High/Medium Head Turbine
These turbines are lightweight, and small in physical size, and yet able to supply high quality electricity, regulated in terms of frequency and voltage by their own internal voltage stabilisation circuitry. They are based on 'Turgo' runners, which provide an ideal alternative for the Pelton wheel at lower heads. The medium head turbines, for example, incorporate a ‘dump load’ ballast heating element in the draught tube, which uses water-cooling to ensure that the load on the turbine remains constant. The machines may be operated for years with minimal maintenance, although it is necessary to apply grease to the bearings using the grease cap a couple of times a month, to ensure a long life. By reducing the jet diameter on these turbines, it is possible to operate them with heads of over 100m
