Abstract: A sensor assembly for measuring movements of a fluid pump driven by an electric motor, the electric motor connectable to a feed voltage, the sensor assembly comprising an accelerometer electrically connected to a bias circuit, the latter comprising a feed terminal electrically connectable to the feed voltage of the motor and a signal terminal electrically connectable to an external measuring terminal. A fluid pump is also described, comprising a cylinder, a piston, a housing comprising a hermetic terminal and hermetically enclosing the cylinder and the piston, thus forming a hermetic assembly, the piston driven by an electric motor, the electric motor connected to an electric voltage by a pair of voltage terminals associated to the hermetic terminal, the fluid pump comprising a sensor assembly associated to the cylinder comprising a feed terminal connected to one of the voltage terminals and a signal terminal electrically connected to an external measuring circuit.

Abstract: A variable speed air compressing system includes a compressor, a motor configured to actuate the compressor, and a rectifier configured to receive alternating current from a first power source and to provide rectified direct current having a first voltage. The system also includes an inverter configured to receive the rectified direct current and to receive direct current from a second power source having a second voltage. The inverter is configured to provide alternating current to the motor. The alternating current provided to the motor is based on the rectified direct current if the first voltage is greater than the second voltage and the alternating current is based on the direct current from the second power source if the second voltage is greater than the first voltage.

Abstract: A method and apparatus for a pump and a pump control system. The apparatus includes a pressure sensor and a temperature sensor coupled to a pump control system. For the method of the invention, the microcontroller provides a pulse-width modulation control signal to an output power stage in order to selectively control the power provided to the pump.

Abstract: When starting a screw-type air compressor in sub-zero conditions, current spikes are mitigated by detecting an over-current condition and/or a below-threshold temperature, and a warm-up routine is initiated in which compressor motor speed is ramped in a sawtooth fashion between two speeds that are substantially lower than a nominal operating speed of the compressor motor. In this manner, the internal components of the compressor are warmed prior to fully starting the compressor, which mitigates current spikes, reduces blown fuses, and extends the life of the compressor motor and other compressor components.

Abstract: Embodiments of the invention provide a method of operating a safety vacuum release system (SVRS) with a controller for a pump including a motor. The method can include measuring an actual power consumption of the motor necessary to pump water and overcome losses. The method can include triggering the SVRS when a dynamic suction blockage is identified in order to shut down the pump substantially immediately. The SVRS can also be triggered when a dead head condition is identified based on the actual power consumption.

Abstract: The present invention relates to a system and method of controlling a linear compressor (10), which is capable of fine-tuning the compressor when necessary, throughout the operating period of the compressor, so that said compressor operates at maximum capacity, wherein the piston (1) achieves a maximum displacement amplitude, closely approaching the cylinder head (2) without colliding with it. The system and the method according to the invention are also intended to control the operation of the linear compressor throughout its operating period, also seeking to maximize its performance and to reduce or optimize its power consumption. According to the present invention, the fine-tuning and control of the operation of the linear compressor are carried out by means of the combination of a technique for controlling a compressor without a sensor, and a technique for controlling the compressor with the aid of a sensor.

Abstract: An apparatus, system and method for more accurately monitoring and determining pump failure. The apparatus and system include at least a power circuit, a current sensing circuit, alarm circuit and a controller. The controller is connectable to and receives an input from the current sensing circuit. The controller is configured to calculate a baseline operating current, current thresholds and operating conditions affecting the operation of the pump. The alarm circuit is connectable to and receives outputs from the controller, and provides alarm indications corresponding to operating conditions determined by the controller.

Abstract: A method of constant airflow control includes various controls to accomplish a substantially constant airflow rate over a significant change of the static pressure in a ventilation duct. One control is a constant I·RPM control, which is primarily used in a low static pressure range. Another control is a constant RPM control, which is primarily used in a high static pressure range. These controls requires neither a static pressure sensor nor an airflow rate sensor to accomplish substantially constant airflow rate while static pressure changes. Also, the method improves the accuracy of the control by correcting certain deviations that are caused by the motor's current—RPM characteristics. To compensate the deviation, the method adopts a test operation in a minimum static pressure condition. Also disclosed is an apparatus for conducting these control methods.

