Accident – explosion and/or fire
PCBs and environment
PCBs in oil and transformer
PCB-based ‘Askarel’ oils
Absence of hazardous product labelling (eg. PCBs, PCAs, additives)
Corrosive sulphur and other corrosions
Lack of data
Lack of nameplate data
Lack of maintenance history
Lack of anamesis history of operative profiles
Lack of purchase requirements
Lack of Inventory management system
Devarnishing
Lack of quality
Non-representative oil sampling
Lack of analytical quality
Intervention of protections
Failures
Electrical failure of transformer and/or accessories
Mechanical failure of transformer and/or accessories
Thermal failure of transformer and/or accessories
Faults
Electrical faults
Mechanical faults
Thermal faults
Degradation of oil and additives
Chemical degradation of oil
Degradation of insulating oil additives
Dielectric degradation of oil
Formation of bubbles
Seal defects and spills
SF6 in oil – Bushing seal defects
Oil levels and spills
Empty transformer (commissioning)
External influxes
Abnormal vibrations and noise