{"id":4694,"date":"2026-11-08T13:38:28","date_gmt":"2026-11-08T13:38:28","guid":{"rendered":"https:\/\/huyuglobal.com\/?p=4694"},"modified":"2026-11-08T13:38:30","modified_gmt":"2026-11-08T13:38:30","slug":"what-is-a-thermal-magnetic-circuit-breaker","status":"publish","type":"post","link":"https:\/\/huyuglobal.com\/vi\/blog\/what-is-a-thermal-magnetic-circuit-breaker\/","title":{"rendered":"B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb l\u00e0 g\u00ec?"},"content":{"rendered":"

B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb<\/a> (TM CB<\/strong>) l\u00e0 lo\u1ea1i b\u1ed9 ng\u1eaft m\u1ea1ch ph\u1ed5 bi\u1ebfn nh\u1ea5t v\u00e0 h\u1ea7u h\u1ebft c\u00e1c m\u1ea1ch \u0111i\u1ec7n s\u1eed d\u1ee5ng trong c\u00e1c thi\u1ebft b\u1ecb n\u00e0y \u0111\u1ec1u c\u00f3 s\u1eb5n tr\u00ean th\u1ecb tr\u01b0\u1eddng cho ng\u01b0\u1eddi ti\u00eau d\u00f9ng. Tuy nhi\u00ean, th\u01b0\u1eddng th\u00ec h\u1ea7u h\u1ebft ng\u01b0\u1eddi ti\u00eau d\u00f9ng kh\u00f4ng hi\u1ec3u c\u00e1ch ho\u1ea1t \u0111\u1ed9ng c\u1ee7a TM CB, do \u0111\u00f3 vi\u1ec7c hi\u1ec3u ch\u1ee9c n\u0103ng c\u1ee7a ch\u00fang tr\u01b0\u1edbc khi mua l\u00e0 r\u1ea5t quan tr\u1ecdng. TM CB c\u00f3 hai lo\u1ea1i c\u01a1 ch\u1ebf ng\u1eaft, m\u1ed9t c\u01a1 ch\u1ebf \u201cnhi\u1ec7t\u201d ph\u1ea3n \u1ee9ng v\u1edbi qu\u00e1 t\u1ea3i k\u00e9o d\u00e0i v\u00e0 m\u1ed9t c\u01a1 ch\u1ebf \u201ct\u1eeb\u201d ph\u1ea3n \u1ee9ng v\u1edbi \u0111i\u1ec1u ki\u1ec7n ng\u1eafn m\u1ea1ch. Ph\u00e2n bi\u1ec7t gi\u1eefa hai c\u01a1 ch\u1ebf n\u00e0y s\u1ebd gi\u00fap ng\u01b0\u1eddi d\u00f9ng cu\u1ed1i x\u00e1c \u0111\u1ecbnh nguy\u00ean nh\u00e2n c\u1ee7a vi\u1ec7c ng\u1eaft kh\u00f4ng mong mu\u1ed1n v\u00e0\/ho\u1eb7c vi\u1ec7c ng\u1eaft ch\u1eadm. Do \u0111\u00f3, n\u1ebfu b\u1ea1n g\u1eb7p ph\u1ea3i v\u1ea5n \u0111\u1ec1 ng\u1eaft kh\u00f4ng mong mu\u1ed1n ho\u1eb7c ng\u1eaft ch\u1eadm v\u1edbi TM CB c\u1ee7a m\u00ecnh, h\u00e3y xem x\u00e9t c\u01a1 ch\u1ebf ng\u1eaft n\u00e0o \u0111ang ho\u1ea1t \u0111\u1ed9ng.<\/p>\n

T\u00f3m l\u1ea1i:<\/strong> TM CB s\u1eed d\u1ee5ng m\u1ed9t d\u1ea3i kim lo\u1ea1i k\u00e9p s\u1ebd u\u1ed1n cong theo th\u1eddi gian (t\u1eeb v\u00e0i gi\u00e2y \u0111\u1ebfn v\u00e0i ph\u00fat) do qu\u00e1 t\u1ea3i k\u00e9o d\u00e0i v\u00e0 m\u1ed9t cu\u1ed9n \u0111i\u1ec7n t\u1eeb s\u1ebd ng\u1eaft trong v\u00e0i mili gi\u00e2y khi d\u00f2ng \u0111i\u1ec7n v\u01b0\u1ee3t qu\u00e1 b\u1ed9i s\u1ed1 c\u1ee7a \u0111\u1ecbnh m\u1ee9c (5 \u0111\u1ebfn 10 l\u1ea7n \u0111\u1ed1i v\u1edbi \u0111\u01b0\u1eddng cong C). C\u01a1 ch\u1ebf nhi\u1ec7t cung c\u1ea5p b\u1ea3o v\u1ec7 ng\u01b0\u1ee3c th\u1eddi gian d\u1ef1a tr\u00ean \u0111\u1ecbnh m\u1ee9c nhi\u1ec7t c\u1ee7a c\u00e1p n\u01a1i TM CB \u0111\u01b0\u1ee3c l\u1eafp \u0111\u1eb7t. C\u01a1 ch\u1ebf t\u1eeb b\u1ed5 sung t\u1ed1c \u0111\u1ed9 ng\u1eaft cho c\u01a1 ch\u1ebf nhi\u1ec7t khi d\u00f2ng \u0111i\u1ec7n v\u01b0\u1ee3t m\u1ee9c g\u00e2y ra \u0111i\u1ec1u ki\u1ec7n ng\u1eaft. C\u1ea5u h\u00ecnh TM CB cung c\u1ea5p m\u1ed9t thi\u1ebft b\u1ecb c\u01a1 h\u1ecdc \u0111\u01a1n gi\u1ea3n s\u1ebd ng\u1eaft khi \u0111i\u1ec1u ki\u1ec7n y\u00eau c\u1ea7u m\u00e0 kh\u00f4ng c\u1ea7n ngu\u1ed3n \u0111i\u1ec7n ph\u1ee5 tr\u1ee3 v\u00e0 ch\u1ec9 c\u1ea7n \u0111i\u1ec1u ch\u1ec9nh c\u01a1 b\u1ea3n c\u00e1c c\u00e0i \u0111\u1eb7t ng\u1eaft. TM CB c\u00f3 gi\u00e1 dao \u0111\u1ed9ng t\u1eeb $2 cho c\u00e1c thi\u1ebft b\u1ecb nh\u1ecf g\u1ecdn \u0111\u1ebfn $400 cho c\u00e1c thi\u1ebft b\u1ecb v\u1ecf \u0111\u00fac l\u1edbn h\u01a1n c\u00f3 d\u00f2ng \u0111\u1ecbnh m\u1ee9c 630 A. C\u00e1c b\u1ed9 ng\u1eaft \u0111i\u1ec7n t\u1eed cung c\u1ea5p ch\u1ee9c n\u0103ng t\u01b0\u01a1ng t\u1ef1 nh\u01b0 TM CB v\u1edbi c\u00f4ng ngh\u1ec7 bi\u1ebfn d\u00f2ng; tuy nhi\u00ean, ch\u00fang c\u00f3 gi\u00e1 mua cao h\u01a1n nhi\u1ec1u (t\u1eeb hai \u0111\u1ebfn n\u0103m l\u1ea7n), c\u0169ng nh\u01b0 c\u00e1c t\u00ednh n\u0103ng b\u1ed5 sung nh\u01b0 c\u00e0i \u0111\u1eb7t ng\u1eaft \u0111i\u1ec1u ch\u1ec9nh \u0111\u01b0\u1ee3c, \u0111o l\u01b0\u1eddng v\u00e0 m\u1ea1ch \u0111i\u1ec1u khi\u1ec3n.<\/p><\/blockquote>\n

B\u00e0i vi\u1ebft n\u00e0y cung c\u1ea5p th\u00f4ng tin v\u1ec1 c\u00e1ch ho\u1ea1t \u0111\u1ed9ng c\u1ee7a TM CB, c\u00e1c k\u00fd hi\u1ec7u c\u01a1 b\u1ea3n d\u00f9ng \u0111\u1ec3 nh\u1eadn bi\u1ebft TM CB, c\u00e1c m\u1eabu \u0111\u01b0\u1eddng cong ng\u1eaft m\u00e0 TM CB tu\u00e2n theo, so s\u00e1nh TM CB v\u1edbi b\u1ed9 ng\u1eaft \u0111i\u1ec7n t\u1eed v\u00e0 thi\u1ebft b\u1ecb ch\u1ec9 c\u00f3 c\u01a1 ch\u1ebf t\u1eeb, gi\u1ea3i th\u00edch c\u00e1ch v\u00e0 khi n\u00e0o s\u1eed d\u1ee5ng c\u00e1c lo\u1ea1i ng\u1eaft kh\u00e1c nhau c\u1ee7a TM CB c\u0169ng nh\u01b0 chi ph\u00ed c\u1ee7a c\u00e1c thi\u1ebft b\u1ecb.<\/p>\n

B\u1ed9 Ng\u1eaft M\u1ea1ch Nhi\u1ec7t T\u1eeb L\u00e0 G\u00ec<\/h2>\n

B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb l\u00e0 b\u1ed9 ng\u1eaft m\u1ea1ch c\u00f3 hai ph\u01b0\u01a1ng ph\u00e1p ng\u1eaft kh\u00e1c nhau, cho ph\u00e9p n\u00f3 b\u1ea3o v\u1ec7 ch\u1ed1ng l\u1ea1i c\u1ea3 qu\u00e1 t\u1ea3i nhi\u1ec7t v\u00e0 t\u1eeb. Hai ph\u01b0\u01a1ng ph\u00e1p n\u00e0y s\u1ebd ng\u1eaft thi\u1ebft b\u1ecb m\u1ed9t c\u00e1ch \u0111\u1ed9c l\u1eadp v\u00ec ch\u00fang \u0111\u01b0\u1ee3c \u0111\u1eb7t trong c\u00e1c bu\u1ed3ng ri\u00eang bi\u1ec7t v\u00e0 ho\u1ea1t \u0111\u1ed9ng d\u1ef1a tr\u00ean c\u00f9ng m\u1ed9t d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua h\u1ec7 th\u1ed1ng \u0111i\u1ec7n.<\/p>\n

C\u01a1 ch\u1ebf ng\u1eaft nhi\u1ec7t bao g\u1ed3m m\u1ed9t d\u1ea3i kim lo\u1ea1i k\u00e9p, \u0111\u01b0\u1ee3c t\u1ea1o th\u00e0nh t\u1eeb hai kim lo\u1ea1i kh\u00e1c nhau \u0111\u01b0\u1ee3c li\u00ean k\u1ebft v\u1edbi nhau c\u00f3 \u0111\u1eb7c t\u00ednh gi\u00e3n n\u1edf nhi\u1ec7t kh\u00e1c nhau. Khi d\u00f2ng \u0111i\u1ec7n \u0111i qua d\u1ea3i kim lo\u1ea1i, n\u00f3 t\u1ea1o ra nhi\u1ec7t, l\u00e0m cho d\u1ea3i kim lo\u1ea1i cong l\u1ea1i. Khi \u0111\u1ea1t \u0111\u1ebfn m\u1ed9t m\u1ee9c \u0111\u1ed9 cong x\u00e1c \u0111\u1ecbnh tr\u01b0\u1edbc, d\u1ea3i kim lo\u1ea1i s\u1ebd k\u00edch ho\u1ea1t ch\u1ed1t v\u00e0 ng\u1eaft m\u1ea1ch. V\u00ec qu\u00e1 tr\u00ecnh sinh nhi\u1ec7t m\u1ea5t th\u1eddi gian, vi\u1ec7c ng\u1eaft s\u1ebd b\u1ecb tr\u00ec ho\u00e3n, nh\u01b0ng khi d\u00f2ng \u0111i\u1ec7n t\u0103ng l\u00ean, vi\u1ec7c ng\u1eaft s\u1ebd x\u1ea3y ra s\u1edbm h\u01a1n. \u0110\u1eb7c t\u00ednh n\u00e0y \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 th\u1eddi gian ngh\u1ecbch \u0111\u1ea3o v\u00e0 cho ph\u00e9p c\u00e1p c\u1ea5p ngu\u1ed3n ch\u1ecbu \u0111\u01b0\u1ee3c qu\u00e1 t\u1ea3i m\u00e0 kh\u00f4ng l\u00e0m ng\u1eaft b\u1ed9 ng\u1eaft m\u1ea1ch.<\/p>\n

