A control device for a compressor includes an operation stop control unit that stops the compressor in a procedure different from a normal stop request signal when a signal different from the normal stop request signal that requests the compressor to stop in a predetermined procedure and a forced stop request signal from a device including the compressor is detected. The operation stop control unit stops the compressor in the different procedure according to a speed of the compressor when the forced stop request signal is detected.

A control device for a compressor includes an operation stop control unit that stops the compressor in a procedure different from a normal stop request signal when a signal different from the normal stop request signal that requests the compressor to stop in a predetermined procedure and a forced stop request signal from a device including the compressor is detected. The operation stop control unit stops the compressor in the different procedure according to a speed of the compressor when the forced stop request signal is detected.

A wheel-mounted air compression apparatus for maintaining a predetermined inflation pressure of a tire mounted on a wheel of a vehicle and the tire having an inflation port includes a housing defining an air compression chamber and has an air compressor device positioned therein. The apparatus includes a plurality of support legs spaced apart from one another. Each support leg is attached to the housing and extends away therefrom and may include a pair of sleeves that are length-adjustable for mounting to wheels of various sizes. A pressure sensor is situated in the housing and operably connected to the air compressor and to a nozzle for determining a current pressure of air within the tire. A controller or other electronics cause the air compressor to pump air into a tire if the air pressure therein is detected as declining below a predetermined amount.

A cordless compressor has an air storage tank, a pump, a motor for driving the pump, and a controller circuit electrically connected to the motor. A pressure switch assembly is connected to the controller circuit. The pressure switch assembly has first and second pressure switches for sensing pressure within the air storage tank. The controller circuit controls de-activation of the motor depending upon status of the first and second pressure switches.

A compressed air supply apparatus for heavy vehicles includes a service reservoir, an air dryer in communication with the service reservoir, a purge reservoir in communication with the air dryer, a compressor for delivering compressed air through the air dryer preferentially to the purge reservoir and then to the service reservoir and a controller. The controller interrupts the charge cycle of the compressor in response to a moisture accumulation value being equal to or exceeding a wetness threshold value and the pressure in the service reservoir being within a predetermined pressure range. The controller then initiates a modified purge cycle of the air dryer, which includes iteratively regenerating the air dryer with air from the purge reservoir until at least one of the moisture accumulation value is less than the wetness threshold value and the pressure in the service reservoir is outside the predetermined pressure range.

A compressed air supply apparatus for heavy vehicles includes a service reservoir, an air dryer in communication with the service reservoir, a purge reservoir in communication with the air dryer, a compressor for delivering compressed air through the air dryer preferentially to the purge reservoir and then to the service reservoir and a controller. The controller interrupts the charge cycle of the compressor in response to a moisture accumulation value being equal to or exceeding a wetness threshold value and the pressure in the service reservoir being within a predetermined pressure range. The controller then initiates a modified purge cycle of the air dryer, which includes iteratively regenerating the air dryer with air from the purge reservoir until at least one of the moisture accumulation value is less than the wetness threshold value and the pressure in the service reservoir is outside the predetermined pressure range.

A fire suppression system includes a motor and a foam pump. The foam pump is driven by the motor to inject one or more chemical additives from an off-board additive container into a discharge conduit. A bypass valve is in fluid communication with the output of the foam pump. One or more sensors are configured to measure at least one operating condition of the foam pump. A controller is in communication with the one or more sensors and is operatively connected to the bypass valve. The controller is configured to determine, based on data received from the one or more sensors regarding the at least one operating condition of the foam pump, whether the foam pump is experiencing a loss of prime, and to open the bypass valve in response. The motor may also selectively operate in one of two modes depending on the rotational speed and torque required.

The present invention relates to a filter unit (10) for a compressor, comprising a housing (12) with an inlet (14) and an outlet (28) for gas to be compressed, a particle pre-filter (16) arranged downstream of the inlet (14) in the flow direction of the gas to be compressed, an ultraviolet irradiation unit (22) which is configured to emit ultraviolet light and is arranged downstream of the particle pre-filter (16) in the flow direction of the gas to be compressed, and a ballast (40) which is configured and arranged to control the ultraviolet irradiation unit (22). The filter unit (10) is designed in such a way that the gas to be compressed which is fed in at the inlet (14) first passes through the particle pre-filter (16), is then irradiated by the ultraviolet irradiation unit (22) and can finally be fed to the compressor through the outlet (28). The invention also relates to a compressor comprising such a filter unit (10) and to a method for compressing breathing air using such a compressor.

An air-conditioning apparatus includes an indoor unit and an outdoor unit including a compressor that compresses a refrigerant and a motor drive system that drives the compressor. The motor drive system includes an inverter that converts a DC voltage into an AC voltage, and an electric motor including three stator windings with both ends open. The electric motor operates based on the AC voltage obtained by the inverter. The motor drive system further includes a connection state switching unit that has a function to change the connection state of the three stator windings included in the electric motor, and sets the connection state to a star connection at the start of operation of the air-conditioning apparatus.

A fracturing apparatus, a starting method thereof and a fracturing apparatus set. The fracturing apparatus includes a fracturing pump, an electric motor and a start device; the fracturing pump is configured to pressurize low-pressure fluid into high-pressure fluid; the electric motor includes a first winding and a second winding; the start device includes a first switch and a second switch. Impedance of the first winding is greater than impedance of the second winding. One terminal of the first switch is connected with the first winding, the other terminal of the first switch is connected with the power supply device, one terminal of the second switch is connected with the second winding, and the other terminal of the second switch is connected with the power supply device.