ean \u00c1p d\u1ee5ng c\u00e1c H\u1ec7 s\u1ed1 B\u1ea3o th\u1ee7 h\u01a1n<\/h3>\n<p>Trong m\u1ed9t s\u1ed1 tr\u01b0\u1eddng h\u1ee3p nh\u1ea5t \u0111\u1ecbnh, vi\u1ec7c \u00e1p d\u1ee5ng m\u1ee9c gi\u1ea3m c\u00f4ng su\u1ea5t b\u1ea3o th\u1ee7 h\u01a1n l\u00e0 th\u1eadn tr\u1ecdng:<\/p>\n<ul>\n<li><strong>C\u00e1c \u1ee9ng d\u1ee5ng quan tr\u1ecdng<\/strong> n\u01a1i b\u1ea5t k\u1ef3 s\u1ef1 c\u1ed1 ng\u1eaft m\u1ea1ch n\u00e0o c\u0169ng g\u00e2y ra h\u1eadu qu\u1ea3 nghi\u00eam tr\u1ecdng<\/li>\n<li><strong>C\u00e1c c\u00e0i \u0111\u1eb7t c\u00f3 kh\u1ea3 n\u0103ng gi\u00e1m s\u00e1t nhi\u1ec7t \u0111\u1ed9 k\u00e9m<\/strong> n\u01a1i nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng th\u1ef1c t\u1ebf c\u00f3 th\u1ec3 v\u01b0\u1ee3t qu\u00e1 c\u00e1c gi\u1ea3 \u0111\u1ecbnh thi\u1ebft k\u1ebf<\/li>\n<li><strong>C\u00e1c c\u00e0i \u0111\u1eb7t c\u0169<\/strong> n\u01a1i hi\u1ec7u chu\u1ea9n MCB c\u00f3 th\u1ec3 \u0111\u00e3 b\u1ecb tr\u00f4i sau nhi\u1ec1u n\u0103m s\u1eed d\u1ee5ng<\/li>\n<li><strong>M\u00f4i tr\u01b0\u1eddng c\u00f3 bi\u1ebfn \u0111\u1ed9ng nhi\u1ec7t \u0111\u1ed9 l\u1edbn<\/strong> g\u00e2y \u1ee9ng su\u1ea5t cho d\u1ea3i l\u01b0\u1ee1ng kim th\u00f4ng qua chu k\u1ef3 nhi\u1ec7t l\u1eb7p \u0111i l\u1eb7p l\u1ea1i<\/li>\n<\/ul>\n<figure style=\"margin: 20px 0; text-align: center;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/reference-table-displaying-mcb-temperature-derating-factors-from-30c-to-70c-with-corresponding-derating-values-and-capacity-examples-for-32a-mcb.webp\" alt=\"Reference table displaying MCB temperature derating factors from 30\u00b0C to 70\u00b0C with corresponding derating values and capacity examples for 32A MCB, VIOX branded\" \/><figcaption style=\"font-style: italic; font-size: 0.9em; color: #666; margin-top: 8px;\">B\u1ea3ng tham kh\u1ea3o hi\u1ec3n th\u1ecb c\u00e1c h\u1ec7 s\u1ed1 gi\u1ea3m c\u00f4ng su\u1ea5t theo nhi\u1ec7t \u0111\u1ed9 MCB t\u1eeb 30\u00b0C \u0111\u1ebfn 70\u00b0C v\u1edbi c\u00e1c gi\u00e1 tr\u1ecb gi\u1ea3m c\u00f4ng su\u1ea5t t\u01b0\u01a1ng \u1ee9ng v\u00e0 c\u00e1c v\u00ed d\u1ee5 v\u1ec1 c\u00f4ng su\u1ea5t cho MCB 32A, th\u01b0\u01a1ng hi\u1ec7u VIOX<\/figcaption><\/figure>\n<h2>\u1ee8ng d\u1ee5ng Th\u1ef1c t\u1ebf &amp; C\u00e2n nh\u1eafc L\u1eafp \u0111\u1eb7t<\/h2>\n<h3>X\u00e1c \u0111\u1ecbnh Nhi\u1ec7t \u0111\u1ed9 M\u00f4i tr\u01b0\u1eddng trong C\u00e0i \u0111\u1eb7t Th\u1ef1c t\u1ebf<\/h3>\n<p>M\u1ed9t \u0111i\u1ec3m quan tr\u1ecdng th\u01b0\u1eddng b\u1ecb hi\u1ec3u l\u1ea7m: nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng cho m\u1ee5c \u0111\u00edch gi\u1ea3m c\u00f4ng su\u1ea5t MCB l\u00e0 <strong>kh\u00f4ng<\/strong> nhi\u1ec7t \u0111\u1ed9 ph\u00f2ng. \u0110\u00f3 l\u00e0 nhi\u1ec7t \u0111\u1ed9 c\u1ee7a kh\u00f4ng kh\u00ed ngay xung quanh ch\u00ednh MCB. Trong c\u00e1c c\u00e0i \u0111\u1eb7t k\u00edn, \u0111i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 cao h\u01a1n \u0111\u00e1ng k\u1ec3 so v\u1edbi m\u00f4i tr\u01b0\u1eddng chung.<\/p>\n<p>M\u1ed9t b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n \u0111\u1eb7t trong ph\u00f2ng c\u00f3 m\u00e1y l\u1ea1nh 25\u00b0C c\u00f3 th\u1ec3 c\u00f3 nhi\u1ec7t \u0111\u1ed9 b\u00ean trong l\u00e0 45\u00b0C tr\u1edf l\u00ean do nhi\u1ec7t do c\u00e1c thi\u1ebft b\u1ecb kh\u00e1c t\u1ea1o ra, t\u1ea3i nhi\u1ec7t m\u1eb7t tr\u1eddi tr\u00ean v\u1ecf ho\u1eb7c th\u00f4ng gi\u00f3 kh\u00f4ng \u0111\u1ee7. Lu\u00f4n \u0111o ho\u1eb7c t\u00ednh to\u00e1n nhi\u1ec7t \u0111\u1ed9 th\u1ef1c t\u1ebf b\u00ean trong v\u1ecf n\u01a1i MCB \u0111\u01b0\u1ee3c g\u1eafn.<\/p>\n<h3>\u1ea2nh h\u01b0\u1edfng c\u1ee7a V\u1ecf v\u00e0 S\u1ef1 T\u00edch t\u1ee5 Nhi\u1ec7t<\/h3>\n<p>V\u1ecf \u0111i\u1ec7n t\u1ea1o ra c\u00e1c v\u00f9ng n\u00f3ng c\u1ee5c b\u1ed9. C\u00e1c ngu\u1ed3n nhi\u1ec7t bao g\u1ed3m:<\/p>\n<ul>\n<li>Ngu\u1ed3n \u0111i\u1ec7n v\u00e0 m\u00e1y bi\u1ebfn \u00e1p t\u1ea1o ra nhi\u1ec7t li\u00ean t\u1ee5c<\/li>\n<li>VFD (Bi\u1ebfn t\u1ea7n) v\u1edbi t\u1ed5n th\u1ea5t chuy\u1ec3n m\u1ea1ch<\/li>\n<li><a href=\"https:\/\/test.viox.com\/vi\/ac-contactor\/\">Ti\u1ebfp x\u00fac<\/a> v\u00e0 <a href=\"https:\/\/test.viox.com\/vi\/timer-relay\/\">r\u01a1 le<\/a> v\u1edbi cu\u1ed9n d\u00e2y \u0111\u01b0\u1ee3c c\u1ea5p \u0111i\u1ec7n<\/li>\n<li>B\u1ea3n th\u00e2n MCB g\u00f3p ph\u1ea7n g\u00e2y ra t\u1ed5n th\u1ea5t I\u00b2R<\/li>\n<\/ul>\n<p>Trong m\u1ed9t b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n \u0111\u01b0\u1ee3c \u0111\u00f3ng g\u00f3i d\u00e0y \u0111\u1eb7c m\u00e0 kh\u00f4ng c\u00f3 th\u00f4ng gi\u00f3 \u0111\u1ea7y \u0111\u1ee7, nhi\u1ec7t \u0111\u1ed9 b\u00ean trong c\u00f3 th\u1ec3 v\u01b0\u1ee3t qu\u00e1 nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng b\u00ean ngo\u00e0i t\u1eeb 20-30\u00b0C. Qu\u1ea1t th\u00f4ng gi\u00f3, t\u1ea3n nhi\u1ec7t v\u00e0 kho\u1ea3ng c\u00e1ch th\u00edch h\u1ee3p l\u00e0 c\u00e1c chi\u1ebfn l\u01b0\u1ee3c gi\u1ea3m thi\u1ec3u c\u1ea7n thi\u1ebft.