Abstract:
A method of installing a connector assembly relative to a terminal assembly of a hermetic compressor assembly, including: aligning the connector assembly with the terminal assembly; positioning an installation tool on the connector assembly; actuating the installation tool; and seating the connector assembly into the terminal assembly. Also, a method of installing a connector assembly relative to a terminal assembly of a hermetic compressor assembly, including: aligning the connector assembly with the terminal assembly; positioning an installation tool on the connector assembly; pneumatically applying force to the connector assembly through the installation tool until a predetermined pneumatic pressure has been reached; seating the connector assembly into the terminal assembly when or before the predetermined pressure has been reached; and retracting the tool after the connector assembly has been seated into the terminal assembly.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is related to and claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application Ser. No. 60/220,563, filed Jul. 25, 2000. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to electrical connections internal to hermetic compressor assemblies and methods of quickly and effectively installing same, particularly with regard to connectors designed to protect against electrical arcing across carbon deposits which may be formed within the compressor assembly. 
     The terminal assembly extending through the sealed shell or housing of a hermetic compressor includes a plurality of conductor pins which extend through apertures located in the terminal body. The terminal body is usually welded or brazed into an aperture provided in the compressor assembly housing. The conductor pins are secured within these apertures, and are electrically insulated from the terminal body and the housing, by fused glass insulators. An electric motor having a stator and a rotor is located within the housing, the rotor operatively coupled to a compression mechanism. The interior ends of the conductor pins are connected to lead wires which are connected to the windings of the motor stator. The exterior ends of the conductor pins are selectively connected, as through a switch device, to a source of electrical power. Thus, the motor is energized by the external power source through the terminal body, the lead wires, and the electrical connections therebetween. The electrical connections typically include an electrical connector attached to each lead wire which is engaged with a corresponding conductor pin. A plurality of connectors, and portions of their respective lead wires, are normally assembled into, and housed by, a cluster block which comprises the connector assembly. The cluster block is dielectric, usually constructed from an injection molded plastic, and facilitates quick assembly of the lead wires to the terminal assembly. The cluster block insulates the electrical connectors therein from each other, from the terminal assembly, and from the compressor housing, to a substantial degree. Usually, the interior of the cluster block is formed with separated passageways, each of which receives one lead wire, and recesses for each of the connectors attached to the ends of the lead wires. Passageways leading to these connectors are provided through the cluster block material, the conductor pins of the terminal assembly extending therethrough. 
     During compressor operation, carbon or other conductive deposits from the motor may collect on the interior surfaces of the housing and terminal assembly. These deposits may provide a conductive path between elements at differing electrical potentials, and a short circuit or arc may develop along that path. Such arcing results in resistive heating of the deposits along the conductive path, which heats the elements on which the deposits collect. Such heating is known to sometimes cause the fused glass insulators about the conductor pins to melt, thereby causing the compressor housing to leak pressurized gas at the terminal assembly. 
     Prior hermetic compressor assemblies often include some means for impeding such arcing, these means are usually designed to prevent the conductive deposits from collecting on the interior surface of the terminal assembly and its glass insulators. These means include electrical connector or cluster block assemblies, through which the lead wires are attached to the interior ends of the conductor pins, which, when assembled to the terminal assembly, substantially covers same. Prior connector assemblies have not completely precluded the formation of a conductive path between the lead wire ends or electrical connectors within the cluster block, and the terminal body or compressor housing. 
     Some of these connector assemblies means may include sealing features which help prevent the conductive deposits from entering the interior of the terminal assembly past its interface with the cluster block. One such cluster block assembly includes a cylindrical exterior wall portion which sealingly engages the cylindrical interior surface of the terminal body, as by an interference fit; the cylindrical interface may also include additional sealing means such as an O-ring. A problem associated with prior connector assemblies which sealably engage the terminal assembly in this manner is that they may be improperly installed, the proper seating of the block relative to the terminal assembly being hindered by the interference fit between the terminal body and the cluster block, or the O-ring therebetween. 
