{"id":4596,"date":"2026-10-22T06:52:41","date_gmt":"2026-10-22T06:52:41","guid":{"rendered":"https:\/\/huyuglobal.com\/?p=4596"},"modified":"2026-10-22T06:52:43","modified_gmt":"2026-10-22T06:52:43","slug":"what-is-overload-protection","status":"publish","type":"post","link":"https:\/\/huyuglobal.com\/vi\/blog\/what-is-overload-protection\/","title":{"rendered":"B\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i l\u00e0 g\u00ec v\u00e0 thi\u1ebft b\u1ecb n\u00e0o th\u1ef1c s\u1ef1 cung c\u1ea5p n\u00f3?"},"content":{"rendered":"

M\u1ed9t b\u0103ng t\u1ea3i b\u1ecb k\u1eb9t. \u0110\u1ed9ng c\u01a1 k\u00e9o d\u00f2ng 38 ampe t\u1eeb m\u1ea1ch \u0111i\u1ec7n \u0111\u01b0\u1ee3c \u0111\u1ecbnh m\u1ee9c ch\u1ec9 32 ampe trong th\u1eddi gian 90 gi\u00e2y trong khi c\u00f3 ng\u01b0\u1eddi \u0111i s\u1eeda. M\u1ecdi th\u1ee9 \u0111\u1ec1u nguy\u00ean v\u1eb9n. B\u1ed9 ng\u1eaft m\u1ea1ch v\u00e0 t\u1ea5t c\u1ea3 c\u00e1c ti\u1ebfp \u0111i\u1ec3m c\u1ee7a n\u00f3 c\u0169ng nguy\u00ean v\u1eb9n. M\u1eb7c d\u00f9 cu\u1ed9n d\u00e2y t\u0103ng nhi\u1ec7t \u0111\u1ed9 l\u00ean 40 \u0111\u1ed9 C cao h\u01a1n gi\u1edbi h\u1ea1n ghi tr\u00ean b\u1ea3ng \u0111\u1ed9ng c\u01a1, l\u1edbp c\u00e1ch \u0111i\u1ec7n b\u1ecb h\u01b0 h\u1ea1i v\u00e0 ch\u00e1y trong v\u00f2ng 3 tu\u1ea7n. M\u1ed9t k\u1ef9 s\u01b0 \u0111i\u1ec7n ph\u1ea3i ch\u1ecbu tr\u00e1ch nhi\u1ec7m. M\u1ed9t \u0111\u1ed9ng c\u01a1 m\u1edbi \u0111\u01b0\u1ee3c mua. M\u1ed9t s\u1ef1 c\u1ed1 kh\u00e1c x\u1ea3y ra trong v\u00f2ng 3 th\u00e1ng.<\/p>\n

Kho\u1ea3ng c\u00e1ch gi\u1eefa c\u00e1c ph\u00e1t bi\u1ec3u \u201cti\u00eau th\u1ee5 \u0111i\u1ec7n n\u0103ng qu\u00e1 l\u1edbn\u201d v\u00e0 \u201cb\u1ea3o v\u1ec7 m\u1ea1ch ho\u1ea1t \u0111\u1ed9ng\u201d ch\u00ednh l\u00e0 kho\u1ea3ng c\u00e1ch m\u00e0 c\u00e1c m\u00e1y ph\u00e1t \u0111i\u1ec7n \u0111\u01b0\u1ee3c ph\u00e1t tri\u1ec3n \u0111\u1ec3 bao ph\u1ee7. C\u00e1c t\u00ecnh hu\u1ed1ng li\u00ean quan \u0111\u1ebfn kho\u1ea3ng c\u00e1ch n\u00e0y l\u00e0 nh\u1eefng tr\u01b0\u1eddng h\u1ee3p ph\u1ed5 bi\u1ebfn nh\u1ea5t c\u1ee7a vi\u1ec7c l\u1eafp \u0111\u1eb7t v\u00e0 c\u00e0i \u0111\u1eb7t sai c\u00e1c ph\u1ea7n t\u1eed b\u1ea3o v\u1ec7 \u0111\u1ed9ng c\u01a1.<\/p>\n

Theo c\u00e2u tr\u1ea3 l\u1eddi nhanh, b\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i l\u00e0 m\u1ed9t lo\u1ea1i b\u1ea3o v\u1ec7 th\u1eddi gian ngh\u1ecbch \u0111\u1ea3o b\u1ea3o v\u1ec7 \u0111\u1ed9ng c\u01a1 kh\u1ecfi d\u00f2ng \u0111i\u1ec7n k\u00e9o d\u00e0i v\u01b0\u1ee3t qu\u00e1 gi\u1edbi h\u1ea1n v\u1eadn h\u00e0nh \u0111\u1ecbnh m\u1ee9c nh\u01b0ng d\u01b0\u1edbi gi\u00e1 tr\u1ecb c\u1ee7a m\u1ed9t ng\u1eafn m\u1ea1ch. Lo\u1ea1i b\u1ea3o v\u1ec7 n\u00e0y \u0111\u01b0\u1ee3c cung c\u1ea5p b\u1edfi r\u01a1 le qu\u00e1 t\u1ea3i nhi\u1ec7t, r\u01a1 le qu\u00e1 t\u1ea3i \u0111i\u1ec7n t\u1eed, b\u1ed9 ng\u1eaft m\u1ea1ch b\u1ea3o v\u1ec7 \u0111\u1ed9ng c\u01a1 ho\u1eb7c ph\u1ea7n t\u1eed nhi\u1ec7t b\u00ean trong b\u1ed9 ng\u1eaft m\u1ea1ch v\u1ecf \u0111\u00fac. Th\u1eddi gian \u0111\u01b0\u1ee3c quy \u0111\u1ecbnh b\u1edfi IEC 60947-4-1 s\u1eed d\u1ee5ng c\u00e1c l\u1edbp 10A, 10, 20 v\u00e0 30 v\u00e0 gi\u1edbi h\u1ea1n tr\u00ean c\u1ee7a c\u00e0i \u0111\u1eb7t \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh b\u1edfi NEC 430.32. HUYU s\u1ea3n xu\u1ea5t c\u00e1c b\u1ed9 kh\u1edfi \u0111\u1ed9ng \u0111i\u1ec7n t\u1eeb ExQ7, contactor ExC7 v\u00e0 b\u1ed9 ng\u1eaft m\u1ea1ch v\u1ecf \u0111\u00fac ExM3 \u0111\u1ec3 th\u1ef1c hi\u1ec7n ch\u1ee9c n\u0103ng n\u00e0y trong c\u00e1c kh\u1edfi \u0111\u1ed9ng \u0111\u1ed9ng c\u01a1.<\/p><\/blockquote>\n