<\/p>\n<h3>C\u00e1c y\u1ebfu t\u1ed1 nh\u00f3m v\u00e0 nhi\u1ec1u MCB<\/h3>\n<p>Khi nhi\u1ec1u MCB \u0111\u01b0\u1ee3c g\u1eafn c\u1ea1nh nhau \u1edf g\u1ea7n nhau, \u0111\u1ea7u ra nhi\u1ec7t k\u1ebft h\u1ee3p c\u1ee7a ch\u00fang t\u1ea1o ra c\u00e1c hi\u1ec7u \u1ee9ng l\u00e0m n\u00f3ng l\u1eabn nhau. \u0110i\u1ec1u n\u00e0y \u0111\u00f2i h\u1ecfi ph\u1ea3i \u00e1p d\u1ee5ng th\u00eam m\u1ed9t <strong>h\u1ec7 s\u1ed1 nh\u00f3m<\/strong> hay <strong>h\u1ec7 s\u1ed1 s\u1eafp x\u1ebfp<\/strong> tr\u00ean \u0111\u1ec9nh c\u1ee7a vi\u1ec7c gi\u1ea3m \u0111\u1ecbnh m\u1ee9c do nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng.<\/p>\n<p>V\u00ed d\u1ee5: IEC 60947-2 c\u00f4ng nh\u1eadn r\u1eb1ng c\u00e1c b\u1ed9 ng\u1eaft m\u1ea1ch \u0111\u01b0\u1ee3c l\u1eafp theo h\u00e0ng trong m\u1ed9t v\u1ecf b\u1ecdc c\u00f3 nhi\u1ec7t \u0111\u1ed9 ho\u1ea1t \u0111\u1ed9ng cao h\u01a1n so v\u1edbi c\u00e1c thi\u1ebft b\u1ecb ri\u00eang l\u1ebb. M\u1ed9t s\u1ed1 nh\u00e0 s\u1ea3n xu\u1ea5t cung c\u1ea5p h\u01b0\u1edbng d\u1eabn c\u1ee5 th\u1ec3: m\u1ed9t h\u00e0ng g\u1ed3m 3-6 MCB li\u1ec1n k\u1ec1 c\u00f3 th\u1ec3 y\u00eau c\u1ea7u gi\u1ea3m \u0111\u1ecbnh m\u1ee9c th\u00eam 5-10% ngo\u00e0i vi\u1ec7c \u0111i\u1ec1u ch\u1ec9nh nhi\u1ec7t \u0111\u1ed9.<\/p>\n<p>Hi\u1ec7u \u1ee9ng t\u00edch l\u0169y c\u00f3 th\u1ec3 \u0111\u00e1ng k\u1ec3:<\/p>\n<ul>\n<li>Gi\u1ea3m \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng: 0,90 (\u1edf 50\u00b0C)<\/li>\n<li>H\u1ec7 s\u1ed1 nh\u00f3m: 0,95 (cho 4 MCB li\u1ec1n k\u1ec1)<\/li>\n<li>H\u1ec7 s\u1ed1 k\u1ebft h\u1ee3p: 0,90 \u00d7 0,95 = 0,855<\/li>\n<li>M\u1ed9t MCB 32A th\u1ef1c t\u1ebf tr\u1edf th\u00e0nh: 32A \u00d7 0,855 = c\u00f4ng su\u1ea5t 27,4A<\/li>\n<\/ul>\n<h3>Th\u00f4ng gi\u00f3 v\u00e0 Qu\u1ea3n l\u00fd nhi\u1ec7t<\/h3>\n<p>Thi\u1ebft k\u1ebf v\u1ecf b\u1ecdc ph\u00f9 h\u1ee3p \u1ea3nh h\u01b0\u1edfng \u0111\u00e1ng k\u1ec3 \u0111\u1ebfn hi\u1ec7u su\u1ea5t nhi\u1ec7t c\u1ee7a