{"id":21209,"date":"2026-01-06T00:10:09","date_gmt":"2026-01-05T16:10:09","guid":{"rendered":"https:\/\/viox.com\/?p=21209"},"modified":"2026-01-06T00:17:14","modified_gmt":"2026-01-05T16:17:14","slug":"electrical-derating-temperature-altitude-grouping-factors","status":"publish","type":"post","link":"https:\/\/test.viox.com\/vi\/electrical-derating-temperature-altitude-grouping-factors\/","title":{"rendered":"H\u01b0\u1edbng D\u1eabn Chi Ti\u1ebft v\u1ec1 Gi\u1ea3m \u0110\u1ecbnh M\u1ee9c \u0110i\u1ec7n: Nhi\u1ec7t \u0110\u1ed9, \u0110\u1ed9 Cao v\u00e0 H\u1ec7 S\u1ed1 Nh\u00f3m"},"content":{"rendered":"<div class=\"product-intro\">\n<h2>T\u00ecm hi\u1ec3u v\u1ec1 Gi\u1ea3m t\u1ea3i \u0111i\u1ec7n: T\u1ea1i sao n\u00f3 quan tr\u1ecdng \u0111\u1ed1i v\u1edbi c\u00e1c c\u00e0i \u0111\u1eb7t an to\u00e0n<\/h2>\n<p>Gi\u1ea3m t\u1ea3i \u0111i\u1ec7n l\u00e0 vi\u1ec7c gi\u1ea3m m\u1ed9t c\u00e1ch c\u00f3 h\u1ec7 th\u1ed1ng kh\u1ea3 n\u0103ng mang d\u00f2ng \u0111i\u1ec7n (ampacity) c\u1ee7a d\u00e2y d\u1eabn \u0111\u1ec3 t\u00ednh \u0111\u1ebfn c\u00e1c \u0111i\u1ec1u ki\u1ec7n l\u1eafp \u0111\u1eb7t th\u1ef1c t\u1ebf kh\u00e1c v\u1edbi m\u00f4i tr\u01b0\u1eddng th\u1eed nghi\u1ec7m ti\u00eau chu\u1ea9n. Khi c\u00e1p ho\u1ea1t \u0111\u1ed9ng \u1edf nhi\u1ec7t \u0111\u1ed9 cao, \u1edf \u0111\u1ed9 cao l\u1edbn ho\u1eb7c b\u00f3 v\u1edbi c\u00e1c d\u00e2y d\u1eabn kh\u00e1c, kh\u1ea3 n\u0103ng t\u1ea3n nhi\u1ec7t c\u1ee7a ch\u00fang gi\u1ea3m \u0111i \u0111\u00e1ng k\u1ec3. N\u1ebfu kh\u00f4ng c\u00f3 c\u00e1c t\u00ednh to\u00e1n gi\u1ea3m t\u1ea3i ph\u00f9 h\u1ee3p, c\u00e1c c\u00e0i \u0111\u1eb7t ph\u1ea3i \u0111\u1ed1i m\u1eb7t v\u1edbi nh\u1eefng r\u1ee7i ro nghi\u00eam tr\u1ecdng: h\u1ecfng c\u00e1ch \u0111i\u1ec7n s\u1edbm, <a href=\"https:\/\/test.viox.com\/vi\/mcb\/\">ng\u1eaft m\u1ea1ch<\/a> ng\u1eaft m\u1ea1ch g\u00e2y phi\u1ec1n to\u00e1i, nguy c\u01a1 h\u1ecfa ho\u1ea1n v\u00e0 kh\u00f4ng tu\u00e2n th\u1ee7 c\u00e1c ti\u00eau chu\u1ea9n NEC \u0110i\u1ec1u 310.15 v\u00e0 IEC 60364-5-52.<\/p>\n<p>\u0110\u1ed1i v\u1edbi c\u00e1c chuy\u00ean gia B2B c\u00e0i \u0111\u1eb7t <a href=\"https:\/\/test.viox.com\/vi\/rccb-ev-charging-type-b-vs-type-f-vs-type-ev\/\">c\u01a1 s\u1edf h\u1ea1 t\u1ea7ng s\u1ea1c xe \u0111i\u1ec7n<\/a>, c\u00e1c d\u00e3y n\u0103ng l\u01b0\u1ee3ng m\u1eb7t tr\u1eddi ho\u1eb7c h\u1ec7 th\u1ed1ng \u0111i\u1ec7n c\u00f4ng nghi\u1ec7p, vi\u1ec7c hi\u1ec3u c\u00e1c y\u1ebfu t\u1ed1 gi\u1ea3m t\u1ea3i kh\u00f4ng ph\u1ea3i l\u00e0 t\u00f9y ch\u1ecdn \u2014 \u0111\u00f3 l\u00e0 m\u1ed9t y\u00eau c\u1ea7u c\u01a1 b\u1ea3n \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o an to\u00e0n, tu\u00e2n th\u1ee7 quy t\u1eafc v\u00e0 tu\u1ed5i th\u1ecd h\u1ec7 th\u1ed1ng. H\u01b0\u1edbng d\u1eabn ch\u00ednh n\u00e0y cung c\u1ea5p khu\u00f4n kh\u1ed5 k\u1ef9 thu\u1eadt b\u1ea1n c\u1ea7n \u0111\u1ec3 t\u00ednh to\u00e1n c\u00e1c y\u1ebfu t\u1ed1 gi\u1ea3m t\u1ea3i ch\u00ednh x\u00e1c v\u00e0 \u0111\u1ecbnh c\u1ee1 d\u00e2y d\u1eabn ch\u00ednh x\u00e1c cho b\u1ea5t k\u1ef3 t\u00ecnh hu\u1ed1ng l\u1eafp \u0111\u1eb7t n\u00e0o.<\/p>\n<figure style=\"text-align: center; margin: 20px 0;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/High-temperature-electrical-installation-showing-VIOX-circuit-protection-equipment-operating-in-extreme-ambient-conditions-requiring-temperature-derating-factors.webp\" alt=\"High-temperature electrical installation showing VIOX circuit protection equipment operating in extreme ambient conditions requiring temperature derating factors\" \/><figcaption style=\"font-style: italic; color: #555; margin-top: 8px;\">C\u00e0i \u0111\u1eb7t \u0111i\u1ec7n nhi\u1ec7t \u0111\u1ed9 cao cho th\u1ea5y thi\u1ebft b\u1ecb b\u1ea3o v\u1ec7 m\u1ea1ch VIOX ho\u1ea1t \u0111\u1ed9ng trong \u0111i\u1ec1u ki\u1ec7n m\u00f4i tr\u01b0\u1eddng kh\u1eafc nghi\u1ec7t \u0111\u00f2i h\u1ecfi c\u00e1c y\u1ebfu t\u1ed1 gi\u1ea3m t\u1ea3i nhi\u1ec7t \u0111\u1ed9.<\/figcaption><\/figure>\n<h2>Ph\u1ea7n 1: C\u00e1c y\u1ebfu t\u1ed1 gi\u1ea3m t\u1ea3i nhi\u1ec7t \u0111\u1ed9<\/h2>\n<h3>\u0110i\u1ec1u ch\u1ec9nh nhi\u1ec7t \u0111\u1ed9 kh\u00f4ng kh\u00ed xung quanh<\/h3>\n<p><strong>\u0110i\u1ec1u ki\u1ec7n tham chi\u1ebfu ti\u00eau chu\u1ea9n<\/strong> gi\u1ea3 \u0111\u1ecbnh nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng xung quanh l\u00e0 30\u00b0C (86\u00b0F) \u0111\u1ed1i v\u1edbi c\u00e1p \u0111\u01b0\u1ee3c l\u1eafp \u0111\u1eb7t trong kh\u00f4ng kh\u00ed. Khi nhi\u1ec7t \u0111\u1ed9 th\u1ef1c t\u1ebf v\u01b0\u1ee3t qu\u00e1 m\u1ee9c c\u01a1 b\u1ea3n n\u00e0y, ampacity c\u1ee7a d\u00e2y d\u1eabn ph\u1ea3i \u0111\u01b0\u1ee3c gi\u1ea3m theo NEC B\u1ea3ng 310.15(B)(1) ho\u1eb7c IEC 60364-5-52 B\u1ea3ng B.52.14.<\/p>\n<p><strong>C\u00e1c y\u1ebfu t\u1ed1 gi\u1ea3m t\u1ea3i nhi\u1ec7t \u0111\u1ed9 quan tr\u1ecdng \u0111\u1ed1i v\u1edbi c\u00e1c lo\u1ea1i c\u00e1ch \u0111i\u1ec7n th\u00f4ng th\u01b0\u1eddng:<\/strong><\/p>\n<table style=\"border-collapse: collapse; width: 100%; margin-bottom: 20px;\" border=\"1\" cellpadding=\"8\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>Nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng<\/th>\n<th>C\u00e1ch \u0111i\u1ec7n PVC (70\u00b0C)<\/th>\n<th>C\u00e1ch \u0111i\u1ec7n XLPE\/EPR (90\u00b0C)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>30\u00b0C (86\u00b0F)<\/td>\n<td>1.00<\/td>\n<td>1.00<\/td>\n<\/tr>\n<tr>\n<td>35\u00b0C (95\u00b0F)<\/td>\n<td>0.94<\/td>\n<td>0.96<\/td>\n<\/tr>\n<tr>\n<td>40\u00b0C (104\u00b0F)<\/td>\n<td>0.87<\/td>\n<td>0.91<\/td>\n<\/tr>\n<tr>\n<td>45\u00b0C (113\u00b0F)<\/td>\n<td>0.79<\/td>\n<td>0.87<\/td>\n<\/tr>\n<tr>\n<td>50\u00b0C (122\u00b0F)<\/td>\n<td>0.71<\/td>\n<td>0.82<\/td>\n<\/tr>\n<tr>\n<td>55\u00b0C (131\u00b0F)<\/td>\n<td>0.61<\/td>\n<td>0.76<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>\u1ee8ng d\u1ee5ng th\u1ef1c t\u1ebf:<\/strong> C\u00e1c c\u00e0i \u0111\u1eb7t n\u0103ng l\u01b0\u1ee3ng m\u1eb7t tr\u1eddi tr\u00ean m\u00e1i nh\u00e0 th\u01b0\u01a1ng m\u1ea1i th\u01b0\u1eddng xuy\u00ean tr\u1ea3i qua nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng xung quanh l\u00e0 50-55\u00b0C v\u00e0o m\u00f9a h\u00e8. M\u1ed9t d\u00e2y d\u1eabn \u0111\u1ed3ng THHN 10 AWG \u0111\u01b0\u1ee3c \u0111\u1ecbnh m\u1ee9c 40A \u1edf 30\u00b0C gi\u1ea3m xu\u1ed1ng ch\u1ec9 c\u00f2n <strong>32,8A<\/strong> (40A \u00d7 0,82) \u1edf 50\u00b0C \u2014 m\u1ee9c gi\u1ea3m 18% c\u00f3 th\u1ec3 l\u00e0m qu\u00e1 t\u1ea3i c\u00e1c d\u00e2y d\u1eabn c\u00f3 k\u00edch th\u01b0\u1edbc nh\u1ecf.