This type of HV vacuum switch-fuse combinations widely serve in the power system for three-phase AC 10kV and 50Hz or in the urban network reconstruction, mineral & industrial enterprise, tall buildings and public facilities by coordinating with power distribution assembly, ring-network switchgear and combination-type substation. It can also function as ring-network power supply unit or terminal unit to distribute, control and protect electricity. The combinations conform to the following standards: IEC60265-1/FDIS, IEC60420, GB16926 and GB3804.
The combinations feature high breaking capacity, security and reliability, long electric endurance, frequent operation, compact volume, light weight and non-maintenance. It also has the capacity to break rated current, overload current (FZRN21-12D/T125-31.5 can break short-circuit current) and to prevent the equipment from operating under phase open. It has a visual clear-ance between open contacts. Fitted with earthing switch
With making capacity and electric-driven spring-operating
Device. It can perform teleactuation and telecontrol.

Structure feature:
1. The combinations are composed of frame, discon-nector (the current limiting fuses are fitted in the disconnector), vacuum arc-extinguishing chamber, earthing switch and spring-operating device etc (See fig. 1).
2. The combinations feature compact structure, small volume, long endurance, high capacity to make and break and convenient operation and maintenance. Fitted with spring-operating device, the vacuum switch stores energy by motor (manual energy storage also available). There are two ways for closing: Solenoid closing and manual closing. The interlock among switch disconnector, vacuum switch and earthing switch (mechanical interlock) can prevent misoperation.