{"id":6409,"date":"2026-11-09T00:00:00","date_gmt":"2026-11-09T00:00:00","guid":{"rendered":"https:\/\/chac-electric.com\/?p=6409"},"modified":"2026-11-09T06:09:32","modified_gmt":"2026-11-09T06:09:32","slug":"kiem-tra-thiet-ke-ve-yeu-cau-giam-dien-ap-khi-noi-voi-mach-duoc-bao-ve","status":"publish","type":"post","link":"https:\/\/chac-electric.com\/vi\/blog\/nec-voltage-drop-requirements-design-checks-for-protected-circuits\/","title":{"rendered":"Y\u00eau c\u1ea7u v\u1ec1 \u0111\u1ed9 gi\u1ea3m \u0111i\u1ec7n \u00e1p c\u1ee7a NEC: Ki\u1ec3m tra thi\u1ebft k\u1ebf cho c\u00e1c m\u1ea1ch \u0111\u01b0\u1ee3c b\u1ea3o v\u1ec7"},"content":{"rendered":"
\n

M\u1ed9t m\u1ea1ch d\u00e0i c\u00f3 th\u1ec3 \u0111\u00e1p \u1ee9ng \u0111\u01b0\u1ee3c y\u00eau c\u1ea7u v\u1ec1 c\u00f4ng su\u1ea5t nh\u01b0ng l\u1ea1i cung c\u1ea5p qu\u00e1 \u00edt \u0111i\u1ec7n \u00e1p trong qu\u00e1 tr\u00ecnh ho\u1ea1t \u0111\u1ed9ng. Vi\u1ec7c t\u0103ng c\u01b0\u1eddng \u0111\u1ed9 d\u00f2ng \u0111i\u1ec7n kh\u00f4ng l\u00e0m gi\u1ea3m \u0111i\u1ec7n tr\u1edf c\u1ee7a d\u00e2y d\u1eabn. C\u00e1ch gi\u1ea3i quy\u1ebft thi\u1ebft k\u1ebf h\u1eefu \u00edch l\u00e0 \u0111\u00e1nh gi\u00e1 m\u1ee9c gi\u1ea3m \u0111i\u1ec7n \u00e1p, t\u1ea3i tr\u1ecdng v\u00e0 \u0111\u01b0\u1eddng d\u1eabn truy\u1ec1n \u0111i\u1ec7n, \u0111\u1ed3ng th\u1eddi v\u1eabn duy tr\u00ec ch\u1ee9c n\u0103ng b\u1ea3o v\u1ec7 qu\u00e1 d\u00f2ng \u0111i\u1ec7n.<\/p>\n

T\u00f3m t\u1eaft:<\/strong> C\u00e1c gi\u00e1 tr\u1ecb ph\u1ed5 bi\u1ebfn c\u1ee7a h\u1ec7 th\u1ed1ng 3% nh\u00e1nh v\u00e0 5% nh\u00e1nh k\u1ebft h\u1ee3p c\u00f9ng v\u1edbi c\u00e1c thi\u1ebft b\u1ecb c\u1ea5p \u0111i\u1ec7n ph\u1ee5 l\u00e0 nh\u1eefng khuy\u1ebfn ngh\u1ecb thi\u1ebft k\u1ebf chung \u0111\u01b0\u1ee3c li\u00ean k\u1ebft v\u1edbi c\u00e1c ghi ch\u00fa th\u00f4ng tin c\u1ee7a NEC, kh\u00f4ng ph\u1ea3i l\u00e0 gi\u1edbi h\u1ea1n b\u1eaft bu\u1ed9c chung cho m\u1ecdi h\u1ec7 th\u1ed1ng. C\u00e1c \u1ee9ng d\u1ee5ng c\u1ee5 th\u1ec3 c\u00f3 th\u1ec3 c\u00f3 c\u00e1c quy \u0111\u1ecbnh b\u1eaft bu\u1ed9c. H\u00e3y ki\u1ec3m tra c\u00e1c quy \u0111\u1ecbnh \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng, h\u01b0\u1edbng d\u1eabn thi\u1ebft b\u1ecb v\u00e0 y\u00eau c\u1ea7u d\u1ef1 \u00e1n.<\/p>\n

C\u00e1c khuy\u1ebfn ngh\u1ecb ri\u00eang bi\u1ec7t t\u1eeb c\u00e1c y\u00eau c\u1ea7u c\u00f3 t\u00ednh b\u1eaft bu\u1ed9c th\u1ef1c thi<\/h2>\n

M\u1ed9t cu\u1ed9c t\u00ecm ki\u1ebfm Y\u00eau c\u1ea7u v\u1ec1 \u0111\u1ed9 gi\u1ea3m \u0111i\u1ec7n \u00e1p c\u1ee7a NEC<\/strong> th\u01b0\u1eddng tr\u1ea3 v\u1ec1 c\u00e1c s\u1ed1 3% v\u00e0 5% m\u00e0 kh\u00f4ng c\u00f3 b\u1ed1i c\u1ea3nh c\u1ee5 th\u1ec3. C\u00e1c ghi ch\u00fa th\u00f4ng tin chung h\u01b0\u1edbng d\u1eabn ho\u1ea1t \u0111\u1ed9ng hi\u1ec7u qu\u1ea3, nh\u01b0ng vai tr\u00f2 ph\u00e1p l\u00fd c\u1ee7a ch\u00fang kh\u00e1c v\u1edbi v\u0103n b\u1ea3n quy ph\u1ea1m ph\u00e1p lu\u1eadt. M\u1ed9t h\u1ee3p \u0111\u1ed3ng ho\u1eb7c y\u00eau c\u1ea7u v\u1ec1 thi\u1ebft b\u1ecb c\u0169ng c\u00f3 th\u1ec3 \u0111\u1eb7t ra m\u1ee5c ti\u00eau thi\u1ebft k\u1ebf nghi\u00eam ng\u1eb7t h\u01a1n.<\/p>\n

Tr\u01b0\u1edbc khi ch\u1ea5p nh\u1eadn k\u1ebft qu\u1ea3 gi\u1ea3m \u0111i\u1ec7n \u00e1p, h\u00e3y x\u00e1c \u0111\u1ecbnh lo\u1ea1i m\u1ea1ch v\u00e0 b\u1ea5t k\u1ef3 quy t\u1eafc c\u1ee5 th\u1ec3 cho t\u1eebng \u1ee9ng d\u1ee5ng n\u00e0o. \u0110\u1eebng cho r\u1eb1ng vi\u1ec7c \u0111\u00e1p \u1ee9ng c\u00e1c khuy\u1ebfn ngh\u1ecb chung \u0111\u00e3 \u0111\u1ea3m b\u1ea3o tu\u00e2n th\u1ee7 t\u1ea5t c\u1ea3 c\u00e1c y\u00eau c\u1ea7u c\u1ee7a thi\u1ebft b\u1ecb. C\u00e1c ch\u1ec9 s\u1ed1 ho\u1ea1t \u0111\u1ed9ng ban \u0111\u1ea7u, gi\u1edbi h\u1ea1n \u0111i\u1ec7n \u00e1p \u0111i\u1ec1u khi\u1ec3n v\u00e0 ng\u1eaft k\u1ebft n\u1ed1i l\u1ed7i v\u1eabn c\u00f3 th\u1ec3 c\u1ea7n \u0111\u01b0\u1ee3c ph\u00e2n t\u00edch ri\u00eang bi\u1ec7t.<\/p>\n

\"M\u1eabu<\/figure>\n

S\u1eed d\u1ee5ng d\u1eef li\u1ec7u v\u1ec1 chi\u1ec1u d\u00e0i m\u1ea1ch, d\u00f2ng \u0111i\u1ec7n v\u00e0 d\u00e2y d\u1eabn th\u1ef1c t\u1ebf<\/h2>\n

