VSV-27.5 indoor high voltage AC vacuum circuit breaker is a single-phase unipolar AC 50Hz switchgear with rated voltage of 27.5kV and maximum working voltage of 31.5 kV, which is supported by a L-type frame. The vacuum circuit breaker (VCB) is mainly applicable to traction substations, sub-switching posts and switching stations of the electric railway power supply system for opening and closing load, breaking fault current, and controlling and protecting circuit. and is also suitable for sites with loads of different nature and frequent operation.

a. The VCB is integrated with the special spring operating mechanism with advanced and reasonable design, multiple functions and high reliability;

b. The main circuit has upper and lower outlets. The vacuum arc-extinguishing chamber and handcart frame are linked into a whole unit through two reinforced epoxy resin insulators, which not only strengthens voltage tolerance of VCB, but also gains high mechanical strength and dynamic and thermal stability;

c. The main body of the energy storage device is the special sealed cast aluminum reduction gearbox with long service life. The internal two-way clutch device is adopted to realize the independent operation of electric and manual energy storage;

d. The lower part of the handcart operating mechanism body is provided with a labor-saving interlocking mechanism, achieving the labor-saving and interlocking function during operation.

e. The handcart of VCB is fitted with the current transformer arranged at the front and lower part of the arc-extinguishing chamber. As a whole, the VCB is reasonable and compact in structure.

No.	Item		Unit	Parameter
1	Rated Voltage		kV	27.5
2	Rated Insulation Level	Power Frequency Withstand Voltage (1min), Phase to Phase, Phase to Earth / Break		95
		Lightning Impulse Withstand Voltage（peak）, Phase to Phase, Phase to Earth / Break		185
3	Rated Current		A	1250， 1600， 2000， 2500
4	Rated Short-circuit Breaking Current		kA	25	31.5
5	Rated Short-circuit Making Current（peak）			63	80
6	Rated Peak Withstand Current			63	80
7	Rated Short-time Withstand Current			25	31.5
8	Rated Short-circuit Breaking Current Breaking Times（E2 class）		Times	20
9	Rated Thermal Stability Time		s	4
10	Rated Operating Sequence			0-0.3s-C0-180s-C0
11	Mechanical Life (M2 class）		Times	10000