Patent Publication Number: US-2022224085-A1

Title: Two-Step Interlock for Modules in a Motor Control Center

Description:
BACKGROUND INFORMATION 
     The subject matter disclosed herein relates to a Motor Control Center (MCC), More specifically, a rotatable push-button is provided which provides a first orientation and a second orientation to selectively engage a connection handle during insertion of a module into the MCC. 
     As is known to those skilled in the art, a Motor Control Center (MCC) is a power distribution center to control multiple motors from a central location. The MCC includes a power infeed configured to receive the power which is, in turn, distributed to each of the motors controlled by the MCC. The power may be a multi-phase alternating current (AC) power supply such as a 230 VAC or a 460 VAC three-phase utility supply. A primary breaker is sized according to the combined current ratings of each module to be included within the MCC and allows for a central disconnect of the MCC from the utility supply. Within the MCC a series of voltage busses extend horizontally and/or vertically to distribute the utility voltage to each module within the MCC. The MCC may include a single vertical unit, configured to receive multiple modules or multiple vertical units stacked adjacent to each other, where each vertical unit is configured to receive one or more modules. 
     The vertical unit includes slots configured to receive modules which are, in turn, configured to control operation of a motor. Each module may be, for example, a contactor configured to enable or disable a motor, a reversing contactor configured to additionally control direction of rotation of the motor, a starter configured to accelerate and/or decelerate a motor according to a preset ramp or acceleration profile, or a motor drive configured to control operation of the motor according to a position, velocity, or torque command. Additional modules may be provided, for example, that measure voltage anchor current being conducted along a bus within the MCC and that display the information to a technician. Each module is inserted into one of the slots on the MCC. Empty slots may receive a cover plate to prevent access internal to the MCC during operation. 
     Modules are configured to be inserted into and removed from the MCC with the module in an off condition. It is contemplated that an individual slot may be accessed with power supplied to the MCC, allowing “hot-swaps” of a module that has failed or insertion of a new module without requiring all motors controlled by the MCC to be shut down. A cover plate is removed, or an old module removed, and a new module is inserted into one of the slots. After insertion into the slot, a handle, also referred to herein as a connection handle, is used to fully engage the module within the MCC. During insertion, the connection handle is initially in an off position. The module is inserted a first distance into the MCC by manual insertion. The connection handle may then be moved between an off position and a test position. In the test position, the module is drawn further into the MCC, establishing connections with control power and network communications. The connection handle may be moved still further to an on position, where moving the handle to the on position mechanically draws the module still further into the MCC, during which contacts on the module engage the bus bars within the MCC and connect the module to the power distributed within the MCC. 
     The connection handle is configured to transition between each of the off, test, and on positions. In one embodiment, the handle may transition sequentially from an off position, to a test position, and then to an on position. In another embodiment, the off position may be a central position and the handle may transition in one direction to a test position and in the opposite direction to an on position. It is contemplated that the handle may include detents, a cam configuration, or some other mechanical assembly which offers some resistance to movement of the connection handle or otherwise provides tactile feedback to a technician that the handle has physically transitioned, between two positions. The potential exists, however, that the connection handle may be moved in an undesired manner during insertion of the module to the MCC. In the first embodiment, the handle may inadvertently travel too far from the off position to the on position when the intention was to stop at the test position. In the second embodiment, the handle may inadvertently be moved in the incorrect direction to an on position rather than to a test position. Consequently, the potential exists that the module may be unintentionally connected to the line power without first completing desired testing of the module. 
     Thus, it would be desirable to provide a system for initially interlocking the connection handle of a module for a motor control center (MCC) as the connection handle transitions between positions to prevent an undesired motion to the on position. 
