Condensate pump assembly & control methods

Abstract

The present disclosure comprises a method of controlling a condensate pump assembly which comprises a pump and a controller connected to the pump, the method comprising measuring a current value drawn by the pump, comparing the measured current value to a predetermined threshold current value and controlling operation of the condensate pump assembly based on the current value comparison. Also provided is a condensate pump assembly for use in an air conditioning system, comprising a housing comprising an upper housing portion and a pump arranged to pump liquid from a liquid inlet to a liquid outlet.

1 . A method of controlling a condensate pump assembly which comprises a pump and a controller connected to the pump, the method comprising:
 powering the pump;   measuring a current value drawn by the pump;   comparing the measured current value to a predetermined threshold current value stored in the controller; and   controlling the pump to be powered to operate in a condensate pumping mode if the measured current value exceeds the predetermined threshold current value; or   rendering the pump unpowered if the measured current value is less than the predetermined threshold current value.   
     
     
         2 . A method according to  claim 1 , wherein the step of powering the pump comprises powering the pump to operate for a predetermined start-test period, and wherein the step of measuring a current value comprises measuring a current value drawn by the pump during the start-test period. 
     
     
         3 . A method according to  claim 2 , wherein if the measured current value is less than the predetermined threshold current value and the pump remains unpowered, then allowing a predetermined start test interval to elapse and then repeating the steps of powering the pump to operate for a predetermined start test period, measuring a current value drawn by the pump during the start test period and comparing the measured current value to a predetermined threshold current value stored in the controller to determine if the pump should be powered or remain unpowered. 
     
     
         4 . A method according to  claim 2  comprising repeating the steps of  claim 2  whilst the condensate pump assembly remains operational. 
     
     
         5 . A method according to  claim 3  , wherein the start test interval comprises between 0.25 seconds to 60 seconds, and may be between 0.5 seconds to 20 seconds, and may be one second. 
     
     
         6 . A method according to  claim 2 , wherein the step of powering the pump to operate for the predetermined start test period comprises providing a pulse width modulated voltage to the pump at a pwm value less than the maximum rated value of the pump. 
     
     
         7 . A method according to  claim 1 , wherein the step of measuring a current value comprises measuring a current value drawn by the pump during a condensate pumping mode whilst the pump is operating; and
 wherein the step of controlling the pump to be powered to operate in a condensate pumping mode comprises continuing to power the pump to operate in the condensate pumping mode.   
     
     
         8 . A method according to  claim 7 , wherein, if the measured current value exceeds the predetermined threshold current value and the pump remains operating in a condensate pumping mode, then allowing a predetermined operating test interval to elapse and then repeating the steps of measuring a current value drawn by the pump during the condensate pumping mode whilst the pump is operating and comparing the measured current value to the predetermined threshold current value stored in the controller to determine if the pump should remain powered to operate in the condensate pumping mode or be switched off. 
     
     
         9 . A method according to  claim 8  comprising repeating the steps of  claim 7  whilst the condensate pump assembly remains in the condensate pumping mode. 
     
     
         10 . A method according to  claim 7 , wherein the step of powering the pump comprises powering the pump to operate for a predetermined start-test period, and wherein the step of measuring a current value comprises measuring a current value drawn by the pump during the start-test period. 
     
     
         11 . A method of controlling a condensate pump assembly which comprises a pump, a liquid receptacle configured to receive condensate to be pumped, a liquid level sensor received in the liquid receptacle to sense a level of condensate within the liquid receptacle, and a controller connected to the pump and liquid level sensor, the method comprising:
 powering the pump to operate for a predetermined start-test period;   measuring a current value drawn by the pump during the start-test period;   comparing the measured current value to a predetermined threshold current value stored in the controller; and   leaving the pump unpowered if the measured current value is less than the predetermined threshold current value; or   if the measured current value exceeds the predetermined threshold current value, then calibrating the liquid level sensor by:   obtaining a liquid level signal from the liquid level sensor; and   storing the liquid level signal as a threshold liquid level sensor signal in the controller.   
     
     
         12 . A method according to  claim 11 , comprising powering the pump to operate in a condensate pumping mode if the measured current value exceeds the predetermined threshold current value. 
     
     
         13 . A method of controlling a condensate pump assembly which comprises a pump, a liquid receptacle configured to receive condensate to be pumped, a liquid level sensor received in the liquid receptacle to sense a level of condensate within the liquid receptacle, and a controller connected to the pump and liquid level sensor, the method comprising:
 measuring a current value drawn by the pump during a condensate pumping mode whilst the pump is operating;   comparing the measured current value to a predetermined threshold current value stored in the controller; and   continuing to powering the pump to operate in the condensate pumping mode if the measured current value exceeds the predetermined threshold current value; or   if the measured current value is below the predetermined threshold current value, then calibrating the liquid level sensor by:   obtaining a liquid level signal from the liquid level sensor; and   storing the liquid level signal as a threshold liquid level sensor signal in the controller.   
     
     
         14 . A method according to  claim 13 , comprising stopping operation of the pump if the measured current value is below the predetermined threshold current value. 
     
     
         15 - 34 . (canceled) 
     
     
         35 . A condensate pump assembly for use in an air conditioning system, the condensate pump assembly comprising:
 a housing comprising an upper housing portion; and   a pump arranged to pump liquid from a liquid inlet to a liquid outlet;   wherein the condensate pump assembly is configured to operate according to the method of  claim 1 .   
     
     
         36 . A condensate pump assembly for use in an air conditioning system, the condensate pump assembly comprising:
 a housing comprising an upper housing portion; and   a pump arranged to pump liquid from a liquid inlet to a liquid outlet;   wherein the condensate pump assembly is configured to operate according to the method of  claim 11 .   
     
     
         37 . A condensate pump assembly for use in an air conditioning system, the condensate pump assembly comprising:
 a housing comprising an upper housing portion; and   a pump arranged to pump liquid from a liquid inlet to a liquid outlet;   wherein the condensate pump assembly is configured to operate according to the method of  claim 13 .