A refrigeration device disposed in a refrigerated container for transportation includes an engine, a generator driven by the engine, an inverter configured to convert an electric power generated by the generator, an electric compressor, and a support member. The electric compressor is driven by the electric power converted by the inverter. The electric compressor constitutes a part of a vapor compression refrigeration cycle. The support member supports the engine, the generator, the inverter, and the electric compressor. The engine, the generator, and the electric compressor are located lower than a middle part of the support member in a vertical direction. The inverter is located lower than the generator in the vertical direction.

An air conditioning system of a vehicle having an internal combustion engine includes a condenser configured to receive refrigerant output by an electric compressor and transfer heat from the refrigerant within the condenser to air passing the condenser. A first evaporator is configured to receive refrigerant from the condenser when a first control valve is open and transfer heat from air passing the first evaporator to the refrigerant within the first evaporator. A first blower is configured to blow air across the first evaporator to a first section of a cabin of the vehicle. A second evaporator is configured to receive refrigerant from the condenser when a second control valve is open and transfer heat from air passing the second evaporator to the refrigerant within the second evaporator. A second blower is configured to blow air across the second evaporator to a second section of the cabin of the vehicle.

In order to improve a method for selecting a frequency converter for a refrigerant compressor unit that includes a refrigerant compressor and an electric drive motor such that the frequency converter is selected in a manner for optimized use, it is proposed that a working state suitable for operation of the refrigerant compressor unit should be selected within an application field of an application graph of the refrigerant compressor, that an operating frequency for this selected working state should be selected, and that a working state operating current value that corresponds to the selected working state and the selected operating frequency should be determined from drive data, for operation of the refrigerant compressor unit.

A domestic refrigeration appliance has a heat-insulated housing with a coolable inner container delimiting a coolable interior for storing foods. The interior is cooled with a coolant circuit that includes a compressor with a three-phase motor operated by an actuator via electrically powered motor windings. The actuator is actuated at least indirectly to operate the compressor in a switched-on state with a rotational speed of the three-phase motor at least approximately equal to a predetermined rotational speed. The actuator is caused to switch off the compressor such that the rotational speed of the three-phase motor decreases to a predetermined minimum rotational speed, and thereafter to switch off the three-phase motor for at least a predetermined period of time by de-energizing the motor windings. The period of time is selected long enough to reduce the speed of the motor, beginning from the minimum rotational speed, to reach standstill.

A fan drive circuit for a variable speed fan motor in a cooling system, includes an inverter configured to supply a current signal to stator windings of the variable speed fan motor, a frequency detection circuit coupled to an output stage of an inverter of a compressor motor of the cooling system and configured to detect a first frequency of a compressor current signal at the output stage of a variable speed compressor drive circuit and generate a frequency signal, and a digital signal processor (DSP) coupled to the inverter and the frequency detection circuit. The DSP is configured to receive the frequency signal corresponding to the first frequency from the frequency detection circuit, select a second frequency corresponding to the first frequency at which to operate the variable speed fan motor, and transmit control signals to the inverter to supply current to the stator windings at the second frequency.

A controller controls a first inverter drive circuit and a second inverter drive circuit. The first inverter drive circuit drives a load having a load current larger than the second inverter drive circuit. The first inverter drive circuit includes a control ground terminal and a drive ground terminal which are isolated from each other. The ground terminal of the second inverter drive circuit is connected to the ground of the controller. The control ground terminal of the first inverter drive circuit is connected to the ground of the controller. The drive ground terminal of the first inverter drive circuit is connected to the negative side of the first inverter circuit.

To reduce the possibility that temperature of refrigerant discharged from a compressor of a refrigeration apparatus becomes excessively high by controlling torque of a motor built into the compressor, the compressor includes the motor having rotation thereof controlled by inverter control. An inverter controller controls torque of the motor using inverter control when operation frequency of the compressor is at least one value within a range of from 10 Hz to 40 Hz. When at least the operation frequency is within the range of from 10 Hz to 40 Hz, torque of the motor is controlled, and under a predetermined condition in which temperature of refrigerant discharged from the compressor easily becomes excessively high, a device controller controls devices provided in a refrigerant circuit such that refrigerant sucked into the compressor is placed in a wet vapor state.

Compressors in a refrigerant loop are driven by variable frequency drives. The variable frequency drives are configured to demand current from an alternating current power source at different phases relative to one another such that at least one current harmonic frequency at the alternating current power source is cancelled.

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.

A water distribution apparatus and method including cold and hot water supplies, a fan coil (or chilled beam device), a control valve having cold and hot water inlets and outlets, cold and hot water outputs configured to supply cold and hot water to the fan coil, cold and hot water return inlets configured to receive from the fan coil the water supplied by the cold and/or water outputs and outputting the cold and/or hot water to the cold and hot water supply lines, respectively, via the cold and hot water outlets, respectively. Cold and hot water is supplied from the cold and/or hot water outputs to the fan coil and received into the cold and hot water return inlets, respectively, and the cold and hot water supplied by the cold and hot water outputs to the fan coil is output to the cold and hot water supply lines, respectively.