Fire at Hala Naka Road grid station in Hyderabad causes six hour outage

What happened

A fire broke out in one of three large power transformers at the Hala Naka Road 220kV grid station in Hyderabad, Pakistan in the early morning, disrupting electricity supply to the city and nine surrounding towns for approximately six hours. Eight urban feeders and ten outlying 132kV grid stations lost supply. A high voltage direct current transmission link connected to the affected system was also impacted, with knock-on effects on supply to a major nearby city.

Fire crews and National Grid staff worked together to bring the blaze under control within about five hours. The damaged transformer was isolated and the network was re-energised through the two remaining transformers of the same capacity, restoring supply. National Grid ordered an investigation into the cause and stated the damaged unit would be repaired or replaced. No injuries were reported in the available account.

Contributing factors

Not reported. National Grid stated an investigation into the cause of the fire had been ordered but no findings were available at the time of reporting.

Lessons learned

1. Redundant transformer capacity at a 220kV grid station allows supply to be restored quickly by isolating the damaged unit and routing load through unaffected units of the same capacity.
2. Transformer fires at grid stations require close coordination between fire crews and National Grid staff to contain the blaze and limit outage duration to six hours.
3. A single transformer fire at a 220kV grid station can affect an HVDC transmission link and cause knock-on supply loss to a major nearby city.

More lessons on electrical protection and isolation, fire suppression and firefighting, outages, backup supply and restoration, from every incident on the register.

Not yet known

• Cause of the fire
• Transformer model and age
• Cost of repair or replacement

This entry is updated when these are reported. Get an alert for the next one like it.

Source

dawn.com