SAVANNAH, Ga. – A maintenance team is improving operational efficiency and cutting costs at the Hartwell Dam Power Plant by rehabilitating deficient generators. Recently, staff thwarted the imminent failure of unit 4 when several burnt coils were discovered during scheduled biennial outages. The timely discovery resulted in an economical response that returned the unit online within its established biennial outage.
Layers of damaged coils were removed, stripped of insulation, re-soldered, and reinsulated during installation repairs. The team placed temperature tape on repaired and additional suspect coils to monitor heat conditions upon returning the unit to service. In a follow-up inspection, repaired coils displayed excellent heat performance but suspect coils greatly overheated. This measure revealed a problem not yet identifiable by visual inspection, said Ryan Hanna, a Hartwell Power Plant hydropower manager.
“Although damage seemed minimal in scale, it was a progressing issue that would have caused imminent failure if not corrected,” said Hanna.
Unit unavailability can amount in losses up to $12,000 per day but contracting repair work can snowball into the millions. About $44,000 in final costs prevented more than $4 million in potential costs, calculated on the basis of probable failure in the event issues weren’t identified and addressed immediately, said Hanna.
Deficiencies that go unnoticed can cause severe damage to a unit’s network of components which work together to produce hydroelectric power. Issues that arise during unscheduled outages can cause the plant to fall short of power production schedules, said George Bramlette, Operations Project Manager at the Hartwell Lake Project.
“I’m glad we didn’t find it any later,” said Bramlette. “Finding burnt coils during a scheduled inspection [was good] because it probably could have done substantial damage to the unit.”
Scheduled inspections require unit outages for a window of time and are coordinated with the Southeast Power Administration. SEPA, a Department of Energy agency, markets Corps hydroelectric power to customers surrounding the Savannah River Basin. The agency coordinates with other Corps projects in the Southeast to meet hydropower demands when Hartwell units are down, said Bramlette.
Checkups normally involve diagnostic tests and routine maintenance to ensure optimal operability. When more serious issues are identified, repairs can require outsourcing to contracting partners which can hike expenses, said Bramlette.
Instead of yielding to often lengthy timelines associated with outsourcing work, the team called on expertise from the Hydropower Technical Center and Hydroelectric Design Center, two Army Centers of Expertise. They put together repair plans to minimize offline periods and maximize cost-savings, he said.
Relying on intra-agency collaboration prevents shifting repair work to third parties and allows teams to put their expertise into practice in a timely, cost-effective manner, said Bramlette.
These self-sustaining standards improve operational efficiency and prevent burnouts among the team and inside generators, he said.