Abstract:
A boom mountable breaker system and a method of using same for interrupting electrical transmission through a portion of an energized conductor downstream of a desired break location. The method includes: mounting the jumper onto the energized conductor across the desired break location so as to form an electrically conductive first parallel electrical path; installing an in-line opener in the energized conductor at the desired break location on the energized conductor; positioning the breaker at the desired break location on the energized conductor, and electrically connecting the breaker, while open, across the desired break location and across the opposite ends of the jumper so as to form a second parallel electrical path when the breaker is closed; closing the breaker to thereby complete the second parallel electrical path; removing the jumper from across the desired break location; and, opening and then removing the breaker.

Description:
FIELD OF INVENTION 
       [0001]    This disclosure generally relates to overhead power transmission lines. In particular, the disclosure relates to a boom mountable breaker and methods of using same for working on overhead power transmission lines. 
       BACKGROUND 
       [0002]    Electric power transfer systems use one or more phases of conductors to transfer electric current within a grid. The conductors may be used for bulk transmission from a power generating plant to centers of high demand and for distribution within the centers of high demand. The conductors are supported above the ground by support structures, including towers, which are usually of metal lattice construction, and poles, which maybe of wood, cement or steel (collectively referred to herein as support structures). 
         [0003]    Over time one or more parts of the electric power transfer system may require maintenance or the installation of new equipment. For example, one or more sections of the conductors may require repair or replacement. One or more of the support towers may also require repair or replacement. Additionally, new equipment, such as sub-stations may be added to the system. For the safety of workers and equipment, the flow of electrical current is often shut off before maintenance, construction or other operations are performed. 
         [0004]    U.S. Pat. No. 7,535,132 entitled “Live Conductor Stringing and Splicing Method and Apparatus” describes a variety of approaches that address working on live conductors. 
       SUMMARY 
       [0005]    The present invention provides an apparatus for interrupting electrical transmission through conductors that includes using a boom mounted breaker. In one embodiment, a boom mounted breaker is mounted on an extendible and retractable arm that is rotatably connected to a vehicle. A support base may be pivotally connected to the arm at the end of the arm distal from the vehicle, and the breaker mounted on the support base. The breaker is actuable between a closed position and an open position. When in the closed position the breaker is a conductor and when in the open position the breaker is an insulator. Actuation and pivoting of the breaker is remotely controlled by an operator. Advantageously, the pivoting of the support base is at least in a vertical plane. 
         [0006]    Another embodiment of the present invention provides a boom mountable breaker for mounting on the end of a boom, the boom mountable breaker includes: a boom adaptor mountable onto the end of the boom, a platform pivotally mounted onto the boom adaptor for pivoting in at least a vertical plane, a selectively actuable actuator mounted to, so as to cooperate between, the boom adaptor and the platform, whereby actuation of the actuator selectively pivots the platform relative to the boom adaptor. A selectively operable electrical circuit breaker is mounted on, so as to be electrically insulated and upstanding from, the platform. 
         [0007]    Another embodiment of the present invention provides a method that interrupts the transmission of electricity through a section of a power transfer system, wherein an in-line opener has been installed in the energized conductor at a desired break location by using a jumper to form a first parallel electrical path. The method comprises the steps of positioning the breaker proximal to the live conductor, and electrically connecting the breaker in an open position across the desired break location, including across both the in-line opener and jumper, and then closing the breaker so as to form a second parallel electrical path. The inline opener prevents the transmission of current load, so that, once the jumper is then removed, the breaker may be opened to safely interrupt the electrical transmission on a high voltage conductor. The breaker may then be removed. 