Nh\u1eefng g\u00ec B\u1ea3o V\u1ec7 Qu\u00e1 T\u1ea3i Bao Ph\u1ee7, v\u00e0 Nh\u1eefng g\u00ec N\u00f3 Kh\u00f4ng Bao Ph\u1ee7<\/h2>\n

C\u00f3 ba lo\u1ea1i l\u1ed7i th\u01b0\u1eddng b\u1ecb nh\u1ea7m l\u1eabn. Ng\u1eafn m\u1ea1ch \u0111\u1ec1 c\u1eadp \u0111\u1ebfn l\u1ed7i t\u1ee9c th\u1eddi c\u00f3 d\u00f2ng l\u1ed7i \u0111\u01b0\u1ee3c \u0111o b\u1eb1ng kiloampe v\u00e0 ch\u1ec9 k\u00e9o d\u00e0i trong v\u00e0i mili gi\u00e2y. L\u1ed7i n\u1ed1i \u0111\u1ea5t x\u1ea3y ra khi d\u00f2ng l\u1ed7i \u0111i xu\u1ed1ng \u0111\u1ea5t v\u00e0 \u0111\u01b0\u1ee3c x\u1eed l\u00fd b\u1edfi RCD ho\u1eb7c GFCI. Qu\u00e1 t\u1ea3i n\u1eb1m gi\u1eefa hai lo\u1ea1i n\u00e0y; x\u1ea3y ra khi d\u00f2ng \u0111i\u1ec7n v\u01b0\u1ee3t nh\u1eb9 so v\u1edbi b\u00ecnh th\u01b0\u1eddng trong th\u1eddi gian d\u00e0i.<\/p>\n

Tuy nhi\u00ean, s\u1ef1 kh\u00e1c bi\u1ec7t nh\u1ecf h\u01a1n nhi\u1ec1u so v\u1edbi m\u1ecdi ng\u01b0\u1eddi ngh\u0129. M\u1ed9t \u0111\u1ed9ng c\u01a1 32 A ho\u1ea1t \u0111\u1ed9ng \u1edf 36 A b\u1ecb qu\u00e1 t\u1ea3i 12,5%, \u0111i\u1ec1u n\u00e0y ch\u1ea5p nh\u1eadn \u0111\u01b0\u1ee3c v\u00e0o m\u1ed9t ng\u00e0y h\u00e8 n\u00f3ng, nh\u01b0ng n\u1ebfu c\u00f9ng \u0111\u1ed9ng c\u01a1 \u0111\u00f3 ch\u1ea1y \u1edf 45 A, cu\u1ed9n d\u00e2y s\u1ebd b\u1ecb qu\u00e1 nhi\u1ec7t. Tr\u01b0\u1eddng h\u1ee3p ch\u1ea1y \u1edf 200 A s\u1ebd ng\u1ee5 \u00fd r\u1eb1ng b\u1ea3o v\u1ec7 t\u1eeb t\u00ednh ph\u1ea3i ho\u1ea1t \u0111\u1ed9ng trong v\u00f2ng ch\u01b0a \u0111\u1ea7y 20 mili gi\u00e2y.<\/p>\n

V\u00ec l\u00fd do n\u00e0y, b\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i ph\u1ea3i ho\u1ea1t \u0111\u1ed9ng ch\u1eadm h\u01a1n r\u00f5 r\u1ec7t. D\u1ef1a tr\u00ean nhi\u1ec7t \u0111\u1ed9 ch\u1ee9 kh\u00f4ng ch\u1ec9 d\u00f2ng \u0111i\u1ec7n, \u0111i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 n\u1ebfu thi\u1ebft b\u1ecb ng\u1eaft sau hai gi\u00e2y \u0111\u1ea1t 1,5 l\u1ea7n d\u00f2ng t\u1ea3i \u0111\u1ea7y \u0111\u1ee7, n\u00f3 s\u1ebd h\u1ecfng \u1edf m\u1ed7i l\u1ea7n kh\u1edfi \u0111\u1ed9ng thi\u1ebft b\u1ecb. N\u00f3 ph\u1ea3i ch\u1ecbu \u0111\u01b0\u1ee3c th\u1eddi gian kh\u1edfi \u0111\u1ed9ng trong khi nh\u1eadn bi\u1ebft qu\u00e1 nhi\u1ec7t c\u00f9ng l\u00fac.<\/p>\n

\"Nh\u1eefng<\/p>\n

C\u00e1ch Ng\u1eaft M\u1ea1ch Th\u1ef1c S\u1ef1 X\u1ea3y Ra<\/h2>\n

M\u1ed9t r\u01a1 le nhi\u1ec7t \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf sao cho n\u00f3 ch\u1ee9a hai th\u00e0nh ph\u1ea7n kim lo\u1ea1i c\u00f3 kh\u1ea3 n\u0103ng gi\u00e3n n\u1edf kh\u00e1c nhau. V\u00ed d\u1ee5, h\u00e0nh \u0111\u1ed9ng u\u1ed1n cong cho ph\u00e9p \u0111\u1ea1t \u0111\u1ebfn ng\u01b0\u1ee1ng \u0111\u1eb7t tr\u01b0\u1edbc \u0111\u1ec3 k\u00edch ho\u1ea1t c\u01a1 ch\u1ebf h\u00e0nh \u0111\u1ed9ng b\u1eadt n\u1ebfu \u0111\u1ed9 u\u1ed1n v\u01b0\u1ee3t qu\u00e1 m\u1ed9t m\u1ee9c nh\u1ea5t \u0111\u1ecbnh.<\/p>\n

Ngo\u00e0i ra, m\u1ed9t bimetal th\u1ee9 hai \u0111\u01b0\u1ee3c cung c\u1ea5p n\u0103ng l\u01b0\u1ee3ng b\u1edfi nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng l\u00e0m n\u00f3ng bimetal c\u00f2n l\u1ea1i ch\u1ecbu tr\u00e1ch nhi\u1ec7m cho ch\u1ee9c n\u0103ng c\u1ee7a \u0111\u1ed9ng c\u01a1. Trong tr\u01b0\u1eddng h\u1ee3p kh\u00f4ng c\u00f3 tu\u1ea7n ho\u00e0n kh\u00f4ng kh\u00ed trong v\u1ecf \u1edf nhi\u1ec7t \u0111\u1ed9 50\u00b0C, r\u01a1le c\u00f3 th\u1ec3 ng\u1eaft kh\u00f4ng mong mu\u1ed1n su\u1ed1t m\u00f9a h\u00e8 ho\u1eb7c cu\u1ed1i m\u00f9a \u0111\u00f4ng.<\/p>\n

