Method for pumping out liquid from e.g. washing machine, involves controlling motor as function of ripple value and threshold value such that rotational speed of pump is reduced and/or increased when ripple value exceeds threshold value

摘要

The method involves deriving vibration behavior of a liquid column in a delivery line from an operating parameter of a drain pump (3) and/or an electric motor (2). A ripple value (W) rising with increasing vibration amplitude of delivery volume flow (V), is determined and compared with a preset threshold value. The electric motor is controlled as a function of the ripple value and the threshold value such that rotational speed (n) of the drain pump is reduced and/or increased when the ripple value exceeds the threshold value. The electric motor is designed as an electronically commutated motor. An independent claim is also included for a device for pumping out liquid from an appliance i.e. household appliance.