12kV AC 50Hz three-phase system, with load current, overload and short circuit protection, 20kA (short circuit current), vacuum arc extinguishing chamber (zero pollution, maintenance free), IP65 (dustproof and waterproof, suitable for harsh outdoor environments), column/pole installation (total weight ≤ 120kg) Working temperature: -40 ℃~+70 ℃, altitude: ≤ 3000m (special design supports 4000m), 10000 maintenance free operations