The agreement replaces one that was settled in 2007 and its immediate effects include wage increases and benefit enhancements.
The agreement also includes a new gain-sharing incentive system, with monthly payouts based on achieving quality and production targets.
Like most other wind turbine manufacturers, Gamesa faced layoffs last year following the global economic downturn but says it is again adding jobs in Pennsylvania. Last year Gamesa installed 600MW in the US.