         [0008]    Another embodiment of the present invention provides a method of using a boom mountable breaker for selectively interrupting electrical transmission in a portion of an energized conductor, wherein, the method comprises the steps of providing: (i) a boom adaptor mountable onto the end of a boom, (ii) a platform pivotally mounted onto the boom adaptor, (iii) a selectively actuable actuator mounted to, so as to cooperate between, the boom adaptor and the platform, whereupon actuation of the actuator selectively pivots the platform relative to the boom adaptor, (iv) a selectively operable electrical circuit breaker mounted on, so as to be electrically insulated and upstanding from, the platform; mounting the boom adaptor onto the end of a boom; positioning the circuit breaker using the actuator and boom into a position proximal the portion of the energized conductor to be interrupted; with the circuit breaker in an open, non-electrically conducting condition, electrically connecting the circuit breaker to upstream and downstream positions on the energized conductor so as to bridge the circuit breaker across the segment of the energized conductor to be interrupted at the desired break location, and across an in-line opener on the conductor at the desired break location and the installed jumper used to install the in-line opener; closing the circuit breaker; then removing the jumper, and then opening the breaker thereby electrically interrupting the downstream portion of the conductor. 
         [0009]    The present invention may allow for a safer and quicker interruption of electrical transmission by positioning the breaker proximal to the energized conductor. For example, electrical connection of the breaker to the energized conductor requires shorter lengths of conductive connecting wires, which are easier to handle safely in comparison to wires that extend to the surface below the energized conductor such as illustrated using the prior art equipment method depicted in  FIGS. 15 and 16  wherein a circuit breaker is mounted on a ground level trailer. Furthermore, shorter lengths of conductive connecting wires may be more easily handled in a safe manner when they are disconnected from the energized conductor. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0010]    Various examples of the apparatus are described in detail below, with reference to the accompanying drawings. The drawings may not be to scale and some features or elements of the depicted examples may purposely be embellished for clarity. Similar reference numbers within the drawings refer to similar or identical elements. The drawings are provided only as examples and, therefore, the drawings should be considered illustrative of the present invention and its various aspects, embodiments and options. The drawings should not be considered limiting or restrictive as to the scope of the invention. 
           [0011]      FIG. 1  is front elevation view of an example support tower for supporting conductors and static wires of an overhead power line system. 
           [0012]      FIG. 2  is the diagrammatic, side elevation view of two example support towers that support a conductor therebetween and form a section of the overhead power line system of  FIG. 1 . 
           [0013]      FIG. 3  is the diagrammatic, side elevation view of  FIG. 2  showing the installation of a jumper line. 
           [0014]      FIG. 4  is the diagrammatic, side elevation view of  FIG. 3  showing the installation of an electrically insulated inline opener. 
           [0015]      FIG. 5  is the diagrammatic, side elevation view of  FIG. 4  showing the positioning of a first boom mounted breaker below the jumper line. 
           [0016]      FIG. 6  is the diagrammatic, side elevation view of  FIG. 5  showing the connecting of the conductor to the first boom mounted breaker, with the breaker in an open position. 
           [0017]      FIG. 7  is the diagrammatic, side elevation view of  FIG. 6  showing the first boom mounted breaker in a closed position. 
           [0018]      FIG. 8  is the diagrammatic, side elevation view of  FIG. 7  showing the removal of the jumper line. 
           [0019]      FIG. 9  is the diagrammatic, side elevation view of  FIG. 8  showing the first boom mounted breaker in the open position for de-energizing a downstream portion of the conductor. 
           [0020]      FIG. 9 a    is an enlarged view of a portion of  FIG. 9 . 
           [0021]      FIG. 10  is the diagrammatic, side elevation view of  FIG. 9  showing the first boom mounted breaker removed from the section of the overhead power line system. 
           [0022]      FIG. 11  is the diagrammatic, side elevation view the section of the overhead power line system of  FIG. 4  showing the connecting of the conductor to the second boom mounted breaker, which is in an open position. 
           [0023]      FIG. 12  is the diagrammatic, side elevation view of  FIG. 11  showing the second boom mounted breaker in a closed position. 
           [0024]      FIG. 13  is the diagrammatic, side elevation view of  FIG. 12  showing the removal of the jumper line. 