     One method of connecting prior connector assemblies involves an assembly operator manually forcing the cluster block into its fully installed position within the terminal body. Other methods involve the use of tools such as pliers or a hammer to make this connection. There are problems associated with these prior installation techniques: When manually installing the cluster block, the person installing the block may not be physically able to force the cluster block into the terminal body far enough to create the sealing engagement required to prevent debris from entering the terminal assembly. When using pliers or a hammer to effect installation of the connector assembly, damage to the cluster block, such as deformation, cracking or splitting thereof, may occur. Thus, improper installation of the connector assembly to the terminal assembly may result in an open circuit, carbon being deposited on the interior of the terminal assembly, or damage to the assembled parts. 
     It is desired to provide a connector assembly and an installation method therefor, which ensure that the connector assembly is properly installed to the terminal assembly easily and consistently, protect against the formation of undesirable conductive paths, and thus electrical arcing, within the compressor assembly, and avoid the above-mentioned shortcomings of previous connector assemblies and installation methods. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a connector assembly which is installed into the terminal assembly and protects against the formation of undesirable conductive paths thereacross, which may result in electrical arcing. The present invention also relates to a method for installing the connector assembly easily and consistently, and without damage to the connector assembly. The cluster block of the inventive connector assembly is provided with a feature engaged by an tool during installation; through use of the inventive method, the connector assembly is properly installed easily and consistently, and without the risk of damage thereto. 
     The tool includes a body portion having two legs, one of which is outside the compressor housing during assembly and supports a pneumatic cylinder, the other of which is inside the compressor housing during assembly and engages the cluster block. The latter leg is provided with a recess or a protrusion which respectively engages a protrusion or a recess provided on the cluster block. The connector assembly is loosely assembled onto the conductor pins of the terminal assembly. As the pneumatic cylinder advances toward the outer surface of the compressor housing, the cluster block is forced into sealing engagement with the terminal body. The force exerted on the cluster block by the tool is automatically controlled to ensure proper seating of the cluster block relative to the terminal body, thereby ensuring that the interior of the terminal assembly is protected from carbon deposits forming therein, and to prevent damage to the assembled parts. 
     The present invention provides a method of installing a connector assembly relative to a terminal assembly of a hermetic compressor assembly including: aligning the connector assembly with the terminal assembly; positioning an installation tool on the connector assembly; actuating the installation tool; and seating the connector assembly into the terminal assembly. 
     The present invention further provides a method of installing a connector assembly relative to a terminal assembly of a hermetic compressor assembly including: aligning the connector assembly with the terminal assembly; positioning an installation tool on the connector assembly; pneumatically applying force to the connector assembly through the installation tool until a predetermined pneumatic pressure has been reached; seating the connector assembly into the terminal assembly when or before the predetermined pressure has been reached; and retracting the tool after the connector assembly has been seated into the terminal assembly. 
     The present invention also provides a tool for installing a connector assembly to the terminal assembly of a hermetic compressor assembly. The tool includes a body member which supports a pneumatic cylinder. Means are provided on the body member for ensuring proper alignment of the tool with the connector assembly during installation of the connector assembly to the terminal assembly. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a longitudinal sectional view of a vertical rotary compressor in accordance with the present invention; 
     FIG. 2 is a longitudinal sectional view of a horizontal rotary compressor in accordance with the present invention; 
     FIG. 3 is an exploded view of one embodiment of the inventive connector assembly and a terminal assembly; 
     FIG. 4 is a sectional view of the connector assembly and terminal assembly of FIG. 3, installed, showing the positioning of the installation tool; 
     FIG. 5 is a first exploded view of the connector assembly of FIG. 3; 
     FIG. 6 is a second exploded view of the connector assembly of FIG. 3; 
     FIG. 7 is a plan view of one embodiment of an inventive installation tool; 
     FIG. 8 is a sectional view of the tool of FIG. 7, taken along the line  8 — 8 ; 
     FIG. 9 is a sectional view of the tool of FIG. 7, taken along the line  9 — 9 ; 
     FIG. 10 is a fragmentary view of the tool of FIG. 7, also showing the connector assembly of FIG. 3 positioned on the tool; 
     FIG. 11 is a sectional view of the installation tool and connector assembly along line  11 — 11  of FIG. 10; 
     FIG. 12 is a perspective view of the installation tool of FIG. 7, shown positioned on a compressor assembly housing portion; 
     FIG. 13 is a perspective view of the installation tool and compressor assembly housing portion of FIG. 12, also showing a compressor/motor subassembly; 
     FIG. 14 is a sectional view of the installation tool, compressor assembly housing portion, and compressor/motor subassembly of FIG. 13, in a first tool position; 
     FIG. 15 is a sectional view of the installation tool, compressor assembly housing portion, and compressor/motor subassembly of FIG. 13, in a second tool position; 
     FIG. 16 is a fragmentary sectional view of the installation tool and compressor assembly housing portion of FIG. 14 along the line  16 — 16 ; 
     FIG. 17 is a schematic of the pneumatic cylinder and control valve in a neutral position; 
     FIG. 18 is a schematic of the pneumatic cylinder and control valve in a first position; and 
     FIG. 19 is a schematic of the pneumatic cylinder and control valve in a second position. 
