Overview
- A blast and fire at the Sector-72 220 kV substation on Friday night caused cascading outages that cut supply to multiple downstream substations and stopped Rapid Metro trains mid-journey.
- Utility teams isolated the fault, dispatched replacement equipment and emergency crews, and officials reported bulk supply and Rapid Metro services largely restored within hours with both 220 kV circuits normalized late that night.
- Residents in many sectors reported prolonged, localized outages lasting several more hours, drained inverter and generator backups, stalled lifts and cooling systems, and footage showed some commuters walking on elevated metro tracks.
- Officials and engineers traced the failure to an oil leak and thermal heating in a current transformer, and said record heat and peak demand — including a one-day city peak above 2,300 MW — worsened overloads on aging 11 kV feeder infrastructure.
- Local RWAs and officials are calling for faster equipment replacement, shifting overloaded 11 kV feeders to 33 kV, routine safety audits and dedicated backups for critical services as the city faces higher summer demand and rising public pressure for upgrades.