MCB:<\/p>\n<p><strong>\u0110\u1ed1i l\u01b0u t\u1ef1 nhi\u00ean<\/strong>: \u0110\u1ea3m b\u1ea3o khe h\u1edf th\u00edch h\u1ee3p ph\u00eda tr\u00ean v\u00e0 ph\u00eda d\u01b0\u1edbi h\u00e0ng MCB. Kh\u00f4ng kh\u00ed n\u00f3ng ph\u1ea3i tho\u00e1t ra t\u1eeb c\u00e1c l\u1ed7 th\u00f4ng h\u01a1i ph\u00eda tr\u00ean trong khi kh\u00f4ng kh\u00ed m\u00e1t h\u01a1n \u0111i v\u00e0o t\u1eeb b\u00ean d\u01b0\u1edbi.<\/p>\n<p><strong>Th\u00f4ng gi\u00f3 c\u01b0\u1ee1ng b\u1ee9c<\/strong>: Trong c\u00e1c c\u00e0i \u0111\u1eb7t m\u1eadt \u0111\u1ed9 cao ho\u1eb7c m\u00f4i tr\u01b0\u1eddng n\u00f3ng, h\u00e3y ch\u1ec9 \u0111\u1ecbnh qu\u1ea1t th\u00f4ng gi\u00f3 c\u00f3 k\u00edch th\u01b0\u1edbc \u0111\u1ec3 duy tr\u00ec nhi\u1ec7t \u0111\u1ed9 b\u00ean trong ch\u1ea5p nh\u1eadn \u0111\u01b0\u1ee3c. M\u1ed9t h\u01b0\u1edbng d\u1eabn chung l\u00e0 gi\u1eef nhi\u1ec7t \u0111\u1ed9 b\u00ean trong v\u1ecf b\u1ecdc trong v\u00f2ng 10-15\u00b0C so v\u1edbi nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng b\u00ean ngo\u00e0i.<\/p>\n<p><strong>R\u00e0o c\u1ea3n nhi\u1ec7t<\/strong>: C\u00e1ch ly c\u00e1c th\u00e0nh ph\u1ea7n t\u1ecfa nhi\u1ec7t cao (VFD, ngu\u1ed3n \u0111i\u1ec7n) kh\u1ecfi c\u00e1c ph\u1ea7n MCB b\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng v\u00e1ch ng\u0103n ho\u1eb7c c\u00e1c ng\u0103n ri\u00eang bi\u1ec7t.<\/p>\n<h3>Ph\u1ed1i h\u1ee3p gi\u1ea3m \u0111\u1ecbnh m\u1ee9c c\u00e1p<\/h3>\n<p>M\u1ed9t \u0111i\u1ec3m quan tr\u1ecdng nh\u01b0ng th\u01b0\u1eddng b\u1ecb b\u1ecf qua: c\u00e1p k\u1ebft n\u1ed1i v\u1edbi MCB c\u0169ng y\u00eau c\u1ea7u gi\u1ea3m \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t \u0111\u1ed9. S\u01a1 \u0111\u1ed3 b\u1ea3o v\u1ec7 m\u1ea1ch t\u1ed5ng th\u1ec3 ch\u1ec9 \u0111\u00e1ng tin c\u1eady nh\u01b0 y\u1ebfu t\u1ed1 y\u1ebfu nh\u1ea5t c\u1ee7a n\u00f3.<\/p>\n<p>N\u1ebfu MCB b\u1ecb gi\u1ea3m \u0111\u1ecbnh m\u1ee9c xu\u1ed1ng 28A do nhi\u1ec7t \u0111\u1ed9 nh\u01b0ng c\u00e1p k\u1ebft n\u1ed1i (c\u0169ng ph\u1ea3i ch\u1ecbu gi\u1ea3m \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t \u0111\u1ed9) ch\u1ec9 c\u00f3 th\u1ec3 mang an to\u00e0n 26A trong c\u00f9ng m\u00f4i tr\u01b0\u1eddng, th\u00ec m\u1ea1ch b\u1ecb gi\u1edbi h\u1ea1n \u1edf 26A\u2014kh\u00f4ng ph\u1ea3i 28A. Lu\u00f4n ph\u1ed1i h\u1ee3p c\u00e1c t\u00ednh to\u00e1n gi\u1ea3m \u0111\u1ecbnh m\u1ee9c MCB v\u00e0 c\u00e1p.