Transformer explosion prevention and fire protection – a peep into over 3 decades of field experience

Users and power utilities the world over are directing focus on the asset management, minimisation of failure rate of key equipments and their consequential damages, enhanced operational reliability, & outage reduction. The analysis of global statistics shows a failure rate of transformers involving explosion and or fire as close to 0.5% of the transformer-years in service. Many utilities insist on protection systems above a minimum power capacity of 10 MVA and having inflammable oils above 2000 litres. While many technologies and practices of explosion prevention & fire protection have evolved over the years, the Nitrogen based Explosion and Fire prevention systems have performed creditably in the Indian context over the last 2 decades. This paper does not get into historical improvements in the protection systems over the last 3 decades as they have been well covered in the past, but provides a peep into the operation reliability of the system in the Indian context. While efforts are on to curtail the root cause of the explosion and fire in transformers, It concludes the absolute necessity for the fire prevention system and agrees totally with the CEA regulation to mandate fire prevention systems even for medium power rated transformers.