<\/p>\n<h3>\u0110i\u1ec1u ch\u1ec9nh nhi\u1ec7t \u0111\u1ed9 \u0111\u1ea5t cho c\u00e1p ng\u1ea7m<\/h3>\n<p>C\u00e1c c\u00e0i \u0111\u1eb7t ng\u1ea7m ph\u1ea3i \u0111\u1ed1i m\u1eb7t v\u1edbi nh\u1eefng th\u00e1ch th\u1ee9c v\u1ec1 nhi\u1ec7t kh\u00e1c nhau. C\u00e1c ti\u00eau chu\u1ea9n IEC 60287 v\u00e0 NEC tham kh\u1ea3o <strong>Nhi\u1ec7t \u0111\u1ed9 \u0111\u1ea5t 20\u00b0C (68\u00b0F)<\/strong> l\u00e0m c\u01a1 s\u1edf cho c\u00e1p ch\u00f4n.<\/p>\n<p><strong>C\u00e1c y\u1ebfu t\u1ed1 \u0111i\u1ec1u ch\u1ec9nh nhi\u1ec7t \u0111\u1ed9 \u0111\u1ea5t:<\/strong><\/p>\n<table style=\"border-collapse: collapse; width: 100%; margin-bottom: 20px;\" border=\"1\" cellpadding=\"8\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>Nhi\u1ec7t \u0111\u1ed9 \u0111\u1ea5t<\/th>\n<th>H\u1ec7 s\u1ed1 \u0111i\u1ec1u ch\u1ec9nh (T\u1ea5t c\u1ea3 c\u00e1c lo\u1ea1i c\u00e1ch \u0111i\u1ec7n)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>20\u00b0C (68\u00b0F)<\/td>\n<td>1.00<\/td>\n<\/tr>\n<tr>\n<td>25\u00b0C (77\u00b0F)<\/td>\n<td>0.96<\/td>\n<\/tr>\n<tr>\n<td>30\u00b0C (86\u00b0F)<\/td>\n<td>0.92<\/td>\n<\/tr>\n<tr>\n<td>35\u00b0C (95\u00b0F)<\/td>\n<td>0.87<\/td>\n<\/tr>\n<tr>\n<td>40\u00b0C (104\u00b0F)<\/td>\n<td>0.82<\/td>\n<\/tr>\n<tr>\n<td>45\u00b0C (113\u00b0F)<\/td>\n<td>0.77<\/td>\n<\/tr>\n<tr>\n<td>50\u00b0C (122\u00b0F)<\/td>\n<td>0.71<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>\u0110\u1ed9 s\u00e2u ch\u00f4n c\u0169ng \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn hi\u1ec7u su\u1ea5t nhi\u1ec7t.<\/strong> C\u00e1p ch\u00f4n \u1edf \u0111\u1ed9 s\u00e2u 80cm c\u00f3 kh\u1ea3 n\u0103ng t\u1ea3n nhi\u1ec7t t\u1ed1t h\u01a1n kho\u1ea3ng 4% so v\u1edbi c\u00e1p \u1edf \u0111\u1ed9 s\u00e2u 50cm, t\u1ea1o ra h\u1ec7 s\u1ed1 \u0111i\u1ec1u ch\u1ec9nh l\u00e0 <strong>0.96<\/strong> b\u00f9 \u0111\u1eafp m\u1ed9t ph\u1ea7n cho nhi\u1ec7t \u0111\u1ed9 \u0111\u1ea5t cao.<\/p>\n<h3>\u1ea2nh h\u01b0\u1edfng c\u1ee7a ti\u1ebfp x\u00fac c\u00e1ch nhi\u1ec7t<\/h3>\n<p>Khi c\u00e1p \u0111i qua ho\u1eb7c \u0111\u01b0\u1ee3c bao quanh b\u1edfi l\u1edbp c\u00e1ch nhi\u1ec7t (th\u01b0\u1eddng th\u1ea5y trong c\u00e1c l\u1ed7 xuy\u00ean t\u01b0\u1eddng c\u1ee7a t\u00f2a nh\u00e0), kh\u1ea3 n\u0103ng t\u1ea3n nhi\u1ec7t s\u1ebd gi\u1ea3m \u0111i \u0111\u00e1ng k\u1ec3. Theo NEC 310.15(A)(3) v\u00e0 IEC 60364-5-52:<\/p>\n<ul>\n<li><strong>C\u00e1p ti\u1ebfp x\u00fac v\u1edbi l\u1edbp c\u00e1ch nhi\u1ec7t trong \u2264100mm:<\/strong> \u00c1p d\u1ee5ng h\u1ec7 s\u1ed1 <strong>0.89<\/strong><\/li>\n<li><strong>C\u00e1p \u0111\u01b0\u1ee3c bao quanh b\u1edfi l\u1edbp c\u00e1ch nhi\u1ec7t trong &gt;500mm:<\/strong> \u00c1p d\u1ee5ng h\u1ec7 s\u1ed1 <strong>0.50<\/strong> (gi\u1ea3m 50%)<\/li>\n<li><strong>M\u1ea1ch v\u00f2ng cu\u1ed1i c\u00f9ng trong kh\u00f4ng gian c\u00e1ch nhi\u1ec7t:<\/strong> C\u00f3 th\u1ec3 y\u00eau c\u1ea7u t\u0103ng k\u00edch th\u01b0\u1edbc t\u1eeb 2,5mm\u00b2 l\u00ean 4mm\u00b2<\/li>\n<\/ul>\n<p>V\u00ec <a href=\"https:\/\/test.viox.com\/vi\/residential-circuit-breakers-vs-industrial-circuit-breakers\/\">c\u00e1c \u1ee9ng d\u1ee5ng c\u1ea7u dao d\u00e2n d\u1ee5ng v\u00e0 th\u01b0\u01a1ng m\u1ea1i<\/a>, y\u1ebfu t\u1ed1 th\u01b0\u1eddng b\u1ecb b\u1ecf qua n\u00e0y g\u00e2y ra c\u00e1c l\u1ed7i \u0111\u1ecbnh c\u1ee1 \u0111\u00e1ng k\u1ec3.<\/p>\n<figure style=\"text-align: center; margin: 20px 0;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/Technical-diagram-comparing-heat-dissipation-in-different-cable-installation-methods-with-corresponding-derating-factors-for-thermal-insulation-contact.webp\" alt=\"Technical diagram comparing heat dissipation in different cable installation methods with corresponding derating factors for thermal insulation contact\" \/><figcaption style=\"font-style: italic; color: #555; margin-top: 8px;\">S\u01a1 \u0111\u1ed3 k\u1ef9 thu\u1eadt so s\u00e1nh kh\u1ea3 n\u0103ng t\u1ea3n nhi\u1ec7t trong c\u00e1c ph\u01b0\u01a1ng ph\u00e1p l\u1eafp \u0111\u1eb7t c\u00e1p kh\u00e1c nhau v\u1edbi c\u00e1c y\u1ebfu t\u1ed1 gi\u1ea3m t\u1ea3i t\u01b0\u01a1ng \u1ee9ng cho ti\u1ebfp x\u00fac c\u00e1ch nhi\u1ec7t.<\/figcaption><\/figure>\n<h2>Ph\u1ea7n 2: C\u00e1c y\u1ebfu t\u1ed1 gi\u1ea3m t\u1ea3i \u0111\u1ed9 cao<\/h2>\n<h3>T\u1ea1i sao \u0111\u1ed9 cao \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn thi\u1ebft b\u1ecb \u0111i\u1ec7n<\/h3>\n<p>\u1ede \u0111\u1ed9 cao tr\u00ean 1.000 m\u00e9t (3.300 feet), <strong>gi\u1ea3m \u00e1p su\u1ea5t kh\u00ed quy\u1ec3n<\/strong> l\u00e0m gi\u1ea3m m\u1eadt \u0111\u1ed9 kh\u00f4ng kh\u00ed, l\u00e0m gi\u1ea3m hi\u1ec7u qu\u1ea3 l\u00e0m m\u00e1t c\u1ee7a thi\u1ebft b\u1ecb \u0111i\u1ec7n. Kh\u1ea3 n\u0103ng t\u1ea3n nhi\u1ec7t t\u1eeb b\u1ec1 m\u1eb7t c\u00e1p, m\u00e1y bi\u1ebfn \u00e1p v\u00e0 c\u1ea7u dao tr\u1edf n\u00ean k\u00e9m hi\u1ec7u qu\u1ea3 h\u01a1n, \u0111\u00f2i h\u1ecfi ph\u1ea3i gi\u1ea3m c\u00f4ng su\u1ea5t.