C\u01a1 ch\u1ebf ng\u1eaft t\u1eeb s\u1eed d\u1ee5ng m\u1ed9t cu\u1ed9n solenoid v\u00e0 b\u1ed9 truy\u1ec1n \u0111\u1ed9ng \u0111\u1ec3 ng\u1eaft b\u1ed9 ng\u1eaft m\u1ea1ch. Khi \u0111\u1ea1t \u0111\u1ebfn m\u1ee9c d\u00f2ng \u0111i\u1ec7n x\u00e1c \u0111\u1ecbnh tr\u01b0\u1edbc, l\u1ef1c t\u1eeb c\u1ee7a cu\u1ed9n solenoid s\u1ebd v\u01b0\u1ee3t qua l\u1ef1c l\u00f2 xo gi\u1eef b\u1ed9 truy\u1ec1n \u0111\u1ed9ng t\u1ea1i v\u1ecb tr\u00ed, t\u1eeb \u0111\u00f3 l\u00e0m cho b\u1ed9 truy\u1ec1n \u0111\u1ed9ng va ch\u1ea1m v\u00e0o ch\u1ed1t v\u00e0 m\u1edf b\u1ed9 ng\u1eaft m\u1ea1ch. C\u01a1 ch\u1ebf n\u00e0y kh\u00f4ng sinh nhi\u1ec7t, n\u00ean vi\u1ec7c ng\u1eaft s\u1ebd x\u1ea3y ra g\u1ea7n nh\u01b0 ngay l\u1eadp t\u1ee9c (th\u01b0\u1eddng trong v\u00f2ng 20 mili gi\u00e2y). Do \u0111\u00f3, c\u01a1 ch\u1ebf t\u1eeb s\u1ebd x\u1eed l\u00fd ng\u1eafn m\u1ea1ch tr\u01b0\u1edbc khi c\u00e1p b\u1ecb h\u01b0 h\u1ecfng.<\/p>\n

C\u1ea3 hai c\u01a1 ch\u1ebf ho\u1ea1t \u0111\u1ed9ng tr\u00ean c\u00f9ng m\u1ed9t ch\u1ed1t, v\u00ec v\u1eady thi\u1ebft b\u1ecb c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c ki\u1ec3m tra nh\u01b0 m\u1ed9t \u0111\u01a1n v\u1ecb v\u00e0 \u0111\u01b0\u1eddng cong ng\u1eaft s\u1ebd hi\u1ec3n th\u1ecb hai \u0111\u01b0\u1eddng ri\u00eang bi\u1ec7t.<\/p>\n

Nguy\u00ean l\u00fd ho\u1ea1t \u0111\u1ed9ng: m\u1ed9t ph\u1ea7n t\u1eed cho m\u1ed7i \u1ee9ng d\u1ee5ng, hai ph\u1ea7n t\u1eed\/m\u1eabu = nhi\u1ec7t + t\u1eeb<\/h2>\n

C\u00e1c ph\u1ea7n t\u1eed nhi\u1ec7t m\u00f4 ph\u1ecfng c\u00e1ch c\u00e1ch \u0111i\u1ec7n c\u00e1p v\u00e0 ch\u1ec9 c\u00f3 th\u1ec3 ch\u1ecbu \u0111\u01b0\u1ee3c m\u1ed9t m\u1ee9c qu\u00e1 t\u1ea3i nh\u1ea5t \u0111\u1ecbnh tr\u01b0\u1edbc khi x\u1ea3y ra h\u01b0 h\u1ecfng v\u0129nh vi\u1ec5n. D\u1ea3i kim lo\u1ea1i k\u00e9p \u0111\u01b0\u1ee3c hi\u1ec7u chu\u1ea9n \u0111\u1ec3 ng\u1eaft ngay d\u01b0\u1edbi \u0111i\u1ec3m g\u00e2y h\u01b0 h\u1ecfng nh\u1eb1m b\u1ea3o v\u1ec7 c\u00e1p ch\u1ee9 kh\u00f4ng ph\u1ea3i thi\u1ebft b\u1ecb.<\/p>\n

Do \u0111\u00f3, c\u00e1c ph\u1ea7n t\u1eed nhi\u1ec7t s\u1ebd ho\u1ea1t \u0111\u1ed9ng ch\u1eadm m\u1ed9t c\u00e1ch c\u00f3 ch\u1ee7 \u00fd \u0111\u1ec3 b\u1ed9 ng\u1eaft cung c\u1ea5p b\u1ea3o v\u1ec7 m\u00e0 kh\u00f4ng ng\u1eaft kh\u00f4ng c\u1ea7n thi\u1ebft. V\u00ed d\u1ee5: m\u1ed9t b\u1ed9 ng\u1eaft 32 A mang d\u00f2ng 40 A (\u0111\u1eb7c bi\u1ec7t khi kh\u1edfi \u0111\u1ed9ng) c\u00f3 th\u1ec3 m\u1ea5t v\u00e0i ph\u00fat \u0111\u1ec3 ng\u1eaft \u2013 \u0111\u00e2y l\u00e0 h\u00e0nh vi \u0111\u00fang v\u00ec c\u00e1p \u0111\u1ecbnh m\u1ee9c 32 A c\u00f3 th\u1ec3 ch\u1ecbu \u0111\u01b0\u1ee3c 40 A trong kho\u1ea3ng th\u1eddi gian \u0111\u00f3 tr\u01b0\u1edbc khi c\u00e1ch \u0111i\u1ec7n b\u1ecb n\u00f3ng ch\u1ea3y.<\/p>\n

Ph\u1ea7n t\u1eed t\u1eeb \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf \u0111\u1eb7c bi\u1ec7t cho t\u00ecnh hu\u1ed1ng l\u1ed7i\/n\u1ed5 x\u1ea3y ra trong m\u1ed9t ph\u1ea7n nh\u1ecf c\u1ee7a gi\u00e2y v\u00e0 kh\u00f4ng c\u00f3 \u0111\u1ed9 tr\u1ec5 c\u1ed1 \u00fd. Ng\u01b0\u1ee1ng ng\u1eaft t\u1eeb l\u00e0 m\u1ed9t b\u1ed9i s\u1ed1 c\u1ee7a d\u00f2ng \u0111\u1ecbnh m\u1ee9c v\u00e0 \u0111\u00e2y l\u00e0 l\u00fd do khi ch\u1ecdn thi\u1ebft b\u1ecb ng\u1eaft t\u1eeb cho \u1ee9ng d\u1ee5ng \u0111\u1ed9ng c\u01a1, c\u1ea7n ch\u00fa \u00fd \u0111\u1ebfn ch\u1eef c\u00e1i tr\u00ean \u0111\u01b0\u1eddng cong thay v\u00ec \u0111\u1ecbnh m\u1ee9c DC.<\/p>\n

H\u1ea7u h\u1ebft c\u00e1c v\u1ea5n \u0111\u1ec1 \u1ee9ng d\u1ee5ng ph\u00e1t sinh trong s\u1ef1 ch\u1ed3ng ch\u00e9o c\u1ee7a c\u00e1c \u0111i\u1ec1u ki\u1ec7n ng\u1eaft nhi\u1ec7t v\u00e0 t\u1eeb t\u00ednh. D\u00f2ng l\u1ed7i ch\u1ec9 v\u1eeba v\u01b0\u1ee3t ng\u01b0\u1ee1ng ng\u1eaft t\u1eeb t\u00ednh c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c x\u00f3a b\u1edfi c\u1ea3 ph\u1ea7n t\u1eed nhi\u1ec7t ho\u1eb7c t\u1eeb t\u00ednh t\u00f9y thu\u1ed9c v\u00e0o nhi\u1ec7t \u0111\u1ed9 v\u00e0 n\u1ebfu b\u1ed9 ng\u1eaft m\u1ea1ch \u0111\u00e3 mang t\u1ea3i hay ch\u01b0a (t\u1ee9c l\u00e0 n\u1ebfu ph\u1ea7n t\u1eed nhi\u1ec7t \u0111\u00e3 \u0111\u01b0\u1ee3c l\u00e0m n\u00f3ng nhi\u1ec1u h\u01a1n so v\u1edbi khi n\u00f3 c\u00f2n l\u1ea1nh). Khi b\u1ea1n quan s\u00e1t c\u00e1ch m\u1ed9t thi\u1ebft b\u1ecb ng\u1eaft ho\u1ea1t \u0111\u1ed9ng \u1edf m\u1ee9c t\u1ea3i 1,3 l\u1ea7n \u0111\u1ecbnh m\u1ee9c, r\u1ea5t kh\u00f3 \u0111\u1ec3 r\u00fat ra k\u1ebft qu\u1ea3 ng\u1eaft phi\u1ec1n l\u1eb7p l\u1ea1i (t\u1ee9c l\u00e0, c\u00e1c t\u00ecnh hu\u1ed1ng ng\u1eaft x\u1ea3y ra m\u00e0 kh\u00f4ng c\u00f3 l\u00fd do r\u00f5 r\u00e0ng). Tuy nhi\u00ean, hi\u1ec7n t\u01b0\u1ee3ng n\u00e0y c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c hi\u1ec3u r\u00f5 h\u01a1n b\u1eb1ng c\u00e1ch xem x\u00e9t c\u00e1c k\u00fd hi\u1ec7u c\u1ee7a b\u1ed9 ng\u1eaft m\u1ea1ch tr\u00ean b\u1ea3n v\u1ebd s\u01a1 \u0111\u1ed3 \u0111i\u1ec7n.<\/p>\n

\"K\u00fd<\/p>\n

K\u00fd hi\u1ec7u v\u00e0 c\u00e1ch \u0111\u1ecdc n\u00f3 tr\u00ean b\u1ea3n v\u1ebd<\/h2>\n

Trong c\u00e1c b\u1ea3n v\u1ebd s\u01a1 \u0111\u1ed3 \u0111i\u1ec7n, k\u00fd hi\u1ec7u ti\u00eau chu\u1ea9n cho b\u1ed9 ng\u1eaft m\u1ea1ch \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng m\u1ed9t ti\u1ebfp \u0111i\u1ec3m c\u00f4ng t\u1eafc v\u1edbi m\u1ed9t h\u00ecnh vu\u00f4ng r\u1ea5t nh\u1ecf ho\u1eb7c h\u00ecnh b\u00e1n nguy\u1ec7t t\u1ea1i \u0111i\u1ec3m ho\u1ea1t \u0111\u1ed9ng. Phi\u00ean b\u1ea3n b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb s\u1ebd th\u00eam c\u00e1c k\u00fd hi\u1ec7u b\u1ed5 sung cho t\u1eebng th\u00e0nh ph\u1ea7n \u0111\u00f3. Th\u00e0nh ph\u1ea7n nhi\u1ec7t xu\u1ea5t hi\u1ec7n d\u01b0\u1edbi d\u1ea1ng m\u1ed9t h\u00ecnh ch\u1eef nh\u1eadt nh\u1ecf ho\u1eb7c h\u00ecnh ch\u1eef C theo ti\u00eau chu\u1ea9n IEC 60617, trong khi th\u00e0nh ph\u1ea7n t\u1eeb xu\u1ea5t hi\u1ec7n d\u01b0\u1edbi d\u1ea1ng m\u1ed9t v\u00f2ng nh\u1ecf ho\u1eb7c n\u1eeda v\u00f2ng tr\u00f2n (c\u1ea3 hai th\u00e0nh ph\u1ea7n \u0111\u1ec1u n\u1eb1m tr\u00ean c\u00f9ng m\u1ed9t c\u1ef1c).<\/p>\n