R\u01a1le \u0111i\u1ec7n t\u1eed hi\u1ec7n \u0111\u1ea1i s\u1eed d\u1ee5ng bi\u1ebfn \u00e1p v\u00e0 vi \u0111i\u1ec1u khi\u1ec3n \u0111\u1ec3 cung c\u1ea5p c\u00e1c ph\u00e9p \u0111o RMS th\u1ef1c b\u1eb1ng c\u00e1ch l\u1ea5y m\u1eabu. Ch\u00fang c\u0169ng c\u00f3 th\u1ec3 th\u00eam c\u00e1c ch\u1ee9c n\u0103ng nh\u01b0 b\u1ed9 nh\u1edb nhi\u1ec7t v\u00e0 ph\u00e1t hi\u1ec7n m\u1ea5t pha c\u0169ng nh\u01b0 l\u1edbp ng\u1eaft c\u00f3 th\u1ec3 \u0111i\u1ec1u ch\u1ec9nh v\u00e0 r\u1ea5t th\u01b0\u1eddng xuy\u00ean, m\u1ed9t \u0111\u1ea7u ra 4\u201320 mA. Trong m\u1ed9t b\u1ed9 kh\u1edfi \u0111\u1ed9ng \u0111\u00f3ng g\u00f3i, r\u01a1le \u0111\u01b0\u1ee3c b\u1eaft v\u00edt tr\u1ef1c ti\u1ebfp d\u01b0\u1edbi contactor v\u00e0 \u0111\u01b0\u1ee3c \u0111\u1ea5u d\u00e2y qua c\u00f9ng m\u1ed9t kh\u1ed1i qu\u00e1 t\u1ea3i, \u0111\u00f3 l\u00e0 c\u00e1ch m\u00e0 HUYU\u2019s b\u1ed9 kh\u1edfi \u0111\u1ed9ng \u0111i\u1ec7n t\u1eeb EXQ7 k\u1ebft h\u1ee3p contactor v\u1edbi ph\u1ea7n t\u1eed qu\u00e1 t\u1ea3i<\/a> trong m\u1ed9t c\u1ee5m thay v\u00ec hai thi\u1ebft b\u1ecb ri\u00eang bi\u1ec7t tr\u00ean thanh DIN.<\/p>\n

L\u1edbp Ng\u1eaft Quy\u1ebft \u0110\u1ecbnh Th\u1eddi Gian<\/h2>\n

S\u1ed1 l\u1edbp \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a trong IEC 60947-4-1 l\u00e0 th\u1eddi gian ng\u1eaft t\u1ed1i \u0111a \u0111\u01b0\u1ee3c bi\u1ec3u th\u1ecb b\u1eb1ng gi\u00e2y t\u1ea1i h\u1ec7 s\u1ed1 7.2 c\u1ee7a d\u00f2ng ng\u1eaft t\u1eeb \u0111i\u1ec1u ki\u1ec7n \u1ea5m. Ti\u00eau chu\u1ea9n n\u00e0y c\u0169ng quy \u0111\u1ecbnh gi\u1edbi h\u1ea1n tr\u00ean l\u00e0 1.05 l\u1ea7n, sao cho r\u01a1le kh\u00f4ng th\u1ec3 ng\u1eaft v\u00e0 gi\u1edbi h\u1ea1n d\u01b0\u1edbi l\u00e0 1.2 l\u1ea7n sao cho r\u01a1le ph\u1ea3i ng\u1eaft kh\u00f4ng qu\u00e1 hai gi\u1edd.<\/p>\n\n\n\n\n\n\n\n
L\u1edbp<\/th>\nTh\u1eddi gian ng\u1eaft t\u1ea1i 7.2 \u00d7 c\u00e0i \u0111\u1eb7t (l\u1ea1nh)<\/th>\nNg\u1eaft t\u1ed1i \u0111a t\u1ea1i 1.5 \u00d7 (\u1ea5m)<\/th>\nT\u1ea3i \u0111i\u1ec3n h\u00ecnh<\/th>\n<\/tr>\n
10A<\/td>\n2\u201310 gi\u00e2y<\/td>\n120 gi\u00e2y<\/td>\nM\u00e1y n\u00e9n k\u00edn, nhi\u1ec7m v\u1ee5 kh\u1edfi \u0111\u1ed9ng l\u1ea1i n\u00f3ng<\/td>\n<\/tr>\n
10<\/td>\n4\u201310 gi\u00e2y<\/td>\n240 gi\u00e2y<\/td>\n\u0110\u1ed9ng c\u01a1 IEC ti\u00eau chu\u1ea9n, b\u01a1m v\u00e0 qu\u1ea1t \u0111i\u1ec1u khi\u1ec3n VFD<\/td>\n<\/tr>\n
20<\/td>\n6\u201320 gi\u00e2y<\/td>\n480 gi\u00e2y<\/td>\n\u0110\u1ed9ng c\u01a1 thi\u1ebft k\u1ebf NEMA B, b\u0103ng t\u1ea3i t\u1ea3i, m\u00e1y n\u00e9n<\/td>\n<\/tr>\n
30<\/td>\n9\u201330 gi\u00e2y<\/td>\n720 gi\u00e2y<\/td>\nM\u00e1y nghi\u1ec1n, m\u00e1y ly t\u00e2m, m\u00e1y nghi\u1ec1n, qu\u1ea1t qu\u00e1n t\u00ednh cao<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Vi\u1ec7c l\u1ef1a ch\u1ecdn l\u1edbp lu\u00f4n \u0111\u01b0\u1ee3c quy\u1ebft \u0111\u1ecbnh b\u1edfi th\u1eddi gian kh\u1edfi \u0111\u1ed9ng v\u00e0 kh\u00f4ng ph\u1ee5 thu\u1ed9c v\u00e0o s\u1edf th\u00edch c\u00e1 nh\u00e2n. M\u1ed9t b\u01a1m nh\u1eadn l\u1edbp 10 \u0111\u01b0\u1ee3c ph\u00e2n lo\u1ea1i ch\u00ednh x\u00e1c khi n\u00f3 ch\u1ea1y \u1edf t\u1ed1c \u0111\u1ed9 t\u1ed1i \u0111a ch\u1ec9 trong ba gi\u00e2y. Ng\u01b0\u1ee3c l\u1ea1i, m\u1ed9t qu\u1ea1t ly t\u00e2m 200 kW m\u1ea5t 25 gi\u00e2y \u0111\u1ec3 \u0111\u1ea1t t\u1ed1c \u0111\u1ed9 t\u1ed1i \u0111a s\u1ebd c\u1ea7n l\u1edbp 30 \u0111\u1ec3 kh\u00f4ng g\u00e2y ng\u1eaft r\u01a1le khi kh\u1edfi \u0111\u1ed9ng trong \u0111i\u1ec1u ki\u1ec7n b\u00ecnh th\u01b0\u1eddng v\u00e0 ng\u01b0\u1eddi v\u1eadn h\u00e0nh s\u1ebd c\u1ea7n xoay n\u00fam \u0111\u1ec3 v\u00f4 hi\u1ec7u h\u00f3a h\u1ec7 th\u1ed1ng b\u1ea3o v\u1ec7.<\/p>\n

