The transformer station type ST-T2/N1U is a device designed for use in underground mining in excavations with no explosion hazard or in conditions with no methane explosion hazard and designated as class A coal dust explosion hazard. The transformer station ST-T2/N1U is equipped with a power protections against short-circuits, overloads and lowered insulation resistance with installed transformer: 630kVA or 800kVA and rated upper voltage of 6 kV or 10 kV or (10-6) kV (switchable transformer) and lower rated voltage 525V AC. Electrical equipment of a transformer station at the upper rated voltage of 10kV and (10-6) kV is matched to 10 kV rated voltage.