6. Rated Power Output (or rated output) (“Pr” or “PN”): refers to the continuous output of turbine at rated head and speed, commonly marked by “Pr”; or the continuous output of generator at rated voltage, speed, and power, commonly marked by “PN”.
7. Rated Head: refers to the small net water head of a Turbine at rated speed and power output.
8.Rated Speed (“nr”): refers to the steady speed of hydropower generating units designed for a hydropower station.
9. Runaway Speed (“nR”): refers to the speed when the torque at axis end is zero after the turbine is in an out-of-control state.
10. Rated Flow (“Qr”): refers to the flow of the turbine at the rated head, speed, and output.
11.Nominal Diameter of Turbine Runner (“D1”): For Francis turbine, it refers to the diameter at the intersection of the front side of blade inlet and the band; for Kaplan and tubular turbines, it refers to the internal diameter of the runner chamber at the intersection of the blade axis; for Pelton turbine, it refers to the pitch circle diameter of the runner.
12. Flowing Parts: refers to all parts through which the water flows from flume inlet of the turbine to the outlet.