<\/p>\n<h3>C\u00e2n nh\u1eafc v\u1ec1 \u0111\u1ed9 cao<\/h3>\n<p>\u1ede \u0111\u1ed9 cao tr\u00ean 2.000 m\u00e9t, m\u1eadt \u0111\u1ed9 kh\u00f4ng kh\u00ed gi\u1ea3m, l\u00e0m gi\u1ea3m hi\u1ec7u qu\u1ea3 l\u00e0m m\u00e1t. \u0110i\u1ec1u n\u00e0y c\u00f3 th\u1ec3 \u0111\u00f2i h\u1ecfi ph\u1ea3i gi\u1ea3m \u0111\u1ecbnh m\u1ee9c b\u1ed5 sung, th\u01b0\u1eddng \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ecbnh trong t\u00e0i li\u1ec7u c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t cho c\u00e1c \u1ee9ng d\u1ee5ng \u1edf \u0111\u1ed9 cao l\u1edbn.<\/p>\n<figure style=\"margin: 20px 0; text-align: center;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/technical-comparison-illustration-showing-three-mcb-installation-scenarios-well-ventilated-panel-30c-enclosed-panel-45c-and-densely-packed-enclosure-60c-with-color-coded-temperature-zones.webp\" alt=\"Technical comparison illustration showing three MCB installation scenarios - well-ventilated panel (30\u00b0C), enclosed panel (45\u00b0C), and densely packed enclosure (60\u00b0C) with color-coded temperature zones, VIOX logo\" \/><figcaption style=\"font-style: italic; font-size: 0.9em; color: #666; margin-top: 8px;\">H\u00ecnh minh h\u1ecda so s\u00e1nh k\u1ef9 thu\u1eadt cho th\u1ea5y ba k\u1ecbch b\u1ea3n l\u1eafp \u0111\u1eb7t MCB \u2013 b\u1ea3ng th\u00f4ng gi\u00f3 t\u1ed1t (30\u00b0C), b\u1ea3ng k\u00edn (45\u00b0C) v\u00e0 v\u1ecf b\u1ecdc d\u00e0y \u0111\u1eb7c (60\u00b0C) v\u1edbi c\u00e1c v\u00f9ng nhi\u1ec7t \u0111\u1ed9 \u0111\u01b0\u1ee3c m\u00e3 h\u00f3a m\u00e0u, logo VIOX<\/figcaption><\/figure>\n<h2>K\u1ebft lu\u1eadn<\/h2>\n<p>Nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng l\u00e0 m\u1ed9t y\u1ebfu t\u1ed1 quan tr\u1ecdng nh\u01b0ng th\u01b0\u1eddng b\u1ecb \u0111\u00e1nh gi\u00e1 th\u1ea5p trong vi\u1ec7c l\u1ef1a ch\u1ecdn v\u00e0 \u1ee9ng d\u1ee5ng MCB. M\u1eb7c d\u00f9 \u0111\u1ecbnh m\u1ee9c tr\u00ean nh\u00e3n c\u1ee7a MCB cung c\u1ea5p th\u00f4ng tin c\u1ea7n thi\u1ebft, nh\u01b0ng n\u00f3 ch\u1ec9 th\u1ec3 hi\u1ec7n hi\u1ec7u su\u1ea5t \u1edf nhi\u1ec7t \u0111\u1ed9 tham chi\u1ebfu ti\u00eau chu\u1ea9n\u2014th\u01b0\u1eddng l\u00e0 30\u00b0C cho c\u00e1c thi\u1ebft b\u1ecb d\u00e2n d\u1ee5ng\/th\u01b0\u01a1ng m\u1ea1i ho\u1eb7c 40\u00b0C cho c\u00e1c \u1ee9ng d\u1ee5ng c\u00f4ng nghi\u1ec7p.