A T\u00ednh to\u00e1n gi\u1ea3m \u0111i\u1ec7n \u00e1p<\/strong> C\u1ea7n bi\u1ebft th\u00f4ng s\u1ed1 v\u1ec1 c\u1ea5u tr\u00fac cung c\u1ea5p, d\u00f2ng t\u1ea3i, chi\u1ec1u d\u00e0i \u0111\u01b0\u1eddng d\u1eabn, v\u1eadt li\u1ec7u v\u00e0 k\u00edch th\u01b0\u1edbc c\u1ee7a d\u00e2y d\u1eabn. \u00dd ngh\u0129a c\u1ee7a chi\u1ec1u d\u00e0i ph\u1ee5 thu\u1ed9c v\u00e0o ph\u01b0\u01a1ng tr\u00ecnh ho\u1eb7c m\u00e1y t\u00ednh. Vi\u1ec7c nh\u1eadp chi\u1ec1u d\u00e0i v\u00f2ng v\u00e0o m\u1ed9t c\u00f4ng c\u1ee5 c\u00f3 kh\u1ea3 n\u0103ng t\u00ednh to\u00e1n chi\u1ec1u d\u00e0i m\u1ed9t chi\u1ec1u c\u00f3 th\u1ec3 d\u1eabn \u0111\u1ebfn k\u1ebft qu\u1ea3 sai l\u1ec7ch.<\/p>\n

\u0110\u1ed1i v\u1edbi m\u1ea1ch \u0111\u01a1n pha DC ho\u1eb7c \u0111i\u1ec7n tr\u1edf \u0111\u01a1n gi\u1ea3n, gi\u1ea3m \u0111i\u1ec7n \u00e1p c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c \u01b0\u1edbc t\u00ednh t\u1eeb d\u00f2ng \u0111i\u1ec7n nh\u00e2n v\u1edbi t\u1ed5ng \u0111i\u1ec7n tr\u1edf v\u00f2ng. \u0110\u1ed1i v\u1edbi m\u1ea1ch AC v\u00e0 ba pha, h\u00e3y s\u1eed d\u1ee5ng c\u00e1c m\u1ed1i quan h\u1ec7 v\u1ec1 tr\u1edf kh\u00e1ng v\u00e0 h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t ph\u00f9 h\u1ee3p. Southwire cung c\u1ea5p c\u00e1c c\u00f4ng c\u1ee5 t\u00ednh to\u00e1n, nh\u01b0ng ng\u01b0\u1eddi d\u00f9ng v\u1eabn ph\u1ea3i cung c\u1ea5p c\u00e1c \u0111\u1ea7u v\u00e0o ch\u00ednh x\u00e1c v\u00e0 ki\u1ec3m tra c\u00e1c gi\u1ea3 \u0111\u1ecbnh c\u1ee7a ph\u01b0\u01a1ng ph\u00e1p.<\/p>\n

Thay \u0111\u1ed5i thi\u1ebft k\u1ebf m\u00e0 kh\u00f4ng l\u00e0m gi\u1ea3m \u0111i m\u1ee9c \u0111\u1ed9 b\u1ea3o v\u1ec7<\/h2>\n

\u0110\u1ec3 minh h\u1ecda cho vi\u1ec7c t\u00ednh to\u00e1n t\u1ef7 l\u1ec7 ph\u1ea7n tr\u0103m, 3% trong s\u1ed1 120 V t\u01b0\u01a1ng \u0111\u01b0\u01a1ng v\u1edbi 3,6 V v\u00e0 5% l\u00e0 6 V. \u0110\u00e2y l\u00e0 t\u1ef7 l\u1ec7 ph\u1ea7n tr\u0103m c\u1ee7a \u0111i\u1ec7n \u00e1p \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ecbnh, kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ee9c t\u1ed5n hao \u0111\u01b0\u1ee3c \u0111o l\u01b0\u1eddng hay quy\u1ebft \u0111\u1ecbnh ch\u1ea5p nh\u1eadn t\u1ef1 \u0111\u1ed9ng. M\u1ed9t t\u1ea3i c\u00f3 \u0111i\u1ec7n \u00e1p ho\u1ea1t \u0111\u1ed9ng t\u1ed1i thi\u1ec3u c\u1ee5 th\u1ec3 c\u00f3 th\u1ec3 y\u00eau c\u1ea7u m\u1ed9t m\u1ee5c ti\u00eau kh\u00e1c nhau.<\/p>\n

