– T? ??ng kh?i ??ng ho?c d?ng ho?t ??ng ( c?a DG ) khi ngu?n ?i?n có s? c?- The ensured a gentle and steady breaking ability whatever the working voltage by means of an open Procedure employing a individual breaking spring.– T? ??ng kh?i ??ng ho?c d?ng ho?t ??ng ( c?a DG ) khi ngu?n ?i?n có s? c?  – The ensured a gradual and stable breaki