AU2012241185B2 - Compressor Sensor Module - Google Patents

Abstract

C \NRPonbADCC'dXF\4679667_ .DOC-10/17/2012 A sensor module for a compressor having an electric motor connected to a power supply, the sensor module comprising: 5 a first input connected to a first voltage sensor that generates a voltage signal corresponding to a voltage of said power supply; a second input connected to a first current sensor that generates a current signal corresponding to a current of said power supply; a processor connected to said first and second inputs that calculates a power factor 10 of said compressor based on voltage measurements from said first input and current measurements from said second input; wherein said processor is disposed within an electrical enclosure attached to an exterior of said compressor, said electrical enclosure being configured to receive electrical leads of said power supply and to house said first voltage sensor, said first current sensor, 15 and electrical terminals that connect said electrical leads of said power supply to said electric motor. WO 2009/061370 PCT/US2008/012364 AC (three phase) 49 102 104 PCB Trans.101 116; Processor 10 Comm relay 20 Ot119 -e e relay 124 -0 126-- To CM

Description

Australian Patents Act 1990 - Regulation 3.2A ORIGINAL COMPLETE SPECIFICATION STANDARD PATENT Invention Title "Compressor Sensor Module" The following statement is a full description of this invention, including the best method of performing it known to me/us: c~p~~ncr~vp4~,a~A Ifl1 C:WRPonblDCC\XIM679667_l.DOC-1tW17/2012 COMPRESSOR SENSOR MODULE RELATED APPLICATIONS 100011 This application is a divisional of Australian Patent Application No. 200832540, the originally filed specification of which is incorporated herein by reference in its entirety. 5 This application is related to U.S. Utility Application 12/261 ,643 Filed on October 30, 2008 and U.S. Provisional Application No. 60/984,902 filed on November 2, 2007, and the entire disclosures of these applications is incorporated herein by reference. FIELD 10002] The present disclosure relates to sensor modules for compressors, methods for 10 sensor modules and systems with a compressor. BACKGROUND 100031 The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. [00041 Compressors are used in a variety of industrial and residential applications to 15 circulate refrigerant within a refrigeration, heat pump, HVAC, or chiller system (generically "refrigeration systems") to provide a desired heating or cooling effect. Compressors may include an electric motor to provide torque to compress vapor refrigerant. The electric motor may be powered by an alternating current (AC) or direct current (DC) power supply. In the case of an AC power supply, single or poly-phase AC 20 may be delivered to windings of the electric motor. For example, the compressor may include an electric motor configured to operate with three phase AC. The electric motor may include at least one set of windings corresponding to each of the three phases. 100051 In each application, it is desirable for the compressor to provide consistent and efficient operation to ensure that the refrigeration system functions properly. Variations in 25 the supply of electric power to the electric motor of the compressor may disrupt operation of the electric motor, the compressor, and the refrigeration system. Such variations may C:NRPonbDCC\lXF%467%67_ .DOC-la/17/2012 -2 include, for example, excessive, or deficient, current or voltage conditions. In the case of a poly-phase AC power supply, such variations may include an unbalanced phase condition wherein the current or voltage of at least one phase of AC is excessively varied from the current or voltage of the other phases. Further, such variations may include a loss of phase 5 condition wherein one phase of AC is interrupted while the remaining phases continue to be delivered. Excessive current or voltage conditions may cause the electric motor to overheat which may damage the electric motor or the compressor. Deficient current or voltage conditions, unbalanced phase conditions, and loss of phase conditions may disrupt operation of the electric motor, the compressor, or the refrigeration system and cause 10 unnecessary damage. 100061 The electric motor of a compressor may be equipped with a temperature or current sensor to detect overheating of the electric motor during electrical power disturbances. For example, a bi-metallic switch may trip and deactivate the electric motor when the electric motor is overheated or drawing excessive electrical current. Such a system, however, does 15 not detect variations in the power supply that may not immediately or drastically increase the temperature of the electric motor. In addition, such systems may not detect a variation in electrical power until the condition has increased the temperature of the electric motor or the electric motor windings. 100071 Further, such systems do not provide sufficient data to evaluate electrical efficiency 20 of the electric motor overall. Variations in the supply of electric power may result in inefficient operation of the compressor, the electric motor, or the refrigeration system. Refrigeration systems generally require a significant amount of energy to operate, with energy requirements being a significant cost to retailers. As a result, it is in the best interest of retailers to closely monitor the supply of electric power to their refrigeration systems to 25 maximize efficiency and reduce operational costs. 10007A] It is desired to address or ameliorate one or more disadvantages or limitations associated with the prior art, or to at least provide a useful alternative.

H:\dxl\lntrovn\NRPortbl\DCC\DXL\6345844_I.doc-20/05/2014 - 2A SUMMARY [0007B] In accordance with the present invention there is provided a sensor module for a compressor having an electric motor connected to a power supply that includes first, 5 second, and third phases, the sensor module comprising: a first input connected to a first voltage sensor that generates a first voltage signal corresponding to a voltage of said first phase of said power supply; a second input connected to a second voltage sensor that generates a second voltage signal corresponding to a voltage of said second phase of said power supply; 10 a third input connected to a third voltage sensor that generates a third voltage signal corresponding to a voltage of said third phase of said power supply; a fourth input connected to a current sensor that generates a current signal corresponding to a current of said first phase of said power supply; a processor connected to said first, second, third, and fourth inputs that calculates a 15 first estimated current corresponding to a current of said second phase of said power supply and a second estimated current corresponding to a current of said third phase of said power supply based on voltage measurements from said first, second, and third inputs and current measurements from said fourth input, and that calculates a power factor of said compressor based on said voltage measurements from said first, second, and third inputs, 20 said current measurements from said fourth input, and said first and second estimated currents. [0007C] The present invention also provides for a sensor module of a compressor having an electric motor connected to a power supply that includes first, second, and third phases, a method comprising: 25 receiving, with a processor of the sensor module, first voltage measurements from a first voltage sensor that generates a first voltage signal corresponding to a voltage of said first phase of said power supply; receiving, with said processor, second voltage measurements from a second voltage sensor that generates a second voltage signal corresponding to a voltage of said second 30 phase of said power supply; H:\dxl\lntrovn\NRPortbl\DCC\DXL\6345844_I.doc-20/05/2014 - 2B receiving, with said processor, third voltage measurements from a third voltage sensor that generates a third voltage signal corresponding to a voltage of said third phase of said power supply; receiving, with said processor, current measurements from a current sensor that 5 generates a current signal corresponding to a current of said first phase of said power supply; calculating, with said processor, a first estimated current corresponding to a current of said second phase of said power supply and a second estimated current corresponding to a current of said third phase of said power supply, based on said first, second, and third 10 voltage measurements, and said current measurements; calculating, with said processor, a power factor of said compressor based on said first, second, and third voltage measurements, said current measurements, and said first and second estimated currents; generating an output, with said processor, based on said power factor. 15 [0007D] The present invention also provides a system comprising: a compressor having an electric motor connected to a power supply; an electrical enclosure attached to an exterior of the compressor, the electrical enclosure being configured to receive electrical leads of the power supply, to house electrical terminals that connect the electrical leads of the power supply to the electric 20 motor, and to house a voltage sensor that generates a voltage signal corresponding to a voltage of the power supply and a current sensor that generates a current signal corresponding to a current of the power supply; the sensor module, located within the electrical enclosure, comprising a communication port connected to the processor; 25 a control module at a different location from the sensor module and outside of the electrical enclosure; a communication link connected to the control module and the sensor module to allow communication between the control module and the sensor module; wherein the sensor module communicates data based on the electrical power 30 measurements to the control module over the communication link and the control module controls operation of the compressor based on the data received from the sensor module.

H:\dxl\Intrwovn\NRPortbl\DCC\DXL\6345844_I.doc-20/05/2014 -2C [0008] In embodiments, a sensor module for a compressor having an electric motor connected to a power supply is provided. The sensor module may comprise a first input connected to a WO 2009/061370 PCT/US2008/012364 3 first current sensor that generates a current signal corresponding to a current of said power supply, and a processor connected to the first and second inputs that calculates a power factor of the compressor based on voltage measurements from the first input and current measurements from the second input. The 5 processor may be disposed within an electrical enclosure of the compressor and the electrical enclosure may being configured to house electrical terminals for connecting the power supply to the electric motor. [0009] In other features, the processor may be disposed within a tamper-resistant enclosure within the electrical enclosure. 10 [0010] In other features, the processor may calculate an active power and an apparent power of the compressor based on the voltage measurements from the first input and current measurements from the second input and may calculate the power factor according to a ratio of the active power to the apparent power. 15 [0011] In other features, the processor may determine a voltage waveform based on voltage measurements from the first input and a current waveform based on current measurements from the second input and may calculate the power factor according to an angular difference between the current waveform and the voltage waveform. 20 [0012] In other features, the processor may calculate a power consumption of the compressor based on the voltage measurements from the first input and the current measurements from the second input. [0013] In other features, the processor may calculate an active power of the compressor based on the voltage measurements from the first input and 25 the current measurements from the second input and calculates the power consumption by averaging the active power over a time period. [0014] In other features, the sensor module may further comprise a communication port for communicating information from the sensor module to a control module for the compressor, a system controller for a system associated 30 with the compressor, a portable computing device, and/or a network device.

WO 2009/061370 PCT/US2008/012364 4 [0015] In other features, the information communicated may include the power factor, a calculated active power, a calculated apparent power, and/or a calculated power consumption of the compressor. [0016] In other features, the power supply may includes first, second, 5 and third phases, with the voltage signal generated by the first voltage sensor corresponding to the first phase, and the current signal generated by the first current sensor corresponding to the first phase. Further, the sensor module may further comprise a third input connected to a second voltage sensor that generates a voltage signal corresponding to a voltage of the second phase. A 10 fourth input connected to a third voltage sensor may generate a voltage signal corresponding to a voltage of the third phase. The processor may be connected to the third and fourth inputs and may calculate the power factor based on voltage measurements received from the third and fourth inputs. [0017] In other features, the processor may estimate a current of the 15 second phase and a current of the third phase and may calculate the power factor based on the estimated currents of the second and third phases. [0018] In other features, the processor may calculate an active power and an apparent power of the compressor based on the voltage measurements from the first input, the current measurements from the second input, the voltage 20 measurements from the third input, the voltage measurements from the fourth input and the estimated currents of the second and third phases and may calculate the power factor according to a ratio of the active power to the apparent power. [0019] In other features, the sensor module may further comprise a 25 fifth input connected to a second current sensor that generates a current signal corresponding to a current of the second phase. The processor may be connected to the fifth input and may calculate the power factor based on current measurements received from the fifth input. [0020] In other features, the processor may estimate a current of the 30 third phase and may calculate the power factor based on the estimated current of the third phase.

C \NRPonbl\DCC\1XIM\67%Xt67_ jDOC-10/7/21)12 -5 100211 In other features, the processor may calculate an active power and an apparent power of the compressor based on the voltage measurements from the first input, the current measurements from the second input, the voltage measurements from the third input, the voltage measurements from the fourth input, the current measurements from the 5 fifth input, and the estimated current of the third phase and calculates the power factor according to a ratio of the active power to the apparent power. 100221 In other features, the sensor module may further comprise a fifth input connected to a second current sensor that generates a current signal corresponding to a current of the second phase and a sixth input connected to a third current sensor that generates a current 10 signal corresponding to a current of the third phase. The processor may be connected to the fifth and sixth inputs and may calculate the power factor based on current measurements received from the fifth and sixth inputs. 100231 In other features, the processor may calculate an active power and an apparent power of the compressor based on the voltage measurements from the first input, the 15 current measurements from the second input, the voltage measurements from the third input, the voltage measurements from the fourth input, the current measurements from the fifth input, and the current measurements from the sixth input and calculates the power factor according to a ratio of the active power to the apparent power. [00241 In other features, a compressor having the sensor module is provided. 20 100251 In other features, a method for a sensor module with a processor disposed within an electrical enclosure of a compressor having an electric motor connected to a power supply is also provided. The electrical enclosure may be configured to house electrical terminals for connecting the power supply to the electric motor. The method may comprise receiving voltage measurements of the power supply from a first voltage sensor connected to the 25 sensor module, receiving current measurements of the power supply from a first current sensor connected to the sensor module, calculating a power factor of the compressor based on the WO 2009/061370 PCT/US2008/012364 6 voltage measurements and the current measurements, and generating an output based on the power factor. [0026] In other features, calculating the power factor may comprise calculating an active power and an apparent power of the compressor based on 5 the voltage measurements and the current measurements and calculating the power factor according to a ratio of the active power to the apparent power. [0027] In other features, calculating the power factor may comprise determining a voltage waveform based on the voltage measurements, determining a current waveform based on the current measurements, and 10 calculating the power factor according to an angular difference between the current waveform and the voltage waveform. [0028] In other features, the method may further comprise calculating a power consumption of the compressor based on the voltage measurements and the current measurements. 15 [0029] In other features, calculating the power consumption may comprise calculating an active power of the compressor based on the voltage measurements and the current measurements and calculating the power consumption by averaging the active power over a time period. [0030] In other features, generating the output based on the power 20 factor may comprise communicating the power factor to a control module, a system controller, a portable computing device, and/or a network device, connected to the sensor module. [0031] In other features, power supply may include first, second, and third phases, with the voltage measurements from the first voltage sensor 25 corresponding to the first phase, and the current measurements from the first current sensor corresponding to the first phase. The method may further comprise receiving voltage measurements corresponding to the second phase of the power supply from a second voltage sensor connected to the sensor module, receiving voltage measurements corresponding to the third phase of the power 30 supply from a third voltage sensor connected to the sensor module. The calculating the power factor may comprise calculating the power factor based on WO 2009/061370 PCT/US2008/012364 7 the voltage measurements corresponding to the second phase and the voltage measurements corresponding to the third phase. [0032] In other features, the method may further comprise calculating a current estimate for the second phase and calculating a current estimate for 5 the third phase. Calculating the power factor may comprise calculating the power factor based on the current estimates for the second and third phases. [0033] In other features, calculating the power factor may comprise calculating an active power and an apparent power of the compressor based on the voltage measurements for the first, second, and third phases, the current 10 measurements for the first phase, and the current estimates for the second and third phases and calculating the power factor according to a ratio of the active power to the apparent power. [0034] In other features, the method may further comprise receiving current measurements corresponding to the second phase of the power supply 15 from a second current sensor connected to the sensor module. Calculating the power factor may comprise calculating the power factor based on the current measurements corresponding to the second phase. [0035] In other features, the method may further comprise calculating a current estimate for the third phase. Calculating the power factor may 20 comprise calculating the power factor based on the current estimate for the third phase. [0036] In other features, calculating the power factor may comprise calculating an active power and an apparent power of the compressor based on the voltage measurements for the first, second, and third phases, the current 25 measurements for the first and second phases, and the current estimate for the third phase and calculating the power factor according to a ratio of the active power to the apparent power. [0037] In other features, the method may further comprise receiving current measurements corresponding to the third phase of the power supply 30 from a third current sensor connected to the sensor module. Calculating the power factor may comprise calculating the power factor based on the current measurements corresponding to the third phase.

C NRPonbPDCC\X)4679667_. DOC-IM/7/21012 -8 100381 In other features, calculating the power factor may comprise calculating an active power and an apparent power of the compressor based on the voltage measurements for the first, second, and third phases, and the current measurements for the first, second, and third phases and calculating the power factor according to a ratio of the active power to the 5 apparent power. 100391 In other features, a computer-readable medium having computer executable instructions for performing the method is provided. 100401 Another sensor module for a compressor having an electric motor connected to a power supply is also provided. The sensor module may comprise a first input connected to 10 a first voltage sensor that generates a voltage signal corresponding to a voltage of the power supply, a second input connected to a first current sensor that generates a current signal corresponding to a current of the power supply, and a processor connected to the first and second inputs that monitors the first and second inputs. The processor may detect an unexpected variation of electric power from the power supply and/or a mechanical 15 malfunction based on voltage measurements from the first input and current measurements from the second input. The processor may be disposed within an electrical enclosure of the compressor, the electrical enclosure being configured to house electrical terminals for connecting the power supply to the electric motor. 100411 In other features, the processor may be disposed within a tamper-resistant enclosure 20 within the electrical enclosure. 100421 In other features, the sensor module may further comprise a communication port for communicating a notification corresponding to the expected variation and/or the mechanical malfunction to a control module for the compressor, a system controller for a system associated with the compressor, a portable computing device, and/or a network 25 device. 100431 In other features, the processor may detect the unexpected variation of electric power including a no-power condition.

C.\NRPonblDCC\Xi,4679667_1 DOC-10/17/2012 -8A 100441 In other features, the processor may compare the voltage measurements from the first input with a predetermined voltage threshold and may determine that the no-power condition exists when the voltage WO 2009/061370 PCTIUS2008/012364 9 measurements remain less than the predetermined voltage threshold for a predetermined time period. [0045] In other features, the sensor module may detects the unexpected variation of electric power including a low-voltage condition. 5 [0046] In other features, the processor may determine a normal operating voltage of the compressor and may determine that the low-voltage condition exists when the voltage measurements from the first input are less than a predetermined percentage of the normal operating voltage. [0047] In other features, the processor may determine the normal 10 operating voltage based on historical data of the compressor. [0048] In other features, the processor may determine the normal operating voltage based on an inputted normal operating voltage. [0049] In other features, the sensor module may detect the unexpected variation of electric power including a current-overload condition. 15 [0050] In other features, the processor may determine a current maximum threshold, may compare the current measurements from the second input with the current maximum threshold, and may determine that the current overload condition exists based on the comparison. [0051] In other features, the power supply may include first, second, 20 and third phases, with the voltage signal generated by the first voltage sensor corresponding to the first phase, and with the current signal generated by the first current sensor corresponding to the first phase. The sensor module may further comprise a third input connected to a second voltage sensor that generates a voltage signal corresponding to a voltage of the second phase and a 25 fourth input connected to a third voltage sensor that generates a voltage signal corresponding to a voltage of the third phase. The processor may be connected to the third and fourth inputs and may detect the unexpected variation of electric power from the power supply based on voltage measurements received from the third and fourth inputs. 30 [0052] In other features, the unexpected variation of electric power may include a phase-loss condition.

WO 2009/061370 PCT/US2008/012364 10 [0053] In other features, the processor may compare voltage measurements received from the first, third, and fourth inputs and may determine that the phase-loss condition exists when voltage measurements from the first input are less than a predetermined percentage of an average of voltage 5 measurements from the third and fourth inputs. [0054] In other features, the unexpected variation of electric power may include a voltage-imbalance condition. [0055] In other features, the processor may calculate an average of voltage measurements received from the first, third, and fourth inputs and may 10 determine that the voltage-imbalance condition based on the greatest of a difference between voltage measurements from the first input and the average, a difference between voltage measurements from the third input and the average, and a difference between voltage measurements from the fourth input and the average. 15 [0056] In other features, the sensor module may further comprise a fifth input connected to a second current sensor that generates a current signal corresponding to a current of the second phase. The processor may be connected to the fifth input and may detect the unexpected variation of electric power from the power supply based on current measurements received from the 20 fifth input. [0057] In other features, the unexpected variation of electric power may include a current-delay condition. [0058] In other features, the processor may determine that the current delay condition exists when a current measurement from the second input is 25 greater than a predetermined current threshold and a current measurement from the fifth input is not greater than the predetermined current threshold within a predetermined time period. [0059] In other features, the sensor module may detect the mechanical malfunction including a welded-contactor condition. 30 [0060] In other features, the processor may receive run-state data corresponding to a current run-state of the compressor, may compare the voltage measurements from the first input with a voltage threshold, and may C\NRPodbl\DCC\1X161X67_) DOC-10/17/2012 - 11 determine that the welded-contactor condition exists based on the current run-state and the comparison. 100611 In other features, the sensor module may detect the mechanical malfunction including a locked-rotor condition. 5 [00621 In other features, the processor may compare the current measurements from the second input with a current threshold and may determine that the locked-rotor condition exists when the current measurements are greater than the current threshold. 100631 In other features, the processor may generate a buffer of the current measurements from the second input, may determine a greatest current value from the buffer, may 10 compare the current measurements with the greatest current value from the buffer, and may determine that the locked-rotor condition exists when the current measurements are greater than a predetermined percentage of the greatest current value. [00641 In other features, the sensor module may detect the mechanical malfunction including a protection-trip condition. 15 [00651 In other features, the processor may compare the voltage measurements with a voltage threshold and the current measurements with a current threshold and may determine that the protection-trip condition exists when the voltage measurements are greater than the voltage threshold and the current measurements are less than the current threshold. 20 [00661 In other features, another method for a sensor module with a processor disposed within an electrical enclosure of a compressor having an electric motor connected to a power supply is also provided. The electrical enclosure may be configured to house electrical terminals for connecting the power supply to the electric motor. The method may comprise receiving voltage measurements of the power supply from a first voltage sensor 25 connected to the sensor module, receiving current measurements of the power supply from a first current sensor connected to the sensor module, detecting an unexpected variation of electric power from the power supply and/or a mechanical malfunction of the compressor C:\NRPortbnDCCXiMA679667. .DOC-iW17/2012 - HA based on the voltage measurements and the current measurements, and generating an output based on the detecting.

WO 2009/061370 PCT/US2008/012364 12 [0067] In other features, generating the output based on the detecting may comprise communicating a result of the detecting to a control module, a system controller, a portable computing device, and/or a network device, connected to the sensor module. 5 [0068] In other features, the detecting may include detecting the unexpected variation of electric power including a no-power condition. [0069] In other features, detecting the no-power condition may comprise comparing the voltage measurements with a predetermined voltage threshold, and determining that the no-power condition exists when the voltage 10 measurements remain less than the predetermined voltage threshold for a predetermined time period. [0070] In other features, the detecting may include detecting the unexpected variation of electric power including a low-voltage condition. [0071] In other features, detecting the low-voltage condition may 15 comprise determining a normal operating voltage of the compressor, and determining that the low-voltage condition exists when the voltage measurements are less than a predetermined percentage of the normal operating voltage. [0072] In other features, determining the normal operating voltage may 20 comprise determining the normal operating voltage based on historical data of the compressor. [0073] In other features, determining the normal operating voltage may comprise determining the normal operating voltage based on an inputted normal operating voltage. 25 [0074] In other features, the detecting may include detecting the unexpected variation of electric power including a current-overload condition. [0075] In other features, detecting the current-overload condition may comprise determining a current maximum threshold, comparing the current measurements with the current maximum threshold, and determining that the 30 current-overload condition exists based on the comparison. [0076] In other features, the power supply may include first, second, and third phases, with the voltage measurements from the first voltage sensor WO 2009/061370 PCT/US2008/012364 13 corresponding to the first phase, and with the current measurements from the first current sensor corresponding to the first phase. The method may further comprise receiving voltage measurements corresponding to the second phase of the power supply from a second voltage sensor connected to the sensor module, 5 and receiving voltage measurements corresponding to the third phase of the power supply from a third voltage sensor connected to the sensor module. Detecting the unexpected variation of electric power from the power supply may be based on the voltage measurements corresponding to the first, second, and third phases and the current measurements. 10 [0077] In other features, detecting the unexpected variation of electric power may include detecting a phase-loss condition. [0078] In other features, detecting the phase-loss condition may comprise comparing voltage measurements corresponding to the first, second, and third phases, and determining that the phase-loss condition exists when 15 voltage measurements corresponding to the first phase are less than a predetermined percentage of an average of voltage measurements corresponding to the second and third phases. (0079] In other features, detecting the unexpected variation of electric power may include detecting a voltage-imbalance condition. 20 [0080] In other features, detecting the voltage-imbalance condition may comprise calculating an average of the voltage measurements corresponding to the first, second, and third phases and determining that the voltage-imbalance condition exists based on the greatest of a difference between voltage measurements corresponding to the first phase and the 25 average, a difference between voltage measurements corresponding to the second phase and the average, and a difference between voltage measurements corresponding to the third phase and the average. [0081] In other features, the method may further comprise receiving current measurements corresponding to the second phase of the power supply 30 from a second current sensor connected to the sensor module. The detecting the unexpected variation of electric power from the power supply may include WO 2009/061370 PCTIUS2008/012364 14 detecting the unexpected variation of electric power based on the current measurements corresponding to the first and second phases. [0082] In other features, detecting the unexpected variation of electric power may include detecting a current-delay condition. 5 [0083] In other features, detecting the current-delay condition may comprise comparing the current measurements corresponding with the first phase and the current measurements corresponding with the second phase with a predetermined current threshold and determining that the current-delay condition exists when the current measurements corresponding to the first phase 10 are greater than the predetermined current threshold and the current measurements corresponding with the second phase are not greater than the predetermined current threshold within a predetermined time period. [0084] In other features, the detecting may include detecting the mechanical malfunction including a welded-contactor condition. 15 [0085] In other features, the method may further comprise receiving run-state data corresponding to a current run-state of the compressor, comparing the voltage measurements with a voltage threshold, and determining that the welded-contactor condition exists based on the current run-state and the comparison. 20 [0086] In other features, the detecting may include detecting the mechanical malfunction of the compressor including a locked-rotor condition. [0087] In other features, the detecting the locked-rotor condition may comprise comparing the current measurements with a current threshold and determining that the locked-rotor condition exists when the current 25 measurements are greater than the current threshold. [0088] In other features, detecting the locked-rotor condition may comprise generating a buffer of the current measurements, determining a greatest current value from the buffer, comparing the current measurements with the current value from the buffer, and determining that the locked-rotor condition 30 exists when the current measurements are greater than a predetermined percentage of the greatest current value.

CkNRPorbl\DCC\X M67967_I.DOC-1017/2012 - 15 100891 In other features, the detecting may include detecting the mechanical malfunction including a protection-trip condition. 100901 In other features, the detecting the protection-trip condition may comprise comparing the voltage measurements with a voltage threshold, comparing the current 5 measurements with a current threshold, and determining that the protection-trip condition exists when the voltage measurements are greater than the voltage threshold and the current measurements are less than the current threshold. 100911 Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for 10 purposes of illustration only and are not intended to limit the scope of the present disclosure. DRAWINGS [00921 The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. 15 10092A] Preferred embodiments of the present invention are hereinafter further described, by way of non-limiting example only, with reference to the accompanying drawings, in which: 100931 Figure 1 is a schematic view of a refrigeration system; [00941 Figure 2 is a schematic view of a compressor with a sensor module and a control 20 module; [00951 Figure 3 is a schematic view of a compressor with a sensor module and a control module; 100961 Figure 4 is a schematic view of a compressor with a sensor module and a control module; C:\NRPonbNDCCAXM4679671_ DOC.I(1117/2012 - 15A 100971 Figure 5 is a perspective view of a compressor with a sensor module and a control module; [00981 Figure 6 is a top view of a compressor with a sensor module and a control module; [00991 Figure 7 is a schematic view of an electrical enclosure of a compressor including a 5 sensor module; [00100] Figure 8 is a schematic view of an electrical enclosure of a compressor including a sensor module; WO 2009/061370 PCT/US2008/012364 16 [00101] Figure 9 is a schematic view of an electrical enclosure of a compressor including a sensor module; [00102] Figure 10 is a schematic view of an electrical enclosure of a compressor including a sensor module; 5 [00103] Figure 11 is a schematic view of an electrical enclosure of a compressor including a sensor module; [00104] Figure 12 is a schematic view of an electrical enclosure of a compressor including a sensor module; [00105] Figure 13 is a flow chart illustrating an operating algorithm of a 10 sensor module in accordance with the present teachings; [00106] Figure 14 is a flow chart illustrating a diagnostic algorithm of a sensor module in accordance with the present teachings; [00107] Figure 15 is a flow chart illustrating a diagnostic algorithm of a sensor module in accordance with the present teachings; 15 [00108] Figure 16 is a flow chart illustrating a diagnostic algorithm of a sensor module in accordance with the present teachings; [00109] Figure 17 is a flow chart illustrating a diagnostic algorithm of a sensor module in accordance with the present teachings; [00110] Figure 18 is a flow chart illustrating a diagnostic algorithm of a 20 sensor module in accordance with the present teachings; [00111] Figure 19 is a flow chart illustrating a diagnostic algorithm of a sensor module in accordance with the present teachings; [00112] Figure 20 is a flow chart illustrating a diagnostic algorithm of a sensor module in accordance with the present teachings; 25 [00113] Figure 21 is a flow chart illustrating a diagnostic algorithm of a sensor module in accordance with the present teachings; [00114] Figure 22 is a flow chart illustrating a diagnostic algorithm of a sensor module in accordance with the present teachings; and [00115] Figure 23 is a flow chart illustrating a diagnostic algorithm of a 30 sensor module in accordance with the present teachings.

WO 2009/061370 PCT/US2008/012364 17 DETAILED DESCRIPTION [00116] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals 5 indicate like or corresponding parts and features. (00117] As used herein, the terms module, control module, and controller refer to one or more of the following: an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a 10 combinational logic circuit, or other suitable components that provide the described functionality. Further, as used herein, computer-readable medium refers to any medium capable of storing data for a computer. Computer readable medium may include, but is not limited to, memory, RAM, ROM, PROM, EPROM, EEPROM, flash memory, punch cards, dip switches, CD-ROM, 15 floppy disk, magnetic tape, other magnetic medium, optical medium, or any other device or medium capable of storing data for a computer. [00118] With reference to Figure 1, an exemplary refrigeration system 10 may include a plurality of compressors 12 piped together with a common suction manifold 14 and a discharge header 16. Compressor 12 may be a 20 reciprocating compressor, a scroll type compressor, or another type of compressor. Compressor 12 may include a crank case. Compressors 12 may be equipped with electric motors to compress refrigerant vapor that is delivered to a condenser 18 where the refrigerant vapor is liquefied at high pressure, thereby rejecting heat to the outside air. The liquid refrigerant exiting the condenser 18 is 25 delivered to an evaporator 20. As hot air moves across the evaporator, the liquid turns into gas, thereby removing heat from the air and cooling a refrigerated space. This low pressure gas is delivered to the compressors 12 and again compressed to a high pressure gas to start the refrigeration cycle again. While a refrigeration system 10 with two compressors 12, a condenser 18, and an evaporator 20 is 30 shown in Figure 1, a refrigeration system 10 may be configured with any number of compressors 12, condensers 18, evaporators 20, or other refrigeration system components.

WO 2009/061370 . PCTIUS2008/012364 18 [00119] Each compressor 12 may be equipped with a control module (CM) 30 and a sensor module (SM) 32. As described herein, SM 32 may be affixed to compressor 12 and may monitor electric power delivered to compressor 12 with one or more voltage sensors and one or more current sensors. Based on 5 electrical power measurements, such as electric current (1) and voltage (V), SM 32 may determine apparent power, actual power, power consumption, and power factor calculations for the electric motor of compressor 12. SM 32 may communicate the electric power measurements and calculations to CM 30. SM 32 may also alert CM 30 of variations in the power supply, or of mechanical failures, 10 based on the measurements and calculations. For example, SM 32 may alert CM 30 of an excessive current or voltage condition, a deficient current or voltage condition, a current or voltage imbalance condition, or a loss of phase or current delay condition (if poly-phase electric power is used). Based on the monitoring of the electric power supply and based on the communication with CM 30, SM 32 15 may detect and alert CM 30 to a welded contactor condition, or a locked rotor condition. [00120] CM 30 may control operation of compressor 12 based on data received from SM 32, based on other compressor and refrigeration system data received from other compressor or refrigeration system sensors, and based on 20 communication with a system controller 34. CM 30 may be a protection and control system of the type disclosed in assignee's commonly-owned U.S. Patent Application No. 11/059,646, Publication No. 2005/0235660, filed February 16, 2005, the disclosure of which is incorporated herein by reference. Other suitable protection and control systems may be used. 25 [00121] In addition to the data received by CM 30 from SM 32, CM 30 may receive compressor and refrigeration system data including discharge pressure, discharge temperature, suction pressure, suction temperature, and other compressor related data from pressure and temperature sensors connected to or, embedded within, compressor 12. In addition, oil level and oil pressure data may 30 be received by SM 32 and communicated to CM 30 and/or received by CM 30 directly. In this way, CM 30 may monitor the various operating parameters of compressor 12 and control operation of compressor 12 based on protection and WO 2009/061370 PCT/US2008/012364 19 control algorithms and based on communication with system controller 34. For example, CM 30 may activate and deactivate the compressor 12 according to a set-point, such as a suction pressure, suction temperature, discharge pressure, or discharge temperature set-point. In the case of a discharge pressure set-point, CM 5 30 may activate compressor 12 when the discharge pressure, as determined by a discharge pressure sensor, falls below the discharge pressure set-point. CM 30 may deactivate compressor 12 when the discharge pressure rises above the discharge pressure set-point. [00122] Further, CM 30 may activate or deactivate compressor 12 based 10 on data and/or alerts received from SM 32. For example, CM 30 may deactivate compressor 12 when alerted of an excessive current or voltage condition, a deficient current or voltage condition, a current or voltage imbalance condition, or a loss of phase or current delay condition (if poly-phase electric power is used). Further, CM 30 may activate compressor 12 when alerted of a welded contactor 15 condition or deactivate compressor 12 when alerted of a locked rotor condition. CM 30 may communicate operating data of compressor 12, including electric power data received from SM 32, to system controller 34. [00123] In this way, SM 32 may be specific to compressor 12 and may be located within an electrical enclosure 72 of compressor 12 for housing electrical 20 connections to compressor 12 (shown in Figures 5-12) at the time of manufacture of compressor 12. CM 30 may be installed on compressor 12 after manufacture and at the time compressor 12 is installed at a particular location in a particular refrigeration system, for example. Different control modules may be manufactured by different manufacturers. However, each CM 30 may be designed and 25 configured to communicate with SM 32. In other words, SM 32 for a particular compressor 12 may provide data and signals that can be communicated to any control module appropriately configured to communicate with SM 32. Further, manufacturers of different control modules may configure a control module to receive data and signals from SM 32 without knowledge of the algorithms and 30 computations employed by SM 32 to provide the data and signals. [00124] System controller 34 may be used and configured to control the overall operation of the refrigeration system 10. System controller 34 is preferably WO 2009/061370 PCT/US2008/012364 20 an Einstein Area Controller offered by CPC, Inc. of Atlanta, Georgia, or any other type of programmable controller that may be programmed to operate refrigeration system 10 and communicate with CM 30. System controller 34 may monitor refrigeration system operating conditions, such as condenser temperatures and 5 pressures, and evaporator temperatures and pressures, as well as environmental conditions, such as ambient temperature, to determine refrigeration system load and demand. System controller 34 may communicate with CM 30 to adjust set points based on operating conditions to maximize efficiency of refrigeration system 10. System controller 34 may evaluate efficiency based on electric power 10 measurements and calculations made by SM 32 and communicated to system controller 34 from CM 30. [00125] With reference to Figure 2, three phase AC electric power 50 may be delivered to compressor 12 to operate an electric motor. SM 32 and CM 30 may receive low voltage power from one of the phases of electric power 50 15 delivered to compressor 12. For example, a transformer 49 may convert electric power 51 from one of the phases to a lower voltage for delivery to SM 32 and CM 30. In this way, SM 32 and CM 30 may operate on single phase AC electric power at a lower voltage than electric power 50 delivered to compressor 12. For example, electric power delivered to SM 32 and CM 30 may be 24V AC. When 20 low voltage power, for example 24 V AC, is used to power CM 30 and SM 32, lower voltage rated components, such as lower voltage wiring connections, may be used. [00126] SM 32 may be connected to three voltage sensors 54, 56, 58, for sensing voltage of each phase of electric power 50 delivered to compressor 25 12. In addition, SM 32 may be connected to a current sensor 60 for sensing electric current of one of the phases of electric power 50 delivered to compressor 12. Current sensor 60 may be a current transformer or current shunt resistor. [00127] When a single current sensor 60 is used, electric current for the other phases may be estimated based on voltage measurements and based on 30 the current measurement from current sensor 60. Because the load for each winding of the electric motor may be substantially the same as the load for each of the other windings, because the voltage for each phase is known from WO 2009/061370 PCT/US2008/012364 21 measurement, and because the current for one phase is known from measurement, current in the remaining phases may be estimated. [00128] Additional current sensors may also be used and connected to SM 32. With reference to Figure 3, two current sensors 57, 60 may be used to 5 sense electric current for two phases of electric power 50. When two current sensors 57, 60 are used, electric current for the remaining phase may be estimated based on voltage measurements and based on the current measurements from current sensors 57, 60. With reference to Figure 4, three current sensors 55, 57, 60 may be used to sense electric current for all three 10 phases of electric power 50. [00129] In the case of a dual winding three phase electric motor, six electrical power terminals may be used, with one terminal for each winding resulting in two terminals for each of the three phases of electric power 50. In such case, a voltage sensor may be included for each of the six terminals, with 15 each of the six voltage sensors being in communication with SM 32. In addition, a current sensor may be included for one or more of the six electrical connections. [00130] With reference to Figures 5 and 6, CM 30 and SM 32 may be mounted on or within compressor 12. CM 30 may include a display 70 for 20 graphically displaying alerts or messages. As discussed above, SM 32 may be located within electrical enclosure 72 of compressor 12 for housing electrical connections to compressor 12. [00131] Compressor 12 may include a suction nozzle 74, a discharge nozzle 76, and an electric motor disposed within an electric motor housing 78. 25 [00132] Electric power 50 may be received by electrical enclosure 72. CM 30 may be connected to SM 32 through a housing 80. In this way, CM 30 and SM 32 may be located at different locations on or within compressor 12, and may communicate via a communication connection routed on, within, or through compressor 12, such as a communication connection routed through housing 80. 30 [00133] With reference to Figures 7 through 12, SM 32 may be located within electrical enclosure 72. In Figures 7 through 12, a schematic view of electrical enclosure 72 and SM 32 is shown. SM 32 may include a processor WO 2009/061370 PCT/US2008/012364 22 100 with RAM 102 and ROM 104 disposed on a printed circuit board (PCB)106. Electrical enclosure 72 may be an enclosure for housing electrical terminals 108 connected to an electric motor of compressor 12. Electrical terminals 108 may connect electric power 50 to the electric motor of compressor 12. 5 [00134] Electrical enclosure 72 may include a transformer 49 for converting electric power 50 to a lower voltage for use by SM 32 and CM 30. For example, electric power 51 may be converted by transformer 49 and delivered to SM 32. SM 32 may receive low voltage electric power from transformer 49 through a power input 110 of PCB 106. Electric power may also 10 be routed through electrical enclosure 72 to CM 30 via electrical connection 52. [00135] Voltage sensors 54, 56, 58 may be located proximate each of electrical terminals 108. Processor 100 may be connected to voltage sensors 54, 56, 58 and may periodically receive or sample voltage measurements. Likewise, current sensor 60 may be located proximate one of electrical power 15 leads 116. Processor 100 may be connected to current sensor 60 and may periodically receive or sample current measurements. Electrical voltage and current measurements from voltage sensors 54, 56, 58 and from current sensor 60 may be suitably scaled for the processor 100. [00136] PCB 106 may include a communication port 118 to allow 20 communication between processor 100 of SM 32 and CM 30. A communication link between SM 32 and CM 30 may include an optical isolator 119 to electrically separate the communication link between SM 32 and CM 30 while allowing communication. Optical isolator 119 may be located within electrical enclosure 72. Although optical isolator 119 is independently shown, optical isolator 119 25 may also be located on PCB 106. At least one additional communication port 120 may also be provided for communication between SM 32 and other devices. A handheld or portable device may directly access and communicate with SM 32 via communication port 120. For example, communication port 120 may allow for in-circuit programming of SM 32 a device connected to communication port 30 120. Additionally, communication port 120 may be connected to a network device for communication with SM 32 across a network.

WO 2009/061370 PCT/US2008/012364 23 [00137] Communication with SM 32 may be made via any suitable communication protocol, such as 12C, serial peripheral interface (SPI), RS232, RS485, universal serial bus (USB), or any other suitable communication protocol. 5 [00138] Processor 100 may access compressor configuration and operating data stored in an embedded ROM 124 disposed in a tamper resistant housing 140 within electrical enclosure 72. Embedded ROM 124 may be a compressor memory system disclosed in assignee's commonly-owned U.S. Patent Application No. 11/405,021, filed April 14, 2006, U.S. Patent Application No. 10 11/474,865, filed June 26, 2006, U.S. Patent Application No. 11/474,821, filed June 26, 2006, U.S. Patent Application No. 11/474,798, filed June 26, 2006, or U.S. Patent Application No. 60/674,781, filed April 26, 2005, the disclosures of which are incorporated herein by reference. In addition, other suitable memory systems may be used. 15 [00139] Embedded ROM 124 may store configuration and operating data for compressor 12. When configuration data for compressor 12 is modified, the modified data may likewise be stored in embedded ROM 124. Configuration data for compressor 12 may be communicated to CM 30 or system controller 34. When compressor and/or SM 32 are replaced, the default configuration data for the new 20 compressor 12 may be communicated to CM 30 and/or system controller 34 upon startup. In addition, configuration data may be downloaded remotely. For example, configuration data in embedded ROM 124 may include operating and diagnostic software that may be upgraded via a network connection. In this way, operating and diagnostic software may be upgraded efficiently over the network 25 connection, for example, via the internet. [00140] Relays 126, 127 may be connected to processor 100. Relay 126 may control activation or deactivation of compressor 12. When SM 32 determines that an undesirable operating condition exists, SM 32 may simply deactivate compressor 12 via relay 126. Alternatively, SM 32 may notify CM 30 of the 30 condition so that CM 30 may deactivate the compressor 12. Relay 127 may be connected to a compressor related component. For example, relay 127 may be connected to a crank case heater. SM 32 may activate or deactivate the crank WO 2009/061370 PCT/US2008/012364 24 case heater as necessary, based on operating conditions or instructions from CM 30 or system controller 34. While two relays 126, 127 are shown, SM 32 may, alternatively, be configured to operate one relay, or more than two relays. [00141] Processor 100 and PCB 106 may be mounted within a housing 5 enclosure 130. Housing enclosure 130 may be attached to or embedded within electrical enclosure 72. Electrical enclosure 72 provides an enclosure for housing electrical terminals 108 and transformer 49. Housing enclosure 130 may be tamper-resistant such6A Tt a user of compressor 12 may be unable to inadvertently or accidentally access processor 100 and PCB 106. In this way, SM 32 may 10 remain with compressor 12, regardless of whether compressor 12 is moved to a different location, returned to the manufacturer for repair, or used with a different CM 30. [00142] LED's 131, 132 may be located on, or connected to, PCB 106 and controlled by processor 100. LED's 131, 132 may indicate status of SM 32 or 15 an operating condition of compressor 12. LED's 131, 132 may be located on housing enclosure 130 or viewable through housing enclosure 130. For example, LED 131 may be red and LED 132 may be green. SM 32 may light green LED 132 to indicate normal operation. SM 32 may light red LED 131 to indicate a predetermined operating condition. SM 32 may also flash the LED's 131, 132 to 20 indicate other predetermined operating conditions. [00143] In Figure 7, one current sensor 60 is shown. Additional current sensors may also be used and connected to SM 32. With reference to Figure 8, two current sensors 57, 60 may be used to sense electric current for two phases of electric power 50. When two current sensors 57, 60 are used, electric current 25 for the remaining phase may be estimated based on voltage measurements and based on the current measurements from current sensors 57, 60. With reference to Figure 9, three current sensors 55, 57, 60 may be used to sense electric current for all three phases of electric power 50. [00144] With reference to Figures 10 to 12, in the case of a dual winding 30 three phase electric motor, electrical enclosure 72 may include additional electrical terminals 109 for additional windings. In such case, six electrical terminals 108, 109 may be located within electrical enclosure 72. Three WO 2009/061370 PCTIUS2008/012364 25 electrical terminals 108 may be connected to the three phases of electric power 50 for a first set of windings of the electric, motor of compressor 12. Three additional electrical terminals 109 may also connected to the three phases of electric power 50 for a second set of windings of the electric motor of 5 compressor 12. [00145] Voltage sensors 61, 62, 63 may be located proximate each of electrical terminals 109. Processor 100 may be connected to voltage sensors 61, 62, 63 and may periodically receive or sample voltage measurements. With reference to Figure 10, processor 100 may periodically receive or sample current 10 measurements from a current sensor 64 for sensing electrical current flowing to one of the additional electrical terminals 109. Additional current sensors may also be used. With reference to Figure 11, four current sensors 57, 60, 64, 65 may be connected to processor 100. Two current sensors 57, 60 may be associated with electrical terminals 108 and two current sensors 64, 65 may be 15 associated with electrical terminals 109. With reference to Figure 12, six current sensors 55, 57, 60, 64, 65, 66 may be connected to processor 100. Three current sensors 55, 57, 60 may be associated with electrical terminals 108 and three current sensors 64, 65, 66 may be associated with electrical terminals 109. With six current sensors 55, 57, 60, 64, 65, 66, processor 100 may receive 20 current measurements for each winding of a dual winding three phase electric motor associated with compressor 12. [00146] Processor 100 may sample current and voltage measurements from the various sensors periodically over each cycle of AC power to determine multiple instantaneous current and voltage measurements. For example, 25 processor 100 may sample current and voltage measurements twenty times per cycle or approximately once every millisecond in the case of alternating current with a frequency of sixty mega-hertz. From these actual current and voltage measurements, processor 100 may calculate additional power related data such as true and apparent power, power consumption over time, and power factor. 30 [00147] Based on actual current and voltage measurements, processor 100 may determine a root mean square (RMS) value for voltage and current for each phase of electric power 50. Processor 100 may calculate an RMS voltage WO 2009/061370 PCT/US2008/012364 26 value by squaring each of the sampled voltage measurements, averaging the squared measurements, and calculating the square root of the average. Likewise, processor 100 may calculate an RMS current value by squaring each of the sampled current measurements, averaging the squared measurements, 5 and calculating the square root of the average. [00148] From RMS voltage and RMS current calculations, processor 100 may calculate apparent power (S) according to the following equation: (1) S =VMsx IRWs , where VRMS is the calculated RMS of voltage over at least one cycle of AC and 10 where IRMS is the calculated RMS of current over at least one cycle of AC. Apparent power may be calculated in units of Volt-Amps (VA) or kilo-Volt-Amps (kVA) [00149] Processor 100 may calculate apparent power for each phase of electric power 50. When current sensors 55, 57, 60, 64, 65, 66 are available for 15 all three phases of electric power 50, actual current measurements may be used to calculate apparent power. When current sensors are not available for all three phases, current for a missing phase may be estimated by interpolation from known current and voltage measurements. [00150] Processor 100 may calculate total apparent power (STotal) for an 20 electric motor of compressor 12 based on apparent power calculations for each of the phases, according to the following equation: (2) Sra =VRMS() X RMS(I) + VRMS(2) X 'RMS(2) + RMS( 3 ) X 'RMS(3) where VRMs(1), VRMS(2), and VRMS{3) are the calculated RMS voltage over a cycle of AC for the first, second, and third phase of AC, respectively, and where IRMS(1), 25 IRMS(2), and IRMS(3) are the calculated RMS current a cycle of AC for the first, second, and third phase of AC, respectively. Apparent power is calculated in units of Volt-Amps (VA) or kilo-Volt-Amps (kVA) [00151] Active power (P), in units of watts (W) or kilo-watts (kW) may be calculated as an integral of the product of instantaneous currents and voltages 30 over a cycle of AC, according to the following equation: (3) P = f (v(t)i(t))dt, WO 2009/061370 PCT/US2008/012364 27 where v(t) is instantaneous voltage at time t, in units of volts; where i(t) is instantaneous current at time t, in units of amps; and where T is the period. [00152] Based on the actual instantaneous electrical current and voltage measurements sampled over a cycle of the AC power, processor 100 may 5 calculate (P) as the sum of the products of instantaneous voltage and current samples for each sample interval (e.g., one millisecond), over one cycle of AC. Thus, P may be calculated by processor 100 according to the following equation: (4) P v(k)i(k)At T k-I where v(k) is the instantaneous voltage measurement for the kth sample; i(k) is the 10 instantaneous current measurement for the kth sample; T is the period; and At is the sampling interval (e.g., 1 millisecond). [00153] P may be calculated for each phase of electric power. Processor 100 may calculate a total active power (PTo) by adding the active power for each phase, according to the following equation: 15 (5) Poa =' PO) +Pm2 + P3, Where P(l), P( 2 ), and P(3) are the active power for the first, second, and third phase of AC, respectively. (00154] Based on the active power calculations, processor 100 may calculate energy consumption by calculating an average of active power over 20 time. Energy consumption may be calculated by processor 100 in units of watt hours (WH) or kilo-watt-hours (kWH). [00155] Further, based on the active power calculation and the apparent power calculation, processor 100 may calculate the power factor (PF) according to the following equation: 25 (6) PF= S where P is active power in units of watts (W) or kilo-watts (kW); and where S is apparent power in units of volt-amps (VA) or kilo-volt-amps (kVA). Generally, PF is the ratio of the power consumed to the power drawn. Processor 100 may calculate PF for each phase of electric power. Processor 100 may also calculate WO 2009/061370 PCT/US2008/012364 28 a total PF as a ratio of total actual power to total apparent power, according to the following equation: (7) PF, -TonI STa where Potal and STota are calculated according to formulas 2 and 5 above. 5 [00156] Alternatively, processor 100 may calculate power factor by comparing the zero crossings of the voltage and current waveforms. The processor may use the angular difference between the zero crossings as an estimate of PF. Processor 100 may monitor voltage and current measurements to determine voltage and current waveforms for electric power 50. Based on the 10 measurements, processor may determine where each waveform crosses the zero axis. By comparing the two zero crossings, processor 100 may determine an angular difference between the voltage waveform and the current waveform. The current waveform may lag the voltage waveform, and the angular difference may be used by processor 100 as an estimate of PF. 15 [00157] PF may be used as an indication of the efficiency of the electric motor or the compressor. Increased lag between the current waveform and the voltage waveform results in a lower power factor. A power factor near one, i.e., a unity power factor, is more desirable than a lower power factor. An electric motor with a lower power factor may require more energy to operate, thereby 20 resulting in increased power consumption. [00158] SM 32 may provide continually updated power factor calculations, as well as RMS voltage, RMS current, active power, apparent power, and energy consumption calculations, based on continually sampled instantaneous electrical current and voltage measurements, to CM 30 and/or 25 system controller 34. CM 30 and system controller 34 may utilize the electrical electric power measurements and calculations communicated from SM 32 to control and evaluate efficiency of compressor 12 or refrigeration system 10. [00159] Further, electrical measurements and calculations, including PF, may be accessed by a user through system controller 34 or CM 30. Additionally, 30 electrical measurements and calculations may be accessed through direct communication with SM 32 via communication port 120. Electrical measurements and calculations may be stored and periodically updated in embedded ROM 124.

WO 2009/061370 PCT/US2008/012364 29 [00160] In this way, electrical calculations and measurements, such as RMS voltage, RMS current, active power, apparent power, power factor, and energy calculations may be accurately and efficiently made at the compressor 12 and communicated to other modules or controllers or to a user of the compressor 5 12 or refrigeration system 10 for purposes of evaluating electrical power usage. [00161] In addition to communicating electrical calculations and measurements to other modules, controllers, or users, SM 32 may use the electrical calculations and measurements diagnostically to detect certain variations in operating conditions. SM 32 may alert CM 30 to certain operating conditions 10 based on the electrical calculations and measurements. [00162] Referring now to Figure 13, a flow chart illustrating an operating algorithm 1300 for SM 32 is shown. In step 1301, SM 32 may initialize. Initialization may include resetting counters, timers, or flags, checking and initializing RAM 102, initializing ports, including communication ports 118, 120, 15 enabling communication with other devices, including CM 30, checking ROM 104, checking embedded ROM 124, and any other necessary initialization functions. SM 32 may load operating instructions from ROM 104 for execution by processor 100. [00163] In step 1302, SM 32 may receive actual electrical 20 measurements from connected voltage and current sensors. SM 32 may receive a plurality of instantaneous voltage and current measurements over the course of a cycle of the AC electrical power. SM 32 may buffer the voltage and current measurements in RAM 102 for a predetermined time period. [00164] In step 1304, SM 32 may calculate RMS voltage and RMS 25 current based on the instantaneous voltage and current measurements. Based on the RMS voltage and RMS current calculations, SM 32 may calculate apparent power in step 1304. Based on the instantaneous voltage and current measurements, SM 32 may also calculate active power. Based on the apparent power calculation and the active power calculation, SM 32 may calculate the 30 power factor. SM 32 may also calculate the power factor from the instantaneous voltage and current measurements by examining an angular difference between the zero crossings of the electrical current waveform and the voltage waveform.

WO 2009/061370 PCT/US2008/012364 30 [00165] In step 1306, SM 32 may receive run state data from CM 30. The run state data may include data indicating whether an electric motor of compressor 12 is currently in an activated or deactivated state. The run state data may also include timing data indicating a period of time that the electric 5 motor has been in the current state. If the electric motor is a dual winding three phase electric motor, the run state data may also including data indicating whether one or both of the windings are activated. [00166] In step 1308, based on the electrical measurements and calculations, and based on the data received from CM 30, SM 32 may perform 10 and/or monitor diagnostic algorithms as described in more detail below. Some diagnostic algorithms may be executed once per each iteration of operating algorithm 1300. Some diagnostic algorithms may be executed concurrently with, and monitored by, operating algorithm 1300. [00167] In step 1310, SM 32 may communicate the results of the 15 electrical measurements and calculations to CM 30. SM 32 may also communicate the results of any diagnostic algorithms to CM 30. As described below, SM 32 may set operating flags corresponding to operating conditions according to diagnostic algorithms. SM 32 may communicate any operating flags to CM 30 in step 1310. 20 [00168] In step 1312, SM 32 may receive and respond to communications from CM 30. For example, CM 30 may request particular data from SM 32. CM 30 may also request certain data from embedded ROM 124. CM 30 may update SM 32 with operating parameters or thresholds for use in diagnostic algorithms. CM 30 may direct SM 32 to activate or deactivate any 25 compressor related devices, such as a crank case heater, controlled by SM 32 via relay 127. [00169] After responding to communications from CM 30 in step 1312, SM 32 may loop back to step 1302 and continue operation. [00170] Referring now to Figure 14, a flow chart illustrating an algorithm 30 1400 for SM 32 to detect a no-power condition is shown. The algorithm 1400 may be one of the diagnostic algorithms performed/monitored by SM 32, as WO 2009/061370 PCT/US2008/012364 31 described with reference to step 1308 of Figure 13 above. Prior to execution of the algorithm 1400, a no-power flag may have been reset by SM 32. [00171] In step 1401, SM 32 may determine whether the current run state is set to run, based on run state data received from CM 30, as described 5 with reference to step 1306 of Figure 13 above. When the run state is not set to run, compressor 12 is not activated, and SM 32 may end execution of the algorithm in step 1402. [00172] When the run state is set to run, SM 32 may. proceed to step 1404 and check voltage measurements. When three phase power is used, SM 10 32 may check each of three voltage measurements, V1, V2, and V 3 . SM 32 may determine whether V1, V2, and V3 are less than a minimum voltage threshold, Vmin.i. In step 1404, when V1, V2, and V 3 are greater than or equal to Vmin-14, SM 32 may determine that compressor 12 has sufficient power, and end execution of algorithm 1400 in step 1402. 15 [00173] In step 1404, when SM 32 determines that V1, V 2 , and V3 are less than Vmi- 4 , SM 32 may proceed to step 1406. In step 1406, SM 32 may determine whether the time since the compressor 12 was activated is greater than a time threshold, Tmnr.14. For example, Tmmr-14 may be set to two seconds. In this way, SM 32 may allow for any bounce of any contactor coil 20 relays. In step 1406, when the time since compressor activation is not greater than Tmmr.

1 4 , SM 32 may return to step 1401. [00174] In step 1406, when the time since compressor activation is greater than TMmr- 14 , SM 32 may proceed to step 1408. In step 1408, SM 32 may set a no-power flag. By setting the no-power flag, SM 32 may indicate that 25 compressor 12 does not have sufficient electrical power to operate. The no power flag may be communicated to, or detected by, CM 30 and/or system controller 34. CM 30 and/or system controller 34 may adjust compressor and refrigeration system operation accordingly. [00175] Referring now to Figure 15, a flow chart illustrating an algorithm 30 1500 for SM 32 to detect a welded contactor condition is shown. The algorithm 1500 may be one of the diagnostic algorithms performed / monitored by SM 32, as described with reference to step 1308 of Figure 13 above. Prior to execution WO 2009/061370 PCT/US2008/012364 32 of the algorithm 1500, a welded-contactor flag may have been reset by SM 32. A welded contactor may cause compressor 12 to continue to operate, even though SM 32 or CM 30 may have attempted to open a contactor to deactivate the compressor. 5 [00176] In step 1501, SM 32 may determine whether the current run state is set to run, based on run state data previously received from CM 30, as described with reference to step 1306 of Figure 13 above. When the run state is set to run, the compressor 12 is activated, and SM 32 may end execution of the algorithm in step 1502. 10 [00177] When the run state is not set to run, SM 32 may proceed to step 1504 and check voltage measurements. When three phase power is used, SM 32 may check each of three voltage measurements, V 1 , V 2 , and V 3 . SM 32 may determine whether voltages V 1 , V 2 , or V 3 are greater than a maximum voltage threshold, Vmax-15. In step 1504, when V 1 , V 2 , or V 3 are not greater than 15 or equal to Vmax.15, SM 32 may determine that a welded contactor condition does not exist, and end execution of the algorithm in step 1502. [00178] When V 1 , V 2 , or V 3 are greater than Vmax.15, SM 32 may proceed to step 1506. In step 1506, SM 32 may determine whether the time since compressor 12 was deactivated is greater than a time threshold, Tmmr-1. For 20 example, Tmmr.

15 may be set to two seconds. By waiting for the Tmmr- 15 , SM 32 may allow for any bounce of any contactor coil relays. In step 1506, when the time since compressor deactivation is not greater than Tmmr-15, SM 32 may return to step 1501. [00179] In step 1506, when the time since compressor deactivation is 25 greater than TMIr-1 5 , SM 32 may proceed to step 1508. In step 1508, SM 32 may set a welded-contactor flag. By setting the welded-contactor flag, SM 32 may indicate that compressor 12 may have at least one welded contactor. In such case, power may be delivered to compressor 12, due to the welded contactor, despite the attempt of CM 30 or SM 32 to deactivate compressor 12. 30 The welded-contactor flag may be communicated to, or detected by, CM 30 and/or system controller 34. CM 30 and/or system controller 34 may adjust compressor and refrigeration system operation accordingly. Specifically, CM 30 WO 2009/061370 PCT/US2008/012364 33 may activate compressor 12 while it is in the welded-contactor state to avoid a voltage imbalance condition and prevent damage or overheating of compressor 12. Further, CM 30 or system controller 34 may notify a user that compressor 12 is being operated in a welded-contactor state. 5 [00180] Referring now to Figure 16, a flow chart illustrating an algorithm 1600 for SM 32 to detect a locked rotor condition is shown. Algorithm 1600 may be one of the diagnostic algorithms performed / monitored by SM 32, as described with reference to step 1308 of Figure 13 above. In a locked rotor condition, a rotor of the electric motor may be seized. Normally, when an electric 10 motor is activated, electric current of the motor (1) increases for an initial period during startup, and then decreases as the motor reaches operating speed. If, however, the rotor is seized, I will not decrease after the initial period. Prior to execution of the algorithm 1600, a locked-rotor flag may have been reset by SM 32. 15 [00181] In step 1601, SM 32 may buffer electrical current measurements for a predetermined buffer period. For example, SM 32 may buffer electrical current measurements for 200 ms. [00182] In step 1602, SM 32 may determine whether I is greater than a minimum electric current threshold (Imin.1). When I is not greater than min.16, SM 20 32 may loop back to step 1601 and continue to buffer 1. In step 1602, when SM 32 determines that I is greater than min-1, SM 32 may proceed to step 1604. [00183] In step 1604, SM 32 may determine the greatest I value currently in the buffer (Igrit.16). In step 1606, SM 32 may determine whether Igrst is greater than an electric current threshold (ima-1e). SM 32 may then wait in 25 steps 1608 and 1610 for a time threshold (TMmr.

1 6 ) to expire. For example, TmTmr-16 may be set to two seconds. In this way, SM 32 allows I to settle to a normal operating current if the electric motor does not have a locked rotor. [00184] When Iri.16 is greater than Ima.16 in step 1606, then in step 1612, SM 32 may use Ima.1e as the current threshold. In step 1612, when I is 30 greater than Imax-16, SM 32 may determine that a locked rotor condition exists and may proceed to step 1614 to set the locked-rotor flag. In step 1612, when I is not greater than Imx16, SM 32 may end execution of the algorithm in step 1616.

WO 2009/061370 PCTIUS2008/012364 34 [00185] In step 1606, when 1grt,.1e is not greater than Imax-16, SM 32 may use a predetermined percentage (X%) of Iftt-.1 as the current threshold in step 1618. In step 1618, when ltr16 is greater than X% of lgrstt-1, SM 32 may determine that a locked rotor condition exists and may set the locked-rotor flag in 5 step 1614. SM 32 may end execution of the algorithm in step 1616. The locked rotor flag may be communicated to, or detected by, CM 30 and/or system controller 34. CM 30 and/or system controller 34 may adjust compressor and refrigeration system operation accordingly. [00186] If a locked-rotor condition is detected a predetermined number 10 of consecutive times, SM 32 may set a locked rotor lockout flag. SM 32 may cease operation of the compressor until the lockout flag is cleared by a user. For example, SM 32 may set the locked rotor lockout flag when it detects ten consecutive locked rotor conditions. [00187] Referring now to Figure 17, a flow chart illustrating an algorithm 15 1700 for SM 32 to detect a motor protection trip is shown. Algorithm 1700 may be one of the diagnostic algorithms performed / monitored by SM 32, as described with reference to step 1308 of Figure 13 above. Compressor 12 may be configured with internal line breaks. The internal line breaks may trip, or deactivate, compressor 12 when electric current is excessive or when 20 compressor 12 is overheating. In such case, SM 32 may detect that an internal line break has occurred and notify CM 30. Prior to execution of the algorithm 1700, a protection-trip flag may have been reset by SM 32. [00188] In step 1701, SM 32 determines whether any voltage, V 1 , V 2 , or

V

3 is greater than a voltage minimum threshold (Vmin-17). When V1, V 2 , or V 3 is 25 not greater than Vmin-17, SM 32 may end execution of algorithm 1700 in step 1702. When V 1 , V 2 , or V 3 is greater than Vmin- 1 7 , SM 32 may proceed to step 1704. In step 1704, SM 32 may determine whether I is less than a current minimum In17. When I is not less than Imin-17, SM 32 may end execution of algorithm 1700 in step 1702. When I is less than Imnl-17, SM 32 may proceed to 30 step 1706 and set a protection-trip flag. In this way, when voltage is present, but electric current is not present, SM 32 may determine that an intemal line break condition has occurred. The protection-trip flag may be communicated to, or WO 2009/061370 PCT/US2008/012364 35 detected by, CM 30 and/or system controller 34. CM 30 and/or system controller 34 may adjust compressor 12 and refrigeration system 10 operation accordingly. [00189] Referring now to Figure 18, a flow chart illustrating an algorithm 1800 for SM 32 to detect a low voltage condition is shown. Algorithm 1800 may 5 be one of the diagnostic algorithms performed / monitored by SM 32, as described with reference to step 1308 of Figure 13 above. Prior to execution of the algorithm 1800, a low-voltage flag may have been reset by SM 32. [00190] In step 1801, SM 32 may determine the normal operating voltage of compressor (Vnmi). SM 32 may determine Vam, based on historical 10 data of previous compressor operating voltages. For example, Vnmi may be calculated by averaging the voltage over the first five electrical cycles of power during the first normal run. Vnmi may alternatively be predetermined and stored in ROM 104, 124, or calculated based on an average voltage over the operating life of the compressor. 15 [00191] In step 1802, SM 32 may monitor V 1

,

2 , and 3 for a predetermined time period TMthr-18. For example, TmThr.18 may be set to two seconds. The time threshold may or may not be the same as the time threshold used in other diagnostic algorithms. In step 1804, SM 32 may determine whether V 1 , 2 , and 3 are less than a predetermined percentage (X%) of Vnm, for more than TMihr-1 8 . For 20 example, the predetermined percentage may be 75 percent. In step 1804, when

V

1 , 2, and 3 are not less than X% of Vnmi for more than TMthr18, SM 32 loops back to step 1802. In step 1804, when V 1 , 2, and 3 are less than X% of Vnmi for more than TMti,1, SM 32 may proceed to step 1806. [00192] In step 1806, SM 32 may determine whether the run state is set 25 to run. When the run state is not set to run in step 1806, SM 32 ends execution of algorithm 1800 in step 1808. When the run state is set to run, SM 32 may determine that a low-voltage condition exists and may set a low-voltage flag in step 1810. The low-voltage flag may be communicated to, or detected by, CM 30 and/or system controller 34. CM 30 and/or system controller 34 may adjust 30 compressor 12 and refrigeration system 10 operation accordingly. [00193] Referring now to Figure 19, a flow chart illustrating an algorithm 1900 for SM 32 to detect a phase loss condition for compressor 12, when three WO 2009/061370 PCT/US2008/012364 36 phase electric power 50 is used. Algorithm 1900 may be one of the diagnostic algorithms performed / monitored by SM 32, as described with reference to step 1308 of Figure 13 above. SM 32 may compare each voltage, V1, V 2 , and V 3 , to determine whether any particular voltage is lower than a predetermined 5 percentage of the average of the other two voltages. Prior to execution of the algorithm 1900, a phase-loss flag may have been reset by SM 32 [00194] In step 1901, SM 32 may Monitor V1, V 2 , and V 3 . In step 1902, SM 32 may determine whether V 1 is less than a predetermined percentage, X%, of the average of V 2 and V 3 , for a time (Tm) greater than a time threshold, Tm-rr 10 1g. When V 1 is less than X% of the average of V 2 and V 3 , SM 32 may set the phase-loss flag in step 1904 and end execution of algorithm 1900 in step 1906. When V 1 is not less than X% of the average of V 2 and V 3 , SM 32 may proceed to step 1908. [00195] In step 1908, SM 32 may determine whether V 2 is less than X% 15 of the average of V 1 and V 3 .for Tm greater than Tmmr.19. When V 2 is less than X%, of the average of V 1 and V 3 , SM 32 may set the phase-loss flag in step 1904 and end execution of algorithm 1900 in step 1906. When V 2 is not less than X% of the average of V 1 and V 3 , SM may proceed to step 1910. [00196] In step 1910, SM 32 may determine whether V 3 is less than X% 20 of the average of V 1 and V 2 , for Tm greater than Tmmhr-19. When V 3 is less than X%, of the average of V 1 and V 2 , SM 32 may set the phase-loss flag in step 1904 and end execution of algorithm 1900 in step 1906. When V 3 is not less than X% of the average of V 1 and V 2 , SM 32 may loop back to step 1901. In this way, algorithm 1900 may operate concurrently with algorithm 1300. The phase-loss 25 flag may be communicated to, or detected by, CM 30 and/or system controller 34. CM 30 and/or system controller 34 may adjust compressor 12 and refrigeration system 10 operation accordingly. [00197] If a phase-loss condition is detected a predetermined number of consecutive times, SM 32 may set a phase-loss lockout flag. SM 32 may cease 30 operation of the compressor until the lockout flag is cleared by a user. For example, SM 32 may set the phase-loss lockout flag when it detects ten consecutive phase-loss conditions.

WO 2009/061370 PCT/US2008/012364 37 [00198] Referring now to Figure 20, a flow chart illustrating an algorithm 2000 for SM 32 to detect a voltage imbalance condition for compressor 12, when three phase electric power 50 is used. Algorithm 2000 may be one of the diagnostic algorithms performed / monitored by SM 32, as described with 5 reference to step 1308 of Figure 13 above. SM 32 may determine whether the difference between any of voltages V 1 , V 2 , or V 3 is greater than a predetermined percentage of the average of V 1 , V 2 , and V 3 . When the difference between any of voltages V 1 , V 2 , or V 3 is greater than a predetermined percentage of the average of V 1 , V 2 , and V 3 , SM 32 may determine that a voltage imbalance 10 condition exists. Prior to execution of the algorithm 2000, a voltage-imbalance flag may have been reset by SM 32 [00199] In step 2001, SM 32 may monitor V 1 , V 2 , and V 3 . In step 2002, SM 32 may calculate the average (Vavg) of V 1 , V 2 , and V 3 . In step 2004, SM 32 may calculate the percentage of voltage imbalance (%Vmb) by determining the 15 maximum of the absolute value of the difference between each of V, and Vavg, V 2 and Vavg, and V 3 and Vavg. The maximum difference is then multiplied by Vavg/1 00. [00200] In step 2006, SM 32 determines whether the run state is set to run. In step 2006, when the run state is not set to run, SM 32 may end execution 20 of algorithm 2000 in step 2008. In step 2006, when the run state is set to run, SM 32 may proceed to step 2010. [00201] In step 2010, SM 32 may determine whether %Vimb is greater than a voltage imbalance threshold (%Vm,.

2 0). When %Vimb is not greater than %Vmr- 20 , SM 32 loops back to step 2001. In this way, algorithm 2000 may 25 execute concurrently with operating algorithm 1300. When %Vmb is greater than %VThr-2o, a voltage imbalance condition exists, and SM 32 may set the voltage imbalance flag in step 2012. SM 32 may end execution of algorithm 2000 in step 2008. The voltage-imbalance flag may be communicated to, or detected by, CM 30 and/or system controller 34. CM 30 and/or system controller 34 may adjust 30 compressor 12 and refrigeration system 10 operation accordingly. [00202] Referring now to Figure 21, a flow chart illustrating an algorithm 2100 for SM 32 to detect a current overload condition is shown. Algorithm 2100 WO 2009/061370 PCT/US2008/012364 38 may be one of the diagnostic algorithms performed / monitored by SM 32, as described with reference to step 1308 of Figure 13 above. Prior to execution of the algorithm 2100, a current-overload flag may have been reset by SM 32 [00203] In step 2101, SM 32 may determine the maximum continuous 5 current (MCC) for the electric motor of compressor 12. MCC may be predetermined and set during the manufacture of compressor 12. MCC may be stored in ROM 104 and/or embedded ROM 124. In addition, MCC may be user configurable. MCC may vary based on the type of refrigerant used. Thus, a user of compressor 12 may modify the default MCC value to conform to actual 10 refrigeration system conditions. [00204] In step 2102, SM 32 may determine whether the run state is set to run. When the run state is not set to run, SM 32 ends execution of algorithm 2100 in step 2104. In step 2102, when the run state is set to run, SM 32 may proceed to step 2106. In step 2106, when run state has not been set to run for a 15 time period greater than a first time threshold (TMnri-21), SM 32 loops back to step 2102. In step 2106, when run state has been set to run for a time period greater than TMnr1.21, SM 32 may proceed to step 2108. [00205] In step 2108, SM 32 monitors 1. In step 2110, SM 32 may determine whether I is greater than MCC multiplied by 1.1. In other words, SM 20 32 may determine whether I is greater than 110% of MCC for a time greater than a second time threshold (TMma-21). When SM 32 determines that I is not greater than 110% of MCC for a time greater than TMa-21, SM 32 may loop back to step 2102. In this way, algorithm 2100 may execute concurrently with operating algorithm 1300. When SM 32 determines that I is greater than 110% of MCC for 25 a time greater than TMa.- 21 , SM 32 may determine that a current-overload condition exists and may set the current-overload flag in step 2112. SM 32 may end execution of the algorithm 2100 in step 2104. The current-overload flag may be communicated to, or detected by, CM 30 and/or system controller 34. CM 30 and/or system controller 34 may adjust compressor and refrigeration system 30 operation accordingly. [00206] Referring now to Figure 22, a flow chart illustrating an algorithm 2200 for SM 32 to detect a current delay condition, in a two current sensor WO 2009/061370 PCT/US2008/012364 39 system; to detect a lag between two electrical currents 11 and 12. Algorithm 2200 may be one of the diagnostic algorithms performed / monitored by SM 32, as described with reference to step 1308 of Figure 13 above. Prior to execution of the algorithm, a current-delay flag may have been reset by SM 32. 5 [00207] When SM 32 detects current greater than a current threshold (Imin-22) from one of the two current sensors, SM 32 may determine whether current indicated by the other current sensor becomes greater than Imin. within a time period threshold (Tmm.22). In step 2201, SM 32 may determine whether 11 is greater than a current threshold Imin-22. When 11 is greater than Imin22, SM 32 10 may proceed to step 2203 and start a time counter (Tm). SM 32 may proceed to step 2205 to determine whether 12 is greater than lmin,2. In step 2205, when 12 is greater than min.2, SM 32 may determine that a current-delay condition does not exist, and end execution of the algorithm in step 2210. In step 2205, when 12 is not greater than ImIn-a, SM 32 may proceed to step 2207 and determine whether 15 Tm is greater than Tmm-22. In step 2207, when TM is not greater than TMThr-22, SM 32 may loop back to step 2205 to compare 12 with lmin.22. In step 2207, when Tm is greater than Tmmr.2, the time period has expired and a current-delay condition exists. SM 32 may proceed to step 2209 to set a current-delay flag. SM 32 may end execution of the algorithm 2200 in step 2210. The current-delay 20 flag may be communicated to, or detected by, CM 30 and/or system controller 34. CM 30 and/or system controller 34 may adjust compressor and refrigeration system operation accordingly. [00208] When 11 is not greater than Imin-22, SM 32 may proceed to step 2202 and determine whether 12 is greater than Imin22. When 12 is not greater than 25 lmin-2, SM 32 loops back to step 2201. When 12 is greater than Imin2, SM 32 may proceed to step 2204 to start time Tm counter. SM 32 may proceed to step 2206 to determine whether 11 is greater than min.2. In step 2206, when 11 is greater than In22, SM 32 may determine that a current-delay condition does not exist, and end execution of the algorithm in step 2210. In step 2206, when 11 is not 30 greater than Imin-., SM 32 may proceed to step 2208 and determine whether Tm is greater than Tmm,.2. In step 2208, when TM is not greater than TMr.

22 , SM 32 may loop back to step 2206 to compare 11 with 1mn-2. In step 2208, when Tm WO 2009/061370 PCT/US2008/012364 40 is greater than Tmmr.22, the time period has expired and a current-delay condition exists. SM 32 may proceed to step 2209 to set the current-delay flag. SM 32 may end execution of the algorithm 2200 in step 2210. As noted above, the current-delay flag may be communicated to, or detected by, CM 30 and/or 5 system controller 34, which may adjust compressor and refrigeration system operation accordingly. [00209] Referring now to Figure 23, a flow chart illustrating an algorithm 2300 for SM 32 to detect a current delay condition is shown, in a three current sensor system, to detect a lag between three electrical currents 11, 12, and 13. 10 Algorithm 2300 may be one of the diagnostic algorithms performed / monitored by SM 32, as described with reference to step 1308 of Figure 13 above. Prior to execution of the algorithm, a current-delay flag may have been reset by SM 32. [00210] When SM 32 detects current greater than a current threshold (Imin.2) from one of the three current sensors, SM 32 may determine whether 15 current indicated by the other current sensors becomes greater than Imin-2 within a predetermined time period (Tmmr.

22 ). In step 2301, SM 32 may determine whether 11 is greater than a current threshold Imin-2. When 11 is greater than Imn u, SM 32 may proceed to step 2302 and start a time counter (Tm). SM 32 may proceed to step 2303 to determine whether 12 and 13 are greater than min-2. In 20 step 2303, when 12 and 13 are greater than Imin*2, SM 32 may determine that a current-delay condition does not exist, and end execution of the algorithm in step 2304. In step 2303, when 12 and 13 are not greater than lmin-2, SM 32 may proceed to step 2305 and determine whether Tm is greater than Tmar.2. In step 2305, when TM is not greater than TM.

22 , SM 32 may loop back to step 2303 25 to compare 12 and 13 with Imin2-. In step 2305, when Tm is greater than Tmar- 22 , the time period has expired and a current-delay condition exists. SM 32 may proceed to step 2306 to set a current-delay flag. SM 32 may end execution of the algorithm 2300 in step 2304. The current-delay flag may be communicated to, or detected by, CM 30 and/or system controller 34. CM 30 and/or system 30 controller 34 may adjust compressor and refrigeration system operation accordingly.

WO 2009/061370 PCT/US2008/012364 41 [00211] In step 2301, when I is not greater than lmin.22, SM 32 may proceed to step 2307 and determine whether 12 is greater than Imin-.. When 12 is greater than Imin-2, SM 32 may proceed to step 2308 to start Tm counter. SM 32 may proceed to step 2309 to determine whether 11 and 13 are greater than Imin-2. 5 In step 2309, when 11 and 13 are greater than lmin-22, SM 32 may determine that a current-delay condition does not exist, and end execution of the algorithm in step 2304. In step 2309, when 11 and 13 are not greater than lIn-2, SM 32 may proceed to step 2310 and determine whether Tm is greater than Tmmh2. In step 2310, when TM is not greater than TMTh-22, SM 32 may loop back to step 2309 10 to compare 11 and 13 with Imin-22. In step 2310, when Tm is greater than Tmh.2, the time period has expired and a current-delay condition exists. SM 32 may proceed to step 2306 to set the current-delay flag. SM 32 may end execution of the algorithm 2300 in step 2304. As noted above, the current-delay flag may be communicated to, or detected by, CM 30 and/or system controller 34, which may 15 adjust compressor and refrigeration system operation accordingly. [00212] In step 2307, when 12 is not greater than mn-2, SM 32 may proceed to step 2311 and determine whether 13 is greater than Imin-22. When 13 is not greater than lmin-m, SM 32 may loop back to step 2301. When 13 is greater than Imn-22, SM 32 may proceed to step 2312 to start Tm counter. SM 32 may 20 proceed to step 2313 to determine whether 11 and 12 are greater than Imin-22. In step 2313, when 11 and 12 are greater than Imin-22, SM 32 may determine that a current-delay condition does not exist, and end execution of the algorithm in step 2304. In step 2313, when 11 and 12 are not greater than Imin-22, SM 32 may proceed to step 2314 and determine whether Tm is greater than Trmr.2. In step 25 2314, when TM is not greater than TMmr-2, SM 32 may loop back to step 2313 to compare 11 and 12 with Imin-22. In step 2314, when Tm is greater than Tmrh.2, the time period has expired and a current-delay condition exists. SM 32 may proceed to step 2306 to set the current-delay flag. SM 32 may end execution of the algorithm 2300 in step 2304. As noted above, the current-delay flag may be 30 communicated to, or detected by, CM 30 and/or system controller 34, which may adjust compressor and refrigeration system operation accordingly.

C :NRPonblDCCIXI'679%67 I.DOC-10/l17/2012 -42 1002131 With respect to each of the diagnostic algorithms described above with reference to Figures 14 to 23, SM 32 may selectively execute the diagnostic algorithms as needed and as data for the diagnostic algorithms is available. When a communication link is not available, or when data from a connected sensor is not available, due to malfunction or 5 otherwise, SM 32 may disable those portions of the diagnostic algorithms that require the missing communication link or data. In this way, SM 32 may execute those portions of the diagnostic algorithms that are executable, based on the data and communication link(s) available to SM 32. 10 1002141 In this way, SM 32 may monitor electrical current and voltage measurements, make data calculations based on the electrical current and voltage measurements, and execute diagnostic algorithms based on the measurements and based on the calculations. SM 32 may communicate the measurements, the calculations, and the results of the diagnostic algorithms to CM 30 or system controller 34. SM 32 may thereby be able to 15 provide efficient and accurate electrical power measurements and calculations to be utilized by other modules and by users to evaluate operating conditions, power consumption, and efficiency. 100215] Throughout this specification and the claims which follow, unless the context 20 requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps. 25 [00216] The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates.

Claims (25)

1. A sensor module for a compressor having an electric motor connected to a power supply that includes first, second, and third phases, the sensor module comprising: 5 a first input connected to a first voltage sensor that generates a first voltage signal corresponding to a voltage of said first phase of said power supply; a second input connected to a second voltage sensor that generates a second voltage signal corresponding to a voltage of said second phase of said power supply; a third input connected to a third voltage sensor that generates a third voltage signal 10 corresponding to a voltage of said third phase of said power supply; a fourth input connected to a current sensor that generates a current signal corresponding to a current of said first phase of said power supply; a processor connected to said first, second, third, and fourth inputs that calculates a first estimated current corresponding to a current of said second phase of said power 15 supply and a second estimated current corresponding to a current of said third phase of said power supply based on voltage measurements from said first, second, and third inputs and current measurements from said fourth input, and that calculates a power factor of said compressor based on said voltage measurements from said first, second, and third inputs, said current measurements from said fourth input, and said first and second estimated 20 currents.

2. The sensor module of claim 1 wherein said processor is disposed within a tamper resistant enclosure within said electrical enclosure. 25

3. The sensor module of claim 1 wherein said processor calculates an active power and an apparent power of said compressor based on said voltage measurements from said first, second, and third inputs, said current measurements from said fourth input, and said first and second estimated currents, and calculates said power factor according to a ratio of said active power to said apparent power. 30 H:\dxl\lnterwoven\NRPortbl\DCC\DXL\6345844_I.doc-20/05/2014 -44

4. The sensor module of claim 1 wherein said processor determines a voltage waveform based on said voltage measurements from said first, second, and third inputs and a current waveform based on said current measurements from said fourth input and said first and second estimated currents, and calculates said power factor according to an 5 angular difference between said current waveform and said voltage waveform.

5. The sensor module of claim 1 wherein said processor calculates a power consumption of said compressor based on said voltage measurements from said first, second, and third inputs, said current measurements from said fourth input, and said first 10 and second estimated currents.

6. The sensor module of claim 5 wherein said processor calculates an active power of said compressor based on said voltage measurements from said first, second, and third inputs, said current measurements from said fourth input, and said first and second 15 estimated currents, and calculates said power consumption by averaging said active power over a time period.

7. The sensor module of claim 1 further comprising a communication port for communicating information from said sensor module to at least one of: a control module 20 for said compressor, a system controller for a system associated with said compressor, a portable computing device, and a network device.

8. The sensor module of claim 7 wherein said information includes at least one of: said power factor, a calculated active power, a calculated apparent power, and a calculated 25 power consumption of said compressor.

9. The sensor module of claim 1 wherein said processor calculates an active power and an apparent power of said compressor based on said voltage measurements from said first, second, and third inputs, said current measurements from said fourth input, and said 30 first and second estimated currents and calculates said power factor according to a ratio of said active power to said apparent power. H:\dxl\lntrovn\NRPortbl\DCC\DXL\6345844_I.doc-20/05/2014 - 45

10. For a sensor module of a compressor having an electric motor connected to a power supply that includes first, second, and third phases, a method comprising: receiving, with a processor of the sensor module, first voltage measurements from a 5 first voltage sensor that generates a first voltage signal corresponding to a voltage of said first phase of said power supply; receiving, with said processor, second voltage measurements from a second voltage sensor that generates a second voltage signal corresponding to a voltage of said second phase of said power supply; 10 receiving, with said processor, third voltage measurements from a third voltage sensor that generates a third voltage signal corresponding to a voltage of said third phase of said power supply; receiving, with said processor, current measurements from a current sensor that generates a current signal corresponding to a current of said first phase of said power 15 supply; calculating, with said processor, a first estimated current corresponding to a current of said second phase of said power supply and a second estimated current corresponding to a current of said third phase of said power supply, based on said first, second, and third voltage measurements, and said current measurements; 20 calculating, with said processor, a power factor of said compressor based on said first, second, and third voltage measurements, said current measurements, and said first and second estimated currents; generating an output, with said processor, based on said power factor. 25

11. The method of claim 10 wherein said calculating said power factor comprises: calculating an active power and an apparent power of said compressor based on said first, second, and third voltage measurements, and said current measurements, and said first and second estimated currents; calculating said power factor according to a ratio of said active power to said 30 apparent power. H:\dxl\lntrovn\NRPortbl\DCC\DXL\6345844_I.doc-20/05/2014 - 46

12. The method of claim 10 wherein said calculating said power factor comprises: determining a voltage waveform based on said first, second, and third voltage measurements; determining a current waveform based on said current measurements and said first 5 and second estimated currents; calculating said power factor according to an angular difference between said current waveform and said voltage waveform.

13. The method of claim 10 further comprising: 10 calculating a power consumption of said compressor based on said first, second, and third voltage measurements, said current measurements, and said first and second estimated currents.

14. A sensor module, substantially as hereinbefore described with reference to the 15 accompanying drawings; or a method, substantially as hereinbefore described with reference to the accompanying drawings.

15 A system comprising: a compressor having an electric motor connected to a power supply; 20 an electrical enclosure attached to an exterior of the compressor, the electrical enclosure being configured to receive electrical leads of the power supply, to house electrical terminals that connect the electrical leads of the power supply to the electric motor, and to house a voltage sensor that generates a voltage signal corresponding to a voltage of the power supply and a current sensor that generates a current signal 25 corresponding to a current of the power supply; the sensor module of claim 1, located within the electrical enclosure, comprising a communication port connected to the processor; a control module at a different location from the sensor module and outside of the electrical enclosure; 30 a communication link connected to the control module and the sensor module to allow communication between the control module and the sensor module; H:\dxl\lntrovn\NRPortbl\DCC\DXL\6345844_I.doc-20/05/2014 -47 wherein the sensor module communicates data based on the electrical power measurements to the control module over the communication link and the control module controls operation of the compressor based on the data received from the sensor module. 5

16. The system of claim 15, wherein the control module is mounted to the exterior of the compressor.

17. The system of claim 15, wherein the communication link includes an optical isolator that electrically separates the sensor module and the control module while 10 allowing communication between the sensor module and the control module.

18. The system of claim 15, wherein the sensor module determines that at least one of an excessive current condition and an excessive voltage condition exists based on the electrical power measurements and communicates an alert to the control module based on 15 at least one of the excessive current condition and the excessive voltage condition and wherein the control module deactivates the compressor based on the alert.

19. The system of claim 15, wherein the sensor module determines that at least one of a deficient current condition and a deficient voltage condition exists based on the electrical 20 power measurements and communicates an alert to the control module based on at least one of the deficient current condition and the deficient voltage condition and wherein the control module deactivates the compressor based on the alert.

20. The system of claim 15, wherein the sensor module determines at least one of a 25 current imbalance condition, a voltage imbalance condition, a loss of phase condition, and a current delay condition exists based on the electrical power measurements and communicates an alert to the control module based on at least one of the current imbalance condition, the voltage imbalance condition, the loss of phase condition, and the current delay condition and wherein the control module deactivates the compressor based on the 30 alert. H:\dxl\lntrovn\NRPortbl\DCC\DXL\6345844_I.doc-20/05/2014 -48

21. The system of claim 15, wherein the sensor module determines that a locked rotor condition exists based on the electrical power measurements and communicates an alert to the control module based on the locked rotor condition and wherein the control module deactivates the compressor based on the alert. 5

22. The system of claim 15, wherein the sensor module determines that a welded contactor condition exists based on the electrical power measurements and communicates an alert to the control module based on the welded contactor condition and wherein the control module activates the compressor based on the alert. 10

23. The system of claim 15, wherein the sensor module determines that an internal line break condition exists based on the electrical power measurements and communicates an alert to the control module based on the internal line break condition and wherein the control module deactivates the compressor based on the alert. 15

24. The system of claim 15, wherein the control module is in communication with a system controller, wherein the sensor module calculates a power factor of the compressor based on voltage measurements from the first input and current measurements from the second input and communicates the power factor to the control module and wherein the 20 system controller communicates the power factor to the system controller.

25. The system of claim 15, wherein the control module is in communication with a system controller, wherein the sensor module communicates the power factor to the control module, and wherein at least one of the control module and the system controller evaluate 25 efficiency of the compressor based on the power factor.