This study had the objective to verify the relationships of Rateaux and the reduction of the power consumed during pumping when a frequency invertor is used it causes the variation of rotation of the motor-pump unit. Using a variable frequency drive, the observed average reduction in the power consumed was 40.7% with the reduction of the rotation from 1800 to 1500 rotations min-1 and 75.0% for reduction from of 1800 to 1100 rotations min-1, respectively. When the power consumption was evaluated using the relationships of Rateaux, the mean error in the reduction of power was 1.33 and 2.00% for 1500 and 1100 rotations min-1, respectively, which shows that the Rateaux relationships may be used for the estimation of manometric height, discharge and the power consumed from the characteristic curve obtained experimentally.
frequency variable drive; hydraulic pump; relationships of Rateaux