Logic n\u00e0y c\u00f3 th\u1ec3 \u00e1p d\u1ee5ng cho tr\u01b0\u1eddng h\u1ee3p b\u1ed9 b\u1ea3o v\u1ec7 m\u1ea1ch \u0111\u1ed9ng c\u01a1 v\u00e0 c\u1ea7u dao v\u1ecf \u0111\u00fac. C\u00e1c thi\u1ebft b\u1ecb n\u00e0y c\u00f3 th\u1ec3 kh\u00f4ng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng thay th\u1ebf cho nhau trong b\u1ed9 kh\u1edfi \u0111\u1ed9ng. C\u00f3 c\u00e1c b\u1ed9 b\u1ea3o v\u1ec7 m\u1ea1ch \u0111\u1ed9ng c\u01a1 ch\u1ec9 ho\u1ea1t \u0111\u1ed9ng theo nguy\u00ean l\u00fd t\u1eeb t\u00ednh v\u00e0 kh\u00f4ng c\u00f3 ph\u1ea7n t\u1eed nhi\u1ec7t t\u00edch h\u1ee3p, \u0111i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 kh\u00f4ng th\u1ec3 th\u1ef1c hi\u1ec7n b\u1ea3o v\u1ec7 nhi\u1ec7t. S\u1ef1 kh\u00e1c bi\u1ec7t \u0111\u01b0\u1ee3c tr\u00ecnh b\u00e0y trong so s\u00e1nh n\u00e0y gi\u1eefa b\u1ed9 b\u1ea3o v\u1ec7 m\u1ea1ch \u0111\u1ed9ng c\u01a1 v\u00e0 c\u1ea7u dao<\/a>, v\u00e0 ch\u00fang quan tr\u1ecdng khi b\u1ea1n \u0111\u1eb7t h\u00e0ng m\u1ed9t b\u1ed9 kh\u1edfi \u0111\u1ed9ng t\u1eeb danh m\u1ee5c v\u1eadt t\u01b0 do ng\u01b0\u1eddi kh\u00e1c vi\u1ebft.<\/p>\n

\"L\u1edbp<\/p>\n

B\u1ed1n Thi\u1ebft B\u1ecb Th\u1ef1c Hi\u1ec7n C\u00f4ng Vi\u1ec7c N\u00e0y<\/h2>\n\n\n\n\n\n\n\n
Thi\u1ebft b\u1ecb<\/th>\nPh\u1ea7n t\u1eed qu\u00e1 t\u1ea3i<\/th>\n\u0110\u00e1nh gi\u00e1 ng\u1eafn m\u1ea1ch<\/th>\n\u0110\u1eb7t l\u1ea1i<\/th>\nPh\u00f9 h\u1ee3p nh\u1ea5t<\/th>\n<\/tr>\n
R\u01a1 le qu\u00e1 t\u1ea3i nhi\u1ec7t<\/td>\nBimetal, th\u1eddi gian ngh\u1ecbch \u0111\u1ea3o<\/td>\nKh\u00f4ng c\u00f3, c\u1ea7n d\u1ef1 ph\u00f2ng<\/td>\nTh\u1ee7 c\u00f4ng ho\u1eb7c t\u1ef1 \u0111\u1ed9ng<\/td>\nB\u1ed9 kh\u1edfi \u0111\u1ed9ng ti\u00eau chu\u1ea9n, \u0111\u1ed9ng c\u01a1 IEC<\/td>\n<\/tr>\n
R\u01a1le qu\u00e1 t\u1ea3i \u0111i\u1ec7n t\u1eed<\/td>\nCT c\u1ed9ng ph\u1ea7n m\u1ec1m nh\u00fang<\/td>\nKh\u00f4ng c\u00f3, c\u1ea7n d\u1ef1 ph\u00f2ng<\/td>\nTh\u1ee7 c\u00f4ng, t\u1eeb xa ho\u1eb7c t\u1ef1 \u0111\u1ed9ng<\/td>\nT\u1ea3i quan tr\u1ecdng, VFD, \u0111\u1eb7t l\u1ea1i t\u1eeb xa<\/td>\n<\/tr>\n
C\u1ea7u dao b\u1ea3o v\u1ec7 m\u1ea1ch \u0111\u1ed9ng c\u01a1<\/td>\nBimetal ho\u1eb7c th\u1ee7y l\u1ef1c-t\u1eeb t\u00ednh<\/td>\nBao g\u1ed3m, th\u01b0\u1eddng l\u00e0 50\u2013100 kA t\u1ea1i 400 V<\/td>\nTay g\u1ea1t th\u1ee7 c\u00f4ng<\/td>\nB\u1ed9 kh\u1edfi \u0111\u1ed9ng nh\u1ecf g\u1ecdn \u0111\u01a1n, c\u00e1ch ly t\u1ea1i ch\u1ed7<\/td>\n<\/tr>\n
B\u1ed9 ng\u1eaft m\u1ea1ch v\u1ecf \u0111\u00fac v\u1edbi ch\u1ee9c n\u0103ng ng\u1eaft nhi\u1ec7t-t\u1eeb<\/td>\nBimetal c\u1ed9ng v\u1edbi t\u1eeb t\u00ednh<\/td>\nBao g\u1ed3m, 25\u2013150 kA<\/td>\nC\u00f4ng t\u1eafc g\u1ea1t th\u1ee7 c\u00f4ng<\/td>\nB\u1ed9 c\u1ea5p ngu\u1ed3n, \u0111\u1ed9ng c\u01a1 l\u1edbn h\u01a1n, b\u1ed9 kh\u1edfi \u0111\u1ed9ng k\u1ebft h\u1ee3p<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