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present invention. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 and 2, reciprocating compressor assembly  20  and rotary compressor assembly  22  are shown as examples of types of hermetic compressor assemblies in which the present invention may be advantageously used. Other hermetic compressor types, such as, for example, a scroll compressor assembly, may also benefit from use of present invention. 
     Reciprocating compressor assembly  20  comprises housing  24  which includes upper housing portion  26  disposed atop lower housing portion  28 . Housing  24  of rotary compressor assembly  22  includes main housing portion  30  and two end portions  32  (FIG.  2 ). The housing portions for both compressor assemblies  20  and  22  are hermetically sealed at  34  by a method such as welding, brazing or the like. 
     Hermetic compressor assemblies  20  and  22  each also include electric motor  36  disposed within housing  24 . Motor  36  comprises stator  38  provided with windings  40 , and rotor  42 , which is surrounded by stator  38 . Rotor  42  has central aperture  43  in which drive shaft or crankshaft  44  is secured by an interference fit. 
     As shown, an end of drive shaft  44  is operatively connected to compression mechanism  46 , which may be of the reciprocating piston type, as in compressor assembly  20 , the rotary type, as in compressor assembly  22 , or the scroll type (not shown), each of which are well-known in the art. The general structure and operation of a reciprocating compressor assembly is disclosed in U.S. Pat. No. 5,266,016, the disclosure of which is expressly incorporated herein by reference. The general structure and operation of a rotary compressor assembly is disclosed in U.S. Pat. No. 5,222,885, the disclosure of which is expressly incorporated herein by reference. The general structure and operation of a scroll compressor assembly is disclosed in U.S. Pat. No. 5,306,126, the disclosure of which is expressly incorporated herein by reference. Each of these patents is assigned to Tecumseh Products Company. 
     The compressor assembly, which may be part of a refrigeration system (not shown) also comprising heat exchangers, an expansion device and refrigerant conveying lines, receives refrigerant substantially at suction pressure and discharges it substantially at discharge pressure. The compressor assembly may be of a “high side” type, in which the portion of the housing in which the motor is located is at discharge pressure, or of a “low side” type, in which the portion of the housing in which the motor is located is at suction pressure. The present invention may be beneficially employed in either type. 
     Rotary compressor assembly  22  (FIG. 2) is of the high side type, and in operation, suction pressure refrigerant gas is drawn from outside its housing  24  directly into its compression mechanism  46  via a suction tube (not shown). Within compression mechanism  46 , the suction pressure gas is compressed to a higher, discharge pressure, and then discharged from the compression mechanism into its housing  24  substantially at discharge pressure. Thereafter, the compressed gas is exhausted from the housing through discharge tube  47  and recirculated through the refrigerant system. 
     Reciprocating compressor assembly  20  (FIG. 1) is of the low side type, and in operation suction pressure refrigerant gas is drawn first into housing  24 , and then into compression mechanism  46 , the compressed gas then discharged directly from the compression mechanism and the housing via discharge tube or shock loop  47  and recirculated through the refrigerant system. 
