Chennai: Power supply back after major outage; tripping caused by fire at Alamathi substation

CHENNAI: Following a massive blackout in many parts of the city on Thursday night after a fire at a substation, electricity was restored in phases starting from midnight, with all areas receiving normal power supply by 2 am, said Tangedco on Friday. Power supply was disrupted in localities including Manali, Madhavaram, Kolathur, Tondiarpet, Purasawalkam, Perambur, Otteri, Egmore, T Nagar, and Adyar.

The power outage was a result of a major line isolator fire that occured at the Alamathi 400/230 kV substation (SS) in Chennai on September 12 around 9:58 PM. This incident led to tripping of two 400 kV power sources — Alamathi and NCTPS II (North Chennai Thermal Power station) —and a jumper disconnect. The fire was quickly extinguished, but the dual power source failure caused power outages in some areas of Chennai, said Electricity Minister Thangam Thennarasu in a social media post.

He added that the Tamil Nadu Electricity Board promptly provided alternative power, and by 2 AM, 100 percent power was restored in all affected areas of the city.

TANGEDCO confirmed that the power blackout did not affect essential services, including services at hospitals in the city and suburbs.

The Manali SS is a critical power source for the city, receiving power from the Alamathi and NCTPS II substations and providing 800-900 MW to substations in the city like Pulianthope, Tondiarpet, Mylapore, RA Puram, Basin Bridge, Vysarpadi, and Sembium.

These substations supply power to important areas in the city including Anna Salai, Parrys, West George Town, Egmore, Chintadripet, Mylapore, Luz, Santhome, Nungambakkam, Royapuram, Tondiarpet, Tollgate, Saidapet, Vysarpadi, Sembium, Kolathur, Periyar Nagar, Madhavaram, Puzhal, Redhills, and Kodungaiyur.

Following the tripping of several substations, Tangedco engineers commenced efforts to restore power supply through back feeding at 11 pm. They also identified a jumper cut in the 230 kV North Chennai - Tondiarpet feeders 1 and 2, the 230 kV Kalivendampatti - Tharamani feeder, and the 230 kV Sriperumbudur- Tharamani feeder.

Following this, power supply was restored to Anna Salai, Chintadripet, Nungambakkam, Sembium, and Periyar Nagar areas by 12 midnight. By 1 am, electricity was back in Pulianthope and Kolathur, followed by Mylapore, Vysarpadi, Adyar, and Ennore areas at 2 am, Tangedco stated.

(With online desk inputs)