S? d?ng cho h? th?ng ?i?n h? th? khi ngu?n c?p ph? t?i b? gián ?o?n B? chuy?n m?ch t? ??ng, giám sát và chuy?n ??i gi?a hai ngu?n ?i?n Chuy?n m?ch three v? trí I - O - II– T? ??ng kh?i ??ng ho?c d?ng ho?t ??ng ( c?a DG ) khi ngu?n ?i?n có s? c?- Each individual period is molded and enclosed independently to improve the breaking ability also