Adaptor module and methods for controlling a replacement motor

An adaptor module and methods for controlling a replacement motor in a heating, ventilation, and air conditioning (HVAC) system are provided. The adaptor module includes a plurality of tap connectors, each configured to receive a control signal. The adaptor module also includes a user interface having a plurality of switches that are adjustable into a plurality of different configurations, wherein each of the plurality of configurations correlates to at least one stored operating parameter for application to the motor. The adaptor module also includes a processing device configured to determine an operating parameter at which to operate the motor based on the configuration of the plurality of switches and based on a determination of which tap connector is receiving the control signal. The adaptor module also transmits a command signal including instructions for the motor to operate in accordance with the determined operating parameter.

BACKGROUND

The embodiments described herein relate generally to motors, and more particularly, to systems and methods for controlling a motor in a heating, ventilation, air conditioning (HVAC) system.

Many known HVAC and fluid circulation systems employ single-phase alternating current (AC) permanent split capacitor (PSC) motors. PSC motors are generally controlled by connecting input power to one of a plurality of input taps of the AC motor depending on a desired operating mode. Environmental regulations continue to increase efficiency and controllability requirements of HVAC motors. However, such AC motors have low efficiencies, consume more energy, and are limited regarding their degree of control.

As a result, direct current (DC) motors such as electronically commutated motors (ECMs) have been developed, and generally have higher efficiencies, are more energy saving and environmentally friendly, and have a much higher degree of control than PSC motors. Therefore, the AC motors in conventional HVAC and fluid circulation systems are gradually being replaced by DC motors. However, the AC motors are coupled directly to line input power signals (such as 120 VAC, 240 VAC, or 277 VAC) provided by an HVAC system controller, whereas the DC motors being used as replacement motors are configured to receive a low-voltage command signal (e.g. a pulse width modulation signal less than about 30 V). The two signals are not compatible.

BRIEF DESCRIPTION

In one aspect, an adaptor module configured to control a motor in a heating, ventilation, and air conditioning (HVAC) system is provided. The adaptor module includes a plurality of tap connectors, each configured to receive a control signal. The adaptor module also includes a user interface having a plurality of switches that are adjustable into a plurality of different configurations, wherein each of the plurality of configurations correlates to at least one stored operating parameter for application to the motor. The adaptor module also includes a processing device configured to determine an operating parameter at which to operate the motor based on the configuration of the plurality of switches and based on a determination of which tap connector is receiving the control signal. The adaptor module also transmits a command signal including instructions for the motor to operate in accordance with the determined operating parameter.

In another aspect, a method of controlling a motor in a heating, ventilation, and air conditioning (HVAC) system using an adaptor module is provided. The method includes receiving a control signal at a tap connector of a plurality of tap connectors. The method also includes determining a configuration of a plurality of switches of a user interface, wherein the configuration of the plurality of switches correlates to at least one stored operating parameter for application to the motor. The method also includes determining an operating parameter at which to operate the motor based on the configuration of the plurality of switches of the user interface and based on a determination of which tap connector is receiving the control signal. The method also includes transmitting a command signal including instructions for the motor to operate in accordance with the determined operating parameter.

In another aspect, a replacement motor system for replacing an alternating current (AC) motor in a heating, ventilation, and air conditioning (HVAC) system is provided. The replacement motor system includes a direct current (DC) motor and an adaptor module configured to control the DC motor. The adaptor module includes a plurality of tap connectors, each tap connector configured to receive a control signal. The adaptor module also includes a user interface having a plurality of switches that are adjustable into a plurality of different configurations, wherein each of the plurality of configurations correlates to at least one stored operating parameter for application to the DC motor. The adaptor module also includes a processing device configured to determine an operating parameter at which to operate the DC motor based on the configuration of the plurality of switches and based on a determination of which tap connector is receiving the control signal. The adaptor module also transmits a command signal including instructions for the DC motor to operate in accordance with the determined operating parameter.

DETAILED DESCRIPTION

Many conventional HVAC systems utilize alternating current (AC) motors for air handlers and condensers. The use of AC motors in an HVAC application may result in a relatively inefficient operation. By contrast, an ECM typically uses less energy than an AC motor or PSC (permanent-split capacitor) motor such as are commonly used to move air in HVAC systems. The ECM may also offer more control over the motor speed than conventional AC motors, which is also beneficial in HVAC applications. However, conventional AC motors are powered and controlled using AC power, and therefore conventionally it has been not been possible to substitute such conventional AC motors via a drop-in replacement DC motor.

