khai niem

la kcd dung de tu dong cat mach dien khi co su co:qua tai, ngan mach, sut ap,...

thuong goi la aptomat khong khi vi ho quang dc dap tat trong khong khi .aptomat thuong d su dung trong cac mach dien ha ap co dien ap dinh muc toi 660v xoay chieu va 330v 1 chieu,dong dien dinh muc toi 6000A

yeu cau

-che do lam viec dinh muc cua aptomat phai la che do dai han ,nghia la tri so dong dien dinh muc chay wa aptomat lau bao nhieu cung dc. mat # mach vong dan dien cua aptomat phai chiu dc dong ngan mach lon luc cac tiep diem cua no đã đóng hoac dang dong

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aptomat phai cat dc tri so dong ngan mach lon co the len den hang chuc kilo ampe.sau khi cat van phai dam bao lam viec tot o tri so dong dien dinh muc.

-de nang cao tinh on dinh nhiet va tinh on dinh dien dong cua cac thiet bi,han che su pha hoai cua dong ngan mach,aptomat phai co thoi gian cat be. muon vay phai ket hop giua luc thao tacco hoc va thiet bi dap ho quang ben trong aptomat. de thuc hien yeu cau thao tac co chon loc aptomat phai co kha nang dieu chinh dc dong dien tac dong va thoi gian tac dong.

nguyen ly lam viec

hing ve

trong so do nguyen ly quan trong nhat la aptomat dong dien cuc dai va aptomat dien ap thap

o trang thai binh thuong sau khi dong dien ap aptomat dc giu o trang thai dong nho moc rang so 1 an khop voi cần rang so 5 cung voi cum tiep diem dong. khi xay ra qua tai hoac ngan mach , nam cham dien so 2 se hut phan dong so 4 xuong lam nhả moc 1 cần 5 dc tu do,ket quala cac tiep diem cua aptomat dc nhả nho lo xo 6, mach dien bi ngat. khi sut ap qua thap ,nam cham dien so 2 se nhả phan dong so 4 lam nhả moc rang 1 giai phong cần rang so 5 do đó cac tiep diem cua aptomat cung dc nhả nho luc lo xo so 6, mach dien bi cat.

phan loai

dua vao ket cau nguoi ta chia ra aptomat 1 cuc,2 cuc,3 cuc

dua vao cac thong so dieu chinh nguyoi ta chia thanh: aptomat van nang, apto dinh hinh,va apto tac dong nhanh.

cau tao:

-he thong tiep diem:he thong tiep diem gom tiep diem tinh va tiep diem dong,yeu cau cua tiep diem la o trang thai dong,dien tro tiep xuc phai du nho de giam ton haodo tiep xuc.khi ngat ,dong dien rat lon tiep diem phai co du do ben nhiet, do ben dien dong de khong bi hu hong do dong dien ngat gay nen.apto thuong dc che tao co 2 cap hoac 3 cap tiep diem,neu co 2 cap thi bao gom tiep diem chinh va tiep diem ho quang ,neu co 3 cap thi co tiep diem chinh, tiep diem phu va tiep diem ho quang. khi dong tiep diem ho quang dong truoc tiep theo la tiep diem phu roi den tiep diem chinhcon khi ngat thi nguoc lai tiep diem chinh ngat truoc sau do den tiep diem phu roi cuoi cung den tiep diem ho quang. 

- he thong dap ho quang: co nhiem vu dap tat ho quang khi ngat trong moi che do cong tac cua luoi dien,co 2 kieu thiet bi dap ho quangla kieu nua kin va kieu hở. kieu nua kin dc dat trog vỏ  cua apto va co lổ thoat khi,loai nay co dong dien cat khong vuot qua 50kA. kieu hở dc su dung voi dong dien cat lon hon 50kA va co dien ap lon. treong cac buong dap ho quang thong dung nguoi ta dung cac tam thep xep thang luoi ngăn de phan chia ho quangthanh nhieu doan ngắn thuan loi cho viec dap ho quang.

-co cau truyebn dong cat apto

truyen dong cat apto dc thuc hien bang 2 cach :bang tay or bang co dien. dieu khien bang tay dc thuc hien voi cac apto co dong dien ko lon hon qua 600A, de tang luc dieu khien bang tay thuong ket hop canh tay don phụ  theo nguyen tac don bẩy voi khop nhả tu do . dieu khien co dien thuc hien voi dong dien ngat lon hon 600A,ngoai ra con dieu khien bang dong co hoac khi nen.

-moc bao ve: apto tu dong cat nho cac moc bao ve. moc bao ve qua tai dung de bao ve thiet bi khoi bi qua tai ,duong dac tinh thoi gian-dong dien cua moc bao ve phai nam duoi duong dac tinh cua thiet bi can dc bao ve. nguoi ta thuong dung he thong dien tu hoac role nhiet lam moc bao ve dat ben trong apto . moc bao ve thap ap dung de bao ve khi dien ap thap qua gtri cho phep hoac mat dien ap,moc co cuon day mac // voi mang dien.trong 1 so truong hop nguoi ta ket hop cac moc bao ve trong apto thanh apto van nang