Abstract:
Disclosed are various embodiments for racking a draw-out circuit breaker. A portable motorized racking device may be connected or disconnected from an racking assembly of the circuit breaker. The portable racking device includes a gearmotor, a drive socket for engaging with the racking screw of the circuit breaker, and a locking disk for securing the portable racking device to the racking assembly of the circuit breaker. The gearmotor may be remotely controlled to rack the draw-out circuit breaker.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. Provisional patent application titled “PORTABLE RACKING DEVICE FOR DRAWOUT CIRCUIT BREAKERS,” filed on Jul. 8, 2014 and assigned application No. 62/021,841, which is incorporated by reference herein in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present disclosure generally relates to the racking of draw-out power air circuit breakers that have a racking mechanism and are operated by rotating a screw mechanism. 
     BACKGROUND 
     In larger power systems, a typical draw-out circuit breaker is connected or disconnected from the energized bus for maintenance or repair by a human operator who physically rotates a racking screw in order to connect or disconnect the breaker from the electrical supply bus. In order to effect the operation described above, a human operator must stand within arms-reach of the circuit breaker, which also means he or she is in close proximity to the circuit breaker. If the circuit breaker should happen to fail catastrophically, the human operator is at risk of serious injury or death from the resulting arc-blast and flying debris. 
     SUMMARY 
     Included are apparatuses, systems, and methods for a portable racking device for draw-out circuit breakers. One embodiment of an apparatus, among others, includes a portable racking device, comprising: a gearmotor comprising a gear box coupled to a motor; a drive socket coupled to an output shaft of the gearmotor, the drive socket sized to engage with a racking screw of a circuit breaker racking assembly; an angled bracket coupled to the gearmotor, the drive socket situated within a hole of a first member of the angled bracket, and a second member of the angled bracket configured to engage with a support angle of the circuit breaker racking assembly; and a locking disk moveably attached to the gearmotor, the angled bracket being disposed between the locking disk and the gearmotor, and the locking disk moveable about an axis of the output shaft of the gearmotor. 
     Another embodiment of an system, among others, includes a racking device system, comprising: a portable racking device detachably attached to a circuit breaker racking assembly of a circuit breaker, the portable racking device comprising: a gearmotor; a drive socket coupled to an output shaft of the gearmotor, the drive socket being engaged with a racking nut of the circuit breaker racking assembly; and a locking disk moveably attached to the gearmotor and situated in a locked position, a portion of the locking disk overlapping a circuit breaker racking assembly support angle of the circuit breaker racking assembly; and a control device in data communication with the portable racking device. 
     Another embodiment of a method, among others, includes a method of remotely racking a circuit breaker, the method comprising: aligning a drive socket of a portable racking device with a circuit breaker racking assembly of the circuit breaker; pushing a sliding breaker interlock of the circuit breaker racking assembly to expose a racking screw of the circuit breaker racking assembly; engaging the drive socket of the portable racking device with the racking screw; and securing the portable racking device to a support angle of the circuit breaker racking assembly. 
     Other embodiments, systems, methods, features, and advantages of this disclosure will be or will become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional apparatuses, methods, features, and advantages be included within this description and be within the scope of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1A  depicts a drawing of an example of a partial view of typical circuit breaker racking assembly, shown in the normal position, according to various embodiments of the present disclosure. 
         FIG. 1B  depicts a drawing of an example of a partial view of the typical circuit breaker racking assembly of  FIG. 1A , shown in the racking position, according to various embodiments of the present disclosure. 
         FIG. 2  depicts a drawing of an example of a portable racking device suitable for use with the circuit breaker racking assembly of  FIGS. 1A and 1B , according to various embodiments of the present disclosure. 
         FIGS. 3A, 3B, 3C, and 3D  depict the process of engaging the portable racking device of  FIG. 2B  with the circuit breaker racking assembly of  FIGS. 1A-1B . 
         FIG. 4A  is a drawing of an example of a front-view of the portable racking device of  FIG. 2  with the locking disk in the unlocked position, according to various embodiments of the present disclosure. 
         FIG. 4B  is a drawing of an example of a front-view of the portable racking device of  FIG. 3  with the locking disk in the locked position and the retaining disk removed, according to various embodiments of the present disclosure. 