     BRIEF DESCRIPTION 
     According to one embodiment of the invention, an apparatus for interlocking selection of an operating mode for a module in a motor control center includes a housing, a first elongated member, a second elongated member, a guide member, and a spring. The housing has a first end and a second end, a first opening in the first end, a second opening in the second end, and a cavity extending through the housing from the first opening to the second opening. The first elongated member is configured to be mounted within the housing and to extend through the first opening. The first elongated member includes a first channel extending along a first length of a surface of the first elongated member, a second channel extending along a second length of the surface of the first elongated member, the second length greater than the first length, and a third channel extending between the first channel and the second channel. The guide member is mounted within the housing and is configured to selectively engage the first channel, the second channel, or the third channel. The second elongated member is configured to be mounted within the housing and to extend through the second opening. The second elongated member has a first end configured to engage the first elongated member within the housing and a second end positioned outside the housing. The spring has a first end mounted to the first elongated member and a second end configured to engage a spring seat at the second end of the housing. 
     According to another embodiment of the invention, an apparatus for interlocking selection of an operating mode for a module in a motor control center includes a housing, an actuator and a spring. The housing has a cavity extending a length of the housing. The actuator includes a first part extending, at least in part, from a first end of the housing and a second part extending, at least in part, from a second end of the housing. The first part of the actuator is configured to receive a compression force and a rotational force, and the second part of the actuator is configured to engage the first part of the actuator within the housing. The spring is mounted within the housing. The first part of the actuator is configured to move between a first orientation and a second orientation responsive to the rotational force. The first part of the actuator enters a first end of the housing a first distance in the first orientation responsive to the compression force, and the first part of the actuator enters the first end of the housing a second distance in the second orientation responsive to the compression force. The spring returns the first part of the actuator to an extended position when the compression force is removed. The second part of the actuator engages the first part of the actuator to extend from and retract into a second end of the housing when the first part of the actuator enters and exits the first end of the housing, and the second part of the actuator is configured to maintain a consistent orientation when the first part of the actuator rotates between the first and second orientations. 
     According to still another embodiment of the invention, a method kw interlocking selection of an operating mode for a module in a motor control center is disclosed. An actuator is pressed to move the actuator from a first position to either a second position or a third position. The actuator includes a first channel extending between the first position and the second position, and the actuator includes a second channel extending between the first position and the third position, where the second channel has a greater length than the first channel. The actuator includes a guide member configured to engage either the first channel or the second channel. A connection handle, extending from a front surface of the module, is moved between one of a plurality of positions, where the operating mode corresponds to the position of the connection handle. The connection handle is movable only between a first position and a second position when the guide member engages the first channel, and the connection handle is movable to a third position when the guide member engages the second channel. 
     These and other advantages and features of the invention will become apparent to those skilled in the art from the detailed description and the accompanying drawings. It should be understood, however, that the detailed description and accompanying drawings, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various exemplary embodiments of the subject matter disclosed herein are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout, and in which: 
         FIG. 1  is a perspective view of a module incorporating one embodiment of the invention; 
         FIG. 2  is a top plan view of the module of  FIG. 1  with an actuator assembly according to one embodiment of the invention in a first position and with a linking plate interlocking a connection handle in an off position; 
         FIG. 3  is a top plan view of the module of  FIG. 1  with the actuator assembly according to one embodiment of the invention in a second position, with the linking plate interlocking the connection handle in either an off position or a test position, and with the connection handle in the off position; 
         FIG. 4  is a top plan view of the module of  FIG. 1  with the actuator assembly according to one embodiment of the invention in the second position, with the linking plate interlocking the connection handle in either an off position or a test position, and with the connection handle in the test position; 
         FIG. 5  is a top plan view of the module of  FIG. 1  with the actuator assembly according to one embodiment of the invention in a third position, with the linking plate no longer interlocking the connection handle, and with the connection handle in the on position; 
         FIG. 6  is a top plan view of the actuator assembly of  FIGS. 1-5 ; 
         FIG. 7  is a side elevation view of the actuator assembly of  FIGS. 1-5 ; 
         FIG. 8  is a partial sectional view of the actuator assembly of  FIG. 6  in an uncompressed position; 
         FIG. 9  is a partial sectional view of the actuator assembly of  FIG. 6  in a compressed position; 
         FIG. 10  is a perspective view of a housing for the actuator assembly of  FIG. 6  from the front, top, and side; 
         FIG. 11  is a perspective view of the housing for the actuator assembly of  FIG. 6  from the top, side, and rear; 
         FIG. 12  is a perspective view of a first part of an actuator for the actuator assembly of  FIG. 6 ; 
         FIG. 13  is a top plan view of the first part of the actuator of  FIG. 12 ; 
         FIG. 14  is a bottom plan view of the first part of the actuator of  FIG. 12 ; 
         FIG. 15  is a perspective view of a second part of the actuator for the actuator assembly of  FIG. 6  from the front, top, and side; 
         FIG. 16  is a perspective view of the second part of the actuator for the actuator assembly of  FIG. 6  from the top, side, and rear; and 
         FIG. 17  is a front elevation view of an exemplary motor control center incorporating one embodiment of the present invention. 