Abstract: Systems and methods for controlling an electrical drive such as is used with electric submersible pumps used in downhole oil production, wherein the drive automatically determines the proper phasing to drive the pump motor in a forward direction. In one embodiment, a method includes generating a drive signal having an initial phasing and driving the pump to establish a column of fluid in the borehole. The drive signal is then discontinued, allowing the column of fluid to fall through the pump and cause the pump to backspin and generate a signal having phasing corresponding to the reverse rotational direction. The forward phasing is then determined to be the opposite of the phasing corresponding to the reverse rotational direction. The pump can be restarted in the forward direction, or an operator can be notified of the proper phasing to produce forward rotation of the pump.

Abstract: A pump assembly and estimation and control system therefor, the pump adapted for continuous flow pumping of blood. In a particular form, the pump is a centrifugal pump wherein the impeller is entirely sealed within the pump housing and is exclusively hydrodynamically suspended therein against movement in three translational and two rotational degrees of freedom as the impeller rotates within the fluid urged by electromagnetic means external to the pump cavity. Hydrodynamic suspension is assisted by the impeller having deformities therein such as blades with surfaces tapered from the leading edges to the trailing edges of bottom and top surfaces thereof.

Abstract: A method of controlling a motor operating a pumping apparatus of a fluid-pumping application. The pumping apparatus includes a pump having an inlet to receive a fluid and an outlet to exhaust the fluid, and the motor coupled to the pump to operate the pump. The method includes the acts of controlling the motor to operate the pump and monitoring the operation of the pump. The monitoring act includes monitoring a power of the motor, and determining whether the monitored power indicates an undesired flow of fluid through the pump. The method further includes the act of controlling the motor to cease operation of the pump when the determination indicates an undesired flow of fluid through the pump and zero or more other conditions exist.

Abstract: A braking controller of a three-phase permanent magnetic brushless DC motor for directly driving a screw pump includes a detection circuit for detecting power supply states of the three-phase permanent magnetic brushless DC motor and a braking circuit for controlling the braking startup according to the power supply states of the three-phase permanent magnetic brushless DC motor. When the motor is supplied with power, the braking circuit is cut off. When the motor is not supplied with power and the screw pump drives the motor to reverse, the braking circuit starts up.

Abstract: An apparatus and method for controlling an operation of a reciprocating compressor are disclosed in which a frequency is variably controlled to uniformly maintain a phase difference between current and stroke, a load is determined with a size of frequency at a point of time when the phase difference between the current and the stroke is uniformly maintained, and capacity is varied according to the determined load, to thus improve an operation efficiency. The apparatus for controlling an operation of a reciprocating compressor includes: a control unit for detecting a phase difference between current and stroke and outputting a frequency variable signal or a frequency detect signal based on the detected phase difference; a load detecting unit for detecting a current operation load according to the frequency detect signal; and a stroke reference value determining unit for determining a stroke reference value corresponding to the detected load.

Abstract: A control system for a fan includes a control housing that is external to a fan housing for the fan. At least one fan control module is within the control housing and communicates remotely with terminals within the fan housing via at least one wire. The at least one fan control module includes a detection module. The detection module detects induced voltages in at least one of a plurality of stator coils within the fan housing via the at least one wire without receiving signals from a sensor in the fan housing.

Abstract: An apparatus and method are provided for monitoring and controlling a power system of an electrical submersible pump assembly. A sensor monitors an alternating current component of a downhole electrical imbalance voltage at a neutral point of a motor of the electrical submersible pump assembly. The sensor measurement is transmitted to a controller at the surface. The controller analyzes the alternating current component of the downhole electrical imbalance voltage and then adjusting an operation of the electrical submersible pump assembly, or scheduling maintenance, accordingly. Also, a model of a power system of an electrical submersible pump assembly is created to predict an alternating current component of a downhole electrical imbalance voltage. The model is modified as necessary responsive to measurements from the sensor. A controller adjusts surface currents according to the model of the power system to match downhole motor drive currents to thereby optimize the power system.

Abstract: A device and method are disclosed for driving an electromagnet for operating a pump. The electromagnet includes a primary winding and a moving element that is attracted within the primary winding when an energizing current is higher than a first threshold value. The moving element lets a liquid dose into an external hydraulic circuit depending on the a travel of the moving element. A control logic unit detects an energizing current to provide the energizing current to the primary winding until the energizing current assumes a second threshold value, depending on a value of the liquid dose to let into the external hydraulic circuit. The second threshold value is higher than the first threshold value and not higher than a third threshold value in correspondence of which the moving element arrives at a stop.