M\u1ed9t \u0111\u01b0\u1eddng d\u00e2y d\u1eabn l\u1edbn h\u01a1n, l\u1ed9 tr\u00ecnh ng\u1eafn h\u01a1n ho\u1eb7c c\u00e1ch b\u1ed1 tr\u00ed ph\u00e2n ph\u1ed1i \u0111\u01b0\u1ee3c s\u1eeda \u0111\u1ed5i c\u00f3 th\u1ec3 l\u00e0m gi\u1ea3m gi\u1ea3m \u0111i\u1ec7n \u00e1p ph\u00e2n nh\u00e1nh<\/strong>. Vi\u1ec7c n\u00e2ng c\u1ea5p c\u1ea5p b\u1ea3o v\u1ec7 kh\u00f4ng ph\u1ea3i l\u00e0 bi\u1ec7n ph\u00e1p kh\u1eafc ph\u1ee5c. Xem l\u1ea1i L\u1ef1a ch\u1ecdn b\u1ed9 ng\u1eaft m\u1ea1ch<\/a> v\u00e0 B\u1ea3o v\u1ec7 ngu\u1ed3n c\u1ea5p d\u1eef li\u1ec7u<\/a> \u0110\u1ed1i v\u1edbi \u0111\u1ea7u n\u1ed1i cu\u1ed1i c\u00f9ng v\u00e0 c\u00e1c \u0111i\u1ec1u ki\u1ec7n l\u1ed7i. N\u1ebfu k\u00edch th\u01b0\u1edbc \u0111\u1ea7u n\u1ed1i thay \u0111\u1ed5i, h\u00e3y \u0111\u1ea3m b\u1ea3o c\u00e1c \u0111\u1ea7u n\u1ed1i ch\u1ea5p nh\u1eadn s\u1ef1 thay \u0111\u1ed5i n\u00e0y v\u00e0 \u0111\u00e1p \u1ee9ng c\u00e1c y\u00eau c\u1ea7u n\u1ed1i \u0111\u1ea5t li\u00ean quan.<\/p>\n

\"M\u1eabu<\/figure>\n

So s\u00e1nh c\u00e1c t\u00f9y ch\u1ecdn cho \u1ee9ng d\u1ee5ng n\u00e0y<\/h2>\n
\n\n\n\n\n\n\n\n\n
Ki\u1ec3m tra<\/th>\nC\u00e2u h\u1ecfi<\/th>\n\u0110i\u1ec1u m\u00e0 vi\u1ec7c th\u00f4ng qua n\u00f3 kh\u00f4ng ch\u1ee9ng minh \u0111\u01b0\u1ee3c<\/th>\n<\/tr>\n<\/thead>\n
Ampacity<\/td>\nNg\u01b0\u1eddi \u0111i\u1ec1u khi\u1ec3n c\u00f3 th\u1ec3 truy\u1ec1n t\u1ea3i d\u00f2ng \u0111i\u1ec7n thi\u1ebft k\u1ebf \u0111\u01b0\u1ee3c kh\u00f4ng?<\/td>\n\u0110i\u1ec7n \u00e1p ch\u1ea5p nh\u1eadn \u0111\u01b0\u1ee3c \u1edf t\u1ea3i<\/td>\n<\/tr>\n
Gi\u1ea3m \u0111i\u1ec7n \u00e1p<\/td>\n\u0110i\u1ec7n \u00e1p \u0111\u01b0\u1ee3c cung c\u1ea5p c\u00f3 ph\u00f9 h\u1ee3p kh\u00f4ng?<\/td>\nGi\u00e1n \u0111o\u1ea1n s\u1ef1 c\u1ed1 \u0111\u1ea7y \u0111\u1ee7<\/td>\n<\/tr>\n
Ch\u1ed1ng qu\u00e1 t\u1ea3i<\/td>\nLi\u1ec7u vi\u1ec7c ng\u1eaft k\u1ebft n\u1ed1i c\u1ea7n thi\u1ebft s\u1ebd x\u1ea3y ra hay kh\u00f4ng?<\/td>\n\u0110\u1ed9 \u0111i\u1ec7n \u00e1p ho\u1ea1t \u0111\u1ed9ng b\u00ecnh th\u01b0\u1eddng ch\u00ednh x\u00e1c<\/td>\n<\/tr>\n
C\u00e1c gi\u1edbi h\u1ea1n v\u1ec1 thi\u1ebft b\u1ecb<\/td>\nHo\u1ea1t \u0111\u1ed9ng c\u00f3 tu\u00e2n th\u1ee7 theo h\u01b0\u1edbng d\u1eabn kh\u00f4ng?<\/td>\nTu\u00e2n th\u1ee7 c\u00e1c y\u00eau c\u1ea7u c\u1ee7a t\u1ea5t c\u1ea3 c\u00e1c m\u1ea1ch kh\u00e1c<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

