An economizer control system includes a compressor including a compression area, a piston chamber, and an economizer inlet configured to receive economizer vapor into the compression area via a flow path that extends between the economizer inlet and the compression area. At least a portion of the flow path traverses the piston chamber. The economizer control system also includes a piston disposed within the piston chamber and configured to contact the economizer vapor. The piston is moveable between an open position that opens the flow path and a closed position that closes the flow path. Additionally, the economizer control system includes a biasing system configured to apply force to the piston to bias the piston toward the closed position.

The unloading of multi-stage compressors may include the introduction of flow from a gas bypass from a condenser into a second-stage inlet duct to induce a swirl in the flow into second stage compression. This unloading may be performed on multi-stage compressors in heating, ventilation, air conditioning and refrigeration (HVACR) circuits that include a gas bypass from a condenser to the second-stage inlet housing of the compressor. The multi-stage compressor may include an impeller inlet duct including a flow straightener receiving fluid flow from the first stage discharge, and one or more channels to introduce gas from the gas bypass into the flow passing through the impeller inlet duct. The flow introduced by the channels may have a direction of flow including a component opposite to the direction of flow of the fluid flow from the first stage discharge via the flow straightener.

In one embodiment, an HVAC system includes an indoor unit having a furnace, an outdoor heat pump unit having a compressor and an outdoor coil, a refrigerant line coupled to the indoor unit and the outdoor heat pump unit, and an EEV coupled to the refrigerant line. The HVAC system further includes one or more controllers operable to determine an occurrence of a first event, initiate a closure of the EEV, initiate operation of the compressor at a completion of the air conditioning cycle to pump down a refrigerant to the outdoor coil, and cease operation of the compressor when a low-pressure switch is tripped.

The present invention provides a compressor that includes: one or more impellers that axially suck and centrifugally compress a refrigerant; a rotary shaft that is connected with the impeller and a motor for rotating the impeller; a plurality of magnetic bearings that supports the rotary shaft in the air so that the rotary shaft can rotate; a gap sensor that senses the distance from the rotary shaft; and a controller that determines abnormal wire connection of the magnetic bearings on the basis of information from the gap sensor. The controller can sense movement of the rotary shaft through the gap sensor while controlling the amount of current supplied to any one of the magnetic bearings and can determine whether there is abnormal wire connection on the basis of the information.

An air conditioning system and a startup control method. The air conditioning system includes: a compressor, a condenser, a thermal expansion valve and an evaporator connected via a pipeline; and a thermal temperature sensing bulb disposed on an outlet pipeline of the evaporator and associated with the thermal expansion valve; the air conditioning system further includes a thermal power source which is thermally coupled to the thermal temperature sensing bulb and controlledly cools or heats the thermal temperature sensing bulb. The thermal temperature sensing bulb is cooled or heated, as needed, by a thermal power source thermally coupled to the thermal temperature sensing bulb, thereby enabling the thermal expansion valve associated with the thermal temperature sensing bulb to be opened and closed more smoothly.

An electric compressor includes a cylindrical motor housing, an inverter case, and a conductive member. The inverter case is joined to an end portion of the motor housing. The inverter case includes a cylindrical case peripheral wall surrounding the end portion. The end portion has an end face that extends in a radial direction of the motor housing and a peripheral surface that extends in an axial direction of the motor housing and is connected to the end face. A ring-shaped sealing member is disposed between the peripheral surface and the case peripheral wall. An accommodation groove for accommodating the sealing member is recessed in the peripheral surface. The sealing member is held by the peripheral surface and the case peripheral wall in a radial direction of the sealing member to seal a space in which the conductive member is disposed.

An HVAC system includes an indoor unit having a return air duct and a supply air duct in an enclosed space. The HVAC system includes an outdoor unit having a variable-speed condenser fan. A first temperature sensor is disposed in at least one of the return air duct, the supply air duct, or an enclosed space. A controller is operatively coupled to the first temperature sensor, and the variable-speed condenser fan. The controller is configured to determine whether at least one of over-cooling or over-heating of air in the enclosed space is occurring. Responsive to a determination that at least one of over-cooling or over-heating of air in the enclosed space is occurring, the controller adjusts a speed of the variable-speed condenser fan.

A system for mounting at least one cylindrical electrolytic capacitor on a heat sink, the heat sink having at least one bore for at least partially receiving a cylindrical electrolytic capacitor, and the bore partially or fully encompassing the cylindrical electrolytic capacitor once it has been received, wherein lateral surfaces of the cylindrical electrolytic capacitor are mechanically and thermally connected to surfaces forming the bore. The system providing thermal cooling of the electrolytic capacitor and enabling substantially uniform thermal cooling of the capacitor. A method for producing a connection between the at least one cylindrical electrolytic capacitor and the heat sink, and to a connection, obtainable by the method, between the at least one electrolytic capacitor and the heat sink.

In one embodiment, an HVAC system includes an indoor unit having a furnace, an outdoor heat pump unit having a compressor and an outdoor coil, a refrigerant line coupled to the indoor unit and the outdoor heat pump unit, and an EEV coupled to the refrigerant line. The HVAC system further includes one or more controllers operable to determine an occurrence of a first event, initiate a closure of the EEV, initiate operation of the compressor at a completion of the air conditioning cycle to pump down a refrigerant to the outdoor coil, and cease operation of the compressor when a low-pressure switch is tripped.

It is disclosed an electrical arrangement assembly structure on the external region of the hermetic housing of the compressor, whereby the insulating box, capable of housing, within the same, at least one electrical arrangement necessary for the operation of the compressor, is coupled to the external region of the hermetic housing of the compressor by means of angular movement between said insulating box and a hinge element attached to the hermetic housing of the compressor.