Block Transformer Station

The block transformer station  25/0,4 kV, 50 Hz (EOV-EŽ-Tr) serves as a power supply source e.g. for electrical heating of switches from single phase traction current system 1 PEN AC 25 kV, 50 Hz / TN-C.

The transformer station cabinet is designed as a closed groundfloor skeleton. The cabinet shielding is IP 43. The cabinet is made of welded ALUZINK metal plates. In the lower part of the transformer station there is a basement 60 mm high.  All the surface cabinet parts, incl. the roof are treated with paint, both inside and outside. The outside surface is further painted with a plaster paint. The inside part of the roof is treated with a special paint absorbing atmospheric humidity.

The cabinet is divided into two separate sections HV/LV, which are separated with an insulation barrier from each other. Both LV and HV sections are equipped with lockable door. It is possible to provide the HV section with a transparent cover, so that shielding IP 20 is secured in case the door is open.

The input from 25 kV contact line is led from the remote controlled section insulator over the input HV fuse and lightning arrester into HV section to the connecting part of an oil hermetized transformer 25/2 x 0,23/2 x 0,2 kV. The oil hermetized transformer has a separated HV/LV winding acc. to the requirement of ČSN 34 1500 ed.2 and tapped secondary winding. After the installation of EOV-EŽ-Tr the connection of the transformer’s return pole to rail has to be performed acc. to the requirements of ČSN EN 31500 ed.2.

The output of the secondary winding of the oil hermetized transformer 25/2x 0,23/2x 0,2 kV, 50 Hz is led to the LV section, in which a plastic power supply switchboard  and separating transformer are placed.  The separating transformer serves for power supply of LV auxiliary circuits.

Technical parameters:

Material: aluzinc
Shielding: IP 43/00 (IP 43/20)
Dimensions (wxdxh): 1100 x 1500 x 2200 mm
Mechanical resistance: IK 30
Operating temperature: -50°C ÷ + 40°C
Rated voltage – main circuits: 25 /2x 0,23 ;/2x 0,2 kV
Rated insulation voltage HV/LV section: 29/0,8 kV
Withstand voltage (50 Hz) HV/LV section: 80/2,5 kV
Impulse withstand voltage HV/LV section: 180/8 kV
Standard: ČSN EN 62271-202