     In lower housing portion  28  of low side reciprocating compressor  20  (FIG. 1) and one of end portions  32  of high side rotary compressor  22  (FIG. 2) is aperture  48 , into which terminal assembly  50  is fitted and sealably secured at  52  by welding, brazing or the like. In the manner discussed above, an external power source is electrically connected to conductor pins  56  of the terminal assembly, which are connected, through inventive connector assembly  54  and jacketed lead wires  58  to stator windings  40 . As shown in FIG. 4, each lead wire  58  is positioned within plastic cluster block  57  of connector assembly  54 , its uninsulated portion and is mechanically crimped and electrically connected at  60  to electrical connector clip  62 , which engages the interior end of a conductor pin  56  in a manner which will be described in more detail hereinafter. Once electrical connection  60  is made, electrical power is transferred from the external power source to stator windings  40  via pins  56  of terminal assembly  50  and lead wires  58 . Energized, the stator electromagnetically induces rotation of rotor  42  to drive compression mechanism  46  through drive shaft  44 . 
     Terminal assembly  50  includes metallic, cup-shaped terminal body  64  having end wall  66  and cylindrical side wall  68 , as best seen in FIGS. 3 and 4. Terminal body side wall  68  is integrally formed with end wall  66  and extends approximately perpendicularly therefrom. Integral with the annular edge of side wall  68  opposite end wall  66  is flange  70 , which abuts the interior periphery of housing aperture  48  (FIGS. 1,  2 ,  14  and  15 ). Located in end wall  66  is a plurality (usually three) of inwardly projecting collars  72  which extend substantially parallel with side wall  68  and define apertures  74  through which conductor pins  56  pass through terminal body  64  (FIG.  4 ). A fused glass insulator  76  is formed in each aperture  74  and attaches conductor pin  56  to collar  72 . Pins  56  are electrically insulated from terminal body  64 , housing  24 , and each other, by insulators  76 , which also form a hermetic seal for housing  24 . 
     As discussed above, unless measures are taken to prevent it, arcing may occur across terminal assembly  50  between lead wires  58  or conductor pins  56 , and terminal body  64  or compressor housing  24  along a conductive path established by debris produced during compressor operation. To protect against the possibility of arcing between lead wires  58  or conductor pins  56 , and terminal body  64  or compressor housing  24 , cluster block  57  sealingly engages the inner surface of terminal body  64  (FIG.  4 ). Further, the uninsulated portions of lead wires  58 , to which electrical connector clips  62  are attached, are sealably disposed within cluster block  57 . 
     Referring to FIGS. 5 and 6, cluster block  57  includes base  78  and cover  80  which are secured together. Base  78  is injection molded plastic and is provided with integral tabs  82  which protrude outwardly from outside surface  84  thereof. Tabs  82  are equally spaced around the periphery of base  78  adjacent edge  86 . Cover  80  is also injection molded plastic and is provided with slots  88  in outer surface  90  of sidewalls  98 . Cover  80  is placed atop base  78  such that each base tab  82  aligns with and engages a respective cover slot  88 . As shown in FIGS. 4,  5 , and  6 , base  78  may be further provided with peripheral receiving groove  92  which is engaged by peripheral lip  94  projecting from inside surface  96  of cover  80 . Lip  94  is offset from sidewalls  98  of cover  80  and follows the entire perimeter thereof. When cover  80  is joined to base  78 , lip  94  is received in groove  92  to create a tortuous path between base  78  and cover  80 , thereby ensuring that conductive debris cannot enter cluster block  57  through this joint. 
     Both base  78  and cover  80  are provided with narrow, U-shaped passages  100  formed in the peripheral walls thereof, each of which receives one of the plurality of lead wires  58 . Each passage  100  in base  78  communicates with a channel defined in the base by walls  102 , each channel being of a length and shape which precisely positions a connector clip  62  directly over conductor pin receiving holes  104  in base  78 . Each passage  100  and channel is dimensioned to fit tightly about the insulation of a lead wire  58 ; notably, channel walls  102  are provided with wire surrounding portions  106  which protrude inwardly, toward and in abutting contact with each lead wire  58 . Additionally, integral wire surrounding portions  108  are provided in cover  80 . Portions  108  extend from cover inner surface  96  into the portions of the channels in the base formed by wire surrounding portions  106 . Wire surrounding portions  108  sealably contact the insulative jackets of lead wires  58 , and retain lead wires  58  in a predetermined position between walls  102 . Wire jacket-contacting surfaces  110  of wire surrounding portions  108  are concave; when wire surrounding portions  108  contact the surface of lead wires  58 , surfaces  110  closely follow the cylindrical contour of the insulative jackets of wires  58  so as not to damage or crimp the wires. 
