American-style compact substation (美式箱变) for 12 kV three-phase AC distribution networks, housing the transformer, high-voltage load switch, and backup fuses inside a single sealed oil tank. Delivers a compact, space-saving footprint with simple installation for industrial parks, residential communities, and commercial centers. Fully sealed, fully insulated, and maintenance-free construction ensures safe, reliable operation with minimal upkeep. Supplied by an experienced switchgear manufacturer and suitable for turnkey overseas projects.