Transformer failure rate dips, but old units continue to fail

Bengaluru: The transformer failure rate in Bescom’s jurisdiction has fallen from 8.07% in 2018-19 to 6.77% in 2025-26. However, the number of failed transformers has increased, with old units continuing to account for a significant share of the failures, officials and sources said.In 2018-19, 30,751 of the 3.81 lakh transformers failed. By 2025-26, the number of transformers had increased to 5.6 lakh, while failures had risen to 38,062.”It is obvious that new transformers will not fail. It’s the old ones that are not being maintained well, and their failure rate is still high,” a source privy to transformer maintenance told DH.Transformer maintenance has come under the scanner after two transformer blasts in the city in two days left four people injured.‘Rat’ sparked transformer blast in Bengaluru, says BESCOMBangalore Electricity Supply Company (Bescom) cited a rather unusual reason for the second explosion, which occurred near Amazon India at Bagalur Cross on October 7.According to the utility, a rat entered the transformer’s Ring Main Unit (RMU) and came into contact with a live wire, causing a short circuit. Officials are still investigating the cause of the first explosion at Benniganahalli, near KR Puram, on October 6.Sources, however, said local residents had complained about low-voltage problems on Monday and highlighted the need to repair the transformer. Bescom officials have yet to take up the repair work.While Bescom officials maintained that some breakdowns and repairs are unavoidable, they cited rising load as one of the major reasons for transformer failures.“The majority of transformer failures are due to overloading. A small number of failures are also because of unauthorised connections drawing power and manufacturing defects. Some failures can be directly attributed to poor maintenance, especially of old transformers,” a senior Bescom official conceded.Sources also attributed some failures to poor maintenance. Although Bescom has been taking measures to ensure that all transformers are serviced periodically, some lapses remain.“There were complaints about poor maintenance. However, we have now launched a mobile application where operators have to upload before-and-after pictures during maintenance activities. They also have to log the maintenance work taken up. This will ensure there are no lapses,” another official said.With power demand increasing significantly over the years, there is a need to add more transformers to prevent failures caused by overloading, experts said.According to Bescom, between 2018-19 and 2025-26, the power utility added 1.8 lakh new transformers, or around 28,000 a year on average.To ensure transformer failures are addressed at the earliest and reduce the duration of unscheduled power cuts, Bescom has established 48 transformer repair centres at the taluk level. Buffer stocks of repaired transformers are kept at 25 divisional stores and 49 transformer banks.

Source: Deccan Herald