     
    
    
     In describing the various embodiments of the invention which are illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, it is not intended that the invention be limited to the specific terms so selected and it is understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose. For example, the word “connected,” “attached,” or terms similar thereto are often used. They are not limited to direct connection but include connection through other elements where such connection is recognized as being equivalent by those skilled in the art. 
     DETAILED DESCRIPTION 
     The various features and advantageous details of the subject matter disclosed herein are explained more fully with reference to the non-limiting embodiments described in detail in the following description. 
     The subject matter disclosed herein describes a system for initially interlocking the connection handle of a module for a motor control center (MCC) as the connection handle transitions between positions to prevent an undesired motion to the on position. Selection of an operating mode for the module is performed by a dual action process. As discussed above, the module may be placed in three operating states, namely an off operating state, a test operating state, or an on operating state. The connection handle extends from the front of the module and may be manually transitioned between one of three positions to select the desired operating state. 
     A second actuator is provided to work with the connection handle to perform the dual action process. The second actuator is configured to receive either a compression force or a rotational force. The end of the second actuator extending from the front of the module may be a push button with a handle portion, allowing the button to either be pressed into the module or rotated within the module. The rotational motion is used to transition the second actuator between a first orientation and a second orientation. In the first orientation, the second actuator is configured to be inserted a first depth into the module, and in the second orientation, the second actuator is configured to be inserted a second depth into the module, where the second depth is greater than the first depth. 
     The second actuator engages a locking plate which, in combination with each other, act to interlock motion of the connection handle, preventing inadvertent motion of the connection handle. The end of the second actuator internal to the module engages the locking plate to move the locking plate between different positions. When the second actuator is not pressed, the end of the second actuator internal to the module either does not engage the locking plate or engages the locking plate only to an extent that allows the locking plate to fully engage the connection handle. When the locking plate fully engages the connection handle, the connection handle may not change position. As a result, the connection handle may not be independently moved without the additional use of the second actuator. With the second actuator in the first position, the second actuator may only be pressed into the module for the first depth. At the first depth, the end of the second actuator internal to the module engages the locking plate such that the locking plate allows the connection handle to transition between the off position and the test position. With the second actuator in the second position, the second actuator may be pressed into the module for the second depth. At the second depth, the end of the second actuator internal to the module engages the locking plate such that the locking plate disengages the connection handle and the connection handle may be moved between any desired position. Thus, during initial installation, the second actuator is oriented into the first position, and the connection handle may only move between the off and test positions. After testing of the module is complete, the second actuator may be rotated to the second position, and the connection handle is now free to move between the off, test, and on positions. 
     Turning initially to  FIG. 1 , one embodiment of a module  10  for insertion into a MCC  20  (see also  FIG. 1 ) is illustrated. Each MCC  20  includes at least one and typically a number of vertical columns  22 . Multiple modules  10  may be inserted into each column. The module  10  has a housing  15  which is generally a box-like construction, and is also referred to sometimes as drawer, for insertion into the MCC  20 . The module  10  is illustrated from the front  12 , side  14 , and top  16 . It is noted that relational terms, such as front, rear, top, bottom, upper, lower, left, right, side, and the like, are used with respect to the figures for ease of description and are not intended to be limiting. The module  10  may, for example, be inserted into a slot within the MCC  20  in a horizontal orientation or a vertical orientation by rotation of the module  10  and by which relational terms are similarly rotated. 