Ki\u1ec3m tra c\u00e1c \u0111i\u1ec1u ki\u1ec7n \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn quy\u1ebft \u0111\u1ecbnh<\/h2>\n
\n\n\n\n\n\n\n\n\n
Thay \u0111\u1ed5i \u0111\u1ea7u v\u00e0o<\/th>\nHi\u1ec7u \u1ee9ng c\u00f3 th\u1ec3 x\u1ea3y ra \u0111\u1ec3 \u0111\u00e1nh gi\u00e1<\/th>\n<\/tr>\n<\/thead>\n
\u0110\u01b0\u1eddng d\u00e0i h\u01a1n<\/td>\nKh\u00e1ng \u0111i\u1ec7n d\u1eabn l\u1edbn h\u01a1n<\/td>\n<\/tr>\n
D\u00f2ng t\u1ea3i cao h\u01a1n<\/td>\nGi\u1ea3m \u0111i\u1ec7n \u00e1p l\u1edbn h\u01a1n<\/td>\n<\/tr>\n
V\u1eadt li\u1ec7u d\u00e2y d\u1eabn kh\u00e1c nhau<\/td>\nY\u00eau c\u1ea7u v\u1ec1 kh\u1ea3 n\u0103ng kh\u00e1ng c\u1ef1 v\u00e0 ch\u1ea5m d\u1ee9t kh\u00e1c nhau<\/td>\n<\/tr>\n
Kh\u1edfi \u0111\u1ed9ng \u0111\u1ed9ng c\u01a1<\/td>\nHi\u1ec7u su\u1ea5t \u0111i\u1ec7n \u00e1p t\u1ea1m th\u1eddi v\u00e0 kh\u1edfi \u0111\u1ed9ng<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

X\u00e1c nh\u1eadn c\u00e1c quy \u0111\u1ecbnh v\u00e0 t\u00e0i li\u1ec7u \u00e1p d\u1ee5ng<\/h2>\n

Xin vui l\u00f2ng ki\u1ec3m tra phi\u00ean b\u1ea3n NEC \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng t\u1ea1i \u0111\u1ecba ph\u01b0\u01a1ng v\u00e0 c\u00e1c quy \u0111\u1ecbnh th\u1ef1c t\u1ebf li\u00ean quan \u0111\u1ebfn m\u1ea1ch \u0111i\u1ec7n. C\u00e1c ghi ch\u00fa th\u00f4ng tin chung, quy t\u1eafc \u00e1p d\u1ee5ng b\u1eaft bu\u1ed9c, h\u01b0\u1edbng d\u1eabn thi\u1ebft b\u1ecb v\u00e0 th\u00f4ng s\u1ed1 k\u1ef9 thu\u1eadt h\u1ee3p \u0111\u1ed3ng kh\u00f4ng th\u1ec3 thay th\u1ebf nhau. Vui l\u00f2ng ghi r\u00f5 c\u01a1 s\u1edf ch\u1ea5p nh\u1eadn trong b\u1ea3ng t\u00ednh.<\/p>\n