Ba \u0111i\u1ec1u quan tr\u1ecdng c\u1ea7n ki\u1ec3m tra khi xem x\u00e9t s\u01a1 \u0111\u1ed3 c\u1ee7a b\u1ed9 ng\u1eaft m\u1ea1ch: k\u00fd hi\u1ec7u c\u00f3 ph\u1ea3i l\u00e0 c\u00f4ng t\u1eafc chuy\u1ec3n m\u1ea1ch hay c\u00f4ng t\u1eafc ng\u1eaft\/b\u1ed9 ng\u1eaft? C\u00f4ng t\u1eafc chuy\u1ec3n m\u1ea1ch v\u00e0 c\u00f4ng t\u1eafc ng\u1eaft b\u1ed9 ng\u1eaft tr\u00f4ng r\u1ea5t gi\u1ed1ng nhau, nh\u01b0ng ch\u1ec9 m\u1ed9t trong hai lo\u1ea1i thi\u1ebft b\u1ecb \u0111\u00f3 cung c\u1ea5p b\u1ea3o v\u1ec7 t\u1ef1 \u0111\u1ed9ng. Th\u00f4ng tin quan tr\u1ecdng th\u1ee9 hai c\u1ea7n ki\u1ec3m tra l\u00e0 c\u00e1c c\u1ef1c (v\u1eadn h\u00e0nh b\u1ed9 ng\u1eaft) c\u00f3 \u0111\u01b0\u1ee3c li\u00ean k\u1ebft v\u1edbi nhau hay kh\u00f4ng.<\/p>\n

Trong b\u1ed9 ng\u1eaft m\u1ea1ch ba pha, \u0111i\u1ec1u quan tr\u1ecdng l\u00e0 t\u1ea5t c\u1ea3 c\u00e1c c\u1ef1c v\u1eadn h\u00e0nh ph\u1ea3i m\u1edf \u0111\u1ed3ng th\u1eddi (c\u1ef1c li\u00ean k\u1ebft n\u00ean \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n b\u1eb1ng m\u1ed9t \u0111\u01b0\u1eddng n\u00e9t \u0111\u1ee9t n\u1ed1i c\u00e1c c\u01a1 c\u1ea5u c\u1ef1c v\u1edbi nhau). Th\u00f4ng tin quan tr\u1ecdng th\u1ee9 ba c\u1ea7n xem x\u00e9t l\u00e0 k\u00fd hi\u1ec7u b\u1ed9 ng\u1eaft m\u1ea1ch c\u00f3 k\u00e8m theo tham chi\u1ebfu \u0111\u01b0\u1eddng cong hay kh\u00f4ng. K\u00fd hi\u1ec7u b\u1ed9 ng\u1eaft kh\u00f4ng c\u00f3 \u0111\u01b0\u1eddng cong \u0111i k\u00e8m kh\u00f4ng cung c\u1ea5p b\u1ea5t k\u1ef3 th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt n\u00e0o v\u1ec1 thi\u1ebft b\u1ecb.<\/p>\n

Bi\u1ec3u di\u1ec5n b\u1ed9 ng\u1eaft trong d\u1ea1ng m\u1ed9t c\u1ef1c, bao g\u1ed3m chi ti\u1ebft b\u1ed9 ng\u1eaft nhi\u1ec7t t\u1eeb, th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u0111\u01a1n gi\u1ea3n h\u00f3a th\u00e0nh m\u1ed9t h\u00ecnh vu\u00f4ng v\u1edbi m\u1ed9t \u0111\u01b0\u1eddng ch\u00e9o v\u1ebd qua n\u00f3, ho\u1eb7c m\u1ed9t h\u00ecnh ch\u1eef nh\u1eadt v\u1edbi m\u1ed9t \u0111\u01b0\u1eddng k\u1ebb ngang. Nh\u01b0 minh h\u1ecda trong b\u1ea3n v\u1ebd m\u1ed9t \u0111\u01b0\u1eddng, k\u00fd hi\u1ec7u nhi\u1ec7t t\u1eeb kh\u00f4ng \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n, \u0111i\u1ec1u n\u00e0y cung c\u1ea5p th\u00f4ng tin \u0111\u1ee7 cho m\u1ee5c \u0111\u00edch b\u1ed1 tr\u00ed. Tuy nhi\u00ean, khi ti\u1ebfn h\u00e0nh nghi\u00ean c\u1ee9u b\u1ea3o v\u1ec7, nghi\u00ean c\u1ee9u b\u1ea3o v\u1ec7 y\u00eau c\u1ea7u m\u1ed9t \u0111\u01b0\u1eddng cong v\u00e0 c\u00e1c c\u00e0i \u0111\u1eb7t v\u00e0 kh\u00f4ng y\u00eau c\u1ea7u bi\u1ec3u di\u1ec5n k\u00fd hi\u1ec7u c\u1ee7a b\u1ed9 ng\u1eaft.<\/p>\n

Thay v\u00ec m\u1ed9t b\u1ea3n v\u1ebd, c\u00e1c nh\u00e0 s\u1ea3n xu\u1ea5t c\u0169ng in m\u1ed9t \u0111\u01b0\u1eddng cong mini \u1edf b\u00ean c\u1ea1nh thi\u1ebft b\u1ecb. \u0110\u01b0\u1eddng cong mini c\u00f3 li\u00ean quan nhi\u1ec1u h\u01a1n \u0111\u1ebfn thi\u1ebft b\u1ecb v\u00ec n\u00f3 li\u00ean quan c\u1ee5 th\u1ec3 \u0111\u1ebfn thi\u1ebft b\u1ecb \u0111\u00f3. N\u1ebfu m\u1ed9t thi\u1ebft b\u1ecb c\u00f3 \u0111\u1ecbnh m\u1ee9c (tr\u00ean \u0111\u01b0\u1eddng cong mini c\u1ee7a n\u00f3) l\u00e0 \u0111\u1ecbnh m\u1ee9c \u0111\u01b0\u1eddng cong C v\u00e0 \u0111\u1ecbnh m\u1ee9c kh\u1ea3 n\u0103ng ng\u1eaft 10 kA, \u0111\u00f3 l\u00e0 t\u1ea5t c\u1ea3 th\u00f4ng tin c\u1ea7n thi\u1ebft \u0111\u1ec3 l\u1ef1a ch\u1ecdn, mi\u1ec5n l\u00e0 m\u1ee9c l\u1ed7i tr\u00ean thi\u1ebft b\u1ecb \u0111\u00f3 d\u01b0\u1edbi 10 kA.<\/p>\n

\u0110\u01b0\u1eddng cong ng\u1eaft: B, C, D v\u00e0 \u00dd ngh\u0129a c\u1ee7a c\u00e1c con s\u1ed1<\/h2>\n

B\u1ed1n \u0111\u01b0\u1eddng cong ng\u1eaft, B, C, D, v\u00e0 c\u00e1c con s\u1ed1 t\u01b0\u01a1ng \u1ee9ng c\u1ee7a ch\u00fang, ch\u1ec9 ra ph\u1ea1m vi ng\u1eaft t\u1eeb t\u00ednh nh\u01b0 m\u1ed9t b\u1ed9i s\u1ed1 c\u1ee7a d\u00f2ng \u0111\u1ecbnh m\u1ee9c. Ch\u1eef c\u00e1i li\u00ean quan \u0111\u1ebfn \u0111\u01b0\u1eddng cong ng\u1eaft l\u00e0 th\u00f4ng tin quan tr\u1ecdng nh\u1ea5t \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh lo\u1ea1i c\u1ea7u dao t\u1ef1 \u0111\u1ed9ng nh\u1ecf n\u00e0o s\u1ebd s\u1eed d\u1ee5ng.<\/p>\n\n\n\n\n\n\n\n\n\n
\u0110\u01b0\u1eddng cong<\/th>\nPh\u1ea1m vi ng\u1eaft t\u1eeb t\u00ednh<\/th>\n\u1ee8ng d\u1ee5ng \u0111i\u1ec3n h\u00ecnh<\/th>\nT\u1ea3i ch\u1ecbu \u0111\u01b0\u1ee3c<\/th>\n<\/tr>\n<\/thead>\n
B<\/td>\n3-5 l\u1ea7n d\u00f2ng \u0111\u1ecbnh m\u1ee9c<\/td>\nt\u1ea3i tr\u1edf kh\u00e1ng, \u0111\u01b0\u1eddng d\u00e2y d\u00e0i, chi\u1ebfu s\u00e1ng<\/td>\n\u00cdt ho\u1eb7c kh\u00f4ng c\u00f3 d\u00f2ng kh\u1edfi \u0111\u1ed9ng. \u0110\u1ea9y m\u1ea1nh vi\u1ec7c ng\u1eaft nhanh.<\/td>\n<\/tr>\n
C<\/td>\n5-10 l\u1ea7n d\u00f2ng \u0111\u1ecbnh m\u1ee9c<\/td>\nm\u1ee5c \u0111\u00edch chung, t\u1ea3i h\u1ed7n h\u1ee3p, \u0111\u1ed9ng c\u01a1 nh\u1ecf<\/td>\nD\u00f2ng kh\u1edfi \u0111\u1ed9ng v\u1eeba ph\u1ea3i.<\/td>\n<\/tr>\n
D<\/td>\n10-20 l\u1ea7n d\u00f2ng \u0111\u1ecbnh m\u1ee9c<\/td>\nm\u00e1y bi\u1ebfn \u00e1p, \u0111\u1ed9ng c\u01a1, m\u00e1y h\u00e0n, b\u01a1m<\/td>\nD\u00f2ng kh\u1edfi \u0111\u1ed9ng l\u1edbn m\u00e0 kh\u00f4ng g\u00e2y ng\u1eaft kh\u00f4ng c\u1ea7n thi\u1ebft.<\/td>\n<\/tr>\n
K<\/td>\n10-14 l\u1ea7n, nhi\u1ec7t 1-2<\/td>\n\u0110\u1ed9ng c\u01a1 d\u00f2ng kh\u1edfi \u0111\u1ed9ng cao<\/td>\nQu\u00e1 t\u1ea3i li\u00ean t\u1ee5c g\u1ea7n v\u1edbi \u0111\u1ecbnh m\u1ee9c.<\/td>\n<\/tr>\n
Z<\/td>\n2-3 l\u1ea7n d\u00f2ng \u0111\u1ecbnh m\u1ee9c<\/td>\n\u0111i\u1ec7n t\u1eed, b\u1ea3o v\u1ec7 b\u00e1n d\u1eabn<\/td>\nR\u1ea5t nh\u1ea1y v\u1edbi kh\u00f4ng c\u00f3 d\u00f2ng kh\u1edfi \u0111\u1ed9ng.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

