Officials said the major transmission lines of Delhi Transco Ltd, which maintains the transmission network in the city, tripped at Wazirabad, Mandola and Rajghat area of the city affecting supply of power in a large number of areas across the city.
An official of the power department said efforts were on to restore the lines.
Meanwhile the maximum power demand in the city today came down to 4,097 from yesterday's 4,477 MW.
The maximum power demand this season was recorded on Thursday when it touched 4633 MW.