Abstract: An apparatus for controlling an air distribution system for maintaining a rate of air flow in the system at substantially the target air flow rate, wherein the apparatus detects current speed and torque of said motor and generates said current speed signal and torque signal after detection; receives the current speed signal and torque signal and calculates the current air flow rate in the air distribution system wherein the calculated current air flow rate is compared to the target speed signal of the air flow rate and the current air flow rate is adjusted according to the target speed signal of the air flow by generating a control signal; and controls the motor speed in response to the control signal for maintaining the rate of air flow in the system at substantially the target speed signal of the airflow rate.

Abstract: A sensorless magnetic bearing type blood pump apparatus includes a blood pump and a control mechanism. The blood pump has electromagnets for rotating a rotating body in a non-contact condition, and a hydrodynamic bearing section for rotating the rotating body in a non-contact condition when operation of the electromagnets is stopped. The apparatus is devoid of any sensors for determining the position of the rotating body. The control mechanism includes a pulse width modulation type electromagnet driving unit, a carrier component measuring unit for measuring carrier components of voltage and current in the driving unit, a modulation factor calculating unit which calculates a modulation factor using the carrier wave data, and a bearing mode changing-over mechanism for effecting change-over from the magnetic bearing mode to the hydrodynamic bearing mode when the calculated modulation factor is outside a predetermined range and for returning to the magnetic bearing mode after the change-over.

Abstract: A compressor overload protection device utilizes a first electrode of an electric connector to electrically connect a first OLP overload protection loop that is electrically connected to a first power line of an external power source. In addition, a second OLP overload protection loop is connected to a second electrode and a third electrode of the electric connector, and a capacitor is electrically connected between the third electrode and the first electrode. When the operation of the compressor is overloaded, the first and second OLP overload protection loop can provide proper protection mechanism with respect to the first power line and the second power line to prevent a motor of the compressor from being overheated and damaged, and the electrodes of the electric connector can be effectively prevented from exploding.

Abstract: Driving controlling apparatus and method for a reciprocating compressor capable of stably driving a reciprocating compressor when a reciprocating compressor is operated or an output capacity of the reciprocating compressor is varied, by matching an impedance of the apparatus to an inductance of a motor, and capable of enhancing an efficiency of the reciprocating compressor. The apparatus comprises an output capacity determining unit for determining an output capacity of a reciprocating compressor; an over-stroke preventing unit for preventing an over-stroke of a motor inside the reciprocating compressor; and an impedance matching unit for matching an inductance of the reciprocating compressor to an impedance of the apparatus.

Abstract: An operation controlling apparatus for a reciprocating compressor, and a method thereof, which are capable of accurately controlling the reciprocating compressor by sensing a size of a load applied to the reciprocating compressor and a stroke estimation value of the reciprocating compressor and then compensating a parameter of a motor in the reciprocating compressor based upon the sensing, the operation controlling apparatus comprising a controlling unit a controlling unit for comparing a phase difference between a detected current and a stroke with a reference phase difference to determine a size of a load, and outputting, according to the determined size of the load, a compensation control signal to compensate a parameter of a motor and a stroke control signal to control the stroke.

Abstract: A control for a linear compressor energises the linear motor in harmony with the present natural frequency of the compressor. The controller monitors the present operating frequency and compares the frequency with one or more outer limit thresholds. The control may remove power from the linear motor if the running frequency drops below a lower threshold. The control may reduce power to the linear motor if the running frequency rises above an upper threshold. The control uses compressor running frequency to operate the comperssor within safe operating limits.

Abstract: An apparatus for controlling an operation of a reciprocating compressor, includes: a control unit for detecting a current pushed amount of a piston when a TDC is detected as an inflection point of a phase difference between stroke and current, comparing the current pushed amount with a pushed amount reference value, and applying a DC voltage applied to a linear motor based on the comparison result. An AC voltage and a DC voltage are applied to the linear motor to increase the stroke, and when the TDC is detected, the current pushed amount is calculated and compared with the pushed amount reference value, and then, the DC voltage or a DC current applied to the linear motor is varied based on the comparison result, thereby obtaining a maximum compression volume without collision of the piston.

