The invention concerns a method for starting a hydroelectric turbine (10) in a pumping mode, said turbine being provided with a runner (6) mechanically coupled to a shaft line (8) and a variable speed electric motor connected to a grid, a distributor (4) comprising guide vanes to control a flow of water to said runner, the method comprising:



a) a step of operating the variable speed motor at least partly at fixed speed, said guide vanes being only partially opened, and of defining or calculating:

data of a plurality of hydraulic characteristics (C1, C2, Ci) of the turbine for an operation without cavitation;
data of an operation range of the electric motor, giving the speed of the motor as a function of its power;


b) then a step of operating the turbine in a power control mode.