Bi\u1ebfn c\u00e1c y\u00eau c\u1ea7u th\u00e0nh m\u1ed9t b\u1ea3n b\u00e1o c\u00e1o mua h\u00e0ng<\/h2>\n

\u0110\u0103ng k\u00fd c\u00e1c gi\u1ea3 \u0111\u1ecbnh v\u1ec1 \u0111\u1ea7u v\u00e0o, ph\u01b0\u01a1ng ph\u00e1p t\u00ednh to\u00e1n v\u00e0 ti\u00eau ch\u00ed ch\u1ea5p nh\u1eadn, sau \u0111\u00f3 l\u01b0u gi\u1eef b\u1ea3n k\u1ebf ho\u1ea1ch b\u1ea3o v\u1ec7 cu\u1ed1i c\u00f9ng. CHAC Electric c\u00f3 th\u1ec3 gi\u00fap x\u00e1c \u0111\u1ecbnh c\u1ea5u h\u00ecnh thi\u1ebft b\u1ecb b\u1ea3o v\u1ec7 \u0111\u1ec3 xem x\u00e9t so v\u1edbi thi\u1ebft k\u1ebf \u0111\u00e3 \u0111\u01b0\u1ee3c ph\u00ea duy\u1ec7t.<\/p>\n

C\u00e1c c\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p<\/h2>\n

Lu\u1eadt gi\u1ea3m \u0111i\u1ec7n \u00e1p 3% l\u00e0 g\u00ec?<\/h3>\n

N\u00f3 th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng nh\u01b0 m\u1ed9t khuy\u1ebfn ngh\u1ecb thi\u1ebft k\u1ebf nh\u00e1nh m\u1ea1ch li\u00ean quan \u0111\u1ebfn c\u00e1c ghi ch\u00fa th\u00f4ng tin c\u1ee7a NEC. Ki\u1ec3m tra xem quy t\u1eafc b\u1eaft bu\u1ed9c ho\u1eb7c y\u00eau c\u1ea7u d\u1ef1 \u00e1n c\u00f3 \u00e1p d\u1ee5ng cho m\u1ea1ch th\u1ef1c t\u1ebf hay kh\u00f4ng.<\/p>\n

Gi\u1ea3m \u0111i\u1ec7n \u00e1p 4%V c\u00f3 ch\u1ea5p nh\u1eadn \u0111\u01b0\u1ee3c kh\u00f4ng?<\/h3>\n

\u0110i\u1ec1u n\u00e0y ph\u1ee5 thu\u1ed9c v\u00e0o m\u1ea1ch \u0111i\u1ec7n, gi\u1edbi h\u1ea1n thi\u1ebft b\u1ecb v\u00e0 ti\u00eau chu\u1ea9n ch\u1ea5p nh\u1eadn. Ch\u1ec9 ri\u00eang t\u1ef7 l\u1ec7 ph\u1ea7n tr\u0103m kh\u00f4ng th\u1ec3 \u0111\u1ea3m b\u1ea3o s\u1ef1 tu\u00e2n th\u1ee7 ho\u1eb7c ho\u1ea1t \u0111\u1ed9ng \u1ed5n \u0111\u1ecbnh.<\/p>\n

C\u00f3 ch\u1ea5p nh\u1eadn \u0111\u01b0\u1ee3c s\u1ef1 gi\u1ea3m \u0111i\u1ec7n \u00e1p 5% volt kh\u00f4ng?<\/h3>\n

Chi ph\u00ed 5% con s\u1ed1 th\u01b0\u1eddng li\u00ean quan \u0111\u1ebfn vi\u1ec7c thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng c\u1ea5p ngu\u1ed3n v\u00e0 ph\u00e2n ph\u1ed1i k\u1ebft h\u1ee3p. N\u00f3 kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t s\u1ef1 cho ph\u00e9p chung \u00e1p d\u1ee5ng cho m\u1ecdi t\u1ea3i \u0111i\u1ec7n ho\u1eb7c \u1ee9ng d\u1ee5ng.<\/p>\n