M\u1ed7i \u0111\u01b0\u1eddng cong ch\u1ee9a hai v\u00f9ng. V\u00f9ng nhi\u1ec7t c\u1ee7a m\u1ed7i \u0111\u01b0\u1eddng cong bao ph\u1ee7 m\u1ed9t ph\u1ea1m vi d\u00f2ng \u0111i\u1ec7n cho thi\u1ebft b\u1ecb = t\u1eeb 1,13 \u0111\u1ebfn 1,45 l\u1ea7n d\u00f2ng \u0111\u1ecbnh m\u1ee9c c\u1ee7a n\u00f3<\/span>. Thi\u1ebft b\u1ecb kh\u00f4ng \u0111\u01b0\u1ee3c ng\u1eaft \u1edf 1,13 l\u1ea7n d\u00f2ng \u0111\u1ecbnh m\u1ee9c v\u00e0 ph\u1ea3i lu\u00f4n ng\u1eaft trong v\u00f2ng 1 gi\u1edd \u1edf 1,45 l\u1ea7n d\u00f2ng \u0111\u1ecbnh m\u1ee9c, theo y\u00eau c\u1ea7u trong IEC 60898-1. Ng\u01b0\u1ee1ng b\u1eaft \u0111\u1ea7u v\u00f9ng t\u1eeb t\u00ednh l\u00e0 \u0111i\u1ec3m th\u1eb3ng \u0111\u1ee9ng tr\u00ean \u0111\u1ed3 th\u1ecb c\u1ee7a \u0111\u01b0\u1eddng cong; do \u0111\u00f3, th\u1eddi gian ng\u1eaft cho s\u1eed d\u1ee5ng \u0111i\u1ec7n v\u1eabn d\u01b0\u1edbi 20 mili gi\u00e2y, b\u1ea5t k\u1ec3 d\u1ecbch v\u1ee5 \u0111i\u1ec7n v\u01b0\u1ee3t ng\u01b0\u1ee1ng \u0111\u00f3 bao xa.<\/p>\n

Gi\u1eefa hai v\u00f9ng n\u00e0y l\u00e0 m\u1ed9t d\u1ea3i chuy\u1ec3n ti\u1ebfp trong \u0111\u00f3 thi\u1ebft b\u1ecb ng\u1eaft c\u00f3 th\u1ec3 nh\u1eadn ho\u1eb7c kh\u00f4ng nh\u1eadn d\u1ecbch v\u1ee5 \u0111i\u1ec7n. Vi\u1ec7c ch\u1ecdn \u0111\u01b0\u1eddng cong ng\u1eaft ch\u1ee7 y\u1ebfu l\u00e0 \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh v\u1ecb tr\u00ed \u0111\u1eb7t d\u1ea3i chuy\u1ec3n ti\u1ebfp \u0111\u00f3 li\u00ean quan \u0111\u1ebfn xung ban \u0111\u1ea7u m\u00e0 t\u1ea3i \u0111\u01b0\u1ee3c b\u1ea3o v\u1ec7 nh\u1eadn \u0111\u01b0\u1ee3c.<\/p>\n

V\u00ed d\u1ee5, m\u1ed9t b\u01a1m c\u1ea7n d\u00f2ng \u0111\u1ecbnh m\u1ee9c tr\u00ean nh\u00e3n g\u1ea5p t\u00e1m l\u1ea7n (8x) cho xung ban \u0111\u1ea7u (t\u1ee9c l\u00e0 trong kho\u1ea3ng th\u1eddi gian \u00bd gi\u00e2y), c\u1ea7n m\u1ed9t \u0111\u01b0\u1eddng cong ng\u1eaft c\u00f3 c\u00e0i \u0111\u1eb7t ng\u01b0\u1ee1ng t\u1eeb t\u00ednh l\u1edbn h\u01a1n 8x, nh\u01b0 \u0111\u01b0\u1eddng cong D ho\u1eb7c K, thay v\u00ec \u0111\u01b0\u1eddng cong C.<\/p>\n

\u0110\u01b0\u1eddng cong ng\u1eaft c\u0169ng s\u1ebd x\u00e1c \u0111\u1ecbnh chi\u1ec1u d\u00e0i t\u1ed1i \u0111a c\u1ee7a c\u00e1p c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c b\u1ea3o v\u1ec7 b\u1edfi c\u1ea7u dao t\u1ef1 \u0111\u1ed9ng. \u0110\u01b0\u1eddng d\u00e2y c\u00e1p d\u00e0i tr\u1ea3i qua tr\u1edf kh\u00e1ng \u0111\u1ee7 \u0111\u1ec3 l\u00e0m gi\u1ea3m d\u00f2ng l\u1ed7i \u1edf \u0111\u1ea7u xa c\u1ee7a \u0111\u01b0\u1eddng d\u00e2y; do \u0111\u00f3, n\u1ebfu d\u00f2ng l\u1ed7i gi\u1ea3m \u1edf \u0111\u01b0\u1eddng d\u00e2y d\u00e0i th\u1ea5p h\u01a1n ng\u01b0\u1ee1ng t\u1eeb t\u00ednh c\u1ee7a \u0111\u01b0\u1eddng cong ng\u1eaft, c\u1ea7u dao s\u1ebd kh\u00f4ng ng\u1eaft ngay l\u1eadp t\u1ee9c. \u0110\u00e2y l\u00e0 l\u00fd do t\u1ea1i sao h\u1ea7u h\u1ebft c\u00e1c m\u1ea1ch chi\u1ebfu s\u00e1ng d\u00e0i s\u1eed d\u1ee5ng \u0111\u01b0\u1eddng cong ng\u1eaft B, c\u00f3 th\u1ec3 ng\u1eaft \u1edf h\u1ec7 s\u1ed1 b\u1ed9i th\u1ea5p h\u01a1n \u0111\u1ec3 gi\u1eef cho c\u00e1c \u0111\u1ea7u xa c\u1ee7a c\u00e1p trong ph\u1ea1m vi b\u1ea3o v\u1ec7.<\/p>\n

C\u1ea7u dao nhi\u1ec7t t\u1eeb so v\u1edbi B\u1ed9 ph\u1eadn ng\u1eaft \u0111i\u1ec7n t\u1eed<\/h2>\n

Trong khi c\u00e1c b\u1ed9 ph\u1eadn ng\u1eaft m\u1ea1ch \u0111i\u1ec7n t\u1eed l\u00e0 m\u1ed9t l\u1ef1a ch\u1ecdn \u0111\u1ec3 s\u1eed d\u1ee5ng thay cho c\u00e1c b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb (MCB), s\u1ef1 kh\u00e1c bi\u1ec7t l\u1edbn l\u00e0 c\u00e1c b\u1ed9 ph\u1eadn ng\u1eaft m\u1ea1ch \u0111i\u1ec7n t\u1eed c\u00f3 kh\u1ea3 n\u0103ng th\u1ef1c hi\u1ec7n nhi\u1ec1u ch\u1ee9c n\u0103ng h\u01a1n so v\u1edbi c\u00e1c b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb.<\/p>\n

M\u1ed9t b\u1ed9 ph\u1eadn ng\u1eaft m\u1ea1ch \u0111i\u1ec7n t\u1eed \u0111o d\u1ecbch v\u1ee5 \u0111i\u1ec7n \u0111\u1ea7u v\u00e0o c\u1ee7a n\u00f3 b\u1eb1ng c\u00e1c bi\u1ebfn d\u00f2ng \u0111i\u1ec7n n\u1ed9i b\u1ed9, s\u1ed1 h\u00f3a (chuy\u1ec3n \u0111\u1ed5i) d\u1ea1ng s\u00f3ng c\u1ee7a d\u1ecbch v\u1ee5 \u0111i\u1ec7n \u0111\u1ea7u v\u00e0o \u0111\u00f3, v\u00e0 x\u00e1c \u0111\u1ecbnh th\u1eddi \u0111i\u1ec3m ng\u1eaft qua m\u00e1y t\u00ednh (ph\u1ea7n m\u1ec1m ch\u01b0\u01a1ng tr\u00ecnh m\u00e1y t\u00ednh). Vi\u1ec7c s\u1eed d\u1ee5ng b\u1ed9 ph\u1eadn ng\u1eaft m\u1ea1ch \u0111i\u1ec7n t\u1eed mang l\u1ea1i cho ng\u01b0\u1eddi d\u00f9ng s\u1ef1 linh ho\u1ea1t \u0111\u1ec3 ch\u1ecdn c\u00e0i \u0111\u1eb7t th\u1eddi gian d\u00e0i (I), c\u00e0i \u0111\u1eb7t th\u1eddi gian ng\u1eafn (Im), \u0111\u1ed9 tr\u1ec5 th\u1eddi gian ng\u1eafn (tsd), v\u00e0 ph\u1ea7n t\u1eed l\u1ed7i \u0111\u1ea5t (tr\u00ean c\u00e1c b\u1ed9 ph\u1eadn ng\u1eaft m\u1ea1ch \u0111i\u1ec7n t\u1eed l\u1edbn h\u01a1n, c\u0169ng c\u00f3 th\u1ec3 c\u00f3 kh\u1ea3 n\u0103ng gi\u00e1m s\u00e1t v\u00e0 truy\u1ec1n th\u00f4ng).<\/p>\n

M\u1ed9t b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb kh\u00f4ng th\u1ec3 \u0111i\u1ec1u ch\u1ec9nh nh\u01b0 \u0111\u01b0\u1ee3c x\u00e1c nh\u1eadn b\u1edfi b\u1ea3ng sau:<\/p>\n

B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb so v\u1edbi B\u1ed9 ng\u1eaft m\u1ea1ch \u0111i\u1ec7n t\u1eed<\/p>\n\n\n\n\n\n\n\n\n
Kh\u1ea3 n\u0103ng \u0111i\u1ec1u ch\u1ec9nh<\/td>\n\u0110\u01b0\u1eddng cong c\u1ed1 \u0111\u1ecbnh<\/td>\nC\u00f3 th\u1ec3 \u0111i\u1ec1u ch\u1ec9nh: Ir, Im, tsd, L\u1ed7i \u0111\u1ea5t<\/td>\n<\/tr>\n
\u0110\u1ed9 ch\u00ednh x\u00e1c<\/td>\n\u00b110%-20%<\/td>\nCh\u00ednh x\u00e1c \u0111\u1ebfn \u00b15% ho\u1eb7c t\u1ed1t h\u01a1n<\/td>\n<\/tr>\n
Ngu\u1ed3n ph\u1ee5 tr\u1ee3<\/td>\nKh\u00f4ng c\u00f3<\/td>\nT\u1ef1 c\u1ea5p ngu\u1ed3n b\u1edfi m\u1ea1ch trong h\u1ea7u h\u1ebft c\u00e1c thi\u1ebft k\u1ebf<\/td>\n<\/tr>\n
\u0110o l\u01b0\u1eddng\/Truy\u1ec1n th\u00f4ng<\/td>\nKh\u00f4ng c\u00f3<\/td>\nD\u00f2ng \u0111i\u1ec7n\/\u0110i\u1ec7n \u00e1p\/N\u0103ng l\u01b0\u1ee3ng, Modbus\/Ethernet<\/td>\n<\/tr>\n
H\u00e0nh vi ng\u1eaft khi n\u00f3ng<\/td>\n\u00c1p d\u1ee5ng ng\u1eaft s\u1edbm v\u00e0 gi\u1ea3m c\u00f4ng su\u1ea5t<\/td>\nB\u00f9 nhi\u1ec7t \u0111\u1ed9<\/td>\n<\/tr>\n
Gi\u00e1 c\u1ee7a 250A<\/td>\n$120-$400<\/td>\n$300-$800<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Khi so s\u00e1nh b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb v\u00e0 b\u1ed9 ng\u1eaft m\u1ea1ch \u0111i\u1ec7n t\u1eed, c\u00e1c m\u1ea1ch nhi\u1ec7t t\u1eeb c\u00f3 m\u1ed9t s\u1ed1 \u01b0u \u0111i\u1ec3m r\u00f5 r\u00e0ng:<\/p>\n