<\/p>\n<p><strong>C\u00e1c y\u1ebfu t\u1ed1 \u0111i\u1ec1u ch\u1ec9nh \u0111\u1ed9 cao theo IEC 60364-5-52 v\u00e0 th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t:<\/strong><\/p>\n<table style=\"border-collapse: collapse; width: 100%; margin-bottom: 20px;\" border=\"1\" cellpadding=\"8\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>\u0110\u1ed9 cao (m\u00e9t)<\/th>\n<th>\u0110\u1ed9 cao (feet)<\/th>\n<th>H\u1ec7 s\u1ed1 gi\u1ea3m t\u1ea3i c\u00f4ng su\u1ea5t<\/th>\n<th>H\u1ec7 s\u1ed1 gi\u1ea3m t\u1ea3i \u0111i\u1ec7n \u00e1p<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>0-1,000<\/td>\n<td>0-3,300<\/td>\n<td>1.00<\/td>\n<td>1.00<\/td>\n<\/tr>\n<tr>\n<td>1,000-1,500<\/td>\n<td>3,300-4,900<\/td>\n<td>0.99<\/td>\n<td>1.00<\/td>\n<\/tr>\n<tr>\n<td>1,500-2,000<\/td>\n<td>4,900-6,600<\/td>\n<td>0.97<\/td>\n<td>0.99<\/td>\n<\/tr>\n<tr>\n<td>2,000-3,000<\/td>\n<td>6,600-9,800<\/td>\n<td>0.94<\/td>\n<td>0.98<\/td>\n<\/tr>\n<tr>\n<td>3,000-4,000<\/td>\n<td>9,800-13,100<\/td>\n<td>0.90<\/td>\n<td>0.97<\/td>\n<\/tr>\n<tr>\n<td>4,000-5,000<\/td>\n<td>13,100-16,400<\/td>\n<td>0.86<\/td>\n<td>0.95<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>\u00dd ngh\u0129a th\u1ef1c t\u1ebf \u0111\u1ed1i v\u1edbi c\u00e1c c\u00e0i \u0111\u1eb7t tr\u00ean n\u00fai<\/h3>\n<p><strong>Nghi\u00ean c\u1ee9u \u0111i\u1ec3n h\u00ecnh:<\/strong> M\u1ed9t tr\u1ea1m s\u1ea1c xe \u0111i\u1ec7n 22kW \u0111\u01b0\u1ee3c l\u1eafp \u0111\u1eb7t \u1edf \u0111\u1ed9 cao 2.500 m\u00e9t \u1edf Colorado y\u00eau c\u1ea7u m\u1ed9t d\u00e2y d\u1eabn c\u00f3 k\u00edch th\u01b0\u1edbc cho <strong>120A \u00f7 0,95 = 126,3A<\/strong> sau khi gi\u1ea3m t\u1ea3i \u0111\u1ed9 cao. \u0110i\u1ec1u n\u00e0y th\u1ec3 hi\u1ec7n m\u1ee9c gi\u1ea3m c\u00f4ng su\u1ea5t 5,3% so v\u1edbi c\u00e1c c\u00e0i \u0111\u1eb7t \u1edf m\u1ef1c n\u01b0\u1edbc bi\u1ec3n.<\/p>\n<p><strong>C\u00e2n nh\u1eafc v\u1ec1 thi\u1ebft b\u1ecb:<\/strong><\/p>\n<ul>\n<li>C\u1ea7u dao c\u00f3 th\u1ec3 b\u1ecb gi\u1ea3m kh\u1ea3 n\u0103ng c\u1eaft \u1edf \u0111\u1ed9 cao<\/li>\n<li>Hi\u1ec7u qu\u1ea3 l\u00e0m m\u00e1t c\u1ee7a m\u00e1y bi\u1ebfn \u00e1p gi\u1ea3m kho\u1ea3ng <strong>1% tr\u00ean 100 m\u00e9t<\/strong> tr\u00ean 1.000m<\/li>\n<li>T\u1ee7 \u0111i\u1ec7n v\u00e0 b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n y\u00eau c\u1ea7u v\u1ecf l\u1edbn h\u01a1n \u0111\u1ec3 l\u00e0m m\u00e1t \u0111\u1ed1i l\u01b0u \u0111\u1ea7y \u0111\u1ee7<\/li>\n<li>VIOX c\u1ea5p c\u00f4ng nghi\u1ec7p <a href=\"https:\/\/test.viox.com\/vi\/circuit-breaker-altitude-derating-guide\/\">b\u1ed9 ng\u1eaft m\u1ea1ch<\/a> k\u1ebft h\u1ee3p c\u00e1c \u0111\u1ecbnh m\u1ee9c b\u00f9 \u0111\u1ed9 cao l\u00ean \u0111\u1ebfn 4.000m<\/li>\n<\/ul>\n<p><strong>Ghi ch\u00fa:<\/strong> Thi\u1ebft b\u1ecb l\u00e0m m\u00e1t b\u1eb1ng ch\u1ea5t l\u1ecfng c\u00f3 th\u1ec3 b\u00f9 \u0111\u1eafp m\u1ed9t ph\u1ea7n \u1ea3nh h\u01b0\u1edfng c\u1ee7a \u0111\u1ed9 cao th\u00f4ng qua vi\u1ec7c gi\u1ea3m nhi\u1ec7t \u0111\u1ed9 ch\u1ea5t l\u00e0m m\u00e1t, nh\u01b0ng c\u00e1c h\u1ec7 th\u1ed1ng l\u00e0m m\u00e1t b\u1eb1ng kh\u00f4ng kh\u00ed y\u00eau c\u1ea7u tu\u00e2n th\u1ee7 nghi\u00eam ng\u1eb7t c\u00e1c b\u1ea3ng gi\u1ea3m \u0111\u1ecbnh m\u1ee9c.<\/p>\n<figure style=\"text-align: center; margin: 20px 0;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/Altitude-derating-factors-illustrated-through-atmospheric-pressure-reduction-and-its-impact-on-electrical-equipment-cooling-efficiency.webp\" alt=\"Altitude derating factors illustrated through atmospheric pressure reduction and its impact on electrical equipment cooling efficiency\" \/><figcaption style=\"font-style: italic; color: #555; margin-top: 8px;\">C\u00e1c y\u1ebfu t\u1ed1 gi\u1ea3m \u0111\u1ecbnh m\u1ee9c do \u0111\u1ed9 cao \u0111\u01b0\u1ee3c minh h\u1ecda th\u00f4ng qua vi\u1ec7c gi\u1ea3m \u00e1p su\u1ea5t kh\u00ed quy\u1ec3n v\u00e0 t\u00e1c \u0111\u1ed9ng c\u1ee7a n\u00f3 \u0111\u1ebfn hi\u1ec7u qu\u1ea3 l\u00e0m m\u00e1t c\u1ee7a thi\u1ebft b\u1ecb \u0111i\u1ec7n.<\/figcaption><\/figure>\n<h2>M\u1ee5c 3: Gi\u1ea3m \u0110\u1ecbnh M\u1ee9c Do Nh\u00f3m v\u00e0 B\u00f3 C\u00e1p<\/h2>\n<h3>\u1ea2nh H\u01b0\u1edfng Nhi\u1ec7t L\u1eabn Nhau Trong L\u1eafp \u0110\u1eb7t Nhi\u1ec1u C\u00e1p<\/h3>\n<p>Khi nhi\u1ec1u d\u00e2y d\u1eabn mang d\u00f2ng \u0111i\u1ec7n d\u00f9ng chung m\u1ed9t \u1ed1ng lu\u1ed3n d\u00e2y, m\u00e1ng c\u00e1p ho\u1eb7c r\u00e3nh ng\u1ea7m, ch\u00fang t\u1ea1o ra <strong>nhi\u1ec7t l\u1eabn nhau<\/strong> l\u00e0m suy gi\u1ea3m kh\u1ea3 n\u0103ng t\u1ea3n nhi\u1ec7t c\u1ee7a m\u1ed7i c\u00e1p. Hi\u1ec7n t\u01b0\u1ee3ng n\u00e0y \u0111\u00f2i h\u1ecfi ph\u1ea3i gi\u1ea3m \u0111\u1ecbnh m\u1ee9c m\u1ea1nh m\u1ebd theo B\u1ea3ng 310.15(C)(1) c\u1ee7a NEC v\u00e0 IEC 60364-5-52.<\/p>\n<p><strong>C\u00e1c y\u1ebfu t\u1ed1 gi\u1ea3m \u0111\u1ecbnh m\u1ee9c do nh\u00f3m (ti\u00eau chu\u1ea9n NEC\/IEC):<\/strong><\/p>\n<table style=\"border-collapse: collapse; width: 100%; margin-bottom: 20px;\" border=\"1\" cellpadding=\"8\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>S\u1ed1 L\u01b0\u1ee3ng D\u00e2y D\u1eabn Mang D\u00f2ng \u0110i\u1ec7n<\/th>\n<th>H\u1ec7 S\u1ed1 \u0110i\u1ec1u Ch\u1ec9nh<\/th>\n<th>T\u1ed5n Th\u1ea5t D\u00f2ng \u0110i\u1ec7n Hi\u1ec7u D\u1ee5ng<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>1-3<\/td>\n<td>1.00<\/td>\n<td>0%<\/td>\n<\/tr>\n<tr>\n<td>4-6<\/td>\n<td>0.80<\/td>\n<td>20%<\/td>\n<\/tr>\n<tr>\n<td>7-9<\/td>\n<td>0.70<\/td>\n<td>30%<\/td>\n<\/tr>\n<tr>\n<td>10-20<\/td>\n<td>0.50<\/td>\n<td>50%<\/td>\n<\/tr>\n<tr>\n<td>21-30<\/td>\n<td>0.45<\/td>\n<td>55%<\/td>\n<\/tr>\n<tr>\n<td>31-40<\/td>\n<td>0.40<\/td>\n<td>60%<\/td>\n<\/tr>\n<tr>\n<td>41+<\/td>\n<td>0.35<\/td>\n<td>65%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong>C\u00e1c