The embodiments described herein provide an adaptor module and methods of controlling a motor. The motor is controlled by a heating, ventilation and air conditioning (HVAC) system controller. The motor may include plurality of operating parameter ranges and the HVAC system controller provides an input operating mode for selecting one of the plurality of operating parameter ranges. The adjustment module is coupled between the HVAC system controller and the motor. The adjustment module may define the plurality of operating parameters, each associated with one of the plurality of operating modes. The adjustment module selects one of the plurality of operating parameters on the basis of control signals received from the HVAC system controller, and commands the motor according to the operating parameter associated with the selected operating mode. Further, the adjustment module includes the ability to manually adjust the values of the operating parameters. The adaptor module facilitates replacing or retrofitting a failed motor in a HVAC system with a readily available, stock, retrofit/replacement motor. The adaptor module provides a cost-effective solution to interfacing between HVAC system controllers, thermostats and replacement motors. Further, the adaptor module facilitates returning a failed HVAC system to operation quickly and efficiently (e.g., in one service call). Further, certain embodiments enable a DC motor system to be used as a drop-in replacement of an AC motor (e.g., a PSC motor), such as in an HVAC system or other air mover system. Further, certain embodiments do not require extensive reconfiguration of the AC interface signals when replacing the AC motor with the DC motor.

FIG. 1is a schematic diagram of a heating, ventilation, and air conditioning (HVAC) system100that includes an adaptor module102and a retrofit motor104. HVAC system100also includes a thermostat106and/or a system controller108. Adaptor module102is coupled to and configured to receive signals from system controller108. Further, adaptor module102is coupled to and configured to transmit signals to motor104.

In the exemplary embodiment, motor104is an electronically commutated motor (ECM), which may also be referred to as a brushless direct current (DC) motor. Motor104is utilized as a fan and/or blower motor in HVAC system100. Alternatively, motor104may be implemented in any other application including, but not limited to, a fluid (e.g., water, air, etc.) moving system, a clean room filtering system, a fan filter unit, a variable air volume system, a refrigeration system, a furnace system, and/or an air conditioning system. In the exemplary embodiment, HVAC system100is retrofit to include motor104that replaces an existing permanent split capacitor (PSC) motor (hereinafter referred to as “replaced motor”, not shown).

Motor104is suitably receptive to speed commands, torque commands, and/or airflow commands. Speed commands may adjust the operating speed of motor104, torque commands may adjust the operating torque of motor104, and airflow commands may adjust an airflow output by motor104. Further, speed commands, torque commands, and/or airflow commands may be embodied by command signal107, such as a pulse width modulated (PWM) signal, a digital serial communication signal, or the like.

System controller108includes thermostat106that controls HVAC system100and provides adaptor module102with control signals109indicating an operating mode of HVAC system100. In certain embodiments, the control signals109include one or more signals generated by thermostat106that specify, for example, a cooling mode, a heating mode, or a fan only mode, and/or at a first stage or at a second stage.

In the exemplary embodiment, system controller108includes a plurality of system tap output connectors110, for example, five tap output connectors LT1, LT2, LT3, LT4, LT5. System tap output connectors110are configured to connect to taps of a motor, such as the replaced PSC motor and/or motor104, where each system tap output connector110is suitably mapped to operating modes (e.g., heating, cooling, etc.) of HVAC system100by system controller108, whereby system tap output connectors110are generally activated on the basis of operating mode. That is, system tap output connectors110provide control signals to the adaptor module102via signals109. An activated system tap output connector110generally provides line voltage from a utility power source as signals113, such as 120 VAC, 240 VAC, or 277 VAC. Only one of system tap output connectors110is selected to be activated at a time, and the remaining system tap output connectors110are not activated and, thus, have no power supplied thereto.

Adaptor module102controls motor104on the basis of command signals. The control signals are suitably received from system controller108and/or thermostat106, and include the operating mode of HVAC system100. When a control signal is received, adaptor module102suitably determines and instructs motor104to run at an associated speed, torque, or airflow.

In the exemplary embodiment, adaptor module102includes components mounted to a printed circuit board. More specifically, in the exemplary embodiment, adaptor module102includes a processing device114, a memory device116, a user interface118, and a communication interface120.

The term “processing device”, as used herein, refers to central processing units, microprocessors, microcontrollers, reduced instruction set circuits (RISC), application specific integrated circuits (ASIC), logic circuits, and any other circuit or processor capable of executing the functions described herein.

It should be noted that the embodiments described herein are not limited to any particular processor for performing the processing tasks of the invention. The term “processing device,” as that term is used herein, is intended to denote any machine capable of performing the calculations, or computations, necessary to perform the tasks of the invention. The term “processing device” also is intended to denote any machine that is capable of accepting a structured input and of processing the input in accordance with prescribed rules to produce an output. It should also be noted that the phrase “configured to” as used herein means that the processor is equipped with a combination of hardware and software for performing the tasks described herein, as will be understood by those skilled in the art.

Communication interface120includes an input tap connector122and a data output connector124. Input tap connector122is configured to receive system tap output connectors110, for example, via individual wires, via a plug/socket arrangement, or otherwise. For example, in the exemplary embodiment, the control signal includes a 120 VAC/240 VAC/277 VAC control signal. Alternatively, the control signal may include a 0-10 volts direct current (VDC) control signal, a 0-5 VDC control signal, a 4-20 milliampere (mA) control signal, and/or any other type of control signal that allows adaptor module102to function as described herein. Data output connector124includes one or more data lines (e.g., PWM/Common/RPMin) for coupling to motor104. Data output connector124may include, for example, a RS-485 connector, a DSI connector, a control wire reception terminal, and/or any other type of interface that enables adaptor module102to communicate with motor104.

Memory device116may be included within processing device114, or may be coupled to processing device114. In the exemplary embodiment, memory device116stores a plurality of different communications protocols. For example, processing device114may access the communications protocols stored in memory device116in order to translate a signal received from a user via communication interface120into a format that may be transmitted to motor104. More specifically, processing device114may receive a signal sent using a protocol with which motor104may not be compatible. Processing device114translates the received signal to a communication suitable to be transmitted to motor104.

Memory device116also stores operating parameter data to be used by processing device114to generate the command signal for motor104based on the control signal received from system controller108. The operating parameter data is stored in the form of a lookup table or a database. When control signal109indicating the operating mode of the HVAC system100is received, processing device114looks up the corresponding operating parameter associated with the operating mode, wherein the operating parameter is an operating speed, operating torque, or operating airflow.

User interface118enables user-interaction with adaptor module102for specifying and/or adjusting the values of the operating parameters associated with system tap output connectors110and stored in memory device116. In the exemplary embodiment, user interface118is a four-switch device that includes a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4. First switch S1enables the user to specify whether to operate switches S2-S4in DIP switch mode or in a near field communication (NFC) mode. DIP switch mode causes user input devices126to operate as DIP switches, where different configurations of switches S2-S4are correlated with individual locations of the lookup table that contain operational values. NFC mode enables the user to view, set, and/or define the operational values in the lookup table that are associated with various positions of switches S2-S4, as described in more detail herein. Second, third, and fourth switches S2-S4enable the user to set 8 different switch configurations associated with 8 different operational values for motor104for each of tap output connectors LT1-LT5.

In the exemplary embodiment, user interface118is either a DIP switch or a rotary switch that includes switches (or switch positions) S1-S4. In alternative embodiments, user interface118may include buttons, relays, and/or any other known input device that enables user interface118to function as described herein. User interface118facilitates configuration (i.e., setup) of adaptor module102. User interface118further enables selection of operational values or operating parameters such as a speed, torque, and/or airflow for association with each tap connector122. In alternative embodiments, user interface118may additionally include a plurality of buttons, a display, and/or any other known devices for interfacing with a user.

Each configuration of switches S2-S4of user interface118correlates to the lookup table stored in memory device116. More specifically, each configuration of switches S2-S4correlates to a predefined level of the operating parameter to be applied to motor104. For example, a first configuration of switches S2-S4may correlate to 30% of the maximum operating parameter (e.g., speed, torque, or airflow) of motor104, a second configuration of switches S2-S4may correlate to 40% of the maximum operating parameter, a third configuration of switches S2-S4may correlate to 50% of the maximum operating parameter, etc.

Further, in the exemplary embodiment, first switch S1may be positioned to specify the NFC mode, enabling adaptor module102to communicate with an external wireless computing device (e.g., smartphone, tablet, PDA, etc., not shown) using wireless communication (e.g., NFC, Wi-Fi, Bluetooth, RFID, etc.). In such an embodiment, communication interface120of adaptor module102includes a wireless communications module128that enables the wireless communication. The external wireless computing device runs/executes an application that provides user interface118and feedback functions. More specifically, the application enables a user to program the command signals provided to motor104. That is, the operating parameters associated with each configuration of switches S2-S4, may be adjusted by the user and stored in memory device116. Wireless communications module128receives adjusted operating parameters transmitted from the external wireless computing device and communicates the adjusted operating parameters to processing device114for storage within memory device116.

To control motor104, adaptor module102determines the operating parameter command based on the control signal received via the activated system tap output connector110. The operating parameter command may be a speed command, a torque command, or an airflow command. Adaptor module102generates command signals to be transmitted to motor104. The command signals may be in the form of PWM signals or DSI signals.