B\u1ea1n c\u00f3 th\u1ea5y \u0111i\u1ec1u g\u00ec thi\u1ebfu trong b\u1ea3ng kh\u00f4ng? Kh\u00f4ng c\u00f3 m\u1ed9t trong b\u1ed1n t\u00f9y ch\u1ecdn n\u00e0y n\u00e0o t\u1ed1t h\u01a1n t\u00f9y ch\u1ecdn kh\u00e1c. R\u01a1 le nhi\u1ec7t gi\u00e1m s\u00e1t cho $25 v\u00e0 th\u1ef1c hi\u1ec7n m\u1ed9t ch\u1ee9c n\u0103ng m\u00e0 kh\u00f4ng c\u1ea7n phi\u00ean b\u1ea3n firmware. B\u1ed9 ng\u1eaft m\u1ea1ch b\u1ea3o v\u1ec7 \u0111\u1ed9ng c\u01a1 c\u00f3 gi\u00e1 g\u1ea5p ba l\u1ea7n r\u01a1 le nhi\u1ec7t v\u00e0 lo\u1ea1i b\u1ecf th\u00e0nh ph\u1ea7n ph\u00e1t hi\u1ec7n ng\u1eafn m\u1ea1ch c\u0169ng nh\u01b0 h\u1ec7 th\u1ed1ng d\u00e2y \u0111i\u1ec7n. T\u1ea5t c\u1ea3 \u0111i\u1ec1u n\u00e0y d\u1eabn \u0111\u1ebfn b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n nh\u1ecf h\u01a1n v\u00e0 l\u1eafp r\u00e1p \u0111\u01a1n gi\u1ea3n h\u01a1n cho d\u1ef1 \u00e1n \u0111\u1ed9ng c\u01a1 500.<\/p>\n

C\u00e1ch c\u00e1c thi\u1ebft b\u1ecb kh\u00e1c nhau trong th\u1ef1c t\u1ebf<\/h2>\n

R\u01a1 le nhi\u1ec7t kh\u00f4ng \u0111\u00e1ng tin c\u1eady. Bimetal b\u1ecb suy gi\u1ea3m, v\u00e0 hi\u1ec7u chu\u1ea9n c\u00f3 th\u1ec3 thay \u0111\u1ed5i v\u00e0i ph\u1ea7n tr\u0103m trong kho\u1ea3ng th\u1eddi gian m\u01b0\u1eddi n\u0103m. V\u00ed d\u1ee5, khi r\u01a1 le m\u1edbi, n\u00f3 c\u00f3 gi\u1edbi h\u1ea1n 1.15, nh\u01b0ng sau 8 n\u0103m trong m\u00f4i tr\u01b0\u1eddng n\u00f3ng c\u1ee7a t\u1ee7, n\u00f3 c\u00f3 kh\u1ea3 n\u0103ng thay \u0111\u1ed5i th\u00e0nh 1.30. Th\u00f4ng th\u01b0\u1eddng, r\u01a1 le nhi\u1ec7t \u0111\u01b0\u1ee3c ki\u1ec3m tra m\u1ed9t l\u1ea7n m\u1ed7i n\u0103m b\u1eb1ng c\u00e1ch \u0111\u01b0a d\u00f2ng \u0111i\u1ec7n g\u1ea5p 1.5 l\u1ea7n. Vi\u1ec7c ki\u1ec3m tra n\u00e0y m\u1ea5t kho\u1ea3ng m\u01b0\u1eddi ph\u00fat cho m\u1ed7i r\u01a1 le v\u1edbi thi\u1ebft b\u1ecb ki\u1ec3m tra ph\u00f9 h\u1ee3p.<\/p>\n

R\u01a1 le \u0111i\u1ec7n t\u1eed gi\u1eef hi\u1ec7u chu\u1ea9n t\u1ed1t h\u01a1n nhi\u1ec1u v\u00e0 cung c\u1ea5p c\u00e1c t\u00ednh n\u0103ng b\u1ed5 sung gi\u1ea3i quy\u1ebft c\u00e1c v\u1ea5n \u0111\u1ec1 th\u1ef1c t\u1ebf. T\u00ednh n\u0103ng nh\u1edb nhi\u1ec7t c\u1ee7a r\u01a1 le \u0111i\u1ec7n t\u1eed ng\u0103n chu tr\u00ecnh kh\u1edfi \u0111\u1ed9ng l\u1ea1i v\u00e0 th\u1eed l\u1ea1i l\u00e0m h\u1ecfng cu\u1ed9n d\u00e2y. Kh\u1ea3 n\u0103ng ph\u00e1t hi\u1ec7n m\u1ea5t pha cho ph\u00e9p r\u01a1 le \u0111i\u1ec7n t\u1eed b\u1eaft \u0111\u01b0\u1ee3c qu\u00e1 t\u1ea3i c\u00f3 h\u1ea1i nh\u1ea5t cho \u0111\u1ed9ng c\u01a1 v\u00ec khi m\u1ea5t hai pha, \u0111\u1ed9ng c\u01a1 s\u1ebd k\u00e9o kho\u1ea3ng 1.7 \u0111\u1ebfn 2 l\u1ea7n c\u00f4ng su\u1ea5t m\u01b0\u1eddi c\u1ef1c trong c\u00e1c cu\u1ed9n d\u00e2y c\u00f2n l\u1ea1i trong khi pha th\u1ee9 ba kh\u00f4ng ho\u1ea1t \u0111\u1ed9ng, v\u00e0 r\u01a1 le bimetal ba ph\u1ea7n t\u1eed \u0111\u01a1n gi\u1ea3n s\u1ebd qu\u00e1 ch\u1eadm v\u00ec ch\u1ec9 c\u00f3 2 ph\u1ea7n t\u1eed c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c l\u00e0m n\u00f3ng.<\/p>\n

\u0110\u1ed1i v\u1edbi contactor, kh\u00f4ng c\u00f3 l\u00fd do g\u00ec \u0111\u1ec3 v\u01b0\u1ee3t qua r\u01a1 le n\u1ebfu contactor kh\u00f4ng ch\u1ecbu \u0111\u01b0\u1ee3c nhi\u1ec7m v\u1ee5. HUYU\u2019s Contactor AC EXC7<\/a> \u0111\u01b0\u1ee3c \u0111\u00e1nh gi\u00e1 cho nhi\u1ec7m v\u1ee5 \u0111\u1ed9ng c\u01a1 AC-3 v\u1edbi lo\u1ea1i s\u1eed d\u1ee5ng \u0111\u01b0\u1ee3c in tr\u00ean b\u1ea3ng t\u00ean, v\u00e0 vi\u1ec7c ph\u00f9 h\u1ee3p lo\u1ea1i n\u00e0y v\u1edbi nhi\u1ec7m v\u1ee5 chuy\u1ec3n m\u1ea1ch th\u1ef1c t\u1ebf quan tr\u1ecdng h\u01a1n vi\u1ec7c so s\u00e1nh \u0111\u1ecbnh m\u1ee9c ampe, con s\u1ed1 m\u00e0 h\u1ea7u h\u1ebft ng\u01b0\u1eddi mua so s\u00e1nh.<\/p>\n

Ph\u00f9 h\u1ee3p thi\u1ebft b\u1ecb v\u1edbi t\u1ea3i<\/h2>\n

Qu\u1ea1t v\u00e0 h\u1ec7 th\u1ed1ng b\u01a1m kh\u1edfi \u0111\u1ed9ng kh\u00f4ng t\u1ea3i l\u00e0 tr\u01b0\u1eddng h\u1ee3p \u0111\u01a1n gi\u1ea3n; L\u1edbp 10, FLA tr\u00ean b\u1ea3ng t\u00ean v\u1edbi vi\u1ec7c s\u1eed d\u1ee5ng b\u00f9 nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng l\u00e0 \u0111\u1ee7.<\/p>\n

B\u0103ng t\u1ea3i v\u00e0 m\u00e1y n\u00e9n v\u00edt ch\u1ea1y t\u1ea3i nh\u01b0ng kh\u1edfi \u0111\u1ed9ng ch\u1ed1ng m\u00f4 men xo\u1eafn. L\u1edbp 20 \u00e1p d\u1ee5ng cho \u0111\u1ed9ng c\u01a1 NEMA c\u00f3 h\u1ec7 s\u1ed1 d\u1ecbch v\u1ee5 1.15. Trong tr\u01b0\u1eddng h\u1ee3p n\u00e0y, c\u00e0i \u0111\u1eb7t l\u00e0 FLA tr\u00ean b\u1ea3ng t\u00ean khi \u0111\u1ed9ng c\u01a1 t\u1ea3i trong ch\u1ebf \u0111\u1ed9 v\u1eadn h\u00e0nh b\u00ecnh th\u01b0\u1eddng.<\/p>\n

B\u01a1m ch\u00ecm, m\u00e1y n\u00e9n l\u1ea1nh k\u00edn v\u00e0 t\u1ea5t c\u1ea3 h\u1ec7 th\u1ed1ng \u0111i\u1ec1u khi\u1ec3n VFD kh\u1edfi \u0111\u1ed9ng v\u1edbi l\u1edbp 10 ho\u1eb7c 10A. VFD gi\u1edbi h\u1ea1n d\u00f2ng kh\u1edfi \u0111\u1ed9ng, l\u00e0m cho r\u01a1 le qu\u00e1 t\u1ea3i b\u1ea3o v\u1ec7 ch\u1ed1ng l\u1ea1i s\u1ef1 ki\u1ec7n nhi\u1ec7t ch\u1eadm thay v\u00ec kh\u1edfi \u0111\u1ed9ng; l\u1edbp nhanh h\u01a1n cung c\u1ea5p b\u1ea3o v\u1ec7 cu\u1ed9n d\u00e2y t\u1ed1t h\u01a1n m\u00e0 kh\u00f4ng g\u00e2y ng\u1eaft kh\u00f4ng c\u1ea7n thi\u1ebft.<\/p>\n

M\u00e1y nghi\u1ec1n, m\u00e1y nghi\u1ec1n bi v\u00e0 qu\u1ea1t h\u00fat l\u1edbn c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng quay \u0111\u00e1ng k\u1ec3, v\u00ec v\u1eady c\u1ea7n t\u1eeb 20 \u0111\u1ebfn 60 gi\u00e2y \u0111\u1ec3 t\u0103ng t\u1ed1c. L\u1edbp 30 t\u1ed3n t\u1ea1i cho c\u00e1c quy tr\u00ecnh nh\u01b0 v\u1eady. Khi t\u1ea3i th\u1ef1c s\u1ef1 n\u1eb7ng nh\u01b0 v\u1eady, ch\u1ebf \u0111\u1ed9 l\u1ed7i c\u1ea7n ch\u00fa \u00fd kh\u00f4ng ph\u1ea3i l\u00e0 ng\u1eaft m\u1ea1ch m\u00e0 l\u00e0 ti\u1ebfp \u0111i\u1ec3m gi\u1eef \u0111\u1ed9ng c\u01a1 b\u1ecb k\u1eb9t \u1edf d\u00f2ng \u0111i\u1ec7n r\u00f4to kh\u00f3a trong m\u1ed9t ph\u00fat m\u1ed7i l\u1ea7n, v\u00e0 c\u00e1c tri\u1ec7u ch\u1ee9ng c\u1ee7a vi\u1ec7c l\u1ea1m d\u1ee5ng \u0111\u00f3 xu\u1ea5t hi\u1ec7n l\u00e2u tr\u01b0\u1edbc khi \u0111\u1ed9ng c\u01a1 h\u1ecfng, nh\u01b0 h\u01b0\u1edbng d\u1eabn n\u00e0y v\u1ec1 tri\u1ec7u ch\u1ee9ng h\u1ecfng ti\u1ebfp \u0111i\u1ec3m<\/a> m\u00f4 t\u1ea3.<\/p>\n

\"C\u00e0i<\/p>\n

C\u00e0i \u0111\u1eb7t n\u00fam v\u1eb7n: C\u00e1c con s\u1ed1 quan tr\u1ecdng<\/h2>\n

NEC 430.32 gi\u1edbi h\u1ea1n c\u00e0i \u0111\u1eb7t qu\u00e1 t\u1ea3i \u1edf 125% d\u00f2ng \u0111i\u1ec7n \u0111\u1ecbnh m\u1ee9c t\u1ea3i \u0111\u1ea7y \u0111\u1ee7 c\u1ee7a \u0111\u1ed9ng c\u01a1 \u0111\u1ed1i v\u1edbi c\u00e1c \u0111\u1ed9ng c\u01a1 c\u00f3 nhi\u1ec7t \u0111\u1ed9 t\u0103ng kh\u00f4ng qu\u00e1 40\u00b0C ho\u1eb7c h\u1ec7 s\u1ed1 d\u1ecbch v\u1ee5 t\u1eeb 1,15 tr\u1edf l\u00ean. N\u1ebfu kh\u00f4ng, gi\u1edbi h\u1ea1n \u0111\u01b0\u1ee3c \u0111\u1eb7t \u1edf 115%. Theo B\u1ea3ng 430.32(A)(1), c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng 140% v\u00e0 130% t\u01b0\u01a1ng \u1ee9ng, khi \u0111\u1ed9ng c\u01a1 kh\u00f4ng kh\u1edfi \u0111\u1ed9ng \u1edf c\u00e0i \u0111\u1eb7t th\u1ea5p h\u01a1n.<\/p>\n

\u0110\u1eb7t n\u00fam v\u1eb7n theo d\u00f2ng \u0111i\u1ec7n tr\u00ean b\u1ea3ng t\u00ean c\u1ee7a \u0111\u1ed9ng c\u01a1 thay v\u00ec d\u00f2ng \u0111i\u1ec7n ng\u1eaft m\u1ea1ch v\u00e0 d\u00f2ng \u0111i\u1ec7n \u0111\u1ecbnh m\u1ee9c. R\u01a1 le 7,5\u201311 A c\u00e0i \u0111\u1eb7t \u1edf 10 A s\u1ebd kh\u00f4ng ng\u1eaft \u1edf 10,5 A nh\u01b0ng s\u1ebd ng\u1eaft \u1edf 12 A trong v\u00f2ng hai gi\u1edd. V\u00ed d\u1ee5, n\u1ebfu \u0111\u1ed3ng h\u1ed3 k\u1eb9p \u0111o d\u00f2ng \u0111i\u1ec7n ch\u1ea1y l\u00e0 9,6 A, c\u00e0i \u0111\u1eb7t l\u00e0 t\u1ed1t v\u00e0 kh\u00f4ng c\u1ea7n \u0111i\u1ec1u ch\u1ec9nh th\u00eam. N\u1ebfu \u0111\u1ecdc \u0111\u01b0\u1ee3c 10,8 A, cho th\u1ea5y c\u00f3 v\u1ea5n \u0111\u1ec1 v\u1edbi t\u1ea3i, ch\u1ec9 c\u1ea7n t\u0103ng c\u00e0i \u0111\u1eb7t l\u00ean 12 A s\u1ebd d\u1eabn \u0111\u1ebfn c\u00e1c ph\u1ee9c t\u1ea1p h\u01a1n.<\/p>\n

C\u00e0i \u0111\u1eb7t cho nhi\u1ec7t \u0111\u1ed9 m\u00f4i tr\u01b0\u1eddng \u0111\u1ee9ng th\u1ee9 hai. R\u01a1 le c\u00f3 b\u00f9 nhi\u1ec7t c\u00f3 th\u1ec3 ho\u1ea1t \u0111\u1ed9ng trong ph\u1ea1m vi t\u1eeb \u221220\u00b0C \u0111\u1ebfn +60\u00b0C m\u00e0 kh\u00f4ng c\u1ea7n \u0111i\u1ec1u ch\u1ec9nh. R\u01a1 le kh\u00f4ng b\u00f9 nhi\u1ec7t l\u1eafp c\u1ea1nh ti\u1ebfp \u0111i\u1ec3m 300 A s\u1ebd \u0111\u01b0\u1ee3c \u0111\u1eb7t th\u1ea5p 10% v\u00e0 \u0111i\u1ec1u ch\u1ec9nh b\u00f9 s\u1ebd \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n b\u1eb1ng c\u00e1ch v\u1eb7n n\u00fam l\u00ean, \u0111i\u1ec1u n\u00e0y kh\u00f4ng ph\u1ea3i l\u00e0 c\u00e1ch \u0111\u00fang \u0111\u1ec3 ch\u1ec9nh c\u00e0i \u0111\u1eb7t.<\/p>\n

Sai l\u1ea7m l\u00e0m m\u1ea5t hi\u1ec7u qu\u1ea3 b\u1ea3o v\u1ec7<\/h2>\n

Sai l\u1ea7m ph\u1ed5 bi\u1ebfn l\u00e0 s\u1eed d\u1ee5ng b\u1ed9 gia nhi\u1ec7t qu\u00e1 l\u1edbn. Khi r\u01a1 le thi\u1ebft k\u1ebf cho \u0111\u1ed9ng c\u01a1 ti\u00eau th\u1ee5 40 A ho\u1ea1t \u0111\u1ed9ng c\u00f9ng thi\u1ebft b\u1ecb c\u1ea7n 32 A, n\u00f3 ho\u1ea1t \u0111\u1ed9ng \u1edf 80% m\u1ee9c \u0111\u00fang v\u00e0 kh\u00f4ng t\u1eaft, ngh\u0129a l\u00e0 kh\u00f4ng cung c\u1ea5p b\u1ea3o v\u1ec7 cho \u0111\u1ebfn khi cu\u1ed9n d\u00e2y \u0111i\u1ec1u khi\u1ec3n b\u1ecb ch\u00e1y.<\/p>\n

V\u1ea5n \u0111\u1ec1 kh\u00e1c l\u00e0 thi\u1ebft b\u1ecb t\u1ef1 \u0111\u1eb7t l\u1ea1i \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng cho thi\u1ebft b\u1ecb t\u1eeb xa. Trong khi s\u1eed d\u1ee5ng thi\u1ebft b\u1ecb t\u1ef1 \u0111\u1eb7t l\u1ea1i cho b\u01a1m ch\u1ec9 t\u1eaft m\u1ed9t l\u1ea7n m\u1ed7i m\u00f9a l\u00e0 \u1ed5n, vi\u1ec7c ch\u00fang k\u00edch ho\u1ea1t m\u1ed7i 90 gi\u00e2y v\u1edbi b\u0103ng t\u1ea3i b\u1ecb k\u1eb9t l\u00e0m t\u00ecnh h\u00ecnh t\u1ec7 h\u01a1n so v\u1edbi ch\u00ednh s\u1ef1 k\u1eb9t \u0111\u00f3.<\/p>\n

H\u01a1n n\u1eefa, ng\u01b0\u1eddi ta th\u01b0\u1eddng b\u1ecf qua ti\u1ebfp \u0111i\u1ec3m 95\u201396 trong qu\u00e1 tr\u00ecnh l\u1eafp \u0111\u1eb7t v\u00ec b\u1ed9 kh\u1edfi \u0111\u1ed9ng kh\u00f4ng kh\u00f3a \u0111\u01b0\u1ee3c v\u1ecb tr\u00ed v\u00e0 th\u1eadm ch\u00ed kh\u00f4ng b\u1eadt l\u1ea1i sau \u0111\u00f3. M\u1eb7c d\u00f9 r\u01a1 le \u0111\u00e3 \u0111\u01b0\u1ee3c hi\u1ec7u chu\u1ea9n \u0111\u00fang, n\u00f3 kh\u00f4ng c\u00f2n ho\u1ea1t \u0111\u1ed9ng \u0111\u00fang n\u1eefa. N\u00ean ki\u1ec3m tra h\u1ec7 th\u1ed1ng \u0111\u1ecbnh k\u1ef3 \u0111\u1ec3 \u0111\u1ea3m b\u1ea3o b\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i kh\u00f4ng k\u1ebft n\u1ed1i v\u1edbi cu\u1ed9n d\u00e2y b\u1ecb l\u1ed7i v\u00e0 vi\u1ec7c ki\u1ec3m tra h\u1ec7 th\u1ed1ng b\u1eb1ng \u0111\u1ed3ng h\u1ed3 \u0111o c\u0169ng kh\u00f4ng ph\u1ea3i l\u00e0 \u00fd t\u01b0\u1edfng t\u1ed3i.<\/p>\n

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

B\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i c\u00f3 gi\u1ed1ng v\u1edbi b\u1ed9 b\u1ea3o v\u1ec7 ch\u1ed1ng s\u00e9t kh\u00f4ng?<\/h3>\n

