This part of IEC 60076 applies to high-voltage/low-voltage self-protected liquid-filled and naturally cooled transformers for rated power 50 kVA to 1 000 kVA for indoor or outdoor use having a- primary winding (high-voltage) with highest voltage for equipment up to 24 kV;- secondary winding (low-voltage) with highest voltage for equipment of 1,1 kV.These transformers are equipped with a self-protection and disconnection device to protect the enviroment, property and people and prevent any disturbance of the high-voltage network from the consequences of an internal transformer fault.Transformers covered by this standard comply with the relevant requirements