     Each module  10  includes a connection handle  30  and a second actuator  100  which must be activated in tandem with the connection handle  30  to permit motion of the connection handle  30 . With reference also to  FIGS. 2-5 , the connection handle  30  may be moved between one of three positions to select a desired operating mode of the module  10 . The connection handle  30  is mounted to a rotating plate  40  within the module  10 . The rotating plate  40  is pivotally mounted around a hub  41  in the rotating plate  40 . The rotating plate  40  also includes three detents  42 ,  44 ,  46  corresponding to desired positions of the connection handle. A first detent  42  may correspond to an off operating state of the module  10 , a second detent  44  may correspond to a test operating state of the module  10 , and a third detent  46  may correspond to an on operating state of the module  10 . Each detent  42 ,  44 ,  46  is configured to receive a protruding member  62  of a locking plate  60 . When the protruding member  62  extends into one of the detents  42 ,  44 ,  46 , the rotating plate  40  and, in turn, the connection handle  30  are prevented from moving to another position. As will be discussed in more detail below, the second actuator  100  engages the locking plate  60  to selectively position the protruding member  62  and, in turn, selectively allow rotation of the connection handle  30 . 
     Turning next to  FIGS. 6-9 , one embodiment of the second actuator  100  is illustrated. The illustrated embodiment of the second actuator  100  includes a housing  110 , a first elongated member  140 , a second elongated member  170 , a guide member  160 , and a spring  180 . As shown in  FIG. 2 , the housing  110  is used to mount the second actuator  100  to the front  12  of the module  10 . The second housing  110  is configured to be inserted through an opening in the front  12  of the module  10 . A first end  120  of the housing  110  includes a collar portion  114 , where the collar portion has a diameter greater than the rest of the housing and is configured to seat against the front  12  of the module rather than extend further through the opening. The housing  110  also includes a threaded portion  112  extending for a distance along the length of the housing proximate to the inner surface of the module  10  when the housing  110  is inserted into the module. A nut  115  may be threaded on to the threaded portion  112  of the housing  110  and rotated until it engages the inner surface of the module  10 . The nut  115  may be tightened to secure the front  12  of the module  10  between the nut  115  and the collar portion  114  of the housing  110  thereby mounting the housing  110  to the module  10 . The use of a nut  115  and threaded portion on the housing  110  is an exemplary method of mounting the housing  110  to the module  10  and is not intended to be limiting. It is contemplated, for example, that a groove on the housing may positioned adjacent the interior surface of the front  12  of the module when the housing  110  is inserted and a retaining clip may be press fit into the groove to prevent removal of the housing  110  from the module. Still other methods of mounting the housing  110  to the module may be utilized without deviating from the scope of the invention. 
     With reference also to  FIGS. 10 and 11 , the housing  110  includes a first end  120  and a second end  122  opposite the first end. The first end  120  includes a first opening  121 , and the second end  122  includes a second opening  123 . A cavity  126  extends through the housing  110  from the first opening  121  in the first end  120  to the second opening  123  in the second end  121  The first opening  121  is circular, allowing rotation of the first elongated member  140  within the opening. The second opening  123  includes a keyed element, and the second elongated member  170  includes a complementary keyed element preventing rotation of the second elongated member  170  within the second opening  123 . According to the illustrated embodiment, the keyed element of the second opening  123  and of the second elongated member  170  is a non-circular opening. The second opening  123  includes a first, circular segment  128  and a second, flat segment  129 . The second elongated member  170  is configured with a sectional profile that corresponds to the shape of the second opening  123  such that the second elongated member slides within the opening. It is contemplated that the shape of the second opening  123  and the sectional profile of the second elongated member  170  may take numerous configurations without deviating from the scope of the invention. For example, the second opening  123  may be oval or square or, alternately, be circular with a tab protruding from one portion of the circular section. The second elongated member  170  may similarly have a sectional profile that is oval or square or, alternately be circular with a channel configured to receive the tab. 