c\u00e2n nh\u1eafc quan tr\u1ecdng:<\/strong><\/p>\n<ul>\n<li><strong>D\u00e2y trung t\u00ednh mang d\u00f2ng \u0111i\u1ec7n h\u00e0i \u0111\u01b0\u1ee3c t\u00ednh l\u00e0 d\u00e2y d\u1eabn mang d\u00f2ng \u0111i\u1ec7n<\/strong><\/li>\n<li>D\u00e2y n\u1ed1i \u0111\u1ea5t\/li\u00ean k\u1ebft kh\u00f4ng \u0111\u01b0\u1ee3c t\u00ednh v\u00e0o vi\u1ec7c gi\u1ea3m \u0111\u1ecbnh m\u1ee9c do nh\u00f3m<\/li>\n<li>C\u00e1p ho\u1ea1t \u0111\u1ed9ng \u1edf &lt;35% \u0111\u1ecbnh m\u1ee9c nh\u00f3m c\u1ee7a ch\u00fang c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c lo\u1ea1i tr\u1eeb kh\u1ecfi s\u1ed1 l\u01b0\u1ee3ng<\/li>\n<li>Chi\u1ec1u d\u00e0i nh\u00f3m ng\u1eafn (&lt;3m \u0111\u1ed1i v\u1edbi d\u00e2y d\u1eabn \u2265150mm\u00b2) c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c mi\u1ec5n gi\u1ea3m \u0111\u1ecbnh m\u1ee9c<\/li>\n<\/ul>\n<h3>T\u00e1c \u0110\u1ed9ng C\u1ee7a Ph\u01b0\u01a1ng Ph\u00e1p L\u1eafp \u0110\u1eb7t<\/h3>\n<p><strong>L\u1eafp \u0111\u1eb7t m\u00e1ng c\u00e1p<\/strong> (Ph\u01b0\u01a1ng Ph\u00e1p L\u1eafp \u0110\u1eb7t NEC 12\/13):<\/p>\n<ul>\n<li><strong>M\u1ed9t l\u1edbp, c\u00f3 kho\u1ea3ng c\u00e1ch:<\/strong> \u00c1p d\u1ee5ng h\u1ec7 s\u1ed1 nh\u00f3m cho s\u1ed1 l\u01b0\u1ee3ng m\u1ea1ch th\u1ef1c t\u1ebf<\/li>\n<li><strong>Nhi\u1ec1u l\u1edbp, ch\u1ea1m nhau:<\/strong> \u00c1p d\u1ee5ng h\u1ec7 s\u1ed1 0,70 cho 2 l\u1edbp, 0,60 cho 3+ l\u1edbp<\/li>\n<li><strong>M\u00e1ng c\u00f3 n\u1eafp \u0111\u1eady v\u1edbi th\u00f4ng gi\u00f3 h\u1ea1n ch\u1ebf:<\/strong> H\u1ec7 s\u1ed1 gi\u1ea3m b\u1ed5 sung 0,95<\/li>\n<\/ul>\n<p><strong>L\u1eafp \u0111\u1eb7t \u1ed1ng d\u1eabn ng\u1ea7m:<\/strong><\/p>\n<ul>\n<li><strong>H\u00ecnh tam gi\u00e1c (3 pha ch\u1ea1m nhau):<\/strong> H\u1ec7 s\u1ed1 0,80 cho m\u1ea1ch \u0111\u01a1n, 0,70 cho nhi\u1ec1u m\u1ea1ch<\/li>\n<li><strong>H\u00ecnh d\u1eb9t v\u1edbi kho\u1ea3ng c\u00e1ch 2\u00d7 \u0111\u01b0\u1eddng k\u00ednh:<\/strong> H\u1ec7 s\u1ed1 0,85<\/li>\n<li><strong>Nhi\u1ec1u \u1ed1ng d\u1eabn trong c\u00f9ng m\u1ed9t r\u00e3nh:<\/strong> H\u1ec7 s\u1ed1 0,70-0,60 t\u00f9y thu\u1ed9c v\u00e0o c\u1ea5u h\u00ecnh<\/li>\n<\/ul>\n<p>V\u00ec <a href=\"https:\/\/test.viox.com\/vi\/100a-panel-ev-charger-upgrade\/\">\u0110\u1ecbnh c\u1ee1 c\u00e1p s\u1ea1c EV<\/a>, vi\u1ec7c gi\u1ea3m \u0111\u1ecbnh m\u1ee9c do nh\u00f3m \u0111\u1eb7c bi\u1ec7t quan tr\u1ecdng trong c\u00e1c b\u00e3i \u0111\u1eadu xe, n\u01a1i nhi\u1ec1u b\u1ed9 s\u1ea1c 7kW ho\u1eb7c 22kW d\u00f9ng chung \u1ed1ng lu\u1ed3n d\u00e2y.<\/p>\n<figure style=\"text-align: center; margin: 20px 0;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/Multiple-power-cables-grouped-in-cable-tray-installation-requiring-ampacity-adjustment-factors-to-prevent-overheating-in-VIOX-electrical-distribution-system.webp\" alt=\"Multiple power cables grouped in cable tray installation requiring ampacity adjustment factors to prevent overheating in VIOX electrical distribution system\" \/><figcaption style=\"font-style: italic; color: #555; margin-top: 8px;\">Nhi\u1ec1u c\u00e1p ngu\u1ed3n \u0111\u01b0\u1ee3c nh\u00f3m trong l\u1eafp \u0111\u1eb7t m\u00e1ng c\u00e1p y\u00eau c\u1ea7u c\u00e1c h\u1ec7 s\u1ed1 \u0111i\u1ec1u ch\u1ec9nh d\u00f2ng \u0111i\u1ec7n \u0111\u1ec3 ng\u0103n ng\u1eeba qu\u00e1 nhi\u1ec7t trong h\u1ec7 th\u1ed1ng ph\u00e2n ph\u1ed1i \u0111i\u1ec7n VIOX.<\/figcaption><\/figure>\n<h2>M\u1ee5c 4: T\u00ednh To\u00e1n C\u00e1c Y\u1ebfu T\u1ed1 Gi\u1ea3m \u0110\u1ecbnh M\u1ee9c K\u1ebft H\u1ee3p<\/h2>\n<h3>Ph\u01b0\u01a1ng Ph\u00e1p Nh\u00e2n<\/h3>\n<p>Khi nhi\u1ec1u \u0111i\u1ec1u ki\u1ec7n gi\u1ea3m \u0111\u1ecbnh m\u1ee9c t\u1ed3n t\u1ea1i \u0111\u1ed3ng th\u1eddi, c\u00e1c y\u1ebfu t\u1ed1 \u0111\u01b0\u1ee3c <strong>nh\u00e2n v\u1edbi nhau<\/strong> \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh d\u00f2ng \u0111i\u1ec7n \u0111i\u1ec1u ch\u1ec9nh cu\u1ed1i c\u00f9ng:<\/p>\n<p><strong>C\u00f4ng Th\u1ee9c T\u1ed5ng Qu\u00e1t:<\/strong><\/p>\n<pre style=\"background: #f4f4f4; padding: 10px; border-radius: 4px; overflow-x: auto;\">D\u00f2ng \u0110i\u1ec7n \u0110i\u1ec1u Ch\u1ec9nh = D\u00f2ng \u0110i\u1ec7n C\u01a1 B\u1ea3n \u00d7 H\u1ec7 S\u1ed1 Nhi\u1ec7t \u0110\u1ed9 \u00d7 H\u1ec7 S\u1ed1 \u0110\u1ed9 Cao \u00d7 H\u1ec7 S\u1ed1 Nh\u00f3m \u00d7 H\u1ec7 S\u1ed1 L\u1eafp \u0110\u1eb7t<\/pre>\n<p><strong>Quy tr\u00ecnh t\u00ednh to\u00e1n t\u1eebng b\u01b0\u1edbc:<\/strong><\/p>\n<ol>\n<li><strong>X\u00e1c \u0111\u1ecbnh d\u00f2ng \u0111i\u1ec7n c\u01a1 b\u1ea3n<\/strong> t\u1eeb B\u1ea3ng 310.16 c\u1ee7a NEC ho\u1eb7c b\u1ea3ng d\u00e2y d\u1eabn IEC (s\u1eed d\u1ee5ng c\u1ed9t 75\u00b0C ho\u1eb7c 90\u00b0C d\u1ef1a tr\u00ean \u0111\u1ecbnh m\u1ee9c \u0111\u1ea7u n\u1ed1i theo NEC 110.14(C))<\/li>\n<li><strong>X\u00e1c \u0111\u1ecbnh t\u1ea5t c\u1ea3 c\u00e1c y\u1ebfu t\u1ed1 gi\u1ea3m \u0111\u1ecbnh m\u1ee9c \u00e1p d\u1ee5ng<\/strong> cho c\u00e0i \u0111\u1eb7t c\u1ee5 th\u1ec3 c\u1ee7a b\u1ea1n<\/li>\n<li><strong>Nh\u00e2n c\u00e1c y\u1ebfu t\u1ed1 v\u1edbi nhau<\/strong> \u0111\u1ec3 c\u00f3 \u0111\u01b0\u1ee3c m\u1ee9c gi\u1ea3m t\u00edch l\u0169y<\/li>\n<li><strong>T\u00ednh to\u00e1n d\u00f2ng \u0111i\u1ec7n \u0111i\u1ec1u ch\u1ec9nh<\/strong> v\u00e0 so s\u00e1nh v\u1edbi y\u00eau c\u1ea7u t\u1ea3i<\/li>\n<li><strong>N\u1ebfu d\u00f2ng \u0111i\u1ec7n \u0111i\u1ec1u ch\u1ec9nh &lt; d\u00f2ng \u0111i\u1ec7n y\u00eau c\u1ea7u, h\u00e3y t\u0103ng k\u00edch th\u01b0\u1edbc d\u00e2y d\u1eabn v\u00e0 t\u00ednh to\u00e1n l\u1ea1i<\/strong><\/li>\n<\/ol>\n<h3>V\u00ed d\u1ee5 Th\u1ef1c T\u1ebf: H\u1ed9p K\u1ebft H\u1ee3p DC M\u1ea3ng N\u0103ng L\u01b0\u1ee3ng M\u1eb7t