<\/p>\n<p>Trong c\u00e1c c\u00e0i \u0111\u1eb7t th\u1ef1c t\u1ebf, \u0111\u1eb7c bi\u1ec7t l\u00e0 b\u00ean trong v\u1ecf \u0111i\u1ec7n ho\u1eb7c m\u00f4i tr\u01b0\u1eddng nhi\u1ec7t \u0111\u1ea7y th\u00e1ch th\u1ee9c, kh\u1ea3 n\u0103ng mang d\u00f2ng \u0111i\u1ec7n hi\u1ec7u qu\u1ea3 c\u1ee7a MCB c\u00f3 th\u1ec3 b\u1ecb gi\u1ea3m \u0111\u00e1ng k\u1ec3. B\u1ecf qua vi\u1ec7c gi\u1ea3m \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t \u0111\u1ed9 d\u1eabn \u0111\u1ebfn v\u1ea5p m\u1ea1ch g\u00e2y phi\u1ec1n to\u00e1i, l\u00e0m gi\u1ea3m \u0111\u1ed9 tin c\u1eady c\u1ee7a b\u1ea3o v\u1ec7 v\u00e0 h\u1ecfng thi\u1ebft b\u1ecb s\u1edbm.<\/p>\n<p>Nh\u1eefng \u0111i\u1ec3m ch\u00ednh d\u00e0nh cho c\u00e1c chuy\u00ean gia \u0111i\u1ec7n:<\/p>\n<ul>\n<li>Lu\u00f4n x\u00e1c \u0111\u1ecbnh nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng th\u1ef1c t\u1ebf t\u1ea1i v\u1ecb tr\u00ed MCB, kh\u00f4ng ch\u1ec9 nhi\u1ec7t \u0111\u1ed9 ph\u00f2ng<\/li>\n<li>Tham kh\u1ea3o b\u1ea3ng gi\u1ea3m \u0111\u1ecbnh m\u1ee9c c\u1ee5 th\u1ec3 c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t thay v\u00ec ch\u1ec9 d\u1ef1a v\u00e0o c\u00e1c h\u01b0\u1edbng d\u1eabn chung<\/li>\n<li>\u00c1p d\u1ee5ng c\u1ea3 gi\u1ea3m \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t \u0111\u1ed9 v\u00e0 h\u1ec7 s\u1ed1 nh\u00f3m cho nhi\u1ec1u MCB li\u1ec1n k\u1ec1<\/li>\n<li>Ph\u1ed1i h\u1ee3p gi\u1ea3m \u0111\u1ecbnh m\u1ee9c MCB v\u1edbi gi\u1ea3m kh\u1ea3 n\u0103ng mang d\u00f2ng \u0111i\u1ec7n c\u1ee7a c\u00e1p<\/li>\n<li>Thi\u1ebft k\u1ebf v\u1ecf b\u1ecdc c\u00f3 h\u1ec7 th\u1ed1ng th\u00f4ng gi\u00f3 \u0111\u1ea7y \u0111\u1ee7 \u0111\u1ec3 qu\u1ea3n l\u00fd s\u1ef1 t\u00edch t\u1ee5 nhi\u1ec7t<\/li>\n<\/ul>\n<p>T\u1ea1i VIOX, ch\u00fang t\u00f4i cung c\u1ea5p t\u00e0i li\u1ec7u k\u1ef9 thu\u1eadt to\u00e0n di\u1ec7n cho t\u1ea5t c\u1ea3 c\u00e1c d\u00f2ng s\u1ea3n ph\u1ea9m MCB c\u1ee7a m\u00ecnh, bao g\u1ed3m c\u00e1c \u0111\u01b0\u1eddng cong gi\u1ea3m \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t \u0111\u1ed9 chi ti\u1ebft v\u00e0 h\u01b0\u1edbng d\u1eabn \u1ee9ng d\u1ee5ng. \u0110\u1ed9i ng\u0169 h\u1ed7 tr\u1ee3 k\u1ef9 thu\u1eadt c\u1ee7a