A variable speed drive (VSD) can be used to vary the voltage-to-frequency ratio (V/f) supplied to a compressor motor of a heating, ventilation, air conditioning or refrigeration (HVAC&R) system to make the motor stronger or weaker to compensate for varying conditions in the HVAC&R system. The VSD and corresponding control system or algorithm can monitor an operating parameter of the HVAC&R system, such as the kW absorbed by the motor, and then raise or lower the V/f of the VSD to obtain the lowest possible power consumption from the motor.

A refrigeration system includes a compressor and a capacitor electrically coupled to the compressor. A method of operating the refrigeration system includes measuring voltage values based on alternating current power powering the compressor. The method includes measuring current values based on the alternating current power. The method includes determining, with a controller, a power factor value based on at least one of the voltage values and at least one of the current values. The method includes receiving a supply air temperature value from an air temperature sensor installed in the refrigeration system. The method includes receiving a return air temperature value from an air temperature sensor installed in the refrigeration system. The method includes determining a temperature split based on a difference between the return and supply air temperature values. The method includes determining a fault in the capacitor based on the power factor value and the temperature split.

The present invention relates to a method for analyzing energy used for producing a unit of mass or volume of compressed gas (Specific Energy Consumption) in relation to a common output flow in a compressor system, said method comprising the following pot steps:—for time interval, T.sub.ref, collecting reference measured data points of common output flow F.sub.ref and energy (or power) consumption E.sub.ref (or P.sub.ref) in the compressor system;—calculating energy (or power) use as a function of the common output flow E.sub.ref (F) (or <P.sub.ref>.sub.t(F)) from the measured data points and calculating volume output as a function of the common output flow V.sub.ref(F);—calculating average energy consumed for producing a unit of mass or volume of compressed gas as a function of the common output

flow<SEC.sub.ref>.sub.t(F) from equation E.sub.ref(F)/V.sub.ref(F) (Or <P.sub.ref.sub.t)/P.sub.ref);—for time interval, T.sub.sav, collecting measured data points of common output flow F.sub.sav and energy (or power) consumption E.sub.sav (P.sub.sav) in the compressor system;—calculating energy consumed for producing a unit of mass or volume of compressed gas as a function of the common output flow <SEC.sub.sav>.sub.t(F) from equation E.sub.sav(F)/V.sub.sav (F) (or <P.sub.sav>.sub.t(F)/F say) or SEC.sub.sav(t,F) from P.sub.sav/F.sub.sav;—calculating the difference between <SEC.sub.ref>.sub.t(F) and <SEC.sub.sav>.sub.t(F) or SEC.sub.sav(t,F) over a range of common output flow F in the compressor system.

A simpler notification is given about identifying causes of abnormalities and indicating dealing methods or countermeasures to deal with the causes of abnormalities.

In a gas compressor including: a compressor body that compresses a gas; a drive source that drives the compressor body; at least one physical sensor that is disposed on at least one of a compressed-gas pipe or an electric system and detects a physical quantity in driving of the compressor body; a display unit; and a controller that processes the detected result from the physical sensor and causes the display unit to display information according to the processing, the controller stores in advance the associated relation between a preset range with respect to a rate of change of the physical quantity and information about at least one of a cause of a change in the physical quantity and a dealing method of dealing the cause, calculates a rate of change of the physical quantity on the basis of the detected result from the physical sensor, and causes the display unit to display information about at least one of the cause corresponding to the preset range and the dealing method of dealing with the cause when the calculated rate of change of the physical quantity is determined as falling in the preset range.

A method of monitoring a volume index valve of a compressor is provided. The method includes recording a first reading of an operating condition of the compressor when the volume index valve is in a first position. The method also includes switching the volume index valve to a second position. The method further includes recording a second reading of the operating condition of the compressor when the volume index valve is in the second position. The method yet further includes calculating a difference between the first reading and the second reading. The method also includes comparing the difference to a predetermined threshold difference to determine if the volume index valve is moving between the first position and the second position in a desired manner.

A vacuum pumping system includes a plurality of positive displacement vacuum pumps, and more particularly a plurality of positive displacement vacuum pumps working in parallel. The vacuum pumping system includes a management unit that carries out a synchronized control of all the positive displacement vacuum pumps of the vacuum pumping system and thus allows to check possible risk of contamination of the vacuum pumping system and carry out, if needed, the necessary corrective actions without requiring any modification to the construction of the vacuum pumping system.

An eccentric screw pump hasa pump housing having a pump inlet opening and a pump outlet opening, a stator disposed in the pump housing, a rotor disposed in the stator, a drive unit comprising a drive motor and a driveshaft which for transmitting a torque connects the drive motor to the rotor, wherein the rotor for a rotating movement about a rotating axle is guided in the stator, a state sensor for detecting a state variable of the eccentric screw pump, where the state sensor, for detecting a state variable on the rotor or on the driveshaft, is disposed on the rotor or the driveshaft, or is connected to the rotor or the driveshaft by means of a signal line and is disposed so as to be spaced apart from the rotor or the driveshaft.

A fuel supply control device (10) is configured to generate an operation amount used for feedback-controlling rotation of a gear pump (3) based on a deviation of a detected fuel flow rate with respect to a target flow rate, wherein the fuel supply control device generates the operation amount such that a rotation speed of the gear pump is equal to or greater than a predetermined lower limit rotation speed Nmin so as to protect a bearing of the gear pump.

A diagnosis method includes: a physical quantity detection step of detecting a physical quantity generated in a diagnosis target by using a physical quantity sensor; a Lissajous figure generation step of generating a three-dimensional Lissajous figure by plotting the physical quantity detected in the physical quantity detection step in a three-dimensional coordinate system including a first axis, a second axis, and a third axis; a vibration plane information acquisition step of acquiring information on a vibration plane of the vibration from the three-dimensional Lissajous figure generated in the Lissajous figure generation step; and a diagnosis step of diagnosing a state of the diagnosis target based on the information on the vibration plane acquired in the vibration plane information acquisition step.

Provided are a compressor and a monitoring system that can specify a cause of an anomaly of a sensed value of a sensor. A compressor (1) includes: a temperature sensor (11A) that senses a temperature of a compressed air on a discharge side of a low-pressure-stage compressor body (3) and on an upstream side of an intercooler (5); a pressure sensor (12A) that senses a pressure of the compressed air on the discharge side of the low-pressure-stage compressor body (3); a temperature sensor (11B) that senses a temperature of the compressed air on an intake side of a high-pressure-stage compressor body (6) and on a downstream side of the intercooler (5); a temperature sensor (11C) that senses a temperature of the compressed air on a discharge side of the high-pressure-stage compressor body (6); a controller (8) that decides whether or not an anomaly has occurred in sensed values of the sensors (11A), (11B), (11C), and (12A), and estimates a cause of the anomaly; and a display device (9) that displays the cause of the anomaly estimated by the controller (8).