         FIG. 5  is a side view of the portable racking device of  FIG. 2  attached to the circuit breaker racking assembly of  FIGS. 1A-1B . 
         FIG. 6A  depicts a drawing of an example of side A of the spacer plate component of the portable racking device of  FIG. 2 , according to various embodiments of the present disclosure. 
         FIG. 6B  depicts a drawing of an example of side B of the spacer plate component of the portable racking device of  FIG. 2 , according to various embodiments of the present disclosure. 
         FIG. 7  is an exploded-view of the portable racking device of  FIG. 2 , according to various embodiments of the present disclosure. 
         FIG. 8  depicts a drawing of an example of a portable remote racking system including the portable racking device of  FIG. 2  according to various embodiments of the present disclosure. 
         FIG. 9  is a flowchart illustrating a method of installing the portable racking device of  FIG. 2  to the circuit breaker racking assembly of  FIGS. 1A-1B  according to various embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In the following discussion, a general description of apparatuses and methods according to various embodiments of the present disclosure is provided, followed by a discussion of the operation of the same. Embodiments of the present disclosure relate to a portable racking system suitable for typical draw-out power circuit breakers. More specifically, disclosed herein are novel approaches to facilitating the remote racking of draw-out power circuit breakers via a portable electrically driven racking device that may be easily affixed to a circuit breaker without the need of permanently modifying the circuit breaker or its enclosure. The portable racking device may be small enough to be stored and/or transported in a hand-held carrying case. 
     Referring now to  FIGS. 1A and 1B , shown are drawings of non-limiting examples of a draw-out circuit breaker racking assembly  200 . Specifically,  FIG. 1A  illustrates a drawing of a partial view of a draw-out circuit breaker racking assembly  200 . The draw-out circuit breaker racking assembly  200 , as will be appreciated by one skilled in the art, is generally included as a portion of a circuit breaker assembly (not shown). The draw-out circuit breaker racking assembly  200  comprises a racking screw engagement nut  202 , a sliding breaker interlock  203 , and a breaker racking assembly support angle  204 . 
       FIG. 1B  is a drawing of a partial view of the circuit breaker racking assembly  200  in the proper position for racking a circuit breaker on and/or off the bus. The sliding breaker interlock  203  has been pushed back to ensure that the circuit breaker is ‘open’ through an interlock mechanism in the circuit breaker (not shown) and the racking screw engagement nut  202  is accessible. It should be noted that while  FIGS. 1A and 1B  illustrate views of a typical draw-out circuit breaker racking assembly  200 , the portable racking device  100  of the present disclosure may be applicable to many other types of draw-out circuit breakers. 
     Referring now to  FIG. 2 , shown is a drawing of a non-limiting example of a portable racking device  100  suitable for attaching to a draw-out circuit breaker racking assembly  200 , according to various embodiments of the present disclosure. The portable racking device  100  comprises a gearmotor  101 , a drive socket  102 , an anti-rotation angle  104 , a locking disk  105 , a retaining disk  106  ( FIG. 7 ), and a spacer plate  107  ( FIG. 7 ). The gearmotor  101  comprises a gear box coupled to a motor. The motor may comprise an alternating current motor, a brushed direct current motor, a brushless direct current motor, and/or any other suitable type of electrically driven motor. The gearmotor  101  may be powered via a power supply  320  ( FIG. 8 ). In some embodiments, the power supply  320  is internal to the portable racking device  100 . In other embodiments, the power supply  320  is external to the portable racking device as shown in  FIG. 8 . The gearmotor  101  may further comprise a motor sensor and motor control circuitry necessary to run the motor of the gearmotor  100  bi-directionally while monitoring the output torque of the gearmotor  101 . In addition, the circuitry may further monitor the number of turns of the racking screw of the draw-out circuit breaker racking assembly  200  for determining the position of the breaker when the portable racking device  100  is engaged with the draw-out circuit breaker racking assembly  200 . Information transmitted to the control device  330  may be used to determine motor current measurement as a function of torque or current. In addition, the distance and direction that the circuit breaker moves at a given time may be determined as a function of revolutions of the racking nut. Motor stall may also be determined from this information. 
     Referring to  FIG. 3C , the drive socket  102  is coupled to the output shaft extending from the gearmotor  101  and may be aligned with the hole in the sliding breaker interlock  203  of the draw-out circuit breaker racking assembly  200 . The drive socket  102  may be used to move the sliding breaker interlock  203  and engage with the racking screw engagement nut  202  ( FIG. 1B ) of the draw-out circuit breaker racking assembly  200  such that rotation of the drive socket  102  rotates the racking screw engagement nut  202 . 
     As shown in  FIG. 5C , the anti-rotation angle  104  may comprise an angled bracket having a primary hole sized to engage with the drive socket  102  that is coupled to the output shaft of the gearmotor  101 . The anti-rotation angle  104  is placed between the locking disk  105  and the gearmotor  101 . The anti-rotation angle  104  extends downwardly from the gearmotor  101  and is configured to engage with the breaker racking assembly support angle  204  of the draw-out circuit breaker racking assembly  200 . 
     As shown in  FIG. 7 , the locking disk  105  comprises a plate having a primary hole and a plurality of semi-circle apertures disposed in a circular configuration substantially surrounding the primary hole. The locking disk  105  may further comprise a handle extending outwardly from the plate. The primary hole of the locking disk  105  is sized to receive the drive socket  102  engaged with the output shaft of the gearmotor  101 . The locking disk  105  is disposed between the spacer plate  107  and the retaining disk  106 . As discussed with respect to  FIG. 7 , the locking disk  105  may be rotated about the axis of the output shaft and drive socket  102  to lock and unlock the portable racking device  100  to and/or from the circuit breaker racking assembly  200 . For example, when the portable racking device  100  is engaged with the circuit breaker racking assembly  200 , the locking disk  105  may be rotated to engage the back side of the breaker racking assembly support angle  204  of the circuit breaker racking assembly  200 , thereby holding the portable racking device  100  in place. When the portable racking device  100  is to be removed from the circuit breaker racking assembly  200 , the locking disk  105  may be rotated in the opposite direction so that the locking disk  105  no longer engages with the back side of the breaker racking assembly support angle  204  allowing the portable racking device  100  to be removed from the circuit breaker racking assembly support angle  204 . 
     In some embodiments, the portable racking device  100  may comprise a video camera  111  ( FIG. 8 ) that obtains images and transmits the images for rendering on a video display  335  ( FIG. 8 ) contained in a remote hand-held control device  330  ( FIG. 8 ). The images rendered on the video display  335  allow a human operator to visually monitor the position and progress of the breaker while it is being racked. 
     Moving on to  FIGS. 3A-3D , shown are drawings of non-limiting examples of the portable racking device  100  in various stages of installation with the circuit breaker racking assembly  200  according to various embodiments of the present disclosure. With reference to  FIG. 3A , shown is the portable racking device  100  detached from the circuit breaker racking assembly  200 .  FIG. 3B  illustrates a drawing of an example of the portable racking device  100  being aligned to engage with the circuit breaker racking assembly  200 . As shown in  FIG. 3B , the drive socket  102  of the portable racking device  100  is aligned with a hole in the sliding breaker interlock  203  of the circuit breaker racking assembly  200 . The diameter of the hole in the sliding breaker interlock  203  is smaller than the diameter of the drive socket  102 . As depicted in  FIG. 3C  the drive socket  102  of the portable racking device  100  is pushed against the sliding breaker interlock  203 , displacing the sliding breaker interlock  203  in the direction of the arrow. As the sliding breaker interlock  203  is moved, the racking screw engagement nut  202  shown in  FIG. 1B  is exposed, and the portable racking device  100  becomes engaged with the circuit breaker racking assembly  200 . Referring next to  FIG. 3D , shown is a drawing of an example of the portable racking device  100  fully engaged with the circuit breaker racking assembly  200 . The handle of the locking disk  105  of the portable racking device  100  has been rotated to latch the portable racking device  100  in place by overlapping a portion of the locking disk over a portion of the circuit breaker racking assembly support angle  204 . 
     To further explain the operation of the portable racking device  100 ,  FIG. 4A  illustrates a drawing of an example of a socket-end view of the portable racking device  100 , shown with the locking disk  105  in the ‘unlatched’ position.  FIG. 4B  illustrates a drawing of an example of the socket-end view of the portable racking device  100  with the locking disk  105 , shown in the ‘latched’ position.  FIG. 4B  is shown without retaining disk  106  that is shown in  FIG. 4A , to clarify the movement of the locking disk  105 . As can be appreciated, the plurality of semi-circular apertures may act as a guide about the screws such that the length of the semi-circular apertures limit the distance of rotation of the locking disk about the portable racking device  100 . 
