Most parts of the city and its suburbs went without power for hours on Thursday morning because of a snag in CESC’s Majerhat substation.
The power cut continued up to four hours in some areas. Between 8.50am and 9am, hospitals, waterworks and Writers’ Buildings did not have electricity supply.
“Around 8.15am, a 132KV outdoor switchyard in our Majerhat substation developed a fault. The cause is yet to be ascertained,” said Mahul Brahma, a spokesperson for CESC.
Within 35 minutes, all three units (250MW each) of the Budge Budge generating station and both units (65MW each) of the Southern generating station — connected to the Majerhat substation — tripped in succession. By 8.50am, there was a shortfall of over 400MW in CESC-served areas with the total demand around 700MW.
“There was no power from around 9am to noon. Such a prolonged power cut is unexpected at this time of the year,” said Pratima Banerjee, a 35-year-old homemaker in Ballygunge.
After the key establishments, power was first restored in north Calcutta and then in central and south Calcutta.
The units at Budge Budge and Southern started generating power in the afternoon. The state-run West Bengal State Electricity Distribution Company Limited helped CESC by exporting between 500MW and 600MW from 9am.
“With support from the state power utility, the shortfall was brought down to 140MW after 11am,” said Brahma.
The Salt Lake distribution station of the state power utility, however, shut down because of overloading, triggering power cuts in the township.
Vast stretches of Salt Lake’s Sector I and II were without power for two hours from 11am.
Around 12.20pm, CESC was finally able to meet the total demand, which had risen to about 1,240MW by then.
CESC has started a probe into the snag at the Majerhat sub-station.