A method of monitoring drainage of a washing appliance such as a dishwasher or washing machine having a pump for draining a washing chamber is disclosed. The method includes receiving a time series of power consumption data relating to the operation of the washing appliance over a monitored period of operation including pumped draining of the washing chamber. A measure of the duration of a portion of the monitored period comprising said pumped draining is derived from the time series of power consumption data. The measure of duration is then compared to a reference value and an indicator of a drainage condition is determined based on the comparison. The method may be used to detect scaling or blockages in drainage flow paths.

A domestic appliance and a method at the domestic appliance for detecting presence of process water in a pump of the domestic appliance are provided. The method of detecting process water in a pump of a domestic appliance may include operating the pump to rotate in a first direction, recording a first response of the pump rotating in the first direction based on a measured pump operation parameter, operating the pump to rotate in a second direction, and recording a second response of the pump rotating in the second direction based on the measured pump operation parameter. The method may further include comparing the first response and the second response, and determining the presence of water in the pump based on the comparison of the first and second response.

A washing machine for controlling optimal operating revolutions per minute (rpm) of a drain pump in a draining course and a dehydrating course includes a washing tub; a drain pump configured to drain water in the washing tub; a pump motor configured to operate the drain pump; an inverter circuit configured to supply a driving current to the pump motor to operate the drain pump; and a controller configured to control the inverter circuit to supply reference power to the pump motor in response to starting a draining course, determine reference revolutions per minute (rpm) based on average rpm of the pump motor during a preset period of time, and control the inverter circuit to operate the pump motor at the reference rpm in response to the determining of the reference rpm.

The present invention relates to a washing machine (7) and pump (8) for a washing machine (7). The pump is driven by a brushless DC motor (38). The pump can be controlled to improve the operation of the washing machine. In one aspect the invention comprises a washing machine (7) with a variable speed pump (8) for pumping out wastewater, a controller (50) for controlling the speed of the pump and a sensor (10) for determining the flow-rate of water being pumped from the washing machine, wherein the controller (50) controls the speed of the pump to maintain the flow-rate at a desirable level.

The present disclosure relates to a laundry treatment machine. According to an embodiment of the present disclosure, a laundry treatment machine includes a controller controlling a motor, during dewatering, to be driven at a first speed when a lift is at a first level and to drive the motor at a second speed greater than the first speed when the lift is at a second level greater than the first level, wherein the lift is a difference between a water level of a water introduction part through which water flows into a drain pump and a water level of a water discharge part through which the water is discharged out of the drain pump. Accordingly, noise or vibration can be reduced even if the lift is changed during the dewatering.

A washing machine appliance is provided including a sump positioned at a bottom of a wash tub for collecting wash fluid, a drain pump assembly for selectively draining the sump, a measurement device configured for measuring movement of the wash tub, and a water level detection system comprising a pressure sensor fluidly coupled to the sump. A controller is configured to operate the drain pump assembly to drain the wash fluid, measure the movement of the wash tub using the measurement device, measure a water level within the sump using the water level detection system, and identify a fault condition in the water level detection system upon determining that the measured movement indicates that the sump is empty and the measured water level indicates that the sump is not empty.

A washing machine appliance, a controller, and a method for operating a washing machine appliance are provided. The appliance includes a controller operably coupled to a motor assembly that is operably coupled to a wash basket, and a drain pump assembly. The controller is configured to rotate the wash basket to at least a desired speed; determine one or more of whether at least the desired speed of the wash basket is achieved within a period of time, or whether an energy parameter threshold of a motor assembly is exceeded when rotating the wash basket within the period of time; and generate an output signal corresponding to fluid detection at a wash tub when the wash basket fails to rotate to at least the desired speed within the period of time or, when the energy parameter threshold is exceeded when rotating the wash basket within the period of time.

A washing machine appliance includes a sump for collecting wash fluid, a drain pump for discharging the wash fluid from the sump, and a water level detection system fluidly coupled to the sump. A controller is configured for monitoring the electric current drawn by the drain pump during a drain cycle and determining that the sump is empty based on a drop in the electric current. The controller then measures the sump pressure and determines that a fault condition exists with the water level detection system when the sump is empty and the sump pressure exceeds a predetermined pressure threshold, e.g., zero pressure corresponding to an empty sump.

A washing machine appliance includes a sump for collecting wash fluid, a water supply valve for supplying wash fluid during a fill cycle, and a drain pump assembly for draining that wash fluid during a drain cycle. A controller is configured for monitoring the sump pressure using a water level detection system, detecting a fill sensing failure such as a slow pressure rise after the fill cycle, detecting a drain sensing failure such as a slow pressure drop during the drain cycle, and determining that the water level detection system is malfunctioning if the fill sensing failure and the drain sensing failure are detected.

The present disclosure relates to a drain pump driving apparatus and a laundry treatment machine including the same. A drain pump driving apparatus according to an embodiment of the present disclosure and a laundry treatment machine including the same include: an inverter converting a direct current (DC) voltage from a converter into an alternating current (AC) voltage based on a switching operation and to output the converted AC voltage to a drain motor; and a controller to control the motor to, when a drain channel in a drain pump is clogged, be temporarily stopped in a period during which a speed of the motor increases and then to repeatedly rotate and stop in a first direction the same as a start-up direction, and to repeatedly rotate and stop in a second direction opposite to the first direction when the drain channel is clogged even after the motor repeatedly rotates and stops in the first direction. Accordingly, when impurities are introduced into the drain pump, the impurities can be removed in a simple manner.