The subject of this document is the latest generation Rotoblok SF medium voltage switchgear, intended for indoor use for the distribution of three-phase alternating current with a frequency of 50 Hz, at a nominal voltage of up to 25 kV, in distribution networks in the industrial and commercial sector. The switches are configured from single standard modules with various equipment. The information and technical data specified here enable the designer to assemble a switchgear from typical modules. If modules with equipment not specified here or with modified dimensions are required, the scope of the equipment must be arranged with the manufacturer.

Basic electrical data:

Rotoblok SF

Rated network voltage 20 kV

Highest device voltage 25 kV

Rated frequency / number of phases 50 Hz / 3

Rated short-time network frequency withstand voltage 50 kV / 60 kV

Rated withstand lightning surge voltage 1.2/50 μs 125 kV / 145 kV

Continuous rated current 630 A

Rated short-time withstand current 20 kA (1s)

Rated peak withstand current 50 kA

Resistance to internal arc effects 16 kA (1s)

IP protection rating IP4X

Service conditions:

Ambient temperature

- peak short-time + 40°C

- highest day average + 35°C

- highest annual average + 20°C

- lowest long-term + 25°C1)

Relative humidity of air

- highest day average 95%

- highest month average 90%

- highest day average vapour pressure 2,2 kPa

- highest month average vapour pressure 1,8 kPa

Atmosphere at the place of installation

• no significant contamination with salt, vapour, dust, smoke, flammable or corrosive gasses and lack of icing, frosting and dewing

Installation altitude

• up to 1000 m asl2)

Vibrations

• vibrations caused by external
• factors or earthquakes negligible

Rated power of transformers that can be connected and disconnected using GTR SF 2V, GTR SF 2VM switch disconnectors, depending on voltages on the MV side.