     Turning now to  FIG. 5 , shown is a drawing of an example of a side view of the portable racking device  100  in the ‘latched’ position according to various embodiments of the present disclosure. For the sake of clarity, only the circuit breaker racking assembly support angle  204  of the circuit breaker racking assembly  200  is shown. Once the vertical flange of the anti-rotation angle  104  is in contact with the vertical flange of the circuit breaker racking assembly support angle  204 , the locking disk  105  is rotated to engage the back side of the circuit breaker racking assembly support angle  204 , thereby holding the portable racking device  100  in place. As such, the locking disk  105  secures the portable racking device  100  to the circuit breaker racking assembly support angle  204  of the circuit breaker racking assembly  200 , and the anti-rotation angle  104  of the portable racking device  100  engages the circuit breaker racking assembly support angle  204 . 
     To further explain the construction of the portable racking device  100 ,  FIG. 7  illustrates a drawing of an example of an exploded view of the portable racking device  100  according to various embodiments of the present disclosure. Four countersunk screws  109  may pass through a spacer plate  107  ( FIGS. 6A and 6B ) and the anti-rotation angle  104 , into the end of the gearmotor  101 . Four additional countersunk head screws  110  pass through the spacer plate  107 , the locking disk  105 , the four spacers  108 , and the retaining disk  106  and are held in place by four locknuts  118 . The locking disk  105  is free to rotate about the axis of the shaft extending form the gearmotor  101  on the spacers  108 .  FIG. 6A  depicts one side of the spacer plate  107 .  FIG. 6B  depicts the opposite side of the spacer plate  107 . The drive socket  102  may passes through the primary hole in the centers of the anti-rotation angle  104 , the spacer plate  107 , the locking disk  105 , and the retaining disk  106  and is mated with output shaft of the gearmotor  101 . 
     Turning now to  FIG. 8 , shown is a drawing of an example of a portable racking system  300  including the portable racking device  100 , according to various embodiments of the present disclosure. The portable racking system  300  may comprise the portable racking device  100 , the power supply  320  and the control device  330 . The portable racking device  100  is equipped with a video camera  111 . The image from the video camera  111  may be displayed on the video display  335  located in the handheld control device  330 . In addition, the operator may control the portable racking device  100  via the handheld control device  330  as may be appreciated by those skilled in the art. The video display  335  may be used to display the motor current measurement value of the portable racking device as a function of torque and/or current. 
     With reference to  FIG. 9 , shown is a flowchart that provides a non-limiting example of a method  900  of various embodiments of the present disclosure. It is understood that the flowchart of  FIG. 9  merely provides examples of the many different types of functional arrangements that may be employed to implement the operation of the methods as described herein. 
     At reference numeral  902 , the portable racking device  100  is aligned with the circuit breaker racking assembly  200  of a circuit breaker prior to attaching. At reference numeral  904 , the portable racking device  100  pushes the sliding breaker interlock  203  of the circuit breaker racking assembly  200  to expose the racking screw engagement nut  202 . As the racking screw engagement nut  202  is exposed, the drive socket  102  engages with the racking screw engagement nut  202  and the bottom portion of the anti-rotation angle  104  engages with the bottom portion of the circuit breaker racking assembly support angle  204 . At reference numeral  906 , the locking disk  105  is rotated to secure placement of the portable racking device  100  with the circuit breaker racking assembly  200 . At reference numeral  908 , the gearmotor  101  is activated to rotate the racking screw engagement nut  202 . At reference numeral  910 , maintenance is performed on the circuit breaker. 
     Although the flowchart of  FIG. 9  shows a specific order of execution, it is understood that the order of execution may differ from that which is depicted. For example, the order of execution of two or more steps may be scrambled relative to the order shown. Also, two or more steps shown in succession in  FIG. 9  may be executed concurrently or with partial concurrence. Further, in some embodiments, one or more of the steps shown in  FIG. 9  may be skipped or omitted. 
     It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.