💧 Water and Power · U.S. Virgin Islands
WAPA said generator failures caused two district-wide outages in St. Thomas-St. John
Official document: http://www.viwapa.vi/docs/default-source/default-document-library/08152021-wapa-explains-cause-of-two-district-wide-outages-this-weekend.pdf?sfvrsn=2b8c74fb_2
The Virgin Islands Water and Power Authority said two district-wide outages in the St. Thomas-St. John district on Aug. 14 and Aug. 15, 2021 were caused by generating units tripping offline and leaving the plant without enough capacity to meet demand.
WAPA said all generating units tripped offline simultaneously on the morning of Aug. 14, causing a district-wide interruption. Service was restored over several hours as plant personnel brought additional units online.
The utility said restoration was complicated because Unit 23, the district's largest generator, tripped and could not be immediately returned to service, while Unit 15 had already been out following an earlier outage that week. WAPA said repairs to Unit 15's lube oil pump motor began over the weekend, and Unit 23 was being worked on for high temperature spreads on fuel nozzles and failures in its direct current system.
With both units unavailable, WAPA said the plant could not meet demand, particularly during peak periods. The utility implemented rotating outages on the night of Aug. 14, taking feeders offline in one-hour intervals, and said a similar schedule would be used on Aug. 15.
At 12:20 a.m. on Aug. 15, WAPA said the plant again could not meet demand and one dispatched unit tripped, leading to another district-wide outage. The utility said all customers were restored by about 5:50 a.m. on Aug. 15.