Gioi Thieu Ve Bang Ampe Cua Aptomat
Viec lua chon aptomat dung cong suat la mot trong nhung yeu to quan trong nhat de dam bao an toan cho he thong dien trong gia dinh va cong trinh. Aptomat hay con goi la Circuit Breaker CB co chuc nang tu dong ngat mach khi xay ra qua tai hoac chay cham, bao ve thiet bi va con nguoi khoi nhung su co dien nguy hiem. Tuy nhien khong phai ai cung hieu ro ve bang ampe cua aptomat va cach xac dinh dong dinh muc phu hop. Mot su lua chon sai co the dan den tinh trang nhay gia lam ngat dien lien tuc hoac nghiem trong hon la khong bao ve duoc duong day khi co su co. Bai viet nay se cung cap cho ban mot cai nhin toan dien ve bang ampe aptomat cung nhu huong dan chi tiet cach chon CB phu hop cho tung loai tai.
Cuong Do Dong Dien Dinh Muc Cua Aptomat La Gi
Dong dien dinh muc cua aptomat la gia tri dong dien toi da ma CB co the cho phep di qua trong dieu kien lam viec binh thuong ma khong ngat mach. Don vi do la Ampe A. Tren than moi aptomat deu co ghi ro chi so ampe nhu 10A, 16A, 20A, 25A, 32A, 40A hay 63A. Day chinh la thong so quan trong nhat ma nguoi dung can can cu vao de chon aptomat cho phu hop. Nguyen tac co ban la dong dien dinh muc cua CB khong duoc vuot qua kha nang chiu tai cho phep cua day dan ma no bao ve. Noi cach khac aptomat va day dan phai duoc phoi hop voi nhau theo mot bang ampe tieu chuan. Neu ban chon aptomat co chi so ampe qua cao so voi tiet dien day dan thi khi xay ra qua tai day dan da bi nong len nguy hiem nhung aptomat chua kip ngat mach nguoc lai neu chon chi so ampe qua thap thi aptomat se thuong xuyen nhay gay mat dien gay kho chiu cho sinh hoat.
Cac Gia Tri Ampe Pho Bien Cho He Thong Dien Dan Dung
Trong bang ampe cua aptomat cho cac cong trinh dan dung tai Viet Nam cac gia tri pho bien thuong duoc su dung la 10A, 16A, 20A, 25A, 32A, 40A va 63A. Moi gia tri nay phu hop voi mot loai tai dien nhat dinh. Vi du aptomat 10A va 16A thuong dung cho cac mach chieu sang va o cam sinh hoat trong phong ngu hoac phong khach. Aptomat 20A dung cho o cam chuyen dung cho tu lanh hoac may bom nuoc. Aptomat 25A va 32A thuong lap cho may nuoc nong hoac dieu hoa nhiet do trung binh. Aptomat 40A su dung cho cac thiet bi co cong suat lon nhu bep tu hoac may nuoc nong cong nghiep nho. Aptomat 63A thuong duoc dung lam CB tong cho bang dien chinh cua can ho hoac nha pho. Hieu ro cac gia tri nay giup ban de dang hon trong viec doc bang ampe va ap dung vao thuc te.
Bang Tra Moi Quan He Giua Tiet Dien Day Dan Va Dong Dien Cua Aptomat
De chon aptomat dung cach truoc het ban can biet tiet dien cua day dan dang su dung. Day dan bang dong co tiet dien cang lon thi kha nang chiu dong cang cao. Bang duoi day the hien moi quan he giua tiet dien day dan theo don vi mm binh phuong va dong dien dinh muc toi da cung nhu dong dinh muc cua aptomat khuyen nghi.
| Tiet dien day dan (mm) | Dong chiu tai toi da (A) | Aptomat khuyen nghi (A) |
|---|---|---|
| 1,5 mm | 14-16 A | 10 A |
| 2,5 mm | 21-24 A | 16 A hoac 20 A |
| 4 mm | 28-32 A | 25 A |
| 6 mm | 36-40 A | 32 A |
| 10 mm | 50-55 A | 40 A |
| 16 mm | 68-75 A | 50 A hoac 63 A |
| 25 mm | 89-100 A | 80 A |
| 35 mm | 110-125 A | 100 A |
Bang ampe tren day cho thay nguyen tac quan trong la dong dinh muc cua aptomat phai nho hon hoac bang dong chiu tai cho phep cua day dan. Vi du neu ban dung day 2,5 mm thi aptomat khong nen chon qua 20A du rang mot so tai co the chay o muc cao hon. Dieu nay dam bao khi xay ra qua tai day dan se khong bi phat nhiet qua muc truoc khi aptomat ngat mach.