     With reference also to  FIGS. 12-14 , the first elongated member  140  forms a first, rotatable element of the actuator assembly  100 . The first elongated member  140  includes a first end  141  and a second end  143  opposite the first end. The first end  141  of the first elongated member  140  includes a handle portion  142  configured to remain external to the module  10  when the actuator assembly  100  is mounted to the module, and the second end  143  of the first elongated member  140  is configured to be located within the housing  110 . The handle portion  142  is configured to receive both a compression force and a rotational force from personnel manually engaging the actuator assembly  100 . The handle portion  142  has a depth, D, extending from the first end  141  of the first elongated member  140  for a portion of the length of the first elongated member  140 . The outer periphery of the handle portion  142  furthest from the first end  141  has an outer periphery  144  that has the greatest sectional area of the handle portion  142 . A narrow center segment  146  of the handle portion  142  extends between sides of the handle portion  142  proximate to the first end  141  of the first elongated member  140 . The center segment  146  of the handle portion  142  includes side surfaces extending generally orthogonal to the first end  141  for a portion of the depth, D, of the handle portion and then the side surfaces curve outward toward the outer periphery  144  of the handle portion. The orthogonal side surfaces of the center segment  146  are configured to be gripped on either side and to receive the rotational force, causing the first elongated member  140  to rotate within the housing  110 . The curved surfaces toward the bottom of the handle portion are configured to receive a compression force, causing the first elongated member  140  to move into the housing  110 . According to the illustrated embodiment, the handle portion  142  also includes an arrow segment  148  at one end of the center segment  146 . The arrow segment  148  may be used to point toward an indicator affixed to the front  12  of the module  10  to identify the orientation of the first elongated member  140  within the housing  110 . The arrow segment  148  is an exemplary indicium provided on the handle portion  142  to identify the orientation of the handle portion  142 , Optionally, the center segment  146  may include, for example, a sticker, a painted surface, or other indicia to identify one end of the center segment and to point toward the complementary indicator affixed to the front  12  of the module  10  to identify the orientation of the first elongated member  140 . 
     The first elongated member  140  also includes a slidable portion  150  configured to move into and out of the housing  110  via the first opening  121  in the housing. The slidable portion  150  includes a first channel  152  and a second channel  154  which each define a length that the first elongated member  140  may move into the housing  110 . The first channel  152  extends longitudinally along the first elongated member  140  for a first length, L 1 , and the second channel  154  extends longitudinally along the first elongated member  140  for a second length, L 2 . The second length, L 2 , is greater than the first length, L 1 . A third channel  156  is defined around the periphery of the first elongated member  140  between the first channel  152  and the second channel  154 . As will be discussed in more detail below, each of the first channel  152 , the second channel  154 , and the third channel  156  is configured to receive a guide member  160 , which extends through an opening  130  in the housing  110 , where the guide member  160  selectively engages one of the channels to define, at least in part, operation of the actuator assembly  100 . 
     With reference to  FIGS. 8 and 9 , one embodiment of the guide member  160  is illustrated. The guide member  160  extends through the opening  130  in the housing  110  and includes a semi-spherical end  162  protruding into the housing  110 , An opposite end  164  may include, for example, a slot  166  configured, for example, to receive a screw driver. An external surface of the guide member  160  may be threaded and an inner periphery of the opening  130  in the housing  110  may also be threaded. The screw driver may be used to insert and secure the guide member  160  into the opening  130 . When inserted into the opening  130 , the semi-spherical end  162  of the guide member  160  engages one of the channels  152 ,  154 ,  156  of the first elongated member. 
     A second elongated member  170  is also fit, at least in part, within the housing  110  of the actuator assembly  100 . With reference to  FIGS. 15 and 16 , the second elongated member  170  includes a first end  172  and a second end  174 . The first end  172  of the second elongated member  170  is fit adjacent to the second end  143  of the first elongated member  140 . The second elongated member  170  extends through the second opening  123  in the second end  122  of the housing  110  and the second end  174  of the second elongated member  170  is configured to be located external to the housing  110 , As previously discussed, the second elongated member  170  is configured with a sectional profile that corresponds to the shape of the second opening  123  such that the second elongated member slides but does not rotate within the second opening  123  of the housing  110 . 
