Patent ID: 9138122
Filing Date: 2015-09-22
Classification: A47L

Abstract:
1. A method of operating a dishwasher having a treating chamber, a spraying system for spraying liquid in the treating chamber, a liquid recirculation system for recirculating the sprayed liquid back to the spraying system, the recirculation system having a pump comprising a single phase synchronous electric motor (SPSEM) rotating an impeller, wherein the method comprises: operating the SPSEM at a rotational speed where the harmonic response frequency of the SPSEM is greater than 50 cycles per second (Hz) and less than 88 Hz, and where the dishwasher has a sound power level of less than 52 A-weighted decibels (dB(A)) for a stainless tub dishwasher and 57 dB(A) for a plastic tub dishwasher.