The territory experienced an island wide power outage, which lasted in some parts for more than 4 hours on Saturday. Executive Director Wallon Young gave the following report:
Lightning struck at least two distribution feeders at 1:34PM, near the Futiga road intersection where three distribution feeders converge.
Although uncommon, lightning sometimes strikes power lines, causing a surge in electrical pressure and significant voltage spikes on power lines that extend into the power plant.
Saturday’s lightning strike damaged, beyond repair, a high voltage Air Break Switch on Feeder-6. Four gen-sets at Tafuna plant needed minor repairs before power could be fully restored to the West side. The 34.5KV Tie Line between the two power plants did not suffer any damage, but the line was tested before it was returned to service at 11:30PM on Saturday night.
All six Satala Plant feeders were restored within 12 minutes of the outage. StarKist feeder was re-energized after the all clear notice was given by StarKist engineers.
Delays in restoring feeders at Tafuna plant were due to repairs to Caterpillar gen-sets T1, T2 and T6, and the reprogramming of GE generator no.2 after the lightning strike. The inability of remaining Caterpillar gen-sets T-5, T6 and T10, to withstand magnetizing inrush currents during feeder energizing also delayed restoration efforts.
Tafuna Feeder-5 was eventually restored at 3:40PM, Feeder-9 at 3:47PM, Feeder-6 at 4:37PM, Feeder-7 at 4:49PM and Feeder-10 at 5:04PM.”
Young said ASPA recently ordered two new 3.5MW GE gensets to replace the six 3516 Caterpillar sets at Tafuna plant. The new GE’s are 33% more fuel efficient, and will mitigate the tripping issues associated with feeder faults and magnetizing inrush currents.
ASPA will also install additional lightning arrestors on primary lines around Futiga road intersection.
ASPA sincerely apologizes for the outage and thanks the public for its patience.
