scope:

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 environment, 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 prescribed in the IEC 60076 series. The self-protected transformer may be used in conjunction with other devices to provide system coordination and sensitive system protection. The protection system is not designed to be functional when the power supply is from the low-voltage side. The self-protected transformer is not intended to function in parallel with another transformer.