    \n
  1. Kh\u00f4ng c\u1ea7n ngu\u1ed3n \u0111i\u1ec7n \u0111\u1ec3 c\u00e1c thi\u1ebft b\u1ecb nhi\u1ec7t t\u1eeb ho\u1ea1t \u0111\u1ed9ng. Ch\u00fang c\u00f3 th\u1ec3 ho\u1ea1t \u0111\u1ed9ng ngay c\u1ea3 khi m\u1ea1ch \u0111i\u1ec7n b\u1ecb ng\u1eaft.<\/li>\n
  2. Kh\u00f4ng c\u00f3 th\u00e0nh ph\u1ea7n \u0111i\u1ec7n t\u1eed trong c\u00e1c thi\u1ebft b\u1ecb nhi\u1ec7t t\u1eeb, do \u0111\u00f3 ch\u00fang c\u00f3 kh\u1ea3 n\u0103ng h\u1ecfng h\u00f3c th\u1ea5p h\u01a1n nhi\u1ec1u trong m\u00f4i tr\u01b0\u1eddng nhi\u1ec7t \u0111\u1ed9 cao ho\u1eb7c s\u00f3ng h\u00e0i cao.<\/li>\n
  3. S\u1ef1 kh\u00e1c bi\u1ec7t v\u1ec1 gi\u00e1 gi\u1eefa b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb v\u00e0 b\u1ed9 ng\u1eaft m\u1ea1ch \u0111i\u1ec7n t\u1eed l\u00e0 \u0111\u00e1ng k\u1ec3. Th\u1ef1c t\u1ebf, gi\u00e1 c\u1ee7a c\u00e1c thi\u1ebft b\u1ecb nhi\u1ec7t t\u1eeb th\u01b0\u1eddng b\u1eb1ng m\u1ed9t ph\u1ea7n ba gi\u00e1<\/span> c\u1ee7a c\u00e1c thi\u1ebft b\u1ecb \u0111i\u1ec7n t\u1eed, \u0111i\u1ec1u n\u00e0y quan tr\u1ecdng \u0111\u1ed1i v\u1edbi c\u00e1c \u1ee9ng d\u1ee5ng y\u00eau c\u1ea7u nhi\u1ec1u thi\u1ebft b\u1ecb. Trong m\u1ed9t s\u1ed1 tr\u01b0\u1eddng h\u1ee3p c\u00f3 th\u1ec3 c\u00f3 t\u1edbi 40 ho\u1eb7c nhi\u1ec1u h\u01a1n c\u00e1p ra t\u1eeb m\u1ed9t b\u1ed9 ng\u1eaft m\u1ea1ch ch\u00ednh.<\/li>\n<\/ol>\n

    B\u1ed9 ng\u1eaft m\u1ea1ch \u0111i\u1ec7n t\u1eed h\u1eefu \u00edch cho c\u00e1c \u1ee9ng d\u1ee5ng y\u00eau c\u1ea7u t\u00ednh ch\u1ecdn l\u1ecdc k\u1ef9 thu\u1eadt. M\u1ed9t v\u00ed d\u1ee5 l\u00e0 \u0111\u1ed9 tr\u1ec5 th\u1eddi gian ng\u1eafn cho ph\u00e9p b\u1ed9 ng\u1eaft ch\u00ednh cung c\u1ea5p th\u1eddi gian cho b\u1ed9 ng\u1eaft nh\u00e1nh \u0111\u1ec3 x\u1eed l\u00fd s\u1ef1 c\u1ed1 tr\u01b0\u1edbc khi ng\u1eaft. \u0110\u00e2y l\u00e0 c\u00e1ch m\u1ed9t nh\u00e0 m\u00e1y c\u00f3 th\u1ec3 tr\u00e1nh m\u1ea5t to\u00e0n b\u1ed9 b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n do m\u1ed9t s\u1ef1 c\u1ed1 \u0111\u1ed9ng c\u01a1 \u0111\u01a1n l\u1ebb.<\/p>\n

    Kh\u1ea3 n\u0103ng thi\u1ebft k\u1ebf t\u00ednh ch\u1ecdn l\u1ecdc v\u00e0o b\u1ed9 ng\u1eaft m\u1ea1ch l\u00e0 m\u1ed9t kh\u1ea3 n\u0103ng v\u1ed1n c\u00f3 c\u1ee7a c\u00e1c thi\u1ebft b\u1ecb \u0111i\u1ec7n t\u1eed v\u00e0 \u0111\u00f3 l\u00e0 l\u00fd do t\u1ea1i sao ch\u00fang th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng l\u00e0m b\u1ed9 ng\u1eaft ch\u00ednh, trong khi c\u00e1c b\u1ed9 ng\u1eaft nhi\u1ec7t t\u1eeb \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng cho c\u00e1c \u1ee9ng d\u1ee5ng nh\u00e1nh. Trong c\u00e1c \u1ee9ng d\u1ee5ng kh\u00f4ng y\u00eau c\u1ea7u c\u00e1c t\u00f9y ch\u1ecdn ch\u1ecdn l\u1ecdc, c\u00f3 c\u00e1c l\u1ef1a ch\u1ecdn chi ph\u00ed th\u1ea5p h\u01a1n, ch\u1eb3ng h\u1ea1n nh\u01b0 b\u1ed9 ng\u1eaft v\u1ecf \u0111\u00fac v\u1edbi c\u00e0i \u0111\u1eb7t ng\u1eaft nhi\u1ec7t t\u1eeb c\u00f3 th\u1ec3 \u0111i\u1ec1u ch\u1ec9nh. Ch\u00fang cung c\u1ea5p c\u00f9ng ch\u1ee9c n\u0103ng nh\u01b0 b\u1ed9 ng\u1eaft m\u1ea1ch \u0111i\u1ec7n t\u1eed v\u1edbi chi ph\u00ed th\u1ea5p h\u01a1n \u0111\u00e1ng k\u1ec3.<\/p>\n

    \"S\u1ef1<\/p>\n

    S\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa b\u1ed9 ng\u1eaft m\u1ea1ch t\u1eeb v\u00e0 b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb l\u00e0 g\u00ec?<\/h2>\n

    B\u1ed9 b\u1ea3o v\u1ec7 m\u1ea1ch \u0111i\u1ec7n (c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 \u201cc\u1ea7u dao\u201d) ch\u1ec9 s\u1eed d\u1ee5ng t\u1eeb t\u00ednh v\u1ec1 c\u01a1 b\u1ea3n ch\u1ec9 bao g\u1ed3m c\u00f4ng t\u1eafc \u0111i\u1ec7n t\u1eeb (solenoid) v\u00e0 kh\u00f4ng c\u00f3 g\u00ec kh\u00e1c. N\u00f3 ch\u1ec9 c\u00f3 th\u1ec3 ph\u00e1t hi\u1ec7n l\u1ed7i ng\u1eafn m\u1ea1ch; do \u0111\u00f3, n\u00f3 kh\u00f4ng th\u1ec3 ph\u00e1t hi\u1ec7n c\u00e1c \u0111i\u1ec1u ki\u1ec7n qu\u00e1 t\u1ea3i n\u00ean \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng nh\u01b0 m\u1ed9t b\u1ed9 b\u1ea3o v\u1ec7 b\u1ed5 sung.<\/p>\n

    S\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa hai lo\u1ea1i thi\u1ebft b\u1ecb b\u1ea3o v\u1ec7 m\u1ea1ch \u0111i\u1ec7n n\u00e0y l\u00e0 v\u1ec1 quy \u0111\u1ecbnh h\u01a1n l\u00e0 k\u1ef9 thu\u1eadt. Ti\u00eau chu\u1ea9n UL 1077 cho B\u1eafc M\u1ef9 \u0111\u1ecbnh ngh\u0129a c\u00e1c b\u1ed9 b\u1ea3o v\u1ec7 m\u1ea1ch ch\u1ec9 s\u1eed d\u1ee5ng t\u1eeb t\u00ednh l\u00e0 \u201cb\u1ed9 b\u1ea3o v\u1ec7 b\u1ed5 sung\u201d c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng nh\u01b0 m\u1ed9t ph\u1ea7n c\u1ee7a h\u1ec7 th\u1ed1ng b\u1ea3o v\u1ec7 m\u1ea1ch nh\u00e1nh, nh\u01b0ng kh\u00f4ng \u0111\u01b0\u1ee3c ph\u00e9p s\u1eed d\u1ee5ng l\u00e0m thi\u1ebft b\u1ecb b\u1ea3o v\u1ec7 m\u1ea1ch nh\u00e1nh<\/span> v\u00ec ch\u00fang ch\u01b0a \u0111\u01b0\u1ee3c ki\u1ec3m tra v\u1ec1 qu\u00e1 t\u1ea3i.<\/p>\n

    C\u00e1c thi\u1ebft b\u1ecb tu\u00e2n th\u1ee7 ti\u00eau chu\u1ea9n UL 489 ho\u1eb7c IEC 60947-2 bao g\u1ed3m c\u1ea3 hai th\u00e0nh ph\u1ea7n (m\u1ed9t c\u00f4ng t\u1eafc t\u1eeb t\u00ednh v\u00e0 c\u01a1 ch\u1ebf ph\u00e1t hi\u1ec7n qu\u00e1 t\u1ea3i) v\u00e0 \u0111\u01b0\u1ee3c ph\u00e9p s\u1eed d\u1ee5ng l\u00e0m thi\u1ebft b\u1ecb b\u1ea3o v\u1ec7 m\u1ea1ch nh\u00e1nh. M\u1eb7c d\u00f9 k\u00edch th\u01b0\u1edbc v\u00e0 h\u00ecnh d\u1ea1ng th\u1ef1c t\u1ebf c\u1ee7a m\u1ed7i lo\u1ea1i thi\u1ebft b\u1ecb r\u1ea5t g\u1ea7n nhau, nh\u01b0ng c\u00f3 s\u1ef1 kh\u00e1c bi\u1ec7t l\u1edbn v\u1ec1 ph\u00e1p l\u00fd v\u00e0 quy \u0111\u1ecbnh gi\u1eefa hai lo\u1ea1i.<\/p>\n

    B\u1ed9 b\u1ea3o v\u1ec7 m\u1ea1ch ch\u1ec9 s\u1eed d\u1ee5ng t\u1eeb t\u00ednh \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng khi c\u00f3 c\u01a1 ch\u1ebf b\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i \u1edf n\u01a1i kh\u00e1c, nh\u01b0 thi\u1ebft b\u1ecb c\u00f3 b\u1ea3o v\u1ec7 nhi\u1ec7t ri\u00eang ho\u1eb7c trong m\u1ea1ch b\u00e1n d\u1eabn n\u01a1i c\u1ea7n x\u1ea3 nhanh d\u00f2ng \u0111i\u1ec7n, ho\u1eb7c trong m\u1ed9t s\u1ed1 \u1ee9ng d\u1ee5ng s\u1eed d\u1ee5ng d\u00f2ng \u0111i\u1ec7n m\u1ed9t chi\u1ec1u li\u00ean t\u1ee5c. B\u1ea3ng ph\u00e2n ph\u1ed1i \u0111i\u1ec7n gia \u0111\u00ecnh \u0111i\u1ec3n h\u00ecnh kh\u00f4ng thu\u1ed9c b\u1ea5t k\u1ef3 lo\u1ea1i n\u00e0o trong s\u1ed1 \u0111\u00f3, do \u0111\u00f3, n\u1ebfu s\u1eed d\u1ee5ng thi\u1ebft b\u1ecb ch\u1ec9 s\u1eed d\u1ee5ng t\u1eeb t\u00ednh \u0111\u1ec3 b\u1ea3o v\u1ec7 b\u1ea3ng ph\u00e2n ph\u1ed1i, n\u00f3 s\u1ebd \u0111\u1ec3 d\u00e2y d\u1eabn mang t\u1ea3i kh\u00f4ng \u0111\u01b0\u1ee3c b\u1ea3o v\u1ec7 kh\u1ecfi qu\u00e1 nhi\u1ec7t do \u0111i\u1ec1u ki\u1ec7n qu\u00e1 t\u1ea3i.<\/p>\n