ch\u00fang t\u00f4i s\u1eb5n s\u00e0ng h\u1ed7 tr\u1ee3 c\u00e1c c\u00e0i \u0111\u1eb7t ph\u1ee9c t\u1ea1p, n\u01a1i qu\u1ea3n l\u00fd nhi\u1ec7t l\u00e0 r\u1ea5t quan tr\u1ecdng. L\u1ef1a ch\u1ecdn MCB ph\u00f9 h\u1ee3p c\u00f3 t\u00ednh \u0111\u1ebfn nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng \u0111\u1ea3m b\u1ea3o r\u1eb1ng h\u1ec7 th\u1ed1ng b\u1ea3o v\u1ec7 \u0111i\u1ec7n c\u1ee7a b\u1ea1n mang l\u1ea1i hi\u1ec7u su\u1ea5t l\u00e2u d\u00e0i, \u0111\u00e1ng tin c\u1eady ch\u00ednh x\u00e1c khi c\u1ea7n thi\u1ebft nh\u1ea5t.<\/p>\n<p>\u0110\u1ec3 bi\u1ebft th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt, b\u1ea3ng gi\u1ea3m \u0111\u1ecbnh m\u1ee9c v\u00e0 h\u1ed7 tr\u1ee3 \u1ee9ng d\u1ee5ng cho MCB VIOX, h\u00e3y tham kh\u1ea3o danh m\u1ee5c s\u1ea3n ph\u1ea9m c\u1ee7a ch\u00fang t\u00f4i ho\u1eb7c li\u00ean h\u1ec7 v\u1edbi nh\u00f3m k\u1ef9 thu\u1eadt c\u1ee7a ch\u00fang t\u00f4i.<\/p>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Introduction When selecting a miniature circuit breaker (MCB) for an electrical installation, most engineers focus on the rated current\u2014but there&#8217;s a critical variable that can drastically affect performance: ambient temperature. An MCB rated at 32A won&#8217;t necessarily carry 32A safely in all environments. In fact, at elevated temperatures, that same MCB might trip at just [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":20748,"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-20745","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"_links":{"self":[{"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/posts\/20745","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/comments?post=20745"}],"version-history":[{"count":2,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/posts\/20745\/revisions"}],"predecessor-version":[{"id":20747,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/posts\/20745\/revisions\/20747"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/media\/20748"}],"wp:attachment":[{"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/media?parent=20745"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/categories?post=20745"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/tags?post=20745"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}