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
Placement of equipment - example custom design solution
|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
|5a||AMI cabinet / Smart Grid / telemetry / auxiliary|
|7||Cable duct hatch door|
|8||Hatch / ladder to the transformer chamber|
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|
|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|
|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.