Abstract: There is provided a condensate pump assembly (100) for use in an air conditioning system. The condensate pump assembly (100) comprises a pump (102) arranged in a housing (104) to pump liquid from a liquid inlet (116) towards a liquid outlet (106). The condensate pump assembly (100) further comprises a liquid receptacle (108) arranged, in a first position in the housing (104), to receive condensate from a condensate inlet (110) and to be in fluid communication with the liquid inlet (116). The liquid receptacle (108) is movable to a second position removed from the housing (104), whereby to empty the liquid receptacle (108). The condensate pump assembly (100) further comprises selective release (112, 114) means operable by a hand of a user to release the liquid receptacle (108) for movement from the first position towards the second position.

Abstract: There is provided a centrifugal pump comprising a pumping chamber (106). The pumping chamber (106) has an inner surface (108) defining a pump cavity (110); a pump inlet (112) defined in a first side of the pumping chamber (106); a shaft opening (116) defined substantially centrally in a second side of the pumping chamber (106), the second side substantially opposing the first side and arranged to be above the first side, in use; and a pump outlet (114). The centrifugal pump further comprises an impeller (120) retained within the pump cavity (110); and a shaft member (140) mechanically connected to the impeller (120) through the shaft opening (116), whereby rotation of the shaft member (140) causes rotation of the impeller (120) about a shaft axis (157) passing through the shaft opening (116) and movement of a pumping liquid from the pump inlet (112) towards the pump outlet (114).

Abstract: A pulsation damper for a condensate pump comprising a housing defining a fluid chamber having a liquid inlet connectable to an outlet of the condensate pump, an air inlet, and a liquid outlet, wherein the air inlet includes a one-way valve configured to selectively introduce air into the housing to maintain a first air pocket within the fluid chamber as liquid flows through the fluid chamber, wherein the liquid outlet is located outside the first air pocket, and wherein the air pocket is configured to dissipate pulsations within liquid entering the housing at the liquid inlet prior to the liquid discharging via the liquid outlet.

Abstract: An anti-vibration arrangement for a condensate pump comprising a housing having a first opening; a pump motor contained within the housing having a pump motor inlet in fluid communication with a pump motor outlet; and a resiliently deformable collar secured within the first opening having an aperture through which the pump motor inlet projects. The resiliently deformable collar comprises an outer portion secured to the housing, an inner portion to support the pump motor inlet and a connecting portion located between the outer portion and the inner portion, such that oscillations of the pump motor cause the connecting portion to deform and allow the inner portion to move in reciprocating manner.

Abstract: The connection box of the present invention provides a simple and safe method to integrate an AC unit and condensate pump into a larger building management system. This is possible because the circuit is configured to require high water level sensors are connected to the connection box in order for power to be provided to operate the AC unit. An installer only has to connect the external wires of the AC unit, condensate pump and building management system to the respective designated connection terminals within the connection box. The designated terminal connections provide a clearly labelled instruction to an installer and aid safe and proper installation of AC units and remove the need to re-wire the internal wiring of the AC unit.

Abstract: A liquid level detector for use in a pump control system comprises a chamber 20 for liquid, a liquid inlet 6 to the chamber 20, a liquid outlet 7 from the chamber and connectable to a pump, and a capacitive sensor comprising mutually spaced capacitive sensor elements (21, 22; 22, 23) forming a capacitance which is sensitive to permittivity within a region of the chamber proximate the capacitive sensor. The chamber is defined at least partially by a barrier member 25 and the capacitive sensor elements are provided on the barrier member outside the chamber.

Abstract: The present invention provides a liquid level sensor and an automatic calibration process which removes the need for prior manual calibration of the liquid level sensor, as this happens dynamically during installation and use of the pump. Further, by frequently monitoring the calibration of the sensor and correcting for long term drift or contamination on the sensing surface, the reliability of the liquid level sensor is considerably better than those of the prior art. By operating a solid state sensor, there are no moving parts in the liquid level sensor described above.

Abstract: There is provided a centrifugal pump comprising a pumping chamber (106). The pumping chamber (106) has an inner surface (108) defining a pump cavity (110); a pump inlet (112) defined in a first side of the pumping chamber (106); a shaft opening (116) defined substantially centrally in a second side of the pumping chamber (106), the second side substantially opposing the first side and arranged to be above the first side, in use; and a pump outlet (114). The centrifugal pump further comprises an impeller (120) retained within the pump cavity (110); and a shaft member (140) mechanically connected to the impeller (120) through the shaft opening (116), whereby rotation of the shaft member (140) causes rotation of the impeller (120) about a shaft axis (157) passing through the shaft opening (116) and movement of a pumping liquid from the pump inlet (112) towards the pump outlet (114).

Abstract: A method of driving a solenoid pump of the type comprising a metal shuttle urged by a solenoid against a spring with the spring providing the force for the pumping stroke of the shuttle is disclosed. The method comprises applying a periodic driving voltage to the solenoid. Each period of the driving voltage comprises a first portion during which the driving voltage increases from a minimum voltage to a maximum voltage to compress the spring, a second portion during which the driving voltage decreases from the maximum voltage to the minimum voltage to release the spring, and a third portion during which the driving voltage is maintained at the minimum voltage. The duration of the second portion is substantially less than the duration of the first portion and may be substantially instantaneous. The driving voltage increases from the minimum voltage to the maximum voltage substantially linearly during the first portion, such that the driving voltage has a sawtooth waveform.

Abstract: A liquid level detector for use in a pump control system comprises a chamber 20 for liquid, a liquid inlet 6 to the chamber 20, a liquid outlet 7 from the chamber and connectable to a pump, and a capacitive sensor comprising mutually spaced capacitive sensor elements (21, 22; 22, 23) forming a capacitance which is sensitive to permittivity within a region of the chamber proximate the capacitive sensor. The chamber is defined at least partially by a barrier member 25 and the capacitive sensor elements are provided on the barrier member outside the chamber.

Abstract: The present invention relates to improvements in or relating to pump installations, It has particular relevance in the field of reciprocating piston pumps, such as condensate removal pumps which are used to remove condensate from air conditioning installations. We describe a liquid pulse damping device (20) comprising a body (21) having an inlet (22) and an outlet (23) in fluid communication. Intermediate the inlet and outlet is at least one liquid flow direction changing element (24, 25). Preferably, the at least one flow direction changing element (24, 25) is in the form of an elongate element having a closed end (30, 31) and a side wall, suitably a cylindrical side wall, having at least one bore (40) formed therethrough.

Abstract: A conduit elbow having first opening and a second opening and housing a pump assembly for use in an air conditioning system, the pump assembly including a pump having a pump inlet and a pump outlet, and wherein the pump inlet is a fluid communication with a reservoir. The reservoir is formed integrally with the pump assembly and has an inlet fluid communication with a first fluid-carrying pipe of an air-conditioning installation and wherein the pump outlet of an air fluid communication with a second fluid-carrying pipe of an air-conditioning installation.