These machines replace many of the traditional ones and have remarkable advantages. Simple installation: thanks to the performances of the Inverter, they can be connected from 200 to 240 Volts, 50-60 Hz, (plugging to single phase system, or three phase 230 – 400 V); they always fit a three phase 230 Volts motor. Better reliability: the motor is fully protected from electricity overcharge, due to accidental causes, motor overheating, short circuit, etc.; it is less stressed for the reduced rpm , from 1.400/2.800 to 900/1.750. Better efficiency: energy saving up to 40% thanks to the best motor exploitation at full load. Higher performances: variable and adjustable speed by a potentiometer, from 8,8 to 17 for the bowl and from 88 to 170 rpm for the spiral. Special working cycles: the parameters of the inverter can be adjusted for special operations (the modifications are applied upon agreement between the Manufacturer and the Operator). Stocking cost optimization: one machine can cover the demand of several traditional ones of the same model. Machine more silent: thanks to the rpm drop and to the chains automatic tension regulation, by chain tensioners, there are less noises and mechanical wear of dynamic components. Cost reduction: the machine is simplified in the mechanical and electric parts. The spiral mixers with inverter are manufactured by ourselves exclusively.