Electrical service to residential customers in the St. Thomas – St. John district was restored at approximately 10:30 a.m. Sunday, two hours after a pair of generating units tripped at the Randolph Harley power plant.
“A combustion system issue with Unit 25 resulted in that unit falling off-line at approximately 8:15 a.m. The unit’s failure had a cascading effect on another unit that was on-line at the time. This series of events led to a district-wide service interruption,” said WAPA Executive Director Lawrence J. Kupfer.
Plant personnel and engineers from APR Energy, the owners of the two tripped units, worked to restore one of the units and another of WAPA’s generators, Unit 15, facilitating the restoration of service to all customers.
Kupfer said the two units that tripped on Sunday morning also failed on the morning of March 5, resulting in a district-wide service interruption as well. Engineers from APR Energy have preliminarily confirmed the cause of that interruption to be issues with the source of electricity which provides power to the two generating unit’s auxiliary components.
WAPA is currently leasing three generating units from Texas-based APR Energy to bridge a gap in generation capacity until such time that new, more reliable and energy- efficient generators are added to WAPA’s generation fleet. The Authority is under contract with Wartsila North America to design, build, and engineer several new generating units over the next two to three years. Three of these new units are expected to be commissioned before the end of this year.