Circuit-breaker failure causes blackout |25 July 2006

The failure, in the circuit-breaker's insulation system, started a fire in the sub-station and triggered off the protection system on the entire electricity network on Mahe.

The managing director of the Electricity Division of the Public Utilities Corporation (PUC), Philip Morin, explained that the failure was severe and massive, and affected all three of the power network's phases.

"Failures on circuit-breakers are common but usually they do not cause such a blackout because they affect only one of the three phases. This time all three phases were affected," he said.

Extensive damage was caused to some of the equipment at the sub-station.

With the sub-station at Foret Noire, Mount Fleuri being close to the main power station at Roche Caiman, the effect of the failure was felt there, activating the network's protection system which caused the entire network to shut down.

The failure happened at 6 a.m. but the quick response of the electricity division's engineers and technicians enabled the network to be gradually switched back on again an hour later.

Mr Morin said his engineers and technicians had to first change the direction of the flow of current in the network to bypass the damaged equipment to allow customers to receive electricity.

They worked throughout the day and by Saturday evening the whole network was functioning properly as before.

The pieces of damaged equipment in the sub-station are being repaired and Mr Morin said this could cost over R50,000.