FZW20—12/630-16 outdoor AC HV vacuum on-load disconnectors, with rated voltage 12kV, rated current 630A, rated frequency 50Hz, are capable of making and breaking load current, and also capable of breaking transformer no-load current, a certain length of overhead line, and capacitive current of cable line and capacitors. FZW20—12/630-16 disconnectors possess functions such as breaking, isolating, making and switchover, and can be coordinated with fuses for protection of distribution lines.