To power motor104, adaptor module102includes an input power connector136and an output power connector138. Input power connector136is configured to be coupled to line input power provided via thermostat106or system controller108. Specifically, input power connector136is configured to receive a line power wire L, a neutral power wire N, and an earth ground wire E. Line, neutral, and earth ground power wires L, N, E pass through adaptor module102and are provided to motor104via output power connector138.

Thus, adaptor module102enables the replacement of an AC motor that is typically used in an HVAC system with a highly efficient electrically commutated motor (“ECM”), optionally as a drop-in replacement. Adjustment module102suitably instructs motor104as to a speed, torque, or airflow to use, where these instructions are based on input from one or more control signals, such as the control signals109ofFIG. 1.

FIG. 2is a flowchart of an exemplary method200of controlling a motor in a HVAC system using adaptor module102(shown inFIG. 1).

Initially, method200includes receiving202a control signal109at a tap output connector110of a plurality of tap output connectors110. Method200also includes determining204, by processing device114, a configuration of switches S1-S4of a user interface118, wherein the configuration of the plurality of switches correlates to at least one stored operating parameter for application to the motor. Method200further includes determining206, by processing device114, an operating parameter at which to operate the motor based on the configuration of the plurality of switches of the user interface and based on a determination of which tap connector is receiving the control signal. Method200also includes transmitting208, by processing device114, a command signal107including instructions for motor104to operate in accordance with the determined operating parameter.

In one embodiment, transmitting command signal107includes transmitting a low-voltage command signal including one of a PWM signal and a DSI signal.

In another embodiment, receiving the control signal includes receiving a high-voltage signal including one of a 120 VAC signal, a 240 VAC signal, and a 277 VAC signal.

In another embodiment, determining the configuration of the plurality of switches includes determining a configuration of one of a DIP switch and a rotary switch.

In another embodiment, adaptor module102includes wireless communication module128. Method200further includes determining the plurality of switches of the user interface are arranged in a predefined configuration, receiving, via wireless communication module128, adjusted operating parameters input by a user using an external computing device, and storing the adjusted operating parameters in the memory device116.

In another embodiment, receiving control signal109further includes receiving the control signal from one of an HVAC system controller and a thermostat.

The embodiments described herein provide an adaptor module and methods of controlling a motor. The motor is controlled by a heating, ventilation and air conditioning (HVAC) system controller. The motor may include plurality of operating parameter ranges and the HVAC system controller provides an input operating mode for selecting one of the plurality of operating parameter ranges. The adjustment module is coupled between the HVAC system controller and the motor. The adjustment module may define the plurality of operating parameters, each associated with one of the plurality of operating modes. The adjustment module selects one of the plurality of operating parameters on the basis of control signals received from the HVAC system controller, and commands the motor according to the operating parameter associated with the selected operating mode. Further, the adjustment module includes the ability to manually adjust the values of the operating parameters. The adaptor module facilitates replacing or retrofitting a failed motor in a HVAC system with a readily available, stock, retrofit/replacement motor. The adaptor module provides a cost-effective solution to interfacing between HVAC system controllers, thermostats and replacement motors. Further, the adaptor module facilitates returning a failed HVAC system to operation quickly and efficiently (e.g., in one service call). Further, certain embodiments enable a DC motor system to be used as a drop-in replacement of an AC motor (e.g., a PSC motor), such as in an HVAC system or other air mover system. Further, certain embodiments do not require extensive reconfiguration of the AC interface signals when replacing the AC motor with the DC motor.

Exemplary embodiments of the adaptor module and methods of controlling a motor are described above in detail. The adaptor module and methods are not limited to the specific embodiments described herein, but rather, components of the adaptor module and/or steps of the method may be utilized independently and separately from other components and/or steps described herein. For example, the control system and methods may also be used in combination with other motor systems and methods, and are not limited to practice with only the HVAC system as described herein. Rather, the exemplary embodiments can be implemented and utilized in connection with many other system applications or other support.

A technical effect of the system described herein includes at least one of: (a) receiving a control signal at a tap connector of a plurality of tap connectors; (b) determining a configuration of a user input device of a plurality of user input devices associated with the tap connector of the plurality of tap connectors receiving the control signal, wherein each user input device is configurable to specify operating parameters for the motor; (c) determining an operating parameter at which to operate the motor based on the configuration of the user input device associated with the tap connector receiving the control signal; (d) transmitting a command signal including instructions for the motor to operate in accordance with the determined operating parameter; (e) replacing or retrofitting a failed motor in a HVAC system with a readily available, stock, retrofit/replacement motor; (f) provides a cost-effective solution to interfacing between HVAC system controllers, thermostats and replacement motors; and (g) facilitates returning a failed HVAC system to operation quickly and efficiently.