Gi\u1ea3m \u0111i\u1ec7n \u00e1p x\u1ea3y ra \u1edf \u0111\u1ed9 cao 100 feet l\u00e0 bao nhi\u00eau?<\/h3>\n

C\u00e2u tr\u1ea3 l\u1eddi ph\u1ee5 thu\u1ed9c v\u00e0o d\u00f2ng \u0111i\u1ec7n, v\u1eadt li\u1ec7u d\u1eabn \u0111i\u1ec7n v\u00e0 k\u00edch th\u01b0\u1edbc, c\u00e1ch b\u1ed1 tr\u00ed ngu\u1ed3n cung c\u1ea5p v\u00e0 \u0111\u1ed9 d\u00e0i c\u1ee7a \u0111\u01b0\u1eddng d\u1eabn. H\u00e3y s\u1eed d\u1ee5ng m\u1ed9t ph\u00e9p t\u00ednh ph\u00f9 h\u1ee3p v\u1edbi c\u00e1c th\u00f4ng s\u1ed1 th\u1ef1c t\u1ebf.<\/p>\n

Th\u00e9p \u0111\u1ed3ng v\u00e0 nh\u00f4m c\u00f3 g\u00ec kh\u00e1c nhau?<\/h3>\n

Kh\u1ea3 n\u0103ng ch\u1ed1ng ch\u1ecbu v\u00e0 k\u00edch th\u01b0\u1edbc d\u00e2y d\u1eabn y\u00eau c\u1ea7u kh\u00e1c nhau. H\u00e3y so s\u00e1nh d\u1eef li\u1ec7u d\u00e2y d\u1eabn th\u1ef1c t\u1ebf v\u00e0 c\u00e1c \u0111\u1ea7u n\u1ed1i t\u01b0\u01a1ng th\u00edch thay v\u00ec \u00e1p d\u1ee5ng m\u1ed9t c\u00e1ch th\u1ee9c chuy\u1ec3n \u0111\u1ed5i c\u1ed1 \u0111\u1ecbnh cho m\u1ecdi h\u1ec7 th\u1ed1ng l\u1eafp \u0111\u1eb7t.<\/p>\n

Li\u1ec7u t\u00f4i c\u00f3 n\u00ean t\u0103ng c\u00f4ng su\u1ea5t c\u1ee7a c\u1ea7u c\u1ea7u ch\u00ec \u0111\u1ec3 kh\u1eafc ph\u1ee5c t\u00ecnh tr\u1ea1ng gi\u1ea3m \u0111i\u1ec7n \u00e1p kh\u00f4ng?<\/h3>\n

Kh\u00f4ng. \u0110i\u1ec1u \u0111\u00f3 kh\u00f4ng l\u00e0m gi\u1ea3m \u0111i\u1ec7n tr\u1edf c\u1ee7a d\u00e2y d\u1eabn v\u00e0 c\u00f3 th\u1ec3 g\u00e2y nguy hi\u1ec3m cho s\u1ef1 b\u1ea3o v\u1ec7 c\u1ee7a d\u00e2y d\u1eabn. Thay v\u00e0o \u0111\u00f3, h\u00e3y xem x\u00e9t l\u1ea1i thi\u1ebft k\u1ebf d\u00e2y d\u1eabn, \u0111\u01b0\u1eddng d\u1eabn v\u00e0 ph\u00e2n ph\u1ed1i.<\/p>\n

B\u00e0i vi\u1ebft li\u00ean quan: C\u00e1ch t\u00ednh Amps: \u01af\u1edbc l\u01b0\u1ee3ng d\u00f2ng \u0111i\u1ec7n cho quy ho\u1ea1ch b\u1ea3o v\u1ec7 \u0111i\u1ec7n<\/a>.<\/p>\n

Tham kh\u1ea3o<\/h2>\n