     In operation, either a compression force or a rotational force is applied to the handle portion  142  of the first elongated member  140  to press or rotate the first elongated member  140  within the housing  110 . The actuator assembly is configured to be angularly oriented in one of two positions. The two different angular orientations are illustrated in  FIGS. 8 and 9 . In  FIG. 8 , the arrow segment  148  of the handle portion is pointing to the right as an indication of the first angular orientation. In the first position, the guide member  160  engages the first channel  152  of the first elongated member  140 . In  FIG. 9 , the arrow segment  148  of the handle portion is pointing to the left as an indication of the second angular orientation. In the second position, the guide member  160  engages the second channel  154  of the first elongated member  140 . The third channel  156  connects the first channel  152  and the second channel  154 . When the guide member  160  is positioned at the end of the first channel  152  to which the third channel  156  connects, a rotational force applied to the handle portion  142  rotates the first elongated member  140  within the first opening  121  of the housing  110 . As the first elongated member  140  rotates, the guide member travels in the third channel  156  between the first and second channels. When the guide member  160  reaches the second channel  154 , the guide member prevents further rotation and the first elongated member is in the second angular orientation. With the guide member  160  located in the second channel  154  and aligned with the third channel  156 , a rotational force in the other direction similarly causes the first elongated member  140  to return to the first angular orientation. 
     A compression force applied to the handle portion  142  will cause the first elongated member  140  to move into the housing  110  for different lengths as a function of the angular orientation at which the first elongated member  140  is located. With reference again to  FIGS. 8 and 14 , the first elongated member  140  is located in the first angular orientation, and the guide member  160  is in the first channel  152 . The first channel  152  has a first length, L 1 , and the guide member  160  restricts travel of the first elongated member  140  inward and outward with respect to the housing  110  for the length, L 1 , of the first channel  152 . With reference to  FIGS. 9 and 13 , the first elongated member  140  is located in the second angular orientation, and the guide member  160  is in the second channel  154 . The second channel  154  has a second length, L 2 , and the guide member  160  restricts travel of the first elongated member  140  inward and outward with respect to the housing  110  for the length, L 2 , of the second channel  152 . 
     Movement of the first elongated member  140  into and out of the housing  110  results alternately from a compression force applied to the handle portion  142  and from an opposing force generated by a spring  180  mounted within the housing  110 . The spring  180  has a first end  182  and a second end  184 . The first end  182  of the spring  180  is configured to mount against a first spring seat  176  located at the first end  172  of the second elongated member  170  and against a second spring seat  132  located at the second end  122  of the housing. The spring  180  exerts a force longitudinally along the actuator assembly  100  pushing the first end  172  of the second elongated member  170  against the first elongated member  140  and, in turn, pushing the first elongated member  140  out the first opening  121  in the housing  110 . The guide member  160  in either the first channel  152  or the second channel  154  acts as a stop, engaging one end of the channel and preventing the first elongated member  140  from being ejected from the housing  110 . When a compression force sufficient to overcome the spring force is applied to the handle portion  142 , the compression force causes the first elongated member  140  to slide into the housing  110 . When the guide member  160  is positioned in the first channel  152 , the first elongated member  140  may travel into the housing  110  for the first length, L 1 , the first channel. When the guide member  160  is positioned in the second channel  154 , the first elongated member  140  may travel into the housing  110  for the second length, L 2 , of the second channel. When the compression force is removed, the counter force generated by the spring  180  causes the first elongated member  140  to extend outwards from the housing  110 . 
     Movement of the first elongated member  140  causes movement of the second elongated member  170 . As previously indicated, the first end  172  of the second elongated member  170  is seated against the second end  143  of the first elongated member  140 . When the first elongated member  140  slides in and out of the first opening  121  in the housing  110 , the motion of the first elongated member  140  causes the second elongated member  170  to slide out of and back into the second opening  123  in the housing  110 . However, the keyed nature of the second opening  123  prevents the second elongated member  170  from rotating as the first elongated member  140  rotates. Thus, the second elongated member  170  only moves longitudinally into and out of the housing  110  for the actuator assembly  100  as a result of the application of the compression force to the handle portion  142  or of the countering force generated by the spring  180  but does not rotate with the application of a rotational force to the handle portion  142 . 