           [0025]      FIG. 14  is the diagrammatic, side elevation view of  FIG. 13  showing the second boom mounted breaker in the open position. 
           [0026]      FIG. 15  is a side elevation view of the first boom mounted breaker. 
           [0027]      FIG. 16  is a side elevation view of the second boom mounted breaker. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]      FIG. 1  depicts an example support structure  12  that is used in an electric power transfer system  1000 . The electric power transfer system  1000  may comprise one or both of transmission systems or distribution systems. Support structures  12  may also be support poles, towers, pylons or other structures all of which are referred to herein collectively as support structures. The support structure  12  is depicted as comprising two support poles  11 , but this is not intended to be limiting. For example, the support structures  12  may comprise a single support pole, multiple support poles, latticed support towers or combinations thereof, as would be known to one skilled in the art. The support structure  12  has a cross arm  14  that supports an insulator or insulators  16  from which a conductor  20  is supported. 
         [0029]      FIG. 1  depicts three phases of conductors  20 ; namely, conductors  20 A,  20 B, and  20 C. Each conductor  20  is supported by at least one corresponding insulator  16  and each conductor  20  may or may not be energized with flowing electric current and/or have a voltage potential. Energized conductors  20  may also be referred to as hot, live or electrified. While  FIG. 1  depicts three phases of conductors  20 , this is not intended to be limiting, as there may be one, two, three, or more phases of conductors  20 .  FIG. 1  also depicts the three phases as being spaced from one another in a horizontal plane with a single conductor  20  for each phase, this is not intended to be limiting. For example, the overhead power transfer system  1000  may comprise phases that are spaced apart in a vertical or non-vertical plane and each phase may comprise multiple conductors  20 . 
         [0030]    When the conductors  20  are energized the conductors  20  conduct high-voltage electricity (for example, above 69 kV or more) for bulk transmission of power from a power plant to both high demand sub-stations and rural sub-stations. 
         [0031]    The support structure  12  may also include an upper portion  15  that supports one or more static lines  18 , which may also be referred to as optic lines or shielding lines. Typically, the static lines  18  are not energized. Rather, the static lines  18  provide protection from lighting strikes and, optionally, they may be or include fiber optic cables that are used to transfer optical signals. 
         [0032]      FIG. 2  is a side elevation view of a section  10  of the electric power transfer system  1000 . The section  10  is depicted, without intending to be limiting, as including two support structures  12 A and  12 B that support one or more conductors  20  and one or more static lines  18  therebetween. Support structures  12 A and  12 B may comprise the same features of one or more support poles  11 , a cross arm  14 , an insulator  16  and an upper portion  15 , or not. The section  10  may comprise one or more phases of conductors  20  and one or more static lines  18 . 
         [0033]    Arrow “X” indicates the direction that electrical current is being transferred through the section  10 , from support structure  12 A to support structure  12 B. Electric current enters the section  10  first at an upstream end of the section  10  near to the support tower  12 A and then exits the section  10  at a downstream end of the section  10 , which may be near the support tower  12 B. The upstream end of the section  10  may also be referred to as the load end. The distance between the two support towers  12 A, B may be in the order of tens of meters to hundreds or thousands of meters. 
         [0034]    Often times it is desired to stop the flow of electric current through the section  10 . For example, maintenance operations may be required on the overhead power transfer system  1000  at a portion that is downstream of the section  10  or it may be necessary to install new equipment downstream of the section  10 . Therefore, it is desirable to stop the flow of current for the safety of the line workers. Various embodiments of the present invention comprise the use of a circuit breaker to create an alternate circuit for the purpose of stopping the flow of current through the section  10 . 
         [0035]      FIG. 3  depicts a step of connecting a jumper  22  to the conductor  20  within section  10 . The jumper  22 , which may also be referred to as a jumper line, and may be rated based upon the ability to conduct the entire current load that is flowing through the section  10 . In an alternative option, the jumper  22  may be rated to only conduct a portion of the entire current load that is flowing through the section  10  and more than one jumper  22  may be used. When installed, the jumper  22  is electrically connected to the conductor  20  to define a first alternate circuit  28 . The first alternate circuit  28  has an upstream end  28 A and a downstream end  28 B. Similarly, the jumper  22  has an upstream end  22 A and a downstream end  22 B. Typically the conductor  20  is energized and, therefore, the jumper  22  can be installed using hot sticks or other live-line techniques. In some instances, however, it may be that the conductor  20  is not energized, for whatever reason, when the jumper  22  is installed and live-line techniques may not be required, keeping in mind that live-line techniques may still be employed if the possibility exists of an induced voltage in the non-energized line. Using techniques known by those skilled in the art, the ends of jumper  22  may be removably installed across where it is desired to install an inline opener  24  in section  10  so that the jumper  22  may subsequently be detached from the conductor  20 . The length of jumper  22  may depend upon the physical characteristics of the section  10 , such as the distance and terrain between the support structures  12 A, B. The length of jumper  22  may also depend upon the electrical characteristics of the section  10 , such as the current load and voltage within the section as would be known to one skilled in the art. The jumper  22  must be long enough to allow the installation of the insulated inline opener  24  seen in  FIG. 4 . Jumper  22  is removably connected using conventional removable connectors such as bolted clamps, etc. 
         [0036]      FIG. 4  shows a step of installing the insulated inline opener  24  on the conductor  20  between the upstream and downstream ends  22 A, B of the jumper  22 . The insulated inline opener  24  may made up of one or more dielectric materials such as, but not limited to, a polymer, a blend of multiple polymers, ceramic or a combination thereof. In a preferred embodiment the insulated inline opener  24  is a polymer insulator that prevents the transmission of current load within the section  10 . 
         [0037]    When the inline opener  24  is installed on the conductor  20 , the entire current load flows through the first jumper  22  around the inline opener  24 , such as via the first alternate circuit  28 . In addition to providing the first alternate circuit  28 , the jumper  22  provides to a worker working in the section  10  a visual cue that the first alternate circuit  28  has been established. 
         [0038]    At high voltages (for example, above 69 kV or more), due to arcing, it may be unsafe to merely disconnect the jumper  22  from the conductor  20  to interrupt current flow or transmission of current load through section  10 . Further, given sufficient high voltages, it may even be impossible to directly electrically disconnect the jumper  22  from the conductor  20  due to the arcing. 
         [0039]      FIG. 5  depicts a step of positioning of a first breaker  100 , into the section  10 , proximal to the conductor  20 . It is understood that the first breaker  100  may be positioned below, and/or to the side, substantially level with, laterally of the conductor  20 , or adjacent combinations thereof. In a preferred embodiment, the first breaker  100  is positioned close, at a distance not less than the minimum approach distance (MAD), to the conductor  20 , so that long lengths of conductive connecting wire (such as for example would be required to reach a circuit breaker positioned on a truck or trailer) are not required to electrically connect the first breaker  100  to the conductor  20 . The MAD is well known to those skilled in the art. 
         [0040]    The first breaker  100  is mounted on the distal end of a boom  101 , which provides a support for a breaker platform or base  106 , that in the illustrated embodiment not intended to be limiting, comprises a lower portion  102 , an upper portion  104  and a support base  106 . The boom  101  may be connected at one end of the lower portion  102  to a vehicle, such as a truck or trailer (not shown). In one embodiment, the boom  101  may be rotatably connected to the vehicle by a rotating pedestal or other known apparatus. The lower portion  102  may comprise one or more extendible and retractable sections that may be telescopically arranged with each other, for changing the axial length of the boom  101 . For example, the length of the lower portion  102  may increase or decrease along a longitudinal axis of the boom  101  (see broken line “Y” in  FIG. 5 ). The upper portion  104  may be connected to the lower portion  102 , opposite from the vehicle. Preferably, the upper portion  104  is made of, or coated in, a dielectric material. The dielectric material prevents electric current from being conducted along or through the upper portion  104 . Optionally, the upper portion  104  may also comprise extendible and retractable sections that move along the longitudinal axis of the boom  101 . 