    C\u00f3 r\u1ea5t nhi\u1ec1u s\u1ef1 nh\u1ea7m l\u1eabn tr\u00ean th\u1ecb tr\u01b0\u1eddng v\u1ec1 thu\u1eadt ng\u1eef \u201cc\u1ea7u dao t\u1eeb t\u00ednh.\u201d Nhi\u1ec1u ng\u01b0\u1eddi s\u1eed d\u1ee5ng thu\u1eadt ng\u1eef n\u00e0y \u0111\u1ec3 ch\u1ec9 b\u1ea5t k\u1ef3 lo\u1ea1i c\u1ea7u dao n\u00e0o s\u1eed d\u1ee5ng y\u1ebfu t\u1ed1 t\u1eeb t\u00ednh; \u0111i\u1ec1u n\u00e0y bao g\u1ed3m m\u1ecdi lo\u1ea1i c\u1ea7u dao nhi\u1ec7t t\u1eeb. Th\u00f3i quen n\u00e0y ph\u1ed5 bi\u1ebfn trong t\u00e0i li\u1ec7u b\u00e1n h\u00e0ng, l\u00e0m cho vi\u1ec7c ng\u01b0\u1eddi \u0111\u00e1nh gi\u00e1 th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt kh\u00f3 ph\u00e2n bi\u1ec7t gi\u1eefa c\u00e1c s\u1ea3n ph\u1ea9m c\u00f3 c\u00e1c lo\u1ea1i ch\u1ee9ng nh\u1eadn kh\u00e1c nhau khi s\u1eed d\u1ee5ng c\u00f9ng m\u1ed9t thu\u1eadt ng\u1eef.<\/p>\n

    C\u1ea7u dao nhi\u1ec7t t\u1eeb so v\u1edbi c\u1ea7u dao v\u1ecf \u0111\u00fac<\/h2>\n

    M\u1eb7c d\u00f9 c\u00f3 v\u1ebb nh\u01b0 so s\u00e1nh gi\u1eefa c\u1ea7u dao nhi\u1ec7t t\u1eeb v\u00e0 c\u1ea7u dao v\u1ecf \u0111\u00fac<\/a> l\u00e0 \u0111\u1ed1i l\u1eadp, nh\u01b0ng th\u1ef1c t\u1ebf kh\u00f4ng ph\u1ea3i v\u1eady, v\u00e0 l\u00fd do so s\u00e1nh n\u00e0y xu\u1ea5t hi\u1ec7n trong k\u1ebft qu\u1ea3 t\u00ecm ki\u1ebfm l\u00e0 do ng\u01b0\u1eddi t\u00ecm ki\u1ebfm gi\u1ea3 \u0111\u1ecbnh nh\u01b0 v\u1eady.<\/p>\n

    V\u1ec1 c\u01a1 b\u1ea3n, MCCB l\u00e0 m\u1ed9t v\u1ecf \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf \u0111\u1ec3 c\u00f3 c\u00f9ng c\u00f4ng su\u1ea5t t\u1ed1i \u0111a v\u1edbi v\u1ecf c\u1ee7a n\u00f3; tuy nhi\u00ean, \u0111\u1ecbnh m\u1ee9c \u0111i\u1ec7n c\u1ee7a c\u1ea7u dao \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh theo c\u00f4ng ngh\u1ec7 ng\u1eaft t\u00edch h\u1ee3p c\u1ee7a n\u00f3. Do \u0111\u00f3, n\u00f3 c\u00f3 th\u1ec3 l\u00e0 \u2018nhi\u1ec7t t\u1eeb\u2019 ho\u1eb7c \u2018\u0111i\u1ec7n t\u1eed\u2019, v\u00e0 c\u1ea3 hai lo\u1ea1i \u0111\u1ec1u \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i.<\/p>\n

    V\u00ed d\u1ee5, m\u1ed9t c\u1ea7u dao v\u1ecf \u0111\u00fac 250 A (\u2018MCCB\u2019) v\u1edbi b\u1ed9 ng\u1eaft nhi\u1ec7t t\u1eeb c\u0169ng s\u1ebd \u0111\u00e1p \u1ee9ng c\u00e1c y\u00eau c\u1ea7u \u0111\u1ecbnh ngh\u0129a c\u1ee7a m\u1ed9t c\u1ea7u dao v\u1ecf \u0111\u00fac (\u2018MCCB\u2019). C\u00f9ng lo\u1ea1i khung v\u1edbi b\u1ed9 ng\u1eaft \u0111i\u1ec7n t\u1eed s\u1ebd kh\u00f4ng ph\u1ea3i l\u00e0 nhi\u1ec7t t\u1eeb, nh\u01b0ng v\u1eabn \u0111\u01b0\u1ee3c ph\u00e2n lo\u1ea1i l\u00e0 \u2018MCCB\u2019.<\/p>\n

    Trong th\u1ef1c t\u1ebf, \u0111i\u1ec1u quan tr\u1ecdng l\u00e0 m\u1ed9t \u0111\u1eb7c t\u1ea3 ph\u1ea3i m\u00f4 t\u1ea3 c\u1ea3 hai \u0111\u1eb7c \u0111i\u1ec3m n\u00e0y, c\u1ee5 th\u1ec3 l\u00e0 lo\u1ea1i khung v\u00e0 c\u00f4ng ngh\u1ec7 ng\u1eaft m\u1ea1ch. M\u1ed9t b\u1ea3ng bi\u1ec3u ghi \u2018250 A MCCB\u2019 m\u00f4 t\u1ea3 lo\u1ea1i khung, nh\u01b0ng kh\u00f4ng cung c\u1ea5p b\u1ea5t k\u1ef3 th\u00f4ng tin n\u00e0o li\u00ean quan \u0111\u1ebfn b\u1ea3o v\u1ec7 \u0111\u01b0\u1ee3c cung c\u1ea5p. \u0110i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 hai nh\u00e0 cung c\u1ea5p kh\u00e1c nhau c\u00f3 th\u1ec3 b\u00e1o gi\u00e1 m\u1ed9t d\u00f2ng \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ecbnh trong b\u1ea3ng bi\u1ec3u c\u1ee7a h\u1ecd b\u1eb1ng c\u00e1c thi\u1ebft b\u1ecb c\u00f3 h\u00e0nh vi r\u1ea5t kh\u00e1c nhau.<\/p>\n

    So s\u00e1nh h\u00e0nh vi gi\u1eefa MCCB v\u00e0 <\/a>b\u1ed9 ng\u1eaft m\u1ea1ch mini<\/a> bao ph\u1ee7 c\u00f9ng m\u1ed9t ch\u1ee7 \u0111\u1ec1 t\u1eeb c\u00e1c g\u00f3c nh\u00ecn kh\u00e1c nhau, v\u00e0 vi\u1ec7c \u0111\u1ecdc c\u1ea3 hai b\u00e1o c\u00e1o c\u00f9ng nhau l\u00e0 h\u1eefu \u00edch v\u00ec hai lo\u1ea1i thi\u1ebft b\u1ecb n\u00e0y th\u01b0\u1eddng \u0111\u01b0\u1ee3c k\u1ebft h\u1ee3p trong c\u00e1c b\u1ea3ng bi\u1ec3u d\u1ef1 \u00e1n.<\/p>\n

    N\u01a1i M\u1ed7i Lo\u1ea1i \u0110\u01b0\u1ee3c S\u1eed D\u1ee5ng<\/h2>\n

    C\u00e1c thi\u1ebft b\u1ecb nhi\u1ec7t t\u1eeb th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng cho b\u1ea3o v\u1ec7 m\u1ea1ch cu\u1ed1i v\u00e0 c\u00e1c m\u1ea1ch ph\u1ee5 ch\u00ednh n\u01a1i t\u1ea3i t\u01b0\u01a1ng \u0111\u1ed1i c\u00f3 th\u1ec3 d\u1ef1 \u0111o\u00e1n \u0111\u01b0\u1ee3c; l\u01b0\u1ee3ng qu\u00e1 t\u1ea3i c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c gi\u1edbi h\u1ea1n; d\u00f2ng s\u1ef1 c\u1ed1 kh\u00f4ng qu\u00e1 cao; v\u00e0 trung t\u00e2m t\u1ea3i ch\u1ee9a nhi\u1ec1u m\u1ea1ch, do \u0111\u00f3 m\u1ed9t thi\u1ebft b\u1ecb th\u1ee5 \u0111\u1ed9ng \u0111\u01a1n gi\u1ea3n, chi ph\u00ed th\u1ea5p l\u00e0 gi\u1ea3i ph\u00e1p k\u1ef9 thu\u1eadt ph\u00f9 h\u1ee3p.<\/p>\n

    M\u1ed9t m\u1ea1ch t\u1ea3i gia \u0111\u00ecnh \u0111i\u1ec3n h\u00ecnh s\u1ebd c\u00f3 m\u1ed9t c\u00f4ng t\u1eafc ch\u00ednh 63 A v\u00e0 nhi\u1ec1u b\u1ed9 ng\u1eaft m\u1ea1ch mini v\u1edbi \u0111\u01b0\u1eddng cong C, t\u1ea5t c\u1ea3 \u0111\u1ec1u l\u00e0 nhi\u1ec7t t\u1eeb.<\/p>\n

    M\u1ed9t thi\u1ebft b\u1ecb RCD (Thi\u1ebft b\u1ecb d\u00f2ng r\u00f2) ho\u1eb7c RCBO (B\u1ed9 ng\u1eaft m\u1ea1ch d\u00f2ng r\u00f2 c\u00f3 b\u1ea3o v\u1ec7 qu\u00e1 d\u00f2ng) \u0111\u01b0\u1ee3c th\u00eam v\u00e0o c\u00e1c m\u1ea1ch \u1ed5 c\u1eafm b\u1edfi nhi\u1ec1u b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n th\u01b0\u01a1ng m\u1ea1i b\u00ean c\u1ea1nh vi\u1ec7c gi\u1eef t\u1ea5t c\u1ea3 c\u00e1c b\u1ea3o v\u1ec7 kh\u00e1c ch\u1ec9 b\u1eb1ng nhi\u1ec7t t\u1eeb. \u0110\u1ed1i v\u1edbi B\u1ea3ng \u0111i\u1ec1u khi\u1ec3n M\u00e1y m\u00f3c s\u1ebd c\u00f3 m\u1ed9t B\u1ed9 ng\u1eaft m\u1ea1ch v\u1ecf \u0111\u00fac 100 A v\u1edbi ng\u1eaft nhi\u1ec7t t\u1eeb do d\u00f2ng kh\u1edfi \u0111\u1ed9ng c\u1ee7a \u0111\u1ed9ng c\u01a1 \u0111\u00e3 bi\u1ebft v\u00e0 b\u1ea3o v\u1ec7 b\u1eb1ng \u0111\u01b0\u1eddng cong D ho\u1eb7c c\u00e0i \u0111\u1eb7t t\u1eeb c\u00f3 th\u1ec3 \u0111i\u1ec1u ch\u1ec9nh cho th\u1eddi gian kh\u1edfi \u0111\u1ed9ng c\u1ee7a \u0111\u1ed9ng c\u01a1.<\/p>\n