     With reference next to  FIGS. 2-5 , operation of the actuator assembly  100  is used to interlock motion of the selection handle  30  and, therefore, to interlock selection of an operating for the module  10  within the MCC  20 . In  FIG. 2 , the module  10  is shown in an off operating state. The connection handle  30  is centrally positioned, the actuator assembly is in the first angular orientation, such that the guide member  160  is engaging the first channel  152 , and no compression force has been applied to the handle portion  142 , such that the first elongated member  140  is fully extending from the housing  110 . The second end  174  of the second elongated member  170  engages the locking plate  60  within the module. According to the illustrated embodiment, a wheel  176  mounted to the second end  174  of the second elongated member  170  engages a ramp  64  on the locking plate  60 . Motion of the second elongated member  170  into the module  10  causes the wheel  176  to engage the ramp  64  and to draw the locking plate  60  away from the rotating plate  40  to which the connection handle  30  is mounted. Optionally, the second end  174  of the second elongated member  170  may have an angled surface configured to engage the ramp  64  on the locking plate  60 . With no compression force applied, the second elongated member  170  is fully retracted within the housing  110  of the actuator assembly  100  and the second end  174  of the second elongated member  170  is positioned at a first end of the ramp  64 . The locking plate  60 , in turn, fully engages one of the detents  42 ,  44 ,  46  in the rotating member  40  preventing rotation. 
     In  FIGS. 3 and 4 , a compression force has been applied to the handle portion  142  of the first elongated member, and the first elongated member  140  is pressed into the housing  110  for the first length, L 1 , of the first channel  152 . The second elongated member  170  has, in turn, been displaced out the second opening  123  of the housing  110 , and the second end  174  of the second elongated member  170  moves along the ramp  64  on the locking plate  60 . As the second end  174  of the second elongated member  170  engages the ramp  64 , the locking plate  60  is drawn away from the rotating plate  40 . With the first elongated member  140  fully pressed into the housing in the first orientation, the connection handle  30  may be rotated between the off and the test positions. The connection handle  30  is shown in the off position in  FIG. 3  and in the test position in  FIG. 4 . The protruding member  62  on the locking plate allows rotation between the first detent  42  (off operating state) and the second detent  44  (test operating state) while preventing rotation to the third detent  46  (on operating state). As a result, with the first elongated member  140  in the first angular orientation, the actuator assembly allows the module  10  to be selectively put in only the off operating state or the test operating state and prevents the module  10  from being put in the on operating state, During initial insertion, therefore, the actuator assembly  100  is configured with the first elongated member  140  in the first angular orientation to prevent inadvertent movement of the connection handle  30  to the on operating stated. 
     Once the module  10  has completed testing, the actuator assembly  100  may be moved to the second angular orientation to allow the module to be put into the on operating state. The rotational force is applied to the handle portion  142  of the first elongated member  140 , rotating the first elongated member  140  from the first angular orientation to the second angular orientation. With the guide member  160  in the second channel  154 , the compression force applied to the handle portion  142  may now cause the first elongated body  140  to fully insert into the housing  110 . The second elongated body  170 , in turn, extends fully from the second end  122  of the housing  110 , and the second end  174  of the second elongated body  170  fully engages the ramp  64  on the locking plate  60 . The protruding member  62  on the locking plate  60  is drawn a sufficient distance from the rotating plate  40  to allow the rotating plate to move between any of the three detents  42 ,  44 , and  46 . Thus, the module  10  may be put into any desired operating state, including the on operating state. The connection handle  30  is illustrated in the on operating state in  FIG. 5 . 
     After a desired operating state has been selected, the compression force to the actuator assembly  100  is removed and the spring  180  forces the first and second elongated bodies hack to their original position. The second end  174  of the second elongated body  170  moves back to the first end of the ramp  64  and the protruding member  62  on the locking plate  60  engages the detect  42 ,  44 ,  46  corresponding to the selected operating state. Transition between operating states requires a two-step actuation process, where the actuator assembly is oriented in the desired orientation and pressed in for the desired depth to remove the locking plate  60  from the rotating plate  40  and then allowing the connection handle  30  to move between positions corresponding to a desired operating state. 
     It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. The invention is capable of other embodiments and of being practiced or carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. 
     In the preceding specification, various embodiments have been described with reference to the accompanying drawings. It will, however, be evident that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense,