Impact of the Spin Cycle on the Acoustic Power Level of a Washing Machine

Abstract

This contribution describes the impact of the spin cycle of a washing machine on its acoustic power level and examines the adverse effects occurring during the spinning. Such effects result in an increase in the rated acoustic power level shown on the rating plate of a particular major appliance type. To enable an objective assessment of this problem, a series of measurements is required since many of those effects are accidental and occur sporadically. The rating declaration for a particular type of washing machine is based on three repeated measurements made on three sample units. The measured values are then used in the final calculation according to the relevant standard, in a manner that allows the repeatability of measurement. The wash cycle ends with the final water discharge, which is followed by a series of spin phases at different speeds and varied drum imbalances. The test code for the determination of airborne acoustic noise foresees the specification of a 50-second interval of the acoustic power maximum profile for use in the declaration calculation. If the measured acoustic power levels differ between the repeated measurements, it can reasonably be supposed that an unwanted effect is present that needs to be identified and eliminated to avoid a further increase in the total acoustic power level of the washing machine during the spin cycle.