Abstract: A method of controlling a motor operating a pumping apparatus of a fluid-pumping application. The pumping apparatus includes a pump having an inlet to receive a fluid and an outlet to exhaust the fluid, and the motor coupled to the pump to operate the pump. The method includes the acts of controlling the motor to operate the pump and monitoring the operation of the pump. The monitoring act includes monitoring a power of the motor, and determining whether the monitored power indicates an undesired flow of fluid through the pump. The method further includes the act of controlling the motor to cease operation of the pump when the determination indicates an undesired flow of fluid through the pump and zero or more other conditions exist.

Abstract: A pumping apparatus for a jetted-fluid system includes a pump having an inlet connectable to the drain, and an outlet connectable to the return. The pump is adapted to receive the fluid from the drain and jet fluid through the return. The apparatus includes a motor coupled to the pump to operate the pump, a sensor configured to generate a signal having a relation to a parameter of the motor, and a switch coupled to the motor and configured to control at least a characteristic of the motor. The apparatus also includes a microcontroller coupled to the sensor and the switch. The microcontroller includes a model observer configured to receive a first value based on the signal and to generate a second value representative of at least one of a modeled flow or a modeled pressure based on the first value. The microcontroller is configured to control the motor based on the second value.

Abstract: Embodiments of the invention provide a method of operating a safety vacuum release system (SVRS) with a controller for a pump including a motor. The method can include measuring an actual power consumption of the motor necessary to pump water and overcome losses. The method can include triggering the SVRS when a dynamic suction blockage is identified in order to shut down the pump substantially immediately. The SVRS can also be triggered when a dead head condition is identified based on the actual power consumption.

Abstract: Disclosed is a method of controlling an electric compressor. The method includes: (I) starting the electric compressor by applying an electric power to an air conditioner; (II) determining, by an inverter, whether the electric compressor is started normally; and normally driving the electric compressor when the electric compressor starts normally in the step (II) and determining again whether the electric compressor starts normally by restarting the electric compressor. Therefore, abnormal operation such as malfunction, short, and overheating of the electric compressor is detected in the early starting stage to determine restarting and failure of starting the electric compressor so that reliability of the electric compressor may be enhanced.

Abstract: The invention relates to a pump device for feeding a delivery medium out of a deep borehole which leads from a floor level into the interior of the earth, which deep borehole is provided at least in sections with borehole piping, having a pump and having a motor which drives the pump. As a result of the motor being arranged outside the borehole piping and as a result of it being possible for the motor to be connected to the pump by means of torque transmitting means which extend laterally through the borehole piping, the motor can be protected from overheating, and in the event of a fault, can be pulled out of the deep borehole independently of the pump.

Abstract: A precharge circuit (20, 20?, 20?) charges at least one capacitor (22, 22?, 22?) associated with an electrical device with high capacitance, such as a motor (14) which drives a compressor (16) of the pneumatic system. One end of the at least one capacitor is connected with a high voltage bus (10). The other end of the at least one capacitor is connected by at least one charge limiting resistor (24, 24?, 24?) with a low reference node. When the at least one capacitor is charged at least to a preselected level, a control circuit (28, 28?, 28?) controls a switch (26, 26?, 26?) to bypass the current limiting resistor. In this manner, the current limiting resistors limit the surge current to charge the capacitors. Once the capacitors are charged, the resistors and their associated heat dissipation are removed from the circuit and only ripple current from across the capacitors flows through the switch reducing a required current carrying capacity and needed heat sinking for the switch.

Abstract: A method of controlling a motor operating a pumping apparatus of a fluid-pumping application. The pumping apparatus includes a pump having an inlet to receive a fluid and an outlet to exhaust the fluid, and the motor coupled to the pump to operate the pump. The method includes the acts of controlling the motor to operate the pump and monitoring the operation of the pump. The monitoring act includes monitoring a power of the motor, and determining whether the monitored power indicates an undesired flow of fluid through the pump. The method further includes the act of controlling the motor to cease operation of the pump when the determination indicates an undesired flow of fluid through the pump and zero or more other conditions exist.

Abstract: A supply current control circuit controls the voltage of a low-voltage direct-current power source so that the average current of an inverter circuit detected by a current detecting circuit becomes constant at a specified current value. Accordingly, characteristics that are little in the amount of change of air volume are obtained.

Abstract: An apparatus and method for controlling an operation of a linear compressor by detecting a phase difference inflection point at a time point when a phase difference between a current and a stroke is placed within a certain region, and by recognizing the phase difference infection point as a top dead center (TDC)=O.