    C\u00e1c thi\u1ebft b\u1ecb ng\u1eaft \u0111i\u1ec7n t\u1eed s\u1ebd \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng t\u1ea1i ngu\u1ed3n c\u1ea5p ch\u00ednh c\u1ee7a nh\u00e0 m\u00e1y c\u0169ng nh\u01b0 tr\u00ean c\u00e1c nh\u00e1nh c\u1ea5p ph\u1ea3i ph\u1ed1i h\u1ee3p v\u1edbi c\u00e1c thi\u1ebft b\u1ecb b\u00ean d\u01b0\u1edbi v\u00e0 b\u1ea5t c\u1ee9 n\u01a1i n\u00e0o c\u00f3 y\u00eau c\u1ea7u xem c\u00e1c ch\u1ec9 s\u1ed1 nh\u01b0 m\u1ee5c \u0111\u00edch qu\u1ea3n l\u00fd n\u0103ng l\u01b0\u1ee3ng. C\u0169ng \u0111\u01b0\u1ee3c t\u00ecm th\u1ea5y tr\u00ean c\u00e1c m\u00e1y ph\u00e1t \u0111i\u1ec7n v\u00e0 c\u00e1c m\u1ea1ch s\u1ebd y\u00eau c\u1ea7u thay \u0111\u1ed5i c\u00e0i \u0111\u1eb7t ng\u1eaft sau khi thi\u1ebft b\u1ecb \u0111\u00e3 \u0111\u01b0\u1ee3c \u0111\u01b0a v\u00e0o v\u1eadn h\u00e0nh m\u00e0 kh\u00f4ng c\u1ea7n ph\u1ea3i thay th\u1ebf thi\u1ebft b\u1ecb.<\/p>\n

    T\u1eeb kinh nghi\u1ec7m tr\u01b0\u1edbc \u0111\u00e2y tr\u00ean nhi\u1ec1u d\u1ef1 \u00e1n, m\u00f4 h\u00ecnh th\u00f4ng th\u01b0\u1eddng s\u1ebd s\u1eed d\u1ee5ng nhi\u1ec7t t\u1eeb cho t\u1ea5t c\u1ea3 c\u00e1c \u1ee9ng d\u1ee5ng d\u01b0\u1edbi 250 A tr\u1eeb khi \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf cho t\u00ednh ch\u1ecdn l\u1ecdc, s\u1eed d\u1ee5ng ng\u1eaft \u0111i\u1ec7n t\u1eed cho t\u1ea5t c\u1ea3 c\u00e1c \u1ee9ng d\u1ee5ng tr\u00ean 400 A, v\u00e0 k\u1ebft h\u1ee3p c\u1ea3 hai trong kho\u1ea3ng t\u1eeb 250 A \u0111\u1ebfn 400 A. Do \u0111\u00f3, m\u00f4 h\u00ecnh n\u00e0y kh\u00f4ng ph\u1ea3i l\u00e0 ti\u00eau c\u1ef1c, n\u00f3 gi\u1ea3i th\u00edch ph\u1ea7n l\u1edbn c\u00e1c b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n \u0111\u01b0\u1ee3c s\u1ea3n xu\u1ea5t trong m\u01b0\u1eddi n\u0103m qua. C\u00e1c B\u1ed9 ng\u1eaft m\u1ea1ch v\u1ecf \u0111\u00fac \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong c\u00e1c B\u1ea3ng \u0111i\u1ec1u khi\u1ec3n Ph\u00e2n ph\u1ed1i \u0111\u00e3 \u0111\u01b0\u1ee3c s\u1ea3n xu\u1ea5t c\u1ea3 hai phi\u00ean b\u1ea3n v\u00ec l\u00fd do \u0111\u00f3.<\/p>\n

    Trong so s\u00e1nh gi\u00e1 thi\u1ebft b\u1ecb \u1edf tr\u00ean, lo\u1ea1i nhi\u1ec7t t\u1eeb l\u00e0 l\u1ef1a ch\u1ecdn \u00edt t\u1ed1n k\u00e9m nh\u1ea5t cho t\u1ea5t c\u1ea3 c\u00e1c thi\u1ebft b\u1ecb; tuy nhi\u00ean, s\u1ef1 ch\u00eanh l\u1ec7ch v\u1ec1 gi\u00e1 t\u1eeb Thermal Magnetic \u0111\u1ebfn Electronic Trip \u1edf khung 250 amp nh\u1ecf h\u01a1n s\u1ef1 ch\u00eanh l\u1ec7ch \u1edf khung 630 amp, \u0111i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 ch\u1ee9c n\u0103ng th\u01b0\u1eddng s\u1ebd l\u00e0 l\u00fd do ch\u00ednh \u0111\u1ec3 ch\u1ecdn m\u1ed9t lo\u1ea1i thay v\u00ec lo\u1ea1i kia, thay v\u00ec gi\u00e1 c\u1ea3. N\u1ebfu b\u1ea1n \u0111ang l\u1eafp \u0111\u1eb7t m\u1ed9t b\u1ea3ng c\u00f3 20 m\u1ea1ch ra v\u00e0 kh\u00f4ng y\u00eau c\u1ea7u ch\u1ecdn l\u1ecdc m\u1ea1ch, kh\u00f4ng c\u00f3 l\u00fd do g\u00ec \u0111\u1ec3 s\u1eed d\u1ee5ng b\u1ed9 ng\u1eaft \u0111i\u1ec7n t\u1eed tr\u00ean c\u00e1c m\u1ea1ch n\u00e0y.<\/p>\n

    Chi ph\u00ed<\/h2>\n

    Ngo\u00e0i chi ph\u00ed thi\u1ebft b\u1ecb, c\u00f2n c\u00f3 hai chi ph\u00ed th\u01b0\u1eddng b\u1ecb b\u1ecf qua: V\u1eadn h\u00e0nh v\u00e0 Ph\u1ee5 t\u00f9ng thay th\u1ebf. \u0110\u1ed1i v\u1edbi thi\u1ebft b\u1ecb Thermal Magnetic, kh\u00f4ng c\u1ea7n thi\u1ebft l\u1eadp thi\u1ebft b\u1ecb khi v\u1eadn h\u00e0nh, trong khi \u0111\u1ed1i v\u1edbi thi\u1ebft b\u1ecb Electronic Trip, s\u1ebd c\u00f3 qu\u00e1 tr\u00ecnh v\u1eadn h\u00e0nh y\u00eau c\u1ea7u ghi l\u1ea1i c\u00e0i \u0111\u1eb7t, \u0111i\u1ec1u n\u00e0y s\u1ebd d\u1eabn \u0111\u1ebfn chi ph\u00ed k\u1ef9 thu\u1eadt b\u1ed5 sung cho m\u1ed7i thi\u1ebft b\u1ecb.<\/p>\n

    Chi ph\u00ed th\u1ee9 hai li\u00ean quan \u0111\u1ebfn Ph\u1ee5 t\u00f9ng thay th\u1ebf l\u00e0 Electronic Trip, \u0111\u01b0\u1ee3c cung c\u1ea5p d\u01b0\u1edbi d\u1ea1ng m\u00f4-\u0111un c\u00f3 th\u1ec3 thay th\u1ebf v\u00e0 c\u00f3 s\u1ed1 b\u1ed9 ph\u1eadn v\u00e0 th\u1eddi gian giao h\u00e0ng kh\u00e1c v\u1edbi thi\u1ebft b\u1ecb Thermal Magnetic, \u0111\u01b0\u1ee3c cung c\u1ea5p d\u01b0\u1edbi d\u1ea1ng b\u1ed9 thi\u1ebft b\u1ecb ho\u00e0n ch\u1ec9nh. Tuy nhi\u00ean, m\u1ed9t s\u1ed1 m\u1eabu c\u1ee7a B\u1ed9 ng\u1eaft m\u1ea1ch v\u1ecf \u0111\u00fac \u0111\u01b0\u1ee3c b\u00e1n v\u1edbi gi\u00e1 ri\u00eang cho khung v\u00e0 lo\u1ea1i b\u1ed9 ng\u1eaft m\u1ea1ch do hai th\u00e0nh ph\u1ea7n c\u1ee7a thi\u1ebft b\u1ecb \u0111\u01b0\u1ee3c \u0111\u1ecbnh gi\u00e1 d\u1ef1a tr\u00ean c\u00e1c y\u1ebfu t\u1ed1 chi ph\u00ed kh\u00e1c nhau.<\/p>\n

    N\u01a1i HUYU<\/strong> ph\u00f9 h\u1ee3p<\/h2>\n

    Ch\u00fang t\u00f4i s\u1ea3n xu\u1ea5t c\u1ea3 b\u1ed9 ng\u1eaft m\u1ea1ch nh\u1ecf g\u1ecdn v\u00e0 b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb v\u1ecf \u0111\u00fac<\/a> v\u1edbi c\u00f4ng su\u1ea5t \u0111\u1ecbnh m\u1ee9c t\u1eeb 1A \u0111\u1ebfn 1600A. T\u1ea5t c\u1ea3 s\u1ea3n ph\u1ea9m c\u1ee7a ch\u00fang t\u00f4i \u0111\u1ec1u tu\u00e2n th\u1ee7 ti\u00eau chu\u1ea9n IEC, c\u1ee5 th\u1ec3 l\u00e0 IEC 60898-1 v\u00e0 IEC 60947-2, c\u0169ng nh\u01b0 UL 489. Ph\u1ea7n l\u1edbn c\u00e1c s\u1ea3n ph\u1ea9m c\u1ee7a ch\u00fang t\u00f4i s\u1ebd \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong c\u00e1c \u1ee9ng d\u1ee5ng kh\u00e1c nhau nh\u01b0 b\u1ea3ng ph\u00e2n ph\u1ed1i, b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n m\u00e1y m\u00f3c v\u00e0 thi\u1ebft b\u1ecb OEM, n\u01a1i kh\u00e1ch h\u00e0ng mu\u1ed1n s\u1eed d\u1ee5ng nhi\u1ec1u s\u1ea3n ph\u1ea9m t\u1eeb m\u1ed9t nh\u00e0 s\u1ea3n xu\u1ea5t thay v\u00ec ph\u1ea3i lo l\u1eafng v\u1ec1 vi\u1ec7c ph\u00f9 h\u1ee3p c\u00e1c th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt cao c\u1ea5p c\u1ee7a t\u1eebng s\u1ea3n ph\u1ea9m ri\u00eang l\u1ebb.<\/p>\n

    D\u00f2ng b\u1ed9 ng\u1eaft m\u1ea1ch nh\u1ecf g\u1ecdn c\u1ee7a ch\u00fang t\u00f4i bao g\u1ed3m nhi\u1ec1u lo\u1ea1i \u0111\u01b0\u1eddng cong: \u0111\u01b0\u1eddng cong B, C v\u00e0 D; v\u00e0 \u0111\u01b0\u1ee3c \u0111\u1ecbnh m\u1ee9c t\u1eeb 6 kA \u0111\u1ebfn 10 kA trong k\u00edch th\u01b0\u1edbc 18 mm r\u1ed9ng. M\u1ed7i b\u1ed9 ng\u1eaft m\u1ea1ch \u0111\u01b0\u1ee3c \u0111\u00e1nh d\u1ea5u lo\u1ea1i \u0111\u01b0\u1eddng cong trip v\u00e0 ng\u01b0\u1ee1ng t\u1eeb t\u00ednh \u0111\u01b0\u1ee3c hi\u1ec3n th\u1ecb r\u00f5 r\u00e0ng, kh\u00f4ng ch\u1ec9 ng\u1ee5 \u00fd. Ngo\u00e0i ra, d\u00f2ng b\u1ed9 ng\u1eaft m\u1ea1ch v\u1ecf \u0111\u00fac c\u1ee7a ch\u00fang t\u00f4i bao g\u1ed3m c\u00e1c s\u1ea3n ph\u1ea9m \u0111\u1ecbnh m\u1ee9c t\u1eeb 16A \u0111\u1ebfn 250A v\u00e0 c\u00f3 nhi\u1ec1u c\u00e0i \u0111\u1eb7t cho m\u1ed7i khung \u0111\u1ec3 cho ph\u00e9p b\u1ea3o v\u1ec7 nhi\u1ec1u k\u00edch th\u01b0\u1edbc c\u00e1p kh\u00e1c nhau.<\/p>\n

    Nh\u1eefng g\u00ec HUYU kh\u00f4ng kh\u1eb3ng \u0111\u1ecbnh l\u00e0 thi\u1ebft b\u1ecb ng\u1eaft nhi\u1ec7t t\u1eeb cung c\u1ea5p ch\u1ee9c n\u0103ng t\u01b0\u01a1ng t\u1ef1 nh\u01b0 thi\u1ebft b\u1ecb ng\u1eaft \u0111i\u1ec7n t\u1eed. Thi\u1ebft b\u1ecb ng\u1eaft nhi\u1ec7t t\u1eeb kh\u00f4ng th\u1ec3 \u0111\u01b0\u1ee3c c\u00e0i \u0111\u1eb7t \u0111\u1ec3 c\u00f3 \u0111\u1ed9 tr\u1ec5 t\u1ee9c th\u1eddi, c\u0169ng kh\u00f4ng c\u00f3 kh\u1ea3 n\u0103ng b\u00e1o c\u00e1o m\u1ee9c ti\u00eau th\u1ee5 n\u0103ng l\u01b0\u1ee3ng. Trong b\u1ea5t k\u1ef3 tr\u01b0\u1eddng h\u1ee3p n\u00e0o y\u00eau c\u1ea7u m\u1ed9t trong hai t\u00ednh n\u0103ng \u0111\u00f3 trong d\u1ef1 \u00e1n, gi\u1ea3i ph\u00e1p \u0111\u00fang s\u1ebd l\u00e0 s\u1eed d\u1ee5ng b\u1ed9 ng\u1eaft m\u1ea1ch \u0111i\u1ec7n t\u1eed v\u00e0 ch\u00fang t\u00f4i s\u1ebd cung c\u1ea5p gi\u1ea3i ph\u00e1p ch\u00ednh x\u00e1c thay v\u00ec b\u00e1o gi\u00e1 m\u1ed9t s\u1ea3n ph\u1ea9m m\u00e0 cu\u1ed1i c\u00f9ng ch\u00fang t\u00f4i s\u1ebd thay th\u1ebf sau nghi\u00ean c\u1ee9u ph\u1ed1i h\u1ee3p \u0111\u1ea7u ti\u00ean.<\/p>\n

    C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p<\/h2>\n

    B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb d\u00f9ng \u0111\u1ec3 l\u00e0m g\u00ec?<\/h3>\n

    B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t t\u1eeb \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng b\u1ea5t c\u1ee9 khi n\u00e0o b\u1ea1n c\u1ea7n c\u1ea3 b\u1ea3o v\u1ec7 qu\u00e1 d\u00f2ng v\u00e0 ng\u1eafn m\u1ea1ch t\u1eeb m\u1ed9t thi\u1ebft b\u1ecb th\u1ee5 \u0111\u1ed9ng.<\/p>\n

    Trong c\u00e1c b\u1ea3ng ph\u00e2n ph\u1ed1i d\u00e2n d\u1ee5ng v\u00e0 th\u01b0\u01a1ng m\u1ea1i, c\u00e1c m\u1ea1ch cu\u1ed1i c\u00f9ng ch\u1ee9a b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t v\u00e0 t\u1eeb \u0111\u1ec3 cung c\u1ea5p b\u1ea3o v\u1ec7 l\u1ed7i v\u00e0 b\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i nhi\u1ec7t cho to\u00e0n b\u1ed9 m\u1ea1ch nh\u00e1nh. Do \u0111\u00f3, c\u00e1c lo\u1ea1i b\u1ed9 ng\u1eaft m\u1ea1ch n\u00e0y c\u00f3 th\u1ec3 b\u1ea3o v\u1ec7 kh\u1ea3 n\u0103ng ch\u1ecbu nhi\u1ec7t c\u1ee7a c\u00e1p \u0111i\u1ec7n v\u00ec ph\u1ea7n t\u1eed nhi\u1ec7t b\u1ea3o v\u1ec7 c\u00e1p \u0111i\u1ec7n ho\u1eb7c m\u1ea1ch cu\u1ed1i tr\u01b0\u1edbc khi c\u00e1p b\u1ecb h\u1ecfng, trong khi ph\u1ea7n t\u1eed t\u1eeb b\u1ea3o v\u1ec7 c\u00e1p \u0111i\u1ec7n ho\u1eb7c m\u1ea1ch cu\u1ed1i kh\u1ecfi c\u00e1c \u0111i\u1ec1u ki\u1ec7n l\u1ed7i ng\u1eafn m\u1ea1ch.<\/p>\n

    S\u1ef1 kh\u00e1c bi\u1ec7t gi\u1eefa b\u1ed9 ng\u1eaft m\u1ea1ch t\u1eeb v\u00e0 b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t\/t\u1eeb l\u00e0 g\u00ec?<\/h3>\n

    B\u1ed9 ng\u1eaft m\u1ea1ch t\u1eeb l\u00e0 b\u1ed9 ng\u1eaft m\u1ea1ch ch\u1ec9 c\u00f3 cu\u1ed9n solenoid, do \u0111\u00f3 ch\u1ec9 b\u1ea3o v\u1ec7 ng\u1eafn m\u1ea1ch. B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t\/t\u1eeb l\u00e0 b\u1ed9 ng\u1eaft m\u1ea1ch c\u00f3 c\u1ea3 cu\u1ed9n solenoid v\u00e0 ph\u1ea7n t\u1eed bimetallic. B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t\/t\u1eeb c\u00f3 th\u1ec3 cung c\u1ea5p c\u1ea3 b\u1ea3o v\u1ec7 ng\u1eafn m\u1ea1ch v\u00e0 b\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i k\u00e9o d\u00e0i. B\u1ed9 ng\u1eaft m\u1ea1ch t\u1eeb \u0111\u01b0\u1ee3c coi l\u00e0 b\u1ea3o v\u1ec7 b\u1ed5 sung v\u00e0 \u0111\u01b0\u1ee3c ch\u1ee9ng nh\u1eadn theo ti\u00eau chu\u1ea9n UL 1077, trong khi b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t\/t\u1eeb c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng nh\u01b0 thi\u1ebft b\u1ecb b\u1ea3o v\u1ec7 m\u1ea1ch nh\u00e1nh v\u00ec ch\u00fang \u0111\u00e3 \u0111\u01b0\u1ee3c ki\u1ec3m tra c\u1ea3 ch\u1ee9c n\u0103ng ng\u1eaft nhi\u1ec7t v\u00e0 t\u1eeb.<\/p>\n

    B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t\/t\u1eeb ho\u1ea1t \u0111\u1ed9ng nh\u01b0 th\u1ebf n\u00e0o?<\/h3>\n

    B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t\/t\u1eeb ho\u1ea1t \u0111\u1ed9ng b\u1eb1ng c\u00e1ch c\u00f3 m\u1ed9t d\u1ea3i bimetallic v\u00e0 m\u1ed9t cu\u1ed9n solenoid, khi c\u00f3 qu\u00e1 t\u1ea3i k\u00e9o d\u00e0i, d\u1ea3i bimetallic s\u1ebd n\u00f3ng l\u00ean, l\u00e0m d\u1ea3i cong l\u1ea1i cho \u0111\u1ebfn khi n\u00f3 nh\u1ea3 ch\u1ed1t. Th\u1eddi gian \u0111\u1ec3 ng\u1eaft m\u1ea1ch s\u1ebd gi\u1ea3m khi d\u00f2ng \u0111i\u1ec7n t\u0103ng l\u00ean, v\u00ec d\u00f2ng \u0111i\u1ec7n c\u00e0ng l\u1edbn trong cu\u1ed9n d\u00e2y th\u00ec l\u1ef1c t\u1eeb ph\u00e1t tri\u1ec3n trong cu\u1ed9n c\u00e0ng m\u1ea1nh, khi\u1ebfn m\u1ed9t b\u1ed9 ph\u1eadn k\u00e9o d\u1ea3i bimetallic, t\u00e1c \u0111\u1ed9ng v\u00e0o ch\u1ed1t, m\u1edf c\u00e1c ti\u1ebfp \u0111i\u1ec3m trong v\u00f2ng ch\u01b0a \u0111\u1ea7y 20 mili gi\u00e2y. C\u1ea3 hai ph\u1ea7n t\u1eed \u0111\u1ec1u t\u00e1c \u0111\u1ed9ng l\u00ean m\u1ed9t c\u01a1 ch\u1ebf, do \u0111\u00f3 b\u1ea5t k\u1ef3 ph\u1ea7n t\u1eed n\u00e0o c\u0169ng c\u00f3 th\u1ec3 ng\u1eaft b\u1ed9 ng\u1eaft m\u1ea1ch.<\/p>\n

    B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t l\u00e0 g\u00ec?<\/h3>\n

    B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t ch\u1ec9 d\u1ef1a v\u00e0o hi\u1ec7u \u1ee9ng nhi\u1ec7t t\u1eeb t\u00ednh ch\u1ea5t nhi\u1ec7t c\u1ee7a d\u1ea3i bimetallic. D\u1ea3i bimetallic b\u1ecb u\u1ed1n cong do d\u00f2ng \u0111i\u1ec7n l\u00e0m n\u00f3ng n\u00f3. Nhi\u1ec7t \u0111\u1ed9 t\u0103ng l\u00ean cho \u0111\u1ebfn khi \u0111\u1ea1t \u0111\u1ebfn nhi\u1ec7t \u0111\u1ed9 hi\u1ec7u chu\u1ea9n, t\u1ea1i \u0111i\u1ec3m \u0111\u00f3 d\u1ea3i bimetallic nh\u1ea3 ch\u1ed1t.<\/p>\n

    B\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t cung c\u1ea5p b\u1ea3o v\u1ec7 theo m\u1ed1i quan h\u1ec7 ngh\u1ecbch \u0111\u1ea3o gi\u1eefa th\u1eddi gian v\u00e0 nhi\u1ec7t \u0111\u1ed9 m\u00f4 ph\u1ecfng kh\u1ea3 n\u0103ng ch\u1ecbu nhi\u1ec7t c\u1ee7a c\u00e1p, do \u0111\u00f3 b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t c\u00f3 th\u1ec3 ch\u1ecbu \u0111\u01b0\u1ee3c qu\u00e1 t\u1ea3i t\u1ea1m th\u1eddi nh\u01b0ng s\u1ebd ng\u1eaft khi qu\u00e1 t\u1ea3i k\u00e9o d\u00e0i. V\u00ec b\u1ed9 ng\u1eaft m\u1ea1ch nhi\u1ec7t kh\u00f4ng c\u00f3 ph\u1ea7n t\u1eed t\u1eeb, ch\u00fang th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng c\u00f9ng v\u1edbi thi\u1ebft b\u1ecb b\u1ed5 sung \u0111\u1ec3 x\u1eed l\u00fd c\u00e1c \u0111i\u1ec1u ki\u1ec7n l\u1ed7i ng\u1eafn m\u1ea1ch.<\/p>\n

    T\u00e0i li\u1ec7u tham kh\u1ea3o<\/h2>\n