- podziemna stacja transformatorowa

In every place where it is not possible to place any “conventional, above ground” substation due to architectural considerations and lack of space, underground substations are the only solution. The station is constructed as a sealed, monolithic concrete container to be placed under ground level, with medium and low voltage switchgears installed inside. The used MV switchgear (TPM, Rotoblok SF) and LV (RW-N) form independent elements of the station. The station may be placed under walkway, square etc.

A bilge between two floors ensures correct operation even in case of surface rainwater infiltration through ventilation openings. Watertight cable entries and sealed concrete enclosure ensure many years of reliable operation.

Height of the main structure of the substation:
External height 2800 mm
Internal height 2050 mm

Placement of equipment

PST-b (4,7x3) 20/630
PST-b (4,7x3) 20/630-4

Placement of equipment - example custom design solution

PST-bS 20/630+800+1000-10
PST-bS 20/630+800+1000-10 PST-bS 20/630+800+1000-10
1 Walls, 120 mm thick - standard, 90 mm - optional
2 Ventilation louvres IP 23D - standard, IP 43 - optional
3 Doors: solid or with ventilation louvres without fire integrity IP 23D - standard, IP 43 - optional
Doors with fire resistance e.g EI 60 lub EI 120 - optional
4 Transformer
5 LV switchgear
5a AMI cabinet / Smart Grid / telemetry / auxiliary
6 MV switchgear
7 Cable duct hatch door
8 Hatch / ladder to the transformer chamber

Electrical diagram

Schemat elektryczny stacji typu PST-b - podziemna stacja transformatorowa

Optional equipment was marked with red on the electrical diagram.

Technical parameters / configuration possibilities

Mass / Area
Main structure 25 000 kg
Usable area 12,32 m2
Technical parameters / configuration possibilities
Transformer* (4) Maximum power / dimension 630 kVA / 950 x 1750 x 1850 [mm]
Internal arc resistance classification IAC-AB-16 kA-1s
Enclosure class 20
Electrical parameters of switchgears MV LV
Rated voltage up to 25 kV up to 0,69 kV
Rated current 630 A up to 1250 A
Rated short-time withstand current up to 20 kA (1s) up to 25 kA (1s)
Rated peak withstand current up to 50 kA up to 52,5 kA
Switchgear** Type Maximum number of bays
LV (5) RN-W 12
MV (6) TPM 4 (TLLL or WLLL)
Rotoblok SF (500 mm) 4

* Transformer inserted from above, before the roof is attached.

** Detailed selection of switchgears and their equipment is listed in chapters dedicated to individual devices in the catalogue. Example layouts of switchgears and corresponding substation configurations are specified in parentheses. The possibility of installing other types and configurations of switchgears should be arranged every time with the substation manufacturer.

Additional information