Kh\u00f4ng, c\u0169ng kh\u00f4ng th\u1ec3 s\u1eed d\u1ee5ng thay th\u1ebf cho nhau. B\u1ed9 b\u1ea3o v\u1ec7 ch\u1ed1ng s\u00e9t gi\u1eef m\u1ed9t \u0111\u1ec9nh \u0111i\u1ec7n \u00e1p t\u1ea1m th\u1eddi x\u1ea3y ra trong micro gi\u00e2y v\u00e0 kh\u00f4ng x\u1eed l\u00fd d\u00f2ng \u0111i\u1ec7n ch\u00fat n\u00e0o. B\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i ho\u1ea1t \u0111\u1ed9ng sau khi ti\u1ebfp x\u00fac v\u1edbi d\u00f2ng \u0111i\u1ec7n v\u01b0\u1ee3t qu\u00e1 li\u00ean t\u1ee5c trong v\u00e0i gi\u00e2y ho\u1eb7c ph\u00fat. M\u1ed9t b\u1ea3ng \u0111i\u1ec1u khi\u1ec3n c\u00f3 th\u1ec3 v\u00e0 th\u01b0\u1eddng c\u1ea7n c\u1ea3 hai, v\u00e0 c\u00e1ch ch\u00fang t\u01b0\u01a1ng t\u00e1c trong m\u1ed9t \u0111i\u1ec3m v\u00e0o d\u1ecbch v\u1ee5 \u0111\u01b0\u1ee3c \u0111\u1ec1 c\u1eadp trong so s\u00e1nh c\u1ee7a m\u1ed9t b\u1ed9 ng\u1eaft m\u1ea1ch so v\u1edbi m\u1ed9t b\u1ed9 b\u1ea3o v\u1ec7 ch\u1ed1ng s\u00e9t<\/a>.<\/p>\n

H\u00ecnh th\u1ee9c \u0111\u01a1n gi\u1ea3n nh\u1ea5t c\u1ee7a b\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i l\u00e0 g\u00ec?<\/h3>\n

R\u01a1 le qu\u00e1 t\u1ea3i nhi\u1ec7t bao g\u1ed3m m\u1ed9t ph\u1ea7n t\u1eed kim lo\u1ea1i k\u00e9p \u0111\u01b0\u1ee3c k\u1ebft n\u1ed1i n\u1ed1i ti\u1ebfp v\u1edbi cu\u1ed9n d\u00e2y ti\u1ebfp \u0111i\u1ec3m th\u00f4ng qua ti\u1ebfp \u0111i\u1ec3m 95-96. C\u00f3 hai d\u00e2y cho \u0111\u1ea7u v\u00e0o v\u00e0 \u0111\u1ea7u ra m\u1ed7i b\u00ean, c\u0169ng nh\u01b0 n\u00fam \u0111i\u1ec1u ch\u1ec9nh d\u00f2ng \u0111i\u1ec7n v\u00e0 n\u00fat \u0111\u1eb7t l\u1ea1i th\u1ee7 c\u00f4ng. N\u00f3 kh\u00f4ng y\u00eau c\u1ea7u ngu\u1ed3n \u0111i\u1ec7n ph\u1ee5 tr\u1ee3 ho\u1eb7c c\u1ea5u h\u00ecnh n\u00e0o, \u0111\u00f3 l\u00e0 l\u00fd do t\u1ea1i sao n\u00f3 v\u1eabn ti\u1ebfp t\u1ee5c l\u00e0 l\u1ef1a ch\u1ecdn h\u00e0ng \u0111\u1ea7u cho c\u00e1c b\u1ed9 kh\u1edfi \u0111\u1ed9ng \u0111a n\u0103ng.<\/p>\n

\u201cKh\u00f4ng c\u00f3 b\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i\u201d c\u00f3 ngh\u0129a l\u00e0 g\u00ec?<\/h3>\n

N\u00f3 cho th\u1ea5y m\u1ea1ch ch\u1ec9 \u0111\u01b0\u1ee3c b\u1ea3o v\u1ec7 kh\u1ecfi ng\u1eafn m\u1ea1ch v\u00e0 l\u1ed7i \u0111\u1ea5t. M\u1ed9t b\u1ed9 ng\u1eaft t\u1eeb ho\u1eb7c m\u1ed9t nh\u00f3m c\u1ea7u ch\u00ec s\u1ebd gi\u1eef cho \u0111\u1ed9ng c\u01a1 ch\u1ea1y \u1edf 150% d\u00f2ng \u0111i\u1ec7n \u0111\u1ecbnh m\u1ee9c li\u00ean t\u1ee5c v\u00ec 150% kh\u00e1 xa \u0111i\u1ec3m ng\u1eaft t\u1eeb. Th\u1eadt kh\u00f4ng may, \u0111\u1ed9ng c\u01a1 s\u1ebd h\u1ecfng, nh\u01b0ng n\u00f3 s\u1ebd h\u1ecfng do nhi\u1ec7t thay v\u00ec h\u1ecfng \u0111\u1ed9t ng\u1ed9t.<\/p>\n

B\u1ed9 b\u1ea3o v\u1ec7 qu\u00e1 t\u1ea3i l\u00e0m g\u00ec?<\/h3>\n

N\u00f3 gi\u00e1m s\u00e1t d\u00f2ng \u0111i\u1ec7n, m\u00f4 ph\u1ecfng nhi\u1ec7t sinh ra trong cu\u1ed9n d\u00e2y c\u1ee7a m\u1ea1ch \u0111\u1ed9ng c\u01a1 \u0111i\u1ec7n, v\u00e0 ng\u1eaft m\u1ea1ch \u0111i\u1ec1u khi\u1ec3n khi nhi\u1ec7t v\u01b0\u1ee3t qu\u00e1 gi\u1edbi h\u1ea1n c\u1ee7a cu\u1ed9n d\u00e2y. H\u00e0nh \u0111\u1ed9ng \u0111\u1ea7u ra kh\u00f4ng li\u00ean quan \u0111\u1ebfn vi\u1ec7c ng\u1eaft c\u00e1c ti\u1ebfp \u0111i\u1ec3m ch\u00ednh m\u00e0 ch\u1ec9 l\u00e0m r\u01a1i cu\u1ed9n d\u00e2y c\u1ee7a ti\u1ebfp \u0111i\u1ec3m, do \u0111\u00f3 ti\u1ebfp \u0111i\u1ec3m qu\u00e1 t\u1ea3i \u0111\u01b0\u1ee3c n\u1ed1i v\u00e0o m\u1ea1ch \u0111i\u1ec1u khi\u1ec3n thay v\u00ec m\u1ea1ch ngu\u1ed3n.<\/p>\n

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