Abstract: It is an object of the invention to provide a pump jack pump-off control method and a pump jack control apparatus in which, even when the speed of a pump jack is reduced due to generation of a pump-off condition, the pump jack is not caused to stop due to the motor overload abnormality or the coagulated crude oil and, even when the pump-off condition is generated, the reduction of the production capacity of the pump jack can be prevented as much as possible. On detecting the pump-off condition, while the pump jack is in operation with the speed thereof being reduced, or while the pump jack is in operation at the lowest speed, according to the overload warning signal of an ac electric motor, the pump jack is switched over to its intermittent operation.

Abstract: Embodiments of the invention provide a pumping system for at least one aquatic application. The pumping system includes a pump, a motor coupled to the pump, and a controller in communication with the motor. The controller determines an actual power consumption of the motor and compares the actual power consumption to a reference power consumption. The controller also determines that the pump is in an unprimed condition if the actual power consumption is less than the reference power consumption and that the pump is in a primed condition if the actual power consumption is at least equal to the reference power consumption.

Abstract: An apparatus and method for controlling an operation of a reciprocating compressor are disclosed in which a point of inflection with respect to an operation frequency of the reciprocating compressor is detected at a point of time when a phase difference between current and stroke is uniformly maintained, and an operation of the reciprocating compressor is controlled upon recognizing the detected point of inflection with respect to the operation frequency as a point TDC=O. The apparatus for controlling an operation of a reciprocating compressor includes: a control unit for detecting a phase difference between current and stroke and outputting a frequency inflection point detect signal or a frequency variable signal; and a stroke reference value control unit for determining whether a frequency inflection point has been detected or not according to the frequency inflection point detect signal and outputting a stroke reference value control signal based on the determining result.

Abstract: Systems and methods for using variable speed drives to restart downhole submersible pump motors. In one embodiment, a downhole pump is controlled using a variable speed drive that includes a control system configured to detect interruptions in the operation of the pump system. After an interruption that requires the restart of the pump motor, the control system determines the reverse rotational speed of the pump motor and restarts the motor when this speed is sufficiently low. The control system may be configured to reduce the output voltage of the variable speed drive and sweep through a range of output frequencies to determine the frequency at which the current drawn by the motor is lowest. This is the frequency at which the drive's output matches the speed of the motor and the apparent impedance of the motor is highest. When the speed is low enough, the motor is restarted.

Abstract: A method is provided for determining faults during the operation of a pump unit. At least two electric variables that determine the electric output of the motor and at least one fluctuating hydraulic variable of the pump are detected. The detected values or values formed from these variables by algorithms are automatically compared to predefined stored values using electronic data processing and the results of this comparison are used to determine whether or not faults have occurred.

Abstract: A control unit for a linear compressor comprises a current sensor for detecting the current consumption of the linear compressor, a deflection sensor for detecting the deflection of the linear compressor and a control circuit for controlling the movement and detecting an overload state of the linear compressor using the current consumption which is detected by the current sensor and the deflection which is detected by the deflection sensor.

Abstract: A linear motor (10), a linear compressor (100), a method of controlling a linear compressor (100), a cooling system (20) and a system of controlling a linear compressor (100) to operate a linear compressor (100) in resonance in it's the greatest possible efficiency throughout its operation are described.

Abstract: To maintain the functionality as a compact and inexpensive motor-mounted internal gear pump and also offer further inexpensiveness and reliability. The motor-mounted internal gear pump 80 has a pump part 81 including: an inner rotor 1, an outer rotor 2, a pump casing and an internal shaft 5. The pump casing has flat inner surfaces facing both end faces of the inner rotor 1 and the outer rotor 2. The internal shaft 5 includes a bearing 51 which is inserted into an axial hole of the inner rotor 1 and a fitting part 53 extending from both its ends in both axial directions. The pump casing includes two pump casing members 3, 4 as separate members with flat inner surfaces 25, 26 respectively.

Abstract: Detection of end of stroke for an electromagnetic pump is performed using, for example, a calculated first flux derivative.

Abstract: A scroll compressor for compressing fluid has a common terminal block for electrical hook-ups. The compressor includes a compressor section; a drive unit operative to drive the compressor section for compressing fluid; a protection module; and a power connector for connecting electrical power to the drive unit to facilitate operation of the scroll compressor bodies. The common terminal block provides for connection to the protection module and the power connector for the compressor.

Abstract: An apparatus and method for driving a compressor of an air conditioner are disclosed. When compensating for load torque of a compressor (e.g., a single-rotary compressor) of an air conditioner, a method for providing a compensation torque using an optimum phase compensation angle is used. In relation to a phase current or a frequency of a given motor, an optimum phase compensation angle causing a minimum speed ripple is measured, and the measured optimum phase compensation angle is stored in the form of a table. In the actual driving of the motor, the method applies a compensation torque having an optimum phase compensation angle to the motor by referring to the table.

Abstract: One form of a hydrogen operated power system according to this invention is a fuel cell system (20) provided with a supply system which supplies a gaseous fuel from a fuel supply tank (24) to a fuel cell (22), characterized in that a pump (32) is provided in the supply system, which is driven by a sensorless motor (34) having no sensor that detects at least a rotational position of the motor (34).

Abstract: A system for controlling a heating and cooling system for use on a machine includes a condenser, an evaporator assembly, an electric motor driven compressor, and a master controller operable to determine and regulate an operational speed of the compressor. The master controller includes a plurality of control algorithms each receiving respective dynamic input information and outputting a respective controller speed request based upon the respective dynamic input information.

Abstract: The present invention relates to a control system for protection against breakage of the lubricating-oil film in the bearings of hermetic compressors, as well as to a control method that has the objective of guaranteeing that a variable-capacity compressor should be maintained above a minimum rotation in order to prevent the oil film close to the respective bearing from breaking. One of the forms of achieving the objectives of the present invention is by means of a control system for protection against break of the lubricating-oil film in bearings of hermetic compressors, a microprocessor (10) actuating a set of switches (SW2M) selectively, so as to generate a rotation at the motor-compressor assembly (20, 21), the compressor (21) having a minimum rotation (RPMmin) of the compressor (21) so that the oil film will not be broken.

Abstract: The present invention relates to a linear compressor, and more particularly to, a linear compressor which employs a conductor member in a linear motor instead of a magnet to produce a driving force by magnetic induction and naturally modulate a cooling capacity according to a load. The linear compressor of the present invention includes a fixed member provided with a compression space, a movable member which linearly reciprocates inside the fixed member to compress refrigerant, a plurality of springs installed to elastically support the movable member in a motion direction, a first stator through which a current flows, a conductor member magnetically induced by the first stator to make the movable member linearly reciprocate, and a control unit which controls supply of a current with respect to the first stator.

Abstract: An electrically operated hydraulic pump having a pump portion and a motor portion includes rotation controlling means controlling rotation of a rotor, first rotor position detecting means detecting rotational position of the rotor on the basis of speed electromotive force induced by exciting coils, second rotor position detecting means detecting the rotational position of the rotor on the basis of magnetic field of a magnet provided at the motor portion, and motor operating condition detecting means detecting operating condition of the motor portion. The rotation controlling means switches a first rotation controlling based on the rotational position of the rotor detected by the first rotor position detecting means, and a second rotation controlling based on the rotational position of the rotor detected by the second rotor position detecting means, on the basis of a result detected by the motor operating condition detecting means.

Abstract: The following invention is an electromechanical system (1) that is to be connected to an electricity supply (7), comprising: an electric machine (2) that can operate as an independent generator with a rotating shaft, and a switching system (9) allowing i) in the first configuration, the electric machine to operate as a motor in the case where the connected device (4) is normally driven or as a generator in the case where the coupled device is normally driving, and ii) in the second configuration, the electric machine to operate as an independent generator, the electrical energy generated by the electric machine (2; 22) being dissipated in the machine and in a dissipative load (13).

Abstract: A system for controlling lubricant displacement from a machine during turbomachine shutdown sequence includes a motor, a pump, a control valve, and a motor control unit. The motor is selectively energized from a power bus to rotate at a rotational speed and supply a drive force to the pump. The pump, in response to the drive force, draws fluid from a fluid and supplies the fluid to the machine. The control valve is movable between at least a first position, in which the control valve fluidly communicates the pump with a lubrication fluid source, and a second position, in which the control valve fluidly communicates the pump with a gaseous fluid source. During the shutdown sequence, the motor control unit controllably energizes the motor from the power bus to thereby control its rotational speed in accordance with a schedule that will displace at least a substantial volume of lubricant in the rotating machine with fluid from the gaseous fluid source.