Abstract: Methods and systems for controlling an electric motor using a motor controller including a processor are provided. The method includes transmitting, by the processor, a no-spin signal commanding the electric motor not to spin, receiving temperature information associated with a temperature of the electric motor, comparing the temperature information to a predetermined threshold temperature to determine whether the temperature is at a sufficient level to prevent icing, and adjusting current applied to the electric motor when the temperature measurement is below the predetermined threshold.

Abstract: Methods and systems for controlling an electric motor using a motor controller including a processor are provided. The method includes transmitting, by the processor, a no-spin signal commanding the electric motor not to spin, receiving temperature information associated with a temperature of the electric motor, comparing the temperature information to a predetermined threshold temperature to determine whether the temperature is at a sufficient level to prevent icing, and adjusting current applied to the electric motor when the temperature measurement is below the predetermined threshold.

Abstract: A drive circuit for an electric motor includes a variable frequency drive (VFD), a drive contactor, and a controller. The VFD is configured to receive line frequency current from a power source and apply a fixed frequency voltage to convert the line frequency current to a fixed frequency current. The drive contactor is configured to selectively couple the drive circuit to windings of the motor. The controller is configured to monitor for presence of a control signal applied to the drive contactor, wherein presence of the control signal closes the drive contactor to couple the drive circuit to the windings of the electric motor. The controller applies the fixed frequency voltage from the VFD to the windings upon determining presence of the control signal, determines whether the motor is motoring or regenerating after applying the fixed frequency voltage, and gradually increases the fixed frequency voltage applied to the windings when the motor is motoring.

Abstract: A drive circuit for an electric motor includes a variable frequency drive (VFD), a drive contactor, and a controller. The VFD is configured to receive line frequency current from a power source and apply a fixed frequency voltage to convert the line frequency current to a fixed frequency current. The drive contactor is configured to selectively couple the drive circuit to windings of the motor. The controller is configured to monitor for presence of a control signal applied to the drive contactor, wherein presence of the control signal closes the drive contactor to couple the drive circuit to the windings of the electric motor. The controller applies the fixed frequency voltage from the VFD to the windings upon determining presence of the control signal, determines whether the motor is motoring or regenerating after applying the fixed frequency voltage, and gradually increases the fixed frequency voltage applied to the windings when the motor is motoring.

Abstract: A circuit for detecting loss of phase in three-phase power systems. The circuit includes a current sensor and a microprocessor. The current sensors are coupled to respective phases of a three-phase power source configured to supply power to a load. The microprocessor is coupled to the current sensors to process current measurements and detect loss of phase in the three-phase power source.

Abstract: A circuit for detecting loss of phase in three-phase power systems. The circuit includes a current sensor and a microprocessor. The current sensors are coupled to respective phases of a three-phase power source configured to supply power to a load. The microprocessor is coupled to the current sensors to process current measurements and detect loss of phase in the three-phase power source.

Abstract: An alternating current (AC) motor system and control methods are provided herein. The AC motor system includes a motor having a first rated horsepower and configured to be coupled to a power source, and a drive circuit configured to be electrically coupled between the power source and the motor. The drive circuit has a second rated horsepower that is lower than the first rated horsepower.

Abstract: An alternating current (AC) motor system and control methods are provided herein. The AC motor system includes a motor having a first rated horsepower and configured to be coupled to a power source, and a drive circuit configured to be electrically coupled between the power source and the motor. The drive circuit has a second rated horsepower that is lower than the first rated horsepower.

Abstract: An electric motor controller for controlling an electric motor and methods of determining a loss of phase condition for at least one phase of three-phase input power provided to an electric motor controller are provided. The controller is configured to obtain phase sample data representing an input power electrical characteristic for at least one phase of three-phase power received by the controller and receive direct current (DC) bus data representing a measured DC bus electrical characteristic. The controller is also configured to calculate a ratio between the phase sample data and the DC bus data, and determine that a loss of phase condition exists for a phase of the three-phase power when the ratio exceeds a predetermined threshold.

Abstract: An electric motor controller for controlling an electric motor and methods of determining a loss of phase condition for at least one phase of three-phase input power provided to an electric motor controller are provided. The controller is configured to obtain phase sample data representing an input power electrical characteristic for at least one phase of three-phase power received by the controller and receive direct current (DC) bus data representing a measured DC bus electrical characteristic. The controller is also configured to calculate a ratio between the phase sample data and the DC bus data, and determine that a loss of phase condition exists for a phase of the three-phase power when the ratio exceeds a predetermined threshold.

Abstract: Methods and systems for controlling an electric motor using a motor controller including a processor are provided. The method includes transmitting, by the processor, a no-spin signal commanding the electric motor not to spin, receiving temperature information associated with a temperature of the electric motor, comparing the temperature information to a predetermined threshold temperature to determine whether the temperature is at a sufficient level to prevent icing, and adjusting current applied to the electric motor when the temperature measurement is below the predetermined threshold.