Tr\u1eddi<\/h3>\n<p><strong>K\u1ecbch b\u1ea3n:<\/strong> 8 chu\u1ed7i n\u0103ng l\u01b0\u1ee3ng m\u1eb7t tr\u1eddi c\u1ea5p v\u00e0o h\u1ed9p k\u1ebft h\u1ee3p tr\u00ean m\u00e1i nh\u00e0 trong \u0111i\u1ec1u ki\u1ec7n m\u00f9a h\u00e8 \u1edf Arizona<\/p>\n<p><strong>C\u00e1c th\u00f4ng s\u1ed1 \u0111\u00e3 cho:<\/strong><\/p>\n<ul>\n<li>D\u00f2ng \u0111i\u1ec7n t\u1ea3i: 64A (8 chu\u1ed7i \u00d7 8A m\u1ed7i chu\u1ed7i)<\/li>\n<li>D\u00e2y d\u1eabn c\u01a1 b\u1ea3n: \u0110\u1ed3ng 4 AWG THHN (85A @ 75\u00b0C, 95A @ 90\u00b0C)<\/li>\n<li>Nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng: 50\u00b0C (ti\u1ebfp x\u00fac tr\u00ean m\u00e1i nh\u00e0)<\/li>\n<li>\u0110\u1ed9 cao: 1.100 m\u00e9t<\/li>\n<li>S\u1ed1 l\u01b0\u1ee3ng d\u00e2y d\u1eabn mang d\u00f2ng \u0111i\u1ec7n: 16 (8 d\u01b0\u01a1ng + 8 \u00e2m)<\/li>\n<li>L\u1eafp \u0111\u1eb7t: M\u00e1ng c\u00e1p, m\u1ed9t l\u1edbp<\/li>\n<\/ul>\n<p><strong>T\u00ednh to\u00e1n:<\/strong><\/p>\n<pre style=\"background: #f4f4f4; padding: 10px; border-radius: 4px; overflow-x: auto;\">D\u00f2ng \u0111i\u1ec7n c\u01a1 b\u1ea3n (90\u00b0C): 95A\n<\/pre>\n<p><strong>K\u1ebft qu\u1ea3:<\/strong> 4 AWG l\u00e0 <strong>kh\u00f4ng \u0111\u1ee7<\/strong> (38,7A &lt; 64A y\u00eau c\u1ea7u). Th\u1eed 1\/0 AWG (150A c\u01a1 b\u1ea3n):<\/p>\n<pre style=\"background: #f4f4f4; padding: 10px; border-radius: 4px; overflow-x: auto;\">C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n \u0111i\u1ec1u ch\u1ec9nh = 150A \u00d7 0.82 \u00d7 0.99 \u00d7 0.50 = 60.8A<\/pre>\n<p><strong>V\u1eabn kh\u00f4ng \u0111\u1ee7.<\/strong> Gi\u1ea3i ph\u00e1p cu\u1ed1i c\u00f9ng: <strong>2\/0 AWG<\/strong> (N\u1ec1n 175A):<\/p>\n<pre style=\"background: #f4f4f4; padding: 10px; border-radius: 4px; overflow-x: auto;\">C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n \u0111i\u1ec1u ch\u1ec9nh = 175A \u00d7 0.82 \u00d7 0.99 \u00d7 0.50 = 70.9A \u2713<\/pre>\n<p>V\u00ed d\u1ee5 n\u00e0y cho th\u1ea5y l\u00fd do t\u1ea1i sao d\u00e2y d\u1eabn c\u00f3 k\u00edch th\u01b0\u1edbc nh\u1ecf h\u01a1n th\u01b0\u1eddng th\u1ea5y trong c\u00e1c h\u1ec7 th\u1ed1ng n\u0103ng l\u01b0\u1ee3ng m\u1eb7t tr\u1eddi\u2014c\u00e1c h\u1ec7 s\u1ed1 suy gi\u1ea3m c\u00f3 th\u1ec3 l\u00e0m gi\u1ea3m c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n xu\u1ed1ng <strong>60% tr\u1edf l\u00ean<\/strong> trong \u0111i\u1ec1u ki\u1ec7n kh\u1eafc nghi\u1ec7t.<\/p>\n<h3>V\u00ed d\u1ee5 v\u1ec1 Tr\u1ea1m S\u1ea1c EV Th\u01b0\u01a1ng M\u1ea1i<\/h3>\n<p><strong>K\u1ecbch b\u1ea3n:<\/strong> \u0110\u01b0\u1eddng d\u00e2y c\u1ea5p ngu\u1ed3n ng\u1ea7m cho tr\u1ea1m s\u1ea1c EV C\u1ea5p 2 22kW<\/p>\n<p><strong>C\u00e1c th\u00f4ng s\u1ed1 \u0111\u00e3 cho:<\/strong><\/p>\n<ul>\n<li>D\u00f2ng \u0111i\u1ec7n t\u1ea3i: 96A (ba b\u1ed9 s\u1ea1c 32A)<\/li>\n<li>D\u00e2y d\u1eabn: \u0110\u1ed3ng 3 AWG XHHW-2 (115A @ 75\u00b0C, 130A @ 90\u00b0C)<\/li>\n<li>Nhi\u1ec7t \u0111\u1ed9 \u0111\u1ea5t: 30\u00b0C<\/li>\n<li>\u0110\u1ed9 s\u00e2u ch\u00f4n: 0.8m<\/li>\n<li>S\u1ed1 l\u01b0\u1ee3ng m\u1ea1ch trong r\u00e3nh: 1 (3 d\u00e2y d\u1eabn + d\u00e2y n\u1ed1i \u0111\u1ea5t)<\/li>\n<li>H\u1ec7 s\u1ed1 t\u1ea3i li\u00ean t\u1ee5c: 1.25 (NEC 625.41 y\u00eau c\u1ea7u k\u00edch th\u01b0\u1edbc 125% cho thi\u1ebft b\u1ecb EV)<\/li>\n<\/ul>\n<p><strong>T\u00ednh to\u00e1n:<\/strong><\/p>\n<pre style=\"background: #f4f4f4; padding: 10px; border-radius: 4px; overflow-x: auto;\">C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n c\u01a1 b\u1ea3n (90\u00b0C): 130A\n<\/pre>\n<p><strong>K\u1ebft qu\u1ea3:<\/strong> 3 AWG l\u00e0 <strong>kh\u00f4ng \u0111\u1ee7<\/strong> (114.8A &lt; 120A). Gi\u1ea3i ph\u00e1p: <strong>2 AWG<\/strong> (N\u1ec1n 150A):<\/p>\n<pre style=\"background: #f4f4f4; padding: 10px; border-radius: 4px; overflow-x: auto;\">C\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n \u0111i\u1ec1u ch\u1ec9nh = 150A \u00d7 0.92 \u00d7 0.96 = 132.5A \u2713<\/pre>\n<p>Hi\u1ec3u bi\u1ebft <a href=\"https:\/\/test.viox.com\/vi\/cable-size-types-mm-awg-bs-conversion-guide\/\">k\u00edch th\u01b0\u1edbc b\u1ed9 ng\u1eaft m\u1ea1ch ph\u00f9 h\u1ee3p cho b\u1ed9 s\u1ea1c EV<\/a> y\u00eau c\u1ea7u ph\u1ed1i h\u1ee3p c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n c\u1ee7a d\u00e2y d\u1eabn v\u1edbi \u0111\u1ecbnh m\u1ee9c OCPD sau khi \u00e1p d\u1ee5ng t\u1ea5t c\u1ea3 c\u00e1c h\u1ec7 s\u1ed1 suy gi\u1ea3m.<\/p>\n<figure style=\"text-align: center; margin: 20px 0;\"><img decoding=\"async\" style=\"max-width: 100%; height: auto;\" src=\"https:\/\/img.viox.com\/Cable-sizing-calculation-flowchart-showing-systematic-application-of-temperature-altitude-and-grouping-derating-factors-per-NEC-and-IEC-standards.webp\" alt=\"Cable sizing calculation flowchart showing systematic application of temperature, altitude, and grouping derating factors per NEC and IEC standards\" \/><figcaption style=\"font-style: italic; color: #555; margin-top: 8px;\">L\u01b0u \u0111\u1ed3 t\u00ednh to\u00e1n k\u00edch th\u01b0\u1edbc c\u00e1p cho th\u1ea5y \u1ee9ng d\u1ee5ng c\u00f3 h\u1ec7 th\u1ed1ng c\u00e1c h\u1ec7 s\u1ed1 suy gi\u1ea3m nhi\u1ec7t \u0111\u1ed9, \u0111\u1ed9 cao v\u00e0 nh\u00f3m theo ti\u00eau chu\u1ea9n NEC v\u00e0 IEC.<\/figcaption><\/figure>\n<h2>B\u1ea3ng Tham Kh\u1ea3o Nhanh v\u1ec1 H\u1ec7 S\u1ed1 Suy Gi\u1ea3m<\/h2>\n<h3>Suy Gi\u1ea3m K\u1ebft H\u1ee3p Nhi\u1ec7t \u0110\u1ed9 v\u00e0 Nh\u00f3m<\/h3>\n<table style=\"border-collapse: collapse; width: 100%; margin-bottom: 20px;\" border=\"1\" cellpadding=\"8\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>K\u1ecbch b\u1ea3n<\/th>\n<th>H\u1ec7 S\u1ed1 Nhi\u1ec7t \u0110\u1ed9<\/th>\n<th>H\u1ec7 S\u1ed1 Nh\u00f3m<\/th>\n<th>K\u1ebft h\u1ee3p<\/th>\n<th>V\u00ed d\u1ee5: N\u1ec1n 100A \u2192 C\u01b0\u1eddng \u0110\u1ed9 D\u00f2ng \u0110i\u1ec7n Cu\u1ed1i C\u00f9ng<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>3 c\u00e1p, 30\u00b0C<\/td>\n<td>1.00<\/td>\n<td>1.00<\/td>\n<td>1.00<\/td>\n<td>100<\/td>\n<\/tr>\n<tr>\n<td>6 c\u00e1p, 40\u00b0C<\/td>\n<td>0.91<\/td>\n<td>0.80<\/td>\n<td>0.73<\/td>\n<td>73A<\/td>\n<\/tr>\n<tr>\n<td>9 c\u00e1p, 50\u00b0C<\/td>\n<td>0.82<\/td>\n<td>0.70<\/td>\n<td>0.57<\/td>\n<td>57A<\/td>\n<\/tr>\n<tr>\n<td>15 c\u00e1p, 50\u00b0C + \u0111\u1ed9 cao 2000m<\/td>\n<td>0.82<\/td>\n<td>0.50<\/td>\n<td>0.39*<\/td>\n<td>39A<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><em>*Bao g\u1ed3m h\u1ec7 s\u1ed1 \u0111\u1ed9 cao 0.94 (0.82 \u00d7 0.50 \u00d7 0.94 = 0.385)<\/em><\/p>\n<h3>So S\u00e1nh \u0110\u1ecbnh M\u1ee9c C\u01a1 B\u1ea3n c\u1ee7a Ph\u01b0\u01a1ng Ph\u00e1p L\u1eafp \u0110\u1eb7t<\/h3>\n<table style=\"border-collapse: collapse; width: 100%; margin-bottom: 20px;\" border=\"1\" cellpadding=\"8\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th>Ph\u01b0\u01a1ng ph\u00e1p c\u00e0i \u0111\u1eb7t<\/th>\n<th>C\u01b0\u1eddng \u0110\u1ed9 D\u00f2ng \u0110i\u1ec7n T\u01b0\u01a1ng \u0110\u1ed1i<\/th>\n<th>\u0110i\u1ec3n H\u00ecnh \u1ee8ng D\u1ee5ng<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>C\u00e1p \u0111\u01a1n trong kh\u00f4ng kh\u00ed t\u1ef1 do<\/td>\n<td>1.00 (cao nh\u1ea5t)<\/td>\n<td>Nh\u1ecbp tr\u00ean kh\u00f4ng, thi\u1ebft l\u1eadp th\u1eed nghi\u1ec7m<\/td>\n<\/tr>\n<tr>\n<td>K\u1eb9p tr\u1ef1c ti\u1ebfp v\u00e0o b\u1ec1 m\u1eb7t<\/td>\n<td>0.95<\/td>\n<td>T\u01b0\u1eddng c\u00f4ng nghi\u1ec7p, l\u1eafp \u0111\u1eb7t k\u1ebft c\u1ea5u<\/td>\n<\/tr>\n<tr>\n<td>Trong \u1ed1ng d\u1eabn\/m\u00e1ng c\u00e1p (1-3 c\u00e1p)<\/td>\n<td>0.80<\/td>\n<td>H\u1ec7 th\u1ed1ng d\u00e2y \u0111i\u1ec7n t\u00f2a nh\u00e0, \u0111\u01b0\u1eddng ch\u1ea1y \u0111\u01b0\u1ee3c b\u1ea3o v\u1ec7<\/td>\n<\/tr>\n<tr>\n<td>M\u00e1ng c\u00e1p, l\u1edbp \u0111\u01a1n<\/td>\n<td>0.75<\/td>\n<td>Ph\u00f2ng ti\u1ec7n \u00edch, trung t\u00e2m d\u1eef li\u1ec7u<\/td>\n<\/tr>\n<tr>\n<td>Ch\u00f4n tr\u1ef1c ti\u1ebfp xu\u1ed1ng \u0111\u1ea5t<\/td>\n<td>0.70<\/td>\n<td>Ph\u00e2n ph\u1ed1i ng\u1ea7m<\/td>\n<\/tr>\n<tr>\n<td>Trong \u1ed1ng ng\u1ea7m<\/td>\n<td>0.65<\/td>\n<td>Truy\u1ec1n t\u1ea3i \u0111\u01b0\u1eddng d\u00e0i<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Nh\u1eefng C\u00e2u H\u1ecfi Th\u01b0\u1eddng<\/h2>\n<p><strong>Q1: T\u00f4i c\u00f3 c\u1ea7n \u00e1p d\u1ee5ng c\u00e1c h\u1ec7 s\u1ed1 suy gi\u1ea3m n\u1ebfu c\u00e1p c\u1ee7a t\u00f4i ho\u1ea1t \u0111\u1ed9ng d\u01b0\u1edbi c\u00f4ng su\u1ea5t \u0111\u1ecbnh m\u1ee9c c\u1ee7a n\u00f3 kh\u00f4ng?<\/strong><\/p>\n<p>\u0110\u00fang v\u1eady, h\u1ec7 s\u1ed1 suy gi\u1ea3m l\u00e0 b\u1eaft bu\u1ed9c \u00e1p d\u1ee5ng b\u1ea5t k\u1ec3 ph\u1ea7n tr\u0103m t\u1ea3i. Ch\u00fang \u0111i\u1ec1u ch\u1ec9nh kh\u1ea3 n\u0103ng ch\u1ecbu t\u1ea3i an to\u00e0n t\u1ed1i \u0111a c\u1ee7a d\u00e2y d\u1eabn d\u1ef1a tr\u00ean c\u00e1c \u0111i\u1ec1u ki\u1ec7n m\u00f4i tr\u01b0\u1eddng. Ngo\u1ea1i l\u1ec7 duy nh\u1ea5t l\u00e0 c\u00e1c c\u00e1p ho\u1ea1t \u0111\u1ed9ng d\u01b0\u1edbi 35% \u0111\u1ecbnh m\u1ee9c khi \u0111i chung tr\u00ean m\u1ed9t \u0111o\u1ea1n ng\u1eafn (&lt;3m), c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c lo\u1ea1i tr\u1eeb kh\u1ecfi vi\u1ec7c t\u00ednh s\u1ed1 l\u01b0\u1ee3ng nh\u00f3m theo ti\u00eau chu\u1ea9n IEC 60364-5-52.<\/p>\n<p><strong>Q2: T\u00f4i c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng c\u1ed9t c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n 90\u00b0C cho d\u00e2y THHN n\u1ebfu n\u00f3 k\u1ebft th\u00fac tr\u00ean b\u1ed9 ng\u1eaft m\u1ea1ch \u0111\u1ecbnh m\u1ee9c 75\u00b0C kh\u00f4ng?<\/strong><\/p>\n<p>Kh\u00f4ng ph\u1ea3i cho quy\u1ebft \u0111\u1ecbnh \u0111\u1ecbnh c\u1ee1 cu\u1ed1i c\u00f9ng. NEC 110.14(C) y\u00eau c\u1ea7u s\u1eed d\u1ee5ng \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t \u0111\u1ed9 \u0111\u1ea7u cu\u1ed1i th\u1ea5p h\u01a1n (75\u00b0C) cho c\u00e1c m\u1ea1ch \u2264100A tr\u1eeb khi thi\u1ebft b\u1ecb \u0111\u01b0\u1ee3c li\u1ec7t k\u00ea c\u1ee5 th\u1ec3 cho 90\u00b0C. Tuy nhi\u00ean, b\u1ea1n <strong>n\u00ean<\/strong> s\u1eed d\u1ee5ng c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n c\u01a1 b\u1ea3n 90\u00b0C khi \u00e1p d\u1ee5ng c\u00e1c h\u1ec7 s\u1ed1 suy gi\u1ea3m, sau \u0111\u00f3 x\u00e1c minh k\u1ebft qu\u1ea3 \u0111\u00e3 suy gi\u1ea3m kh\u00f4ng v\u01b0\u1ee3t qu\u00e1 \u0111\u1ecbnh m\u1ee9c 75\u00b0C. C\u00e1ch ti\u1ebfp c\u1eadn n\u00e0y t\u1ed1i \u0111a h\u00f3a c\u00f4ng su\u1ea5t d\u00e2y d\u1eabn \u0111\u1ed3ng th\u1eddi \u0111\u1ea3m b\u1ea3o k\u1ebft n\u1ed1i an to\u00e0n.<\/p>\n<p><strong>Q3: L\u00e0m c\u00e1ch n\u00e0o \u0111\u1ec3 x\u1eed l\u00fd c\u00e1c \u0111i\u1ec1u ki\u1ec7n suy gi\u1ea3m h\u1ed7n h\u1ee3p, ch\u1eb3ng h\u1ea1n nh\u01b0 c\u00e1p m\u1ed9t ph\u1ea7n \u0111\u01b0\u1ee3c ch\u00f4n v\u00e0 m\u1ed9t ph\u1ea7n trong kh\u00f4ng kh\u00ed?<\/strong><\/p>\n<p>\u00c1p d\u1ee5ng <strong>h\u1ea1n ch\u1ebf nh\u1ea5t<\/strong> h\u1ec7 s\u1ed1 suy gi\u1ea3m cho \u0111o\u1ea1n l\u1eafp \u0111\u1eb7t t\u1ea1o th\u00e0nh n\u00fat th\u1eaft nhi\u1ec7t. V\u00ed d\u1ee5: n\u1ebfu 80% \u0111\u01b0\u1eddng ch\u1ea1y c\u00e1p \u1edf trong kh\u00f4ng kh\u00ed t\u1ef1 do nh\u01b0ng 20% \u0111i qua l\u1edbp c\u00e1ch nhi\u1ec7t, th\u00ec to\u00e0n b\u1ed9 m\u1ea1ch ph\u1ea3i \u0111\u01b0\u1ee3c suy gi\u1ea3m cho ph\u1ea7n c\u00e1ch nhi\u1ec7t. Th\u1ef1c h\u00e0nh k\u1ef9 thu\u1eadt b\u1ea3o th\u1ee7 l\u00e0 lu\u00f4n s\u1eed d\u1ee5ng c\u00e1c \u0111i\u1ec1u ki\u1ec7n x\u1ea5u nh\u1ea5t cho to\u00e0n b\u1ed9 chi\u1ec1u d\u00e0i m\u1ea1ch.<\/p>\n<p><strong>Q4: C\u00f3 ngo\u1ea1i l\u1ec7 n\u00e0o cho c\u00e1c \u0111o\u1ea1n c\u00e1p ng\u1eafn kh\u00f4ng y\u00eau c\u1ea7u suy gi\u1ea3m ho\u00e0n to\u00e0n kh\u00f4ng?<\/strong><\/p>\n<p>C\u00f3. NEC cho ph\u00e9p mi\u1ec5n tr\u1eeb cho <strong>\u0111o\u1ea1n \u1ed1ng ng\u1eafn<\/strong> (c\u00e1c \u0111o\u1ea1n \u1ed1ng ng\u1eafn \u2264600mm) ch\u1ee9a b\u1ea5t k\u1ef3 s\u1ed1 l\u01b0\u1ee3ng d\u00e2y d\u1eabn n\u00e0o. IEC 60364-5-52 cho ph\u00e9p b\u1ecf qua vi\u1ec7c suy gi\u1ea3m nh\u00f3m \u0111\u1ed1i v\u1edbi chi\u1ec1u d\u00e0i c\u00e1p d\u01b0\u1edbi 1m \u0111\u1ed1i v\u1edbi d\u00e2y d\u1eabn &lt;150mm\u00b2 ho\u1eb7c 3m \u0111\u1ed1i v\u1edbi d\u00e2y d\u1eabn \u2265150mm\u00b2. Tuy nhi\u00ean, vi\u1ec7c suy gi\u1ea3m nhi\u1ec7t \u0111\u1ed9 v\u00e0 \u0111\u1ed9 cao lu\u00f4n \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng b\u1ea5t k\u1ec3 chi\u1ec1u d\u00e0i c\u00e1p.<\/p>\n<p><strong>Q5: Nh\u1eefng h\u1ec7 s\u1ed1 suy gi\u1ea3m n\u00e0o \u00e1p d\u1ee5ng cho c\u00e1p c\u00e1ch \u0111i\u1ec7n kho\u00e1ng (MI)?<\/strong><\/p>\n<p>C\u00e1p MI (c\u1ea5u tr\u00fac MIMS) c\u00f3 hi\u1ec7u su\u1ea5t nhi\u1ec7t v\u01b0\u1ee3t tr\u1ed9i v\u00e0 th\u01b0\u1eddng kh\u00f4ng y\u00eau c\u1ea7u <strong>kh\u00f4ng suy gi\u1ea3m<\/strong> \u0111\u1ec3 nh\u00f3m khi kh\u00f4ng ti\u1ebfp x\u00fac v\u1edbi c\u00e1c lo\u1ea1i c\u00e1p kh\u00e1c. Tuy nhi\u00ean, v\u1eabn \u00e1p d\u1ee5ng vi\u1ec7c gi\u1ea3m \u0111\u1ecbnh m\u1ee9c theo nhi\u1ec7t \u0111\u1ed9 v\u00e0 \u0111\u1ed9 cao. Tham kh\u1ea3o th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt c\u1ee7a nh\u00e0 s\u1ea3n xu\u1ea5t v\u00e0 AS\/NZS 3008.1 ho\u1eb7c IEC 60702 \u0111\u1ec3 \u0111\u01b0\u1ee3c h\u01b0\u1edbng d\u1eabn c\u1ee5 th\u1ec3 v\u1ec1 d\u00e2y d\u1eabn c\u00e1ch \u0111i\u1ec7n b\u1eb1ng kho\u00e1ng ch\u1ea5t.<\/p>\n<p><strong>C\u00e2u 6: S\u00f3ng h\u00e0i \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn y\u00eau c\u1ea7u gi\u1ea3m \u0111\u1ecbnh m\u1ee9c nh\u01b0 th\u1ebf n\u00e0o?<\/strong><\/p>\n<p><strong>D\u00f2ng \u0111i\u1ec7n h\u00e0i b\u1eadc ba<\/strong> trong d\u00e2y trung t\u00ednh t\u1ea1o ra t\u1ed5n th\u1ea5t I\u00b2R b\u1ed5 sung, y\u00eau c\u1ea7u d\u00e2y trung t\u00ednh ph\u1ea3i \u0111\u01b0\u1ee3c t\u00ednh l\u00e0 d\u00e2y d\u1eabn mang d\u00f2ng \u0111i\u1ec7n cho m\u1ee5c \u0111\u00edch gi\u1ea3m \u0111\u1ecbnh m\u1ee9c theo nh\u00f3m. Trong c\u00e1c h\u1ec7 th\u1ed1ng l\u1eafp \u0111\u1eb7t c\u00f3 t\u1ea3i phi tuy\u1ebfn \u0111\u00e1ng k\u1ec3 (VFD, tr\u00ecnh \u0111i\u1ec1u khi\u1ec3n LED, ch\u1ea5n l\u01b0u \u0111i\u1ec7n t\u1eed), h\u00e0m l\u01b0\u1ee3ng d\u00f2ng \u0111i\u1ec7n h\u00e0i c\u00f3 th\u1ec3 \u0111\u00f2i h\u1ecfi d\u00e2y trung t\u00ednh c\u00f3 k\u00edch th\u01b0\u1edbc b\u1eb1ng 200% d\u00e2y pha v\u00e0 c\u00e1c \u0111i\u1ec1u ch\u1ec9nh gi\u1ea3m \u0111\u1ecbnh m\u1ee9c t\u01b0\u01a1ng \u1ee9ng.<\/p>\n<p><strong>C\u00e2u 7: T\u00f4i c\u00f3 th\u1ec3 b\u00f9 cho nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng cao b\u1eb1ng c\u00e1ch t\u0103ng k\u00edch th\u01b0\u1edbc d\u00e2y d\u1eabn thay v\u00ec \u00e1p d\u1ee5ng c\u00e1c h\u1ec7 s\u1ed1 gi\u1ea3m \u0111\u1ecbnh m\u1ee9c kh\u00f4ng?<\/strong><\/p>\n<p>Kh\u00f4ng. B\u1ea1n ph\u1ea3i <strong>lu\u00f4n \u00e1p d\u1ee5ng c\u00e1c h\u1ec7 s\u1ed1 gi\u1ea3m \u0111\u1ecbnh m\u1ee9c th\u00edch h\u1ee3p<\/strong> \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh d\u00f2ng \u0111i\u1ec7n \u0111\u1ecbnh m\u1ee9c \u0111\u00e3 \u0111i\u1ec1u ch\u1ec9nh c\u1ee7a d\u00e2y d\u1eabn, sau \u0111\u00f3 ch\u1ecdn k\u00edch th\u01b0\u1edbc d\u00e2y d\u1eabn m\u00e0 d\u00f2ng \u0111i\u1ec7n \u0111\u1ecbnh m\u1ee9c \u0111\u00e3 \u0111i\u1ec1u ch\u1ec9nh \u0111\u00e1p \u1ee9ng ho\u1eb7c v\u01b0\u1ee3t qu\u00e1 y\u00eau c\u1ea7u t\u1ea3i. \u0110\u01a1n gi\u1ea3n ch\u1ec9 c\u1ea7n t\u0103ng k\u00edch th\u01b0\u1edbc m\u00e0 kh\u00f4ng t\u00ednh to\u00e1n \u0111\u00fang c\u00e1ch s\u1ebd vi ph\u1ea1m ph\u01b0\u01a1ng ph\u00e1p NEC v\u00e0 v\u1eabn c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn d\u00e2y d\u1eabn b\u1ecb thi\u1ebfu k\u00edch th\u01b0\u1edbc. C\u00e1c h\u1ec7 s\u1ed1 gi\u1ea3m \u0111\u1ecbnh m\u1ee9c t\u00ednh \u0111\u1ebfn c\u00e1c gi\u1edbi h\u1ea1n nhi\u1ec7t d\u1ef1a tr\u00ean v\u1eadt l\u00fd kh\u00f4ng th\u1ec3 b\u1ecf qua.<\/p>\n<h2>K\u1ebft lu\u1eadn: S\u1ef1 xu\u1ea5t s\u1eafc trong k\u1ef9 thu\u1eadt th\u00f4ng qua vi\u1ec7c gi\u1ea3m \u0111\u1ecbnh m\u1ee9c th\u00edch h\u1ee3p<\/h2>\n<p>T\u00ednh to\u00e1n gi\u1ea3m \u0111\u1ecbnh m\u1ee9c ch\u00ednh x\u00e1c l\u00e0 \u0111i\u1ec1u ki\u1ec7n ti\u00ean quy\u1ebft cho an to\u00e0n \u0111i\u1ec7n, tu\u00e2n th\u1ee7 quy chu\u1ea9n v\u00e0 tu\u1ed5i th\u1ecd h\u1ec7 th\u1ed1ng. C\u00e1c v\u00ed d\u1ee5 trong h\u01b0\u1edbng d\u1eabn n\u00e0y ch\u1ee9ng minh r\u1eb1ng c\u00e1c h\u1ec7 th\u1ed1ng l\u1eafp \u0111\u1eb7t th\u1ef1c t\u1ebf th\u01b0\u1eddng ph\u1ea3i \u0111\u1ed1i m\u1eb7t v\u1edbi vi\u1ec7c gi\u1ea3m d\u00f2ng \u0111i\u1ec7n \u0111\u1ecbnh m\u1ee9c t\u1eeb 40-60% so v\u1edbi c\u00e1c gi\u00e1 tr\u1ecb b\u1ea3ng ti\u00eau chu\u1ea9n\u2014m\u1ed9t th\u1ef1c t\u1ebf \u0111\u00f2i h\u1ecfi ph\u00e2n t\u00edch k\u1ef9 thu\u1eadt nghi\u00eam ng\u1eb7t.<\/p>\n<p><strong>C\u00e1c ph\u01b0\u01a1ng ph\u00e1p hay nh\u1ea5t cho c\u00e1c h\u1ec7 th\u1ed1ng l\u1eafp \u0111\u1eb7t chuy\u00ean nghi\u1ec7p:<\/strong><\/p>\n<ul>\n<li><strong>Lu\u00f4n s\u1eed d\u1ee5ng \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t \u0111\u1ed9 d\u00e2y d\u1eabn cao nh\u1ea5t<\/strong> (90\u00b0C) l\u00e0m \u0111i\u1ec3m kh\u1edfi \u0111\u1ea7u cho c\u00e1c t\u00ednh to\u00e1n gi\u1ea3m \u0111\u1ecbnh m\u1ee9c<\/li>\n<li><strong>X\u00e1c minh \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t \u0111\u1ed9 \u0111\u1ea7u cu\u1ed1i<\/strong> v\u00e0 \u0111i\u1ec1u ch\u1ec9nh c\u00e1c l\u1ef1a ch\u1ecdn cu\u1ed1i c\u00f9ng theo NEC 110.14(C)<\/li>\n<li><strong>Ghi l\u1ea1i t\u1ea5t c\u1ea3 c\u00e1c h\u1ec7 s\u1ed1 gi\u1ea3m \u0111\u1ecbnh m\u1ee9c<\/strong> \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng trong c\u00e1c t\u00ednh to\u00e1n c\u1ee7a b\u1ea1n \u0111\u1ec3 tu\u00e2n th\u1ee7 ki\u1ec3m tra<\/li>\n<li><strong>Xem x\u00e9t t\u1ea3i trong t\u01b0\u01a1ng lai<\/strong> v\u00e0 \u00e1p d\u1ee5ng h\u1ec7 s\u1ed1 t\u1ea3i li\u00ean t\u1ee5c 125% khi c\u00f3 th\u1ec3 \u00e1p d\u1ee5ng<\/li>\n<li><strong>Ch\u1ec9 \u0111\u1ecbnh b\u1ea3o v\u1ec7 m\u1ea1ch ch\u1ea5t l\u01b0\u1ee3ng<\/strong> t\u1eeb c\u00e1c nh\u00e0 s\u1ea3n xu\u1ea5t nh\u01b0 VIOX, nh\u1eefng ng\u01b0\u1eddi cung c\u1ea5p x\u1ebfp h\u1ea1ng b\u00f9 \u0111\u1ed9 cao v\u00e0 \u0111\u1ed9 ch\u00ednh x\u00e1c t\u1eeb t\u00ednh nhi\u1ec7t<\/li>\n<\/ul>\n<p>D\u00f2ng s\u1ea3n ph\u1ea9m to\u00e0n di\u1ec7n c\u1ee7a VIOX Electric v\u1ec1 <a href=\"https:\/\/test.viox.com\/vi\/what-is-a-molded-case-circuit-breaker-mccb\/\">c\u1ea7u dao c\u00f4ng nghi\u1ec7p v\u00e0 thi\u1ebft b\u1ecb b\u1ea3o v\u1ec7<\/a> \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf v\u1edbi c\u00e1c h\u1ec7 th\u1ed1ng qu\u1ea3n l\u00fd nhi\u1ec7t duy tr\u00ec hi\u1ec7u su\u1ea5t tr\u00ean c\u00e1c ph\u1ea1m vi nhi\u1ec7t \u0111\u1ed9 t\u1eeb -40\u00b0C \u0111\u1ebfn +70\u00b0C v\u00e0 \u0111\u1ed9 cao l\u00ean \u0111\u1ebfn 4.000 m\u00e9t. Nh\u00f3m h\u1ed7 tr\u1ee3 k\u1ef9 thu\u1eadt c\u1ee7a ch\u00fang t\u00f4i cung c\u1ea5p h\u01b0\u1edbng d\u1eabn gi\u1ea3m \u0111\u1ecbnh m\u1ee9c c\u1ee5 th\u1ec3 cho \u1ee9ng d\u1ee5ng cho c\u00e1c h\u1ec7 th\u1ed1ng l\u1eafp \u0111\u1eb7t n\u0103ng l\u01b0\u1ee3ng m\u1eb7t tr\u1eddi, s\u1ea1c EV v\u00e0 c\u00f4ng nghi\u1ec7p tr\u00ean to\u00e0n th\u1ebf gi\u1edbi.<\/p>\n<p><strong>Khi \u0111\u1ed9 ch\u00ednh x\u00e1c c\u1ee7a th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt quan tr\u1ecdng, vi\u1ec7c gi\u1ea3m \u0111\u1ecbnh m\u1ee9c th\u00edch h\u1ee3p kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t ph\u00e9p t\u00ednh\u2014m\u00e0 l\u00e0 m\u1ed9t cam k\u1ebft v\u1ec1 an to\u00e0n.<\/strong> \u0110\u1ec3 \u0111\u01b0\u1ee3c t\u01b0 v\u1ea5n k\u1ef9 thu\u1eadt v\u1ec1 d\u1ef1 \u00e1n ti\u1ebfp theo c\u1ee7a b\u1ea1n, h\u00e3y li\u00ean h\u1ec7 v\u1edbi nh\u00f3m k\u1ef9 thu\u1eadt c\u1ee7a VIOX Electric ho\u1eb7c kh\u00e1m ph\u00e1 <a href=\"https:\/\/test.viox.com\/vi\/types-of-circuit-breakers\/\">c\u00e1c gi\u1ea3i ph\u00e1p b\u1ea3o v\u1ec7 m\u1ea1ch ho\u00e0n ch\u1ec9nh c\u1ee7a ch\u00fang t\u00f4i<\/a>.<\/p>\n<hr \/>\n<p><strong>T\u00e0i nguy\u00ean k\u1ef9 thu\u1eadt li\u00ean quan:<\/strong><\/p>\n<ul>\n<li><a href=\"https:\/\/test.viox.com\/vi\/how-to-know-if-circuit-breaker-is-bad\/\">L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 bi\u1ebft c\u1ea7u dao b\u1ecb h\u1ecfng<\/a><\/li>\n<li><a href=\"https:\/\/test.viox.com\/vi\/rccb-ev-charging-type-b-vs-type-f-vs-type-ev\/\">B\u1ea3o v\u1ec7 s\u1ea1c EV: H\u01b0\u1edbng d\u1eabn tu\u00e2n th\u1ee7 NEC\/IEC<\/a><\/li>\n<li><a href=\"https:\/\/test.viox.com\/vi\/100a-panel-ev-charger-upgrade\/\">\u0110\u1ecbnh c\u1ee1 c\u1ea7u dao cho b\u1ed9 s\u1ea1c EV 7kW v\u00e0 22kW<\/a><\/li>\n<\/ul>\n<\/div>\n<div class=\"simg-pop-btn\" style=\"top: 283.828px; left: 14px; display: none;\"><\/div>\n<div class=\"simg-pop-btn\" style=\"top: 283.828px; left: 14px; display: none;\"><\/div>\n<div class=\"simg-pop-btn\" style=\"top: 3215.05px; left: 14px; display: none;\"><\/div>\n<div class=\"simg-pop-btn\" style=\"top: 3215.05px; left: 14px; display: none;\"><\/div>\n<div class=\"simg-pop-btn\" style=\"top: 2357.05px; left: 14px; display: none;\"><\/div>\n<div class=\"simg-pop-btn\" style=\"top: 2357.05px; left: 14px; display: none;\"><\/div>\n<div class=\"simg-pop-btn\" style=\"top: 283.828px; left: 14px; display: none;\"><\/div>\n<div class=\"simg-pop-btn\" style=\"top: 4434.05px; left: 14px; display: none;\"><\/div>\n<div class=\"simg-pop-btn\" style=\"top: 4434.05px; left: 14px; display: none;\"><\/div>\n<div class=\"simg-pop-btn\" style=\"top: 2386.75px; left: 14px; display: none;\"><\/div>\n<div class=\"simg-pop-btn\" style=\"top: 2386.75px; left: 14px; display: none;\"><\/div>","protected":false},"excerpt":{"rendered":"<p>Understanding Electrical Derating: Why It Matters for Safe Installations Electrical derating is the systematic reduction of a conductor&#8217;s current-carrying capacity (ampacity) to account for real-world installation conditions that deviate from standard testing environments. When cables operate in high temperatures, at elevated altitudes, or bundled with other conductors, their ability to dissipate heat diminishes significantly. Without [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":21210,"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-21209","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\/21209","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=21209"}],"version-history":[{"count":3,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/posts\/21209\/revisions"}],"predecessor-version":[{"id":21213,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/posts\/21209\/revisions\/21213"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/media\/21210"}],"wp:attachment":[{"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/media?parent=21209"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/categories?post=21209"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/test.viox.com\/vi\/wp-json\/wp\/v2\/tags?post=21209"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}