         [0041]    The support base  106  is connected to the distal end of the upper portion  104 , opposite to the lower portion  102 , for example by means of a boom adaptor  106   a.  The support base  106  is able to pivot into various positions relative to the longitudinal axis of the boom  101 . The first breaker  100  is mounted to the support base  106  so as to be upstanding therefrom. 
         [0042]    The position of the boom  101  may be controlled remotely by an operator. 
         [0043]    For example, the position of the boom  101  relative to the vehicle can be changed, as can the axial length of the boom  101 . Furthermore, the operator can change the position of the support base  106  relative to the upper portion  104 . For example, the support base  106  may be rotated by a scissor linkage  107  mounted along boom adaptor  106   a.  The scissor linkage  107  may include one or more actuators  107   a , whose actuation can be selectively controlled hydraulically, or otherwise, acting on the common hinged joint  107   b  between linkage members  107   c,  as would be known to one skilled in the art. As will also be appreciated by those skilled in the art, changing the position of the support base  106  relative to the upper portion  104  may be achieved by methods and means that are not limited to the scissor linkage  107 . For example, various other pivots, hinges, actuators, telescopic or sliding arrangements or combinations thereof may also be used. 
         [0044]    Positioning of the boom  101  may be controlled by a control system (not shown) which may consist of a hydraulic system (not shown) having hydraulic hoses and valves. For example, the hydraulic system may fluidly connect an auxiliary hydraulic port of the vehicle, the lower portion  102  and the support base  106 . The control system may be remotely operated by means of digital radio signals, fiber optic cables, or other suitable insulated control means. 
         [0045]    U.S. Pat. No. 5,538,207 “Boom-mountable Robotic Arm” and U.S. Pat. No. 8,684,333 entitled “Boom Mountable Robotic Arm”, the entire disclosures of which are incorporated herein by reference, both describe booms that are suitable for use as the boom  101  in the present invention. 
         [0046]    The first breaker  100  can be actuated between a closed position and an open position. When in the closed position the first breaker  100  comprises electrical contacts that are in direct contact with each other and can conduct the electric current that is flowing through the section  10  without generating unacceptable amounts of resistance or heat. When in the open position, the electrical contacts within the first breaker  100  are physically separated and any arcing therebetween has been suppressed so that the first breaker  100  acts as an electrical insulator that does not conduct electric current. Actuation of the first breaker  100  between the closed and open positions is controlled remotely, and may be manually controlled or it may be automatically controlled. In a preferred embodiment, actuation of the first breaker  100  is manually controlled remotely, as seen by way of example in  FIG. 9 , by the operator to permit or stop the flow of current through the first breaker  100  as desired. 
         [0047]      FIG. 5  and corresponding magnified views provided in  FIGS. 9 a    and  15  each depict one embodiment of the first breaker  100  that comprises a boom-mounted control box or housing  108 , a support insulator  110 , a breaking or breaker unit  112 , as used interchangeably herein, or interrupter, having terminals  115 ,  117  at the ends thereof. 
         [0048]    The boom-mounted control box or housing  108  contains an actuating mechanism (not shown) for actuating the first breaker  100  between the open and closed positions. For example, the actuating mechanism may be a single motion or a double motion design that may be selected from, but not limited to, the following: an energy storage mechanism, such as a spring; a driven mechanism, such as an electric motor, a hydraulic motor, a pneumatic-based mechanism; or combinations thereof. 
         [0049]    The support insulator  110  insulates the breaking unit  112  and the terminals  115 ,  117  from earth ground. The support insulator  110  may be a hollow body made of porcelain, or a dielectric composite, that may contain SF 6 . 
         [0050]    The breaking unