Patent Publication Number: US-11641079-B2

Title: Mistake-proof electrical connectors for HVAC systems

Description:
BACKGROUND 
     The present disclosure relates generally to heating, ventilation, and/or air conditioning (HVAC) systems, and more particularly to mistake-proof electrical connectors for compressors of HVAC systems. 
     Residential, light commercial, commercial, and industrial HVAC systems are used to control temperatures and air quality in residences and buildings. Generally, an HVAC system may include a compressor to circulate a refrigerant through a closed refrigeration circuit that includes an evaporator, where the refrigerant absorbs heat, and a condenser, where the refrigerant releases heat. The compressor utilizes electrical power to energize a motor that increases a pressure and/or a temperature of the refrigerant received from the evaporator and directed to the condenser. As such, the refrigerant flows within the refrigerant circuit and undergoes phase changes within normal operating temperatures and pressures of the HVAC system to enable an interior space to be conditioned to occupant specifications. 
     In certain embodiments, the compressor includes a shell, the motor within the shell, and a terminal assembly mounted within an opening of the shell. An interior portion of the terminal assembly may be electrically connected to the motor, while an exterior portion of the terminal assembly may include terminal posts designed to be coupled to a power source. The terminal posts may be individually coupled to specific lead wires or, alternatively, coupled to an electrical connector or wiring harness that positions multiple lead wires for simultaneous and efficient assembly. However, because the terminal posts may be symmetrically distributed relative to one another, the electrical connector may be aligned with and coupled to the terminal assembly in multiple positions. Unfortunately, only one position of the multiple positions correctly supplies the proper electrical power to the motor, without negatively affecting operation of the compressor. 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure and are described below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be noted that these statements are to be read in this light, and not as admissions of prior art. 
     SUMMARY 
     A summary of certain embodiments disclosed herein is set forth below. It should be noted that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below. 
     In one embodiment of the present disclosure, an electrical connector for a compressor of a heating, ventilation, and/or air conditioning (HVAC) system includes a plurality of electrical leads extending from a portion of the HVAC system and a plug communicatively coupled to the plurality of electrical leads. The plug includes a plug body and a plurality of first connectors configured to electrically couple the plurality of electrical leads to a plurality of second connectors of the compressor via engagement of the plurality of first connectors with the plurality of second connectors. The plurality of first connectors is symmetrically distributed on the plug body such that the plurality of first connectors can align with the plurality of second connectors in a plurality of alignment orientations of the plurality of first connectors and the plurality of second connectors. The plug also includes at least one interference projection radially extending from a periphery of the plug body. The at least one interference projection is configured to physically interfere with a positioning guide of the compressor and block engagement between the plurality of first connectors and the plurality of second connectors in all except for one alignment orientation of the plurality of alignment orientations. 
     In another embodiment of the present disclosure, an electrical connector for a compressor of a heating, ventilation, and/or air conditioning (HVAC) system includes a plurality of electrical leads configured to supply power to the compressor and a plug communicatively coupled to the plurality of electrical leads. The plug includes a plug body and a connector cavity assembly formed in the plug body and configured to electrically couple the plurality of electrical leads to a terminal post assembly of the compressor. The connector cavity assembly includes at least one axis of symmetry to enable the connector cavity assembly to align with the terminal post assembly in a plurality of alignment orientations. The plug also includes at least one interference projection radially extending from a periphery of the plug body. The at least one interference projection is configured to physically interfere with a stud of the compressor in all except for one alignment orientation of the plurality of alignment orientations. 
     In a further embodiment of the present disclosure, a wiring harness for a compressor of a heating, ventilation, and/or air conditioning (HVAC) system includes a plurality of electrical leads configured to supply power to the compressor and a plug communicatively coupled to the plurality of electrical leads. The plug includes a plug body and a plurality of connector cavities configured to electrically couple the plurality of electrical leads to a plurality of terminal posts of the compressor. The plurality of connector cavities is symmetrically distributed on the plug body in a regular polygon shape such that the plurality of connector cavities can align with the plurality of terminal posts in a plurality alignment orientations of the plurality of connector cavities and the plurality of terminal posts. Additionally, the plug includes at least one interference projection radially extending from a periphery of the plug body. The at least one interference projection is configured to physically interfere with a positioning guide of the compressor in all except for one alignment orientation of the plurality of alignment orientations. 
     Other features and advantages of the present application will be apparent from the following, more detailed description of the embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the application. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which: 
         FIG.  1    is a perspective view of an embodiment of a building that may utilize a heating, ventilation, and/or air conditioning (HVAC) system in a commercial setting, in accordance with an aspect of the present disclosure; 
         FIG.  2    is a perspective view of an embodiment of a packaged HVAC unit, which may be utilized with a residence or the building of  FIG.  1   , in accordance with an aspect of the present disclosure; 
         FIG.  3    is a perspective view of an embodiment of a split, residential HVAC system, in accordance with an aspect of the present disclosure; 
         FIG.  4    is a schematic diagram of an embodiment of a vapor compression system that may be used in an HVAC system, in accordance with an aspect of the present disclosure; 
         FIG.  5    is a partially exploded side view of an electrical connector for a compressor of an HVAC system aligned over terminal posts and a positioning guide of the compressor, in accordance with an aspect of the present disclosure; 
         FIG.  6    is a perspective view of a compressor-facing surface of the electrical connector of  FIG.  5    having electrical leads electrically coupled to connector cavities, in accordance with an aspect of the present disclosure; 
         FIG.  7    is an overhead perspective view of the electrical connector of  FIG.  5    in a correct alignment orientation relative to the compressor, in accordance with an aspect of the present disclosure; 
         FIG.  8    is a partially exploded perspective view of the electrical connector of  FIG.  7    in the correct alignment orientation relative to the compressor, in accordance with an aspect of the present disclosure; 
         FIG.  9    is a partially exploded perspective view of the electrical connector of  FIG.  7    in a first incorrect alignment orientation relative to the compressor, in accordance with an aspect of the present disclosure; 
         FIG.  10    is a partially exploded perspective view of the electrical connector of  FIG.  7    in a second incorrect alignment orientation relative to the compressor, in accordance with an aspect of the present disclosure; 
         FIG.  11    is a perspective view of the electrical connector of  FIG.  5    having multiple interference projections and a guiding projection, in accordance with an aspect of the present disclosure; 
         FIG.  12    is an overhead view of the electrical connector of  FIG.  11   , in accordance with an aspect of the present disclosure; 
         FIG.  13    is a top view of an electrical connector having multiple interference projections without a guiding projection, in accordance with an aspect of the present disclosure; 
         FIG.  14    is a perspective view of an electrical connector having a guiding projection and a single interference projection that extends along a majority of a periphery of a plug body of the electrical connector, in accordance with an aspect of the present disclosure; 
         FIG.  15    is a schematic view of a compressor-facing surface of an electrical connector having three interference projections and four connector cavities, in accordance with an aspect of the present disclosure; and 
         FIG.  16    is a schematic view of a compressor-facing surface of an electrical connector having one interference projection and two connector cavities, in accordance with an aspect of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be noted that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be noted that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Additionally, it should be noted that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Further, certain terms are used herein, such as “symmetrically,” such terms should be interpreted in context (e.g., within relevant tolerances and applications) and not as having rigid or mathematically perfect definitions. 
     As noted above, electrical connectors or wiring harnesses may be utilized to simultaneously couple multiple electrical leads to a terminal assembly of a compressor, thereby supplying power to a motor therein that facilitates operation of a heating, ventilation, and/or air conditioning (HVAC) system. For example, in certain embodiments, the terminal assembly (e.g., terminal post assembly) includes terminal posts that are symmetrically distributed relative to one another, such as within a regular polygon shape (e.g., equilateral triangle, square, pentagon) or any other suitable arrangement having at least one axis of symmetry. In such embodiments, an electrical connector (e.g., wiring harness) having a connector assembly (e.g., connector cavity assembly) with connector cavities may be aligned with and coupled to the terminal assembly in multiple alignment orientations. As such, certain compressors may include a stud, a bolt, a post, or another positioning guide around which a guiding loop or ear of the electrical connector may be disposed to facilitate assembly. However, these alignment features may still enable inadvertent user errors in assembly to occur that incorrectly supply electrical power to the motor. 
     Accordingly, the present disclosure is directed to various embodiments of a mistake-proof electrical connector that mitigates inadvertently incorrect installation of the connector assembly of the electrical connector relative to the terminal assembly of the compressor. For example, a plug body of the electrical connector includes the connector assembly and at least one radially extending interference projection that physically obstructs assembly of the electrical connector onto the compressor in all except for one, correct alignment orientation. Indeed, via “poka-yoke” or “mistake-proofing” techniques, the at least one interference projection of the electrical connector provides physical interference with the positioning guide of the compressor in each incorrect alignment orientation, thereby causing the only possible alignment orientation to be the correct one. As discussed in detail below, the at least one interference projection may be integrally formed with or otherwise attached to the plug body. Moreover, the at least one interference projection may include multiple, discrete extensions, or a single radial extension (e.g., skirt). In any case, the presently disclosed mistake-proof electrical connector, having the at least one interference projection, leverages the existence of the positioning guide of the compressor to provide mistake-proof power supply to the compressor. 