Cach Chon Aptomat Theo Ung Dung Thuc Te
Viec ap dung bang ampe vao tung loai tai cu the se giup ban de dang hon trong thiet ke bang dien cho nha o. Duoi day la mot so goi y cu the cho tung nhom thiet bi thong dung trong gia dinh.
- Aptomat 10A den 16A: dung cho he thong den chieu sang va o cam da nang trong phong ngu, phong khach, hanh lang. Day dan su dung thuong la 1,5 mm hoac 2,5 mm.
- Aptomat 20A: dung cho cac o cam chuyen dung cho tu lanh, may bom nuoc, may giat hoac lo vi song. Day dan tuong ung la 2,5 mm.
- Aptomat 25A: dung cho may nuoc nong co cong suat khoang 5500W khi su dung dien 220V hoac lo nuong dien co cong suat vua phai. Day dan toi thieu la 4 mm.
- Aptomat 32A: dung cho may nuoc nong cong suat khoang 7500W tren dien 220V hoac may dieu hoa cong suat 18000 BTU. Day dan can dung it nhat 6 mm.
- Aptomat 40A: dung cho may nuoc nong lon dung dien 127V hoac dieu hoa cong suat 24000 BTU. Day dan tuong ung la 10 mm.
- Aptomat 63A: dung lam CB tong cho bang dien chinh cua can ho hoac nha pho, cung cap cho toan bo tai trong nha. Day dan vao nha thuong la 16 mm hoac 25 mm tuy theo cong suat tong.
Khi chon aptomat theo ung dung thuc te ban can tinh toan cu the cong suat cua tung thiet bi hoac nhom thiet bi roi quy ra dong dien bang cong thuc co ban I bang P chia cho U. Sau do chon CB co dong dinh muc cao hon mot chut so voi dong tinh toan nhung khong vuot qua dong chiu tai cua day dan. Bang ampe o tren la co so de ban thuc hien viec phoi hop nay mot cach an toan va chinh xac.
Nguyen Tac Chon Aptomat Cho Tai Lien Tuc
Mot diem quan trong khac trong bang ampe aptomat la can phan biet giua tai lien tuc va tai khong lien tuc. Tai lien tuc la nhung thiet bi hoat dong lien tuc tu ba gio tro len nhu may nuoc nong, lo suoi hoac he thong chieu sang chinh. Theo tieu chuan ky thuat khi tinh toan chon aptomat cho tai lien tuc dong dien cua CB khong duoc vuot qua 80 phan tram dong dinh muc. Dieu nay co nghia la neu ban co mot tai lien tuc tieu thu dong dien 16A thi ban can chon aptomat co dong dinh muc it nhat la 20A de tranh tinh trang phat nhiet va nhay gia trong qua trinh hoat dong keo dai. Tuong tu neu tinh nguoc lai ban co the dat dinh muc cua CB o muc 125 phan tram dong dien cua tai lien tuc. Nguyen tac nay dac biet quan trong khi ap dung vao thuc te vi nhieu truong hop chon aptomat dung bang dong tinh toan dan den CB thuong xuyen ngat mach ma khong ro nguyen nhan.
Luu Y Khi Chon Aptomat Theo Tieu Chuan Viet Nam Va Quoc Te
Tai Viet Nam cac quy dinh ve thiet ke lap dat he thong dien ha ap duoc quy chuan boi tieu chuan TCVN 7447 va TCVN 9206. Tuy nhien trong qua trinh ap dung bang ampe aptomat ban cung co the tham khao them cac tieu chuan quoc te nhu NBR 5410 cua Brazil hoac cac tai lieu ky thuat tu cac nha san xuat lon. Mot trong nhung tai lieu huu ich la bang ampe thuong mai tu trang chinh thuc cua ABNT ve tieu chuan NBR 5410 cho cac huong dan chi tiet ve phoi hop day dan va CB. Ngoai ra ban co the tra cuu bang ampe duoc cung cap boi Schneider Electric Brazil la mot trong nhung nha san xuat thiet bi dien hang dau the gioi. Cac tai lieu nay deu dua tren nguyen tac co ban la dong dinh muc cua CB khong duoc lon hon ampacity cua day dan. O Viet Nam day dan thuong duoc ky hieu bang mm trong khi mot so nuoc dung AWG American Wire Gauge vi du day 12 AWG tuong duong khoang 4 mm va thuong dung voi CB 20A. Can chu y su khac biet nay khi doc tai lieu nuoc ngoai de ap dung chinh xac vao bang ampe thuc te cua minh.
Bang Ampe Va Kha Nang Chiu Tai Theo Nhiet Do
Mot yeu to khac anh huong den bang
