A sudden blast in an automatic transformer at a sub-station in Tondiarpet on Sunday evening resulted in a three-hour blackout in many areas in the northern parts of the city.
No one was injured in the blaze, but up until Monday evening, two fire tenders were attempting to douse the smoke from the gutted transformer.
Residents of the Shivaji Nagar quarters, which houses around 20,000 families and is located just behind the 230 KV sub-station in Durga Devi Nagar, were alarmed when around 6.45 p.m., the 100 MVA transformer blew up.
The residents alerted the police and fire services. Tenders from Tondiarpet, Korukkupet, Washermanpet, Esplanade, Ambattur and Sembium arrived. It took fire fighters over three hours to put out the blaze.
Officials said the two tenders working on Monday were a precautionary measure.
Power was cut off in several areas including Tondiarpet, R.K. Puram, MKB Nagar, SM Nagar, Vysarpadi, Perambur and Kodungaiyur. It was only restored around 10 p.m., after the transformer was replaced.
“We were quite scared when we saw huge flames shooting up from the sub-station,” said S. Mahalakshmi, a resident.
Tamil Nadu Generation and Distribution Corporation (Tangedco) officials, who inspected the site, said coolant oil, 40,000 litres of which had been stored inside the compound, had leaked, leading to a rise in temperature and triggering the blast. The cost of a 100 MVA transformer is around Rs. 3 crore, an official said.
“We are still awaiting a full report of the incident. However, an internal fault in the transformer could also have caused the accident. As it was a holiday, only a few Tangedco staff members were at the sub-station to attend to the emergency,” said the official.
A case has been filed at the R.K. Nagar police station.