     Turning now to the drawings,  FIG.  1    illustrates an embodiment of a heating, ventilation, and/or air conditioning (HVAC) system for environmental management that may employ one or more HVAC units, which include electrical connectors in accordance present embodiments. As used herein, an HVAC system includes any number of components configured to enable regulation of parameters related to climate characteristics, such as temperature, humidity, air flow, pressure, air quality, and so forth. For example, an “HVAC system” as used herein is defined as conventionally understood and as further described herein. Components or parts of an “HVAC system” may include, but are not limited to, all, some of, or individual parts such as a heat exchanger, a heater, an air flow control device, such as a fan, a sensor configured to detect a climate characteristic or operating parameter, a filter, a control device configured to regulate operation of an HVAC system component, a component configured to enable regulation of climate characteristics, or a combination thereof. An “HVAC system” is a system configured to provide such functions as heating, cooling, ventilation, dehumidification, pressurization, refrigeration, filtration, or any combination thereof. The embodiments described herein may be utilized in a variety of applications to control climate characteristics, such as residential, commercial, industrial, transportation, or other applications where climate control is desired. 
     In the illustrated embodiment, a building  10  is air conditioned by a system that includes an HVAC unit  12 . The building  10  may be a commercial structure or a residential structure. As shown, the HVAC unit  12  is disposed on the roof of the building  10 ; however, the HVAC unit  12  may be located in other equipment rooms or areas adjacent the building  10 . The HVAC unit  12  may be a single package unit containing other equipment, such as a blower, integrated air handler, and/or auxiliary heating unit. In other embodiments, the HVAC unit  12  may be part of a split HVAC system, such as the system shown in  FIG.  3   , which includes an outdoor HVAC unit  58  and an indoor HVAC unit  56 . 
     The HVAC unit  12  is an air cooled device that implements a refrigeration cycle to provide conditioned air to the building  10 . Specifically, the HVAC unit  12  may include one or more heat exchangers across which an air flow is passed to condition the air flow before the air flow is supplied to the building. In the illustrated embodiment, the HVAC unit  12  is a rooftop unit (RTU) that conditions a supply air stream, such as environmental air and/or a return air flow from the building  10 . After the HVAC unit  12  conditions the air, the air is supplied to the building  10  via ductwork  14  extending throughout the building  10  from the HVAC unit  12 . For example, the ductwork  14  may extend to various individual floors or other sections of the building  10 . In certain embodiments, the HVAC unit  12  may be a heat pump that provides both heating and cooling to the building with one refrigeration circuit configured to operate in different modes. In other embodiments, the HVAC unit  12  may include one or more refrigeration circuits for cooling an air stream and a furnace for heating the air stream. 
     A control device  16 , one type of which may be a thermostat, may be used to designate the temperature of the conditioned air. The control device  16  also may be used to control the flow of air through the ductwork  14 . For example, the control device  16  may be used to regulate operation of one or more components of the HVAC unit  12  or other components, such as dampers and fans, within the building  10  that may control flow of air through and/or from the ductwork  14 . In some embodiments, other devices may be included in the system, such as pressure and/or temperature transducers or switches that sense the temperatures and pressures of the supply air, return air, and so forth. Moreover, the control device  16  may include computer systems that are integrated with or separate from other building control or monitoring systems, and even systems that are remote from the building  10 . 
       FIG.  2    is a perspective view of an embodiment of the HVAC unit  12 . In the illustrated embodiment, the HVAC unit  12  is a single package unit that may include one or more independent refrigeration circuits and components that are tested, charged, wired, piped, and ready for installation. The HVAC unit  12  may provide a variety of heating and/or cooling functions, such as cooling only, heating only, cooling with electric heat, cooling with dehumidification, cooling with gas heat, or cooling with a heat pump. As described above, the HVAC unit  12  may directly cool and/or heat an air stream provided to the building  10  to condition a space in the building  10 . 
     As shown in the illustrated embodiment of  FIG.  2   , a cabinet  24  encloses the HVAC unit  12  and provides structural support and protection to the internal components from environmental and other contaminants. In some embodiments, the cabinet  24  may be constructed of galvanized steel and insulated with aluminum foil faced insulation. Rails  26  may be joined to the bottom perimeter of the cabinet  24  and provide a foundation for the HVAC unit  12 . In certain embodiments, the rails  26  may provide access for a forklift and/or overhead rigging to facilitate installation and/or removal of the HVAC unit  12 . In some embodiments, the rails  26  may fit into “curbs” on the roof to enable the HVAC unit  12  to provide air to the ductwork  14  from the bottom of the HVAC unit  12  while blocking elements such as rain from leaking into the building  10 . 
     The HVAC unit  12  includes heat exchangers  28  and  30  in fluid communication with one or more refrigeration circuits. Tubes within the heat exchangers  28  and  30  may circulate refrigerant, such as R-410A, through the heat exchangers  28  and  30 . The tubes may be of various types, such as multichannel tubes, conventional copper or aluminum tubing, and so forth. Together, the heat exchangers  28  and  30  may implement a thermal cycle in which the refrigerant undergoes phase changes and/or temperature changes as it flows through the heat exchangers  28  and  30  to produce heated and/or cooled air. For example, the heat exchanger  28  may function as a condenser where heat is released from the refrigerant to ambient air, and the heat exchanger  30  may function as an evaporator where the refrigerant absorbs heat to cool an air stream. In other embodiments, the HVAC unit  12  may operate in a heat pump mode where the roles of the heat exchangers  28  and  30  may be reversed. That is, the heat exchanger  28  may function as an evaporator and the heat exchanger  30  may function as a condenser. In further embodiments, the HVAC unit  12  may include a furnace for heating the air stream that is supplied to the building  10 . While the illustrated embodiment of  FIG.  2    shows the HVAC unit  12  having two of the heat exchangers  28  and  30 , in other embodiments, the HVAC unit  12  may include one heat exchanger or more than two heat exchangers. 
     The heat exchanger  30  is located within a compartment  31  that separates the heat exchanger  30  from the heat exchanger  28 . Fans  32  draw air from the environment through the heat exchanger  28 . Air may be heated and/or cooled as the air flows through the heat exchanger  28  before being released back to the environment surrounding the rooftop unit  12 . A blower assembly  34 , powered by a motor  36 , draws air through the heat exchanger  30  to heat or cool the air. The heated or cooled air may be directed to the building  10  by the ductwork  14 , which may be connected to the HVAC unit  12 . Before flowing through the heat exchanger  30 , the conditioned air flows through one or more filters  38  that may remove particulates and contaminants from the air. In certain embodiments, the filters  38  may be disposed on the air intake side of the heat exchanger  30  to prevent contaminants from contacting the heat exchanger  30 . 
     The HVAC unit  12  also may include other equipment for implementing the thermal cycle. Compressors  42 , which utilize an electrical connector in accordance with present embodiments, increase the pressure and temperature of the refrigerant before the refrigerant enters the heat exchanger  28 . The compressors  42  may be any suitable type of compressors, such as scroll compressors, rotary compressors, screw compressors, or reciprocating compressors. In some embodiments, the compressors  42  may include a pair of hermetic direct drive compressors arranged in a dual stage configuration  44 . However, in other embodiments, any number of the compressors  42  may be provided to achieve various stages of heating and/or cooling. As may be appreciated, additional equipment and devices may be included in the HVAC unit  12 , such as a solid-core filter drier, a drain pan, a disconnect switch, an economizer, pressure switches, phase monitors, and humidity sensors, among other things. 
     The HVAC unit  12  may receive power through a terminal block  46 . For example, a high voltage power source may be connected to the terminal block  46  to power the equipment. The operation of the HVAC unit  12  may be governed or regulated by a control board  48 . The control board  48  may include control circuitry connected to a thermostat, sensors, and alarms. One or more of these components may be referred to herein separately or collectively as the control device  16 . The control circuitry may be configured to control operation of the equipment, provide alarms, and monitor safety switches. Wiring  49  may connect the control board  48  and the terminal block  46  to the equipment of the HVAC unit  12 . 
       FIG.  3    illustrates a residential heating and cooling system  50 , also in accordance with present techniques. Indeed, the residential heating and cooling system  50  employs at least one electrical connector in accordance with present embodiments. The residential heating and cooling system  50  may provide heated and cooled air to a residential structure, as well as provide outside air for ventilation and provide improved indoor air quality (IAQ) through devices such as ultraviolet lights and air filters. In the illustrated embodiment, the residential heating and cooling system  50  is a split HVAC system. In general, a residence  52  conditioned by a split HVAC system may include refrigerant conduits  54  that operatively couple the indoor unit  56  to the outdoor unit  58 . The indoor unit  56  may be positioned in a utility room, an attic, a basement, and so forth. The outdoor unit  58  is typically situated adjacent to a side of residence  52  and is covered by a shroud to protect the system components and to prevent leaves and other debris or contaminants from entering the unit. The refrigerant conduits  54  transfer refrigerant between the indoor unit  56  and the outdoor unit  58 , typically transferring primarily liquid refrigerant in one direction and primarily vaporized refrigerant in an opposite direction. 
     When the system shown in  FIG.  3    is operating as an air conditioner, a heat exchanger  60  in the outdoor unit  58  serves as a condenser for re-condensing vaporized refrigerant flowing from the indoor unit  56  to the outdoor unit  58  via one of the refrigerant conduits  54 . In these applications, a heat exchanger  62  of the indoor unit functions as an evaporator. Specifically, the heat exchanger  62  receives liquid refrigerant, which may be expanded by an expansion device, and evaporates the refrigerant before returning it to the outdoor unit  58 . 
     The outdoor unit  58  draws environmental air through the heat exchanger  60  using a fan  64  and expels the air above the outdoor unit  58 . When operating as an air conditioner, the air is heated by the heat exchanger  60  within the outdoor unit  58  and exits the unit at a temperature higher than it entered. The indoor unit  56  includes a blower or fan  66  that directs air through or across the indoor heat exchanger  62 , where the air is cooled when the system is operating in air conditioning mode. Thereafter, the air is passed through ductwork  68  that directs the air to the residence  52 . The overall system operates to maintain a desired temperature as set by a system controller. When the temperature sensed inside the residence  52  is higher than the set point on the thermostat, or a set point plus a small amount, the residential heating and cooling system  50  may become operative to refrigerate additional air for circulation through the residence  52 . When the temperature reaches the set point, or a set point minus a small amount, the residential heating and cooling system  50  may stop the refrigeration cycle temporarily. 
     The residential heating and cooling system  50  may also operate as a heat pump. When operating as a heat pump, the roles of heat exchangers  60  and  62  are reversed. That is, the heat exchanger  60  of the outdoor unit  58  will serve as an evaporator to evaporate refrigerant and thereby cool air entering the outdoor unit  58  as the air passes over outdoor the heat exchanger  60 . The indoor heat exchanger  62  will receive a stream of air blown over it and will heat the air by condensing the refrigerant. 
     In some embodiments, the indoor unit  56  may include a furnace system  70 . For example, the indoor unit  56  may include the furnace system  70  when the residential heating and cooling system  50  is not configured to operate as a heat pump. The furnace system  70  may include a burner assembly and heat exchanger, among other components, inside the indoor unit  56 . Fuel is provided to the burner assembly of the furnace  70  where it is mixed with air and combusted to form combustion products. The combustion products may pass through tubes or piping in a heat exchanger, separate from heat exchanger  62 , such that air directed by the blower  66  passes over the tubes or pipes and extracts heat from the combustion products. The heated air may then be routed from the furnace system  70  to the ductwork  68  for heating the residence  52 . 
       FIG.  4    is an embodiment of a vapor compression system  72  that can be used in any of the systems described above. The vapor compression system  72  may circulate a refrigerant through a circuit starting with a compressor  74 , which utilizes an electrical connector in accordance with present embodiments. The circuit may also include a condenser  76 , an expansion valve(s) or device(s)  78 , and an evaporator  80 . The vapor compression system  72  may further include a control panel  82  that has an analog to digital (A/D) converter  84 , a microprocessor  86 , a non-volatile memory  88 , and/or an interface board  90 . The control panel  82  and its components may function to regulate operation of the vapor compression system  72  based on feedback from an operator, from sensors of the vapor compression system  72  that detect operating conditions, and so forth. 
     In some embodiments, the vapor compression system  72  may use one or more of a variable speed drive (VSDs)  92 , a motor  94 , the compressor  74 , the condenser  76 , the expansion valve or device  78 , and/or the evaporator  80 . The motor  94  may drive the compressor  74  and may be powered by the variable speed drive (VSD)  92 . The VSD  92  receives alternating current (AC) power having a particular fixed line voltage and fixed line frequency from an AC power source, and provides power having a variable voltage and frequency to the motor  94 . In other embodiments, the motor  94  may be powered directly from an AC or direct current (DC) power source. The motor  94  may include any type of electric motor that can be powered by a VSD or directly from an AC or DC power source, such as a switched reluctance motor, an induction motor, an electronically commutated permanent magnet motor, or another suitable motor. 
     The compressor  74  compresses a refrigerant vapor and delivers the vapor to the condenser  76  through a discharge passage. In some embodiments, the compressor  74  may be a centrifugal compressor. The refrigerant vapor delivered by the compressor  74  to the condenser  76  may transfer heat to a fluid passing across the condenser  76 , such as ambient or environmental air  96 . The refrigerant vapor may condense to a refrigerant liquid in the condenser  76  as a result of thermal heat transfer with the environmental air  96 . The liquid refrigerant from the condenser  76  may flow through the expansion device  78  to the evaporator  80 . 
     The liquid refrigerant delivered to the evaporator  80  may absorb heat from another air stream, such as a supply air stream  98  provided to the building  10  or the residence  52 . For example, the supply air stream  98  may include ambient or environmental air, return air from a building, or a combination of the two. The liquid refrigerant in the evaporator  80  may undergo a phase change from the liquid refrigerant to a refrigerant vapor. In this manner, the evaporator  80  may reduce the temperature of the supply air stream  98  via thermal heat transfer with the refrigerant. Thereafter, the vapor refrigerant exits the evaporator  80  and returns to the compressor  74  by a suction line to complete the cycle. 
     In some embodiments, the vapor compression system  72  may further include a reheat coil in addition to the evaporator  80 . For example, the reheat coil may be positioned downstream of the evaporator relative to the supply air stream  98  and may reheat the supply air stream  98  when the supply air stream  98  is overcooled to remove humidity from the supply air stream  98  before the supply air stream  98  is directed to the building  10  or the residence  52 . 
     It should be appreciated that any of the features described herein may be incorporated with the HVAC unit  12 , the residential heating and cooling system  50 , or other HVAC systems. Additionally, while the features disclosed herein are described in the context of embodiments that directly heat and cool a supply air stream provided to a building or other load, embodiments of the present disclosure may be applicable to other HVAC systems as well. For example, the features described herein may be applied to mechanical cooling systems, free cooling systems, chiller systems, or other heat pump or refrigeration applications. 
     As noted above, HVAC systems typically include a compressor that drives or motivates refrigerant flow within a refrigerant circuit. A power source usually provides electrical energy to a terminal assembly extending from a shell of the compressor, such as via an electrical connector or wiring harness coupled to the terminal assembly. However, because the terminals of the terminal assembly may be symmetrically distributed relative to one another, traditional electrical connectors may be coupled to the terminal assembly in multiple orientations. Unfortunately, all but one orientation may be incorrect and cause non-operation of, reduced operating efficiency of, or damage to the compressor. In some cases, the electrical connector includes a guiding projection, ear, or loop that guides a user to install the guiding projection over or near a positioning guide (e.g., stud, bolt, post, extension, pipe stub) of the compressor. However, these guiding projections do not block installation of the electrical connector in an incorrect orientation. Indeed, the electrical connector may be installed in an orientation having the guiding position radially distant from the positioning of the compressor. Accordingly, the present embodiments of the electrical connector include one or more interference projections that physically interfere with the stud or other feature of the compressor to ensure that the assembly of the electrical connector onto the compressor is mistake proof. As will be understood, any resulting increase in manufacturing cost is thereby offset by the assurance of proper power supply to the compressor. 
     With the foregoing in mind,  FIG.  5    is a partially exploded side view of an electrical connector  102  (e.g., wiring harness) aligned over a compressor  106  of an HVAC system  110 , such as any of the compressors of any of the HVAC systems discussed above. Indeed, it should be understood that the electrical connector  102  may be utilized on any suitable compressor or components included within the HVAC unit  12 , the split, residential HVAC system  50 , the vapor compression system  72 , a rooftop unit (RTU), or any other suitable HVAC system. In other embodiments, the electrical connector  102  may additionally be utilized for supplying power to other components for which assembly in only one of multiple possible orientations is desired. For facilitated discussion, the electrical connector  102  will be discussed herein with reference to a longitudinal axis  120 , a radial axis  122 , and a circumferential axis  124  defined around the longitudinal axis  120 . The longitudinal axis  120  of the electrical connector  102  is parallel to a compressor longitudinal axis  126  of the compressor  106  in the illustrated embodiment of  FIG.  5   , which depicts a correct alignment orientation  130  of the electrical connector  102  relative to a terminal post assembly  140  (e.g., terminal assembly) that is formed in a top portion  142  of a shell  144  (e.g., hermetic shell) of the compressor  106 . Additionally, it should be understood that the terminal post assembly  140  may be positioned elsewhere on the compressor  106  and the electrical connector  102  may be suitably coupled to the terminal post assembly  140  according to the techniques disclosed herein. 
     In the illustrated embodiment, the electrical connector  102  is aligned over terminal posts  150  (e.g., first connectors) of the terminal post assembly  140 . The terminal post assembly  140  includes three terminal posts  150  in the present embodiment. However, as discussed below with reference to later figures, it should be understood that any other suitable number of terminal posts  150  may be implemented via extension of the present techniques. The terminal posts  150  are illustrated as having flags  152  to enhance surface area for establishing electrical connections, though it should be understood that any other suitable type of terminal posts  150  may be implemented, including terminal posts without flags. Generally, the electrical connector  102  may include a number of connector cavities (e.g., second connectors) that is equal to a number of the terminal posts  150 , thereby enabling a one-to-one electrical connection therebetween. It should be understood that other embodiments may alternatively include terminal posts  150  on the electrical connector  102  and include connector cavities on the compressor  106 . 
     The compressor  106  also includes a positioning guide  160  that provides a reference point for locating the correct alignment orientation  130 . In the illustrated embodiment, the positioning guide  160  is illustrated as a stud  162 , having a removable fastener  164  (e.g., nut) that may retain the electrical connector  102  in position relative to the terminal post assembly  140 . In other embodiments, the positioning guide  160  may additionally or alternatively include a pipe portion  166  (e.g., pipe stub) that extends from the shell  144 . Indeed, the positioning guide  160  of the compressor  106  may include any suitable fastener, extension, protrusion, or component that provides a suitable, physical reference point for assembly of the electrical connector  102 . 
     Notably, the electrical connector  102  includes at least one interference projection  170  (e.g., discrete unperforated radial extension) which, when misaligned, physically interferes with the positioning guide  160  of the compressor  106  to enhance mistake-proof installation of the electrical connector  102 . In certain embodiments, the electrical connector  102  may also include a guiding projection  174  (e.g., a radial projection of the electrical connector  102  that defines an ear, loop, channel, tunnel) designed to receive the positioning guide  160 . For example, the guiding projection  174  in the illustrated embodiment includes a hollow space that receives the stud  162 , which may retain the properly-aligned electrical connector  102  against the compressor  106  via the removable fastener  164 . The following figures and descriptions exemplify many non-limiting embodiments of the mistake-proof electrical connector  102  and the interference projections  170  thereof. 
       FIG.  6    is a perspective view of a compressor-facing surface  200  of the electrical connector  102 , which includes electrical leads  202  extending into a plug body  204 . The electrical connector  102  includes a connector cavity assembly  210  with connector cavities  212  formed within the plug body  204 , where each connector cavity  212  is electrically coupled to a respective electrical lead  202  (e.g., within the plug body  204 ). The present embodiment of the connector cavity assembly  210  includes three connector cavities  212  symmetrically distributed in a regular or equilateral triangular shape and spaced a common distance from a center point  220  of the connector cavity assembly  210 . The connector cavity assembly  210  is therefore theoretically able to interface with the terminal post assembly  140  discussed above in three different alignment orientations. 
     However, it is important that the electrical connector  102  be coupled to the compressor  106  in the single correct alignment orientation  130  of the multiple possible alignment orientations to enable each terminal post  150  of the compressor  106  to be communicatively coupled to a particular, predetermined electrical lead  202 . As such, the electrical connector  102  includes interference projections  170  extending from the plug body  204  along respective, offset radial directions discussed below. These interference projections  170  physically interface or interfere with the positioning guide  160  of the compressor  106  when user assembly is attempted in any incorrect alignment orientations. As such, the interference projections  170  selectively block incorrect engagement between the connector cavity assembly  210  and the terminal post assembly  140 . The interference projections  170  may be discrete extensions or components that are integrally molded during manufacturing of the plug body  204 , such as via injection molding. In other embodiments, the interference projections  170  may be coupled to the plug body  204 , such as via any suitable adhesive or fasteners. Each of the interference projections  170  and the plug body  204  may be made of any suitable material, such as non-conductive plastic or rubber. Moreover, although illustrated as having rounded tips that may conserve material costs, it should be understood that the interference projections may be formed in any shape that suitably interferes with the positioning guide  160  of the compressor  106 . 
     In the illustrated embodiment, the electrical connector  102  also includes the guiding projection  174  extending radially from the plug body  204 . The guiding projection  174  is radially offset from each of the interference projections  170  in the present embodiment, such that a separation angle  230  of 120 degrees is formed between a radially-extending centerline  232  of each of the interference projections  170  and the guiding projection  174 . The guiding projection  174  includes at least one through-hole  236  (e.g., opening, channel, perforation) that receives the positioning guide  160  of the compressor  106  when assembly is attempted in the correct alignment orientation  130 . The guiding projection  174  may be a loop, ear, or other alignment device that visually indicates a proper installation position of the electrical connector  102 . Indeed, certain traditional electrical connectors may include guiding components, and it is presently recognized that the interference projections disclosed herein may be retrofitted onto such connectors (e.g., attached after manufacturing) to provide them with mistake-proof features. 
       FIG.  7    is an overhead perspective view of the electrical connector  102  in the correct alignment orientation  130  relative to the compressor  106 . The guiding projection  174  of the electrical connector  102  is aligned over the positioning guide  160  of the compressor  106 , which is a stud in the present embodiment. Indeed, due to the radial distribution of the interference projections  170  and the guiding projection  174 , the interference projections  170  do not interfere with the positioning guide  160  of the compressor when the guiding projection  174  is disposed over the positioning guide  160 .  FIG.  8    illustrates a partially exploded perspective view of the electrical connector  102  in the correct alignment orientation  130  relative to the compressor  106 , where the interference projections  170  are radially offset from the guiding projection  174  and the positioning guide  160 . As will be understood with respect to other embodiments discussed below, the positioning guide  160  may be omitted in certain embodiments. 
       FIG.  9    is a partially exploded perspective view of the electrical connector  102  of  FIG.  8   , where the electrical connector  102  is rotated relative the compressor  106  by 120 degrees (e.g., along the circumferential axis  124 ). As such, one interference projection  170  is aligned over the positioning guide  160  of the compressor  106 , preventing installation of the compressor in a first incorrect alignment orientation  240 . Similarly,  FIG.  10    is partially exploded perspective view of the electrical connector of  FIG.  7    in a second incorrect alignment orientation  250 , such as one in which the electrical connector  102  is rotated relative to the compressor  106  by an additional 120 degrees compared to the embodiment of  FIG.  9   . In this embodiment, the other interference projection  170  interfaces with the positioning guide  160  of the compressor  106 , preventing installation of the electrical connector  102 . As should be understood, the interference projections  170  therefore enable the electrical connector  102  to be coupled to the compressor  106  in a mistake-proof manner. 
       FIG.  11    is a perspective view of the electrical connector  102  having the two interference projections  170  and the guiding projection  174 . The electrical connector  102  may also include lead receptacles  260  that receive the electrical leads  202  discussed above. In some embodiments, the plug body  204  also includes labeled indicators  262  to provide information about which electrical lead  202  is coupled (or intended to be coupled) to which lead receptacle  260 . Indeed, the lead receptacles  260  are offset along the longitudinal axis  120  relative to the interference projections  170  of the present embodiment. As such, it should be understood that the lead receptacles  260  may be positioned along the plug body  204  in any radial suitable location. 
     With additional focus on the radial offset components of the electrical connector  102 ,  FIG.  12    shows an overhead view of the electrical connector  102  of  FIG.  11   . When taken together, each of the interference projections  170  and the guiding projection  174  are generally symmetrically distributed (e.g., within manufacturing and/or practical tolerances). Indeed, the respective radially-extending centerline  232  through each of the projections  170 ,  174  may originate at the center point  220  of the plug body  204  and proceed radially outward to be separated from its nearest neighbor by 360 degrees divided by the number of interference and guiding projections (e.g., within 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10% tolerance). For the present embodiment, the separation angle  230  is 120 degrees, as discussed above. However, it should be understood that these techniques may extend to other embodiments having different numbers of connector cavities  212  and/or terminal posts  150 . 
       FIG.  13    is an overhead view of an electrical connector  102  having the interference projections  170  discussed above, while omitting the guiding projection  174 . That is, the mistake-proofing qualities of the electrical connector  102  may be maintained without the guiding projection  174 . For example, the installing technician may place the electrical connector  102  over the terminal post assembly  140  in the single correct alignment orientation  130  that is not blocked by the interference projections  170 . 
       FIG.  14    is a perspective view of an electrical connector  300  having the guiding projection  174  and a single interference projection  302  or skirt. The single interference projection  302  extends along at least half or a majority (e.g., more than 50%, 60%, 70%, 80%) of a periphery  306  of the plug body  204  of the electrical connector  102 . Although there may be a slight increase in material costs, this single interference projection  302  may be easier to manufacture than embodiments with discrete interference projections, in some embodiments. 
     As mentioned, the above described qualities of the electrical connectors  102  having three connector cavities  212  may be extended to other embodiments having more or less connector cavities. Indeed, any embodiment in which the connector cavities  212  and corresponding terminal posts  150  are symmetrically distributed relative to at least one axis of symmetry, or formed in a regular polygon shape, may benefit from the mistake-proofing of the presently disclosed interference projections  170 . As non-limiting examples,  FIG.  15    is a schematic view of a compressor-facing surface  200  of an electrical connector  340  having three interference projections  170  and four connector cavities  212 . Indeed, the connector cavities  212  are distributed in a regular square shape. Additionally,  FIG.  16    is a schematic view of a compressor-facing surface  200  of an electrical connector  360  having one interference projection  170  and two connector cavities  212 , which have at least one axis of symmetry relative to one another. It should be understood that the guiding projection  174  may be added to these electrical connectors  340 ,  360  to further facilitate assembly of the electrical connectors  340 ,  360  on the compressor  106 . Indeed, any of the techniques discussed herein may be combined in any suitable manner that would be understood by one of skill in the art of electrical connectors. 
     Accordingly, the present disclosure is directed to a mistake-proof, “poka-yoke” electrical connector that enhances correct installation of an electrical connector to a compressor, such as a hermetic compressor having a symmetrically distributed terminal post assembly. A plug body of the electrical connector includes a connector assembly and at least one radially extending interference projection that physically obstructs assembly of the electrical connector onto the compressor in all except for one, correct alignment orientation. That is, at least one interference projection of the electrical connector provides physical interference with the positioning guide of the compressor in each incorrect alignment orientation. The at least one interference projection may include multiple, discrete extensions, or a single radial extension (e.g., skirt). In any case, the presently disclosed electrical connector, having the at least one interference projection, leverages the existence of the positioning guide of the compressor to provide mistake-proof power supply to the compressor. 
     While only certain features and embodiments of the present disclosure have been illustrated and described, many modifications and changes may occur to those skilled in the art, such as variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters including temperatures, pressures, and so forth, mounting arrangements, use of materials, orientations, and so forth, without materially departing from the novel teachings and advantages of the subject matter recited in the claims. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure. Furthermore, in an effort to provide a concise description of the embodiments, all features of an actual implementation may not have been described, such as those unrelated to the presently contemplated best mode of carrying out the disclosure, or those unrelated to enabling the claimed features. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation specific decisions may be made. Such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure, without undue experimentation.