     Extending downwardly from base  78  is integrally formed cylindrical portion  112  which is the portion of cluster block  57  which sealably engages the cylindrical inner surface of terminal body  64 . In order for connector assembly  54  to effectively prevent debris from contacting the inner surfaces of terminal assembly  50  and to make a good electrical connection  60 , cluster block  57  must be properly seated within terminal body  64 . The shown embodiment illustrates recess or groove  114  that may be circumferentially disposed in outer surface  116  of cylindrical portion  112  to receive O-ring  118 . When cluster block  57  is seated within terminal body  64 , conductor pins  56  are aligned with holes  104  in base  78 . As cluster block  57  is forced into terminal body  64 , the interior ends of pins  56  are engaged by connector clips  62  to provide an electrical connection therebetween. As shown in FIG. 4, O-ring  118  is compressed into groove  114 , and provides an interference fit which retains connector assembly  54  to terminal assembly  50 , and seals the interface between surface  116  of cluster block  57  and the inner surface of terminal body  64 . 
     Located in outer surface  120  of cover  80  is blind recess  122  which is provided to receive protrusion  124  of installation tool  126  (FIGS. 7-11) as discussed further hereinbelow. Recess  122 , formed in cover  80 , protrudes inwardly from outer surface  120  and is closed from the inner chamber of cluster block  57  to prevent debris from entering the same. Recess  122  is shown as being rectangular, but may be of any shape suitable to receive tool protrusion  124 . Additional recess  123 , shown in FIG. 5, may also be provided in cover  80  to receive other tool protrusions (not shown) and aid in the placement of cluster block  57  on tool  126 . 
     Referring now to FIGS. 7-15, connector assembly installation tool  126  includes integrally formed C-shaped body member  128  having central portion  130  and downwardly depending legs  132  and  134  positioned at each end thereof; C-shaped body member  128  is steel, but may be constructed from any suitably rigid material that is able to withstand repeated use, and is preferably lightweight so that an operator may easily manipulate tool  126 . Located on the lower portion of leg  132  is protrusion  124  which is received in blind recess  122 . Also located on leg  132  is locating pin  136  which abuts cover outer edge  138  of cluster block  57  to ensure that connector assembly  54  is properly positioned on tool  126  (FIGS.  8  and  10 ). Although protrusion  124  and locating pin  136  are respectively shown as being rectangular and round in cross section, they may be of any suitable shape. 
     As best shown in FIG. 8, located within leg  134  of body portion  128  is aperture  140  through which pneumatic cylinder  142  is secured by any suitable method, such as by being threaded. Rod  144  is disposed within cylinder  142  and has piston  146  fixedly attached to one end thereof. Piston  146  slidably, sealingly engages the cylindrical, defining walls of chambers  147  and  148  in pneumatic cylinder  142 . Located at the end of rod  144  opposite piston  146  are threads  150  which engage threaded recess  154  of terminal-receiving cup  156 . Terminal receiving cup  156  has cavity  158  into which is received the external portion of terminal assembly  50  during installation of connector assembly  54  as described further hereinbelow. The axial surface of cup  156  surrounding cavity  158  is brought into abutment with the outside of compressor housing  24  when installation tool  126  is being actuated. 
     Pneumatic cylinder  142  includes apertures  160  and  161  which communicate with chambers  147  and  148 , respectively. Chamber  147  is disposed between piston  146  and end  166  of cylinder  142 , and chamber  148  is located near end  164  of cylinder  142 . Referring to FIGS. 13,  14 , and  15 , fluid supply hoses  162  and  163  are secured by any suitable means, such as by threaded engagement in apertures  160  and  161 , which respectively provide a passageway into chambers  147  and  148 . Control valve  165  receives the opposite end of each supply hose  162  and  163 , placing valve  165  in fluid communication with chambers  147  and  148 . Referring to FIGS. 17,  18  and  19 , control valve  165  includes therein plunger  174  which is disposed in passage  176 , substantially extending the length of valve housing  178 . Intersecting passage  176  are passages  180  and  182  which permit fluid flow from passage  176  to fluid supply hoses  162  and  163 . Extending approximately perpendicularly from the opposite side of passage  176  are exhaust passages  184  and  186  which are open to ambient, as well as input passage  188  which receives fluid from fluid supply  190  through supply hose  192 . 
     Plunger  174  has three positions which determine the path of the fluid into or out of chambers  147  and  148 . When in the position shown in FIG. 17, control valve  165  is in a neutral position such that the pressure in portion  194  of passage  176  on one side of plunger  174  is substantially equal to the pressure in portion  196  of passage  176 . The pressure centers plunger  174  in passage  176  to close input passage  188 . Pressure switch  198  is located in fluid supply line  163  to control the pressure differential between portions  194  and  196  of passage  176  and thus the position of plunger  174 . Pressure switch  198  includes a pressure gauge (not shown) for monitoring the pressure within hose  163 . Trigger  200  on switch  198  actuates a valve (not shown) located in hose  163  to control the fluid flow in supply hose  163 . Pressure switch  198  is shown and described as being operable by air although pressure switch  198  may also be operable by electronic means. 
     When an operator depresses trigger  200 , the valve in hose  163  is actuated, creating a difference in pressure between portions  194  and  196  of passage  176 . The pressure in portion  196  of passage  176  is then greater than in portion  194 , thereby forcing plunger  174  to the first position illustrated in FIG. 18 in which fluid input passage  188  aligns with, i.e., is placed in fluid communication with, passage  180 , thereby allowing fluid to flow into chamber  148  of cylinder  142 . Simultaneously, supply hose  162  aligns with exhaust passage  186  such that as fluid flows into chamber  148 , forcing piston  146  towards end  166  of cylinder  142 , fluid is forced out of chamber  147  to the ambient air. The pressure gauge of pressure switch  198  measures the pressure in supply hose  163 . Once the pressure has reached a predetermined level that ensures the seating of cluster block  57 , the pressure in portion  194  is made greater than that in portion  196 . This causes plunger  174  to slide within passage  176  to its second position shown in FIG.  19 . In this position, input passage  188  aligns with passage  182 , allowing fluid to flow into chamber  147 . In this position, exhaust passage  184  aligns with passage  180  such that as fluid flows into chamber  147 , piston  146  is forced towards end  164  of cylinder  142 , the fluid in chamber  148  being exhausted to the ambient. Fluid flowing into chamber  147  moves piston  146  until it abuts an interior surface of cylinder  142 . 
     To ensure proper seating of cluster block  57 , a predetermined maximum pressure level within chamber  148  is set in the range of 30 to 50 psi, and preferably around 40 psi. This pressure level also determines the point at which plunger  174  moves to its second position. Venting the fluid from chamber  148  when the desired maximum force on the cluster block has been attained is preferable to releasing tool  126  when it reaches a mechanical stop. The tolerances involved when manufacturing and/or assembling certain compressor assembly components can sometimes be substantial. For example, thicknesses of the housing portions may vary from one compressor to the next, as may the distance by which the terminal assembly protrudes from the interior wall of the housing. With significant dimensional differences possible between different compressor assemblies, the predetermined distance of travel for rod  144  would not always be the same for each compressor. Reliance on a mechanical stop to limit the movement of rod  144  might not provide consistent, proper seating of cluster block  57  into terminal body  64 . 
     Pneumatic cylinder  142  may be of a suitable type well-known in the art, such as, for example, a double acting Series SR or SRM stainless steel pneumatic cylinder manufactured by Parker Hannifin Corporation and described in the May, 1986, Schrader Bellows product catalog CYL-SR/SRM, the disclosure of which is expressly incorporated by reference. The specific size of cylinder  142  may be optimally selected based on the force required to properly seat connector assembly  54  into terminal assembly  50 , and the amount of fluid pressure available to power the cylinder. It is envisioned that with appropriate revisions to the control apparatus and fluid circuits, pneumatic cylinder  142  may be replaced with a suitable hydraulic cylinder. 
     Before connector assembly  54  is installed, compressor/motor subassembly is first prepared. Referring to FIGS. 13,  14  and  15 , subassembly  168  includes motor  36  and compression mechanism  46 . As described above, compression mechanism may be of the reciprocating piston type, the rotary type, or the scroll type. Motor  36  comprises a stator and a rotor, the rotor operatively coupled to the compression mechanism to drive same. In the drawings, subassembly  168  is represented by a polyhedron or other descriptive form. As described above, lead wires  58  are electrically connected to the stator windings, and it is envisioned that the stator would be provided by its manufacturer to the compressor assembly facility with connector assembly  54  already attached thereto. 
     Once subassembly  168  is complete, and before it is fully installed into housing  24 , tool  126  is used to install connector assembly  54  onto terminal assembly  50 . The use of tool  126  ensures that cluster block  57  is properly seated within terminal body  64  to effectively prevent carbon deposits from later forming conductive paths between components at different electrical potentials, such as between the unjacketed portions of lead wire  58  and housing  24 , or between conductor pins  56  and terminal body  64 , to thus preclude arcing. 
     Before installation of connector assembly  54 , during assembly of the housing portions into which the connector assemblies will be installed, terminal assemblies  50  are secured within housing apertures  48  such that conductor pins  56  are consistently oriented in a predetermined angular position relative to the housings. Fence  169  is attached to the exterior of housing  24 , about terminal assembly  50 , in a predetermined orientation, thereby ensuring that the connector assembly (not shown), by which electrical power is provided to the terminal assembly from the power source, is later properly connected to the conductor pins. Tool  126  properly orients connector assembly  54  to terminal assembly  50 , ensuring that the matching of the lead wires to their respective conductor pins is proper. As best illustrated in FIGS. 10 and 11, connector assembly  54  is positioned on leg  132  of tool  126  such that protrusion  124  engages blind recess  122 . As shown in FIG. 11, cluster block  57  is installed at an angle with locating pin  136  supporting block  57  along cover outer edge  138 . 
     With cluster block  57  in position on leg  132  of tool  126 , tool  126  is placed in its first position relative to housing portion  28 , shown in FIGS. 13 and 14, and connector assembly  54  may be loosely assembled onto conductor pins  56 , and the angular alignment of cluster block  57  to terminal body  64  is thus established. Subassembly  168  remains outside of housing portion  28  (FIGS. 13,  14  and  15 ) to provide clearance for tool  126 . Once aligned, tool  126  is actuated, and tool terminal cup  156  moves from the first tool position (FIG. 14) to the second tool position shown in FIG. 15 in which terminal cup  156  abuts the exterior surface of housing portion  28 , about terminal assembly  50 , the exterior ends of conductor pins  56  being received in cavity  158 . 
     With reference to FIGS. 14,  15  and  18 , during actuation of tool  126 , plunger  174  is aligned with input passage  188  such that fluid from supply  190  is forced into chamber  148  of cylinder  142  through fluid supply hose  163 . This forces rod  144  out of chamber  148 , advancing terminal cup  156  toward housing portion  28 . The pressure in chamber  148  continues to increase, forcing terminal cup  156  against housing portion  28  in the direction of arrow  170  and C-shaped tool body member  128  in the direction of arrow  172 , thereby forcing connector assembly  54  into engagement with terminal assembly  50 . As the pressure in chamber  148  approaches the predetermined maximum level, cluster block  57  moves further into engagement with terminal body  64  until it is properly seated. 
     Once the preselected maximum pressure level in fluid cylinder chamber  148  has been reached, connector assembly  54  is fully installed into terminal assembly  50 , and plunger  174  in pressure control valve  165  moves to its second position (FIG.  19 ), allowing fluid within chamber  148  to be vented. Simultaneously, plunger  174  is aligned with input passage  188  such that fluid from pressurized fluid supply  190  is forced into chamber  147  of cylinder  142  through fluid supply hose  162 . The fluid entering chamber  147  forces piston  146  to return to the first position of FIGS. 13,  14  and  19 . Installation tool  126  is removed from housing  24  so that the assembly of compressor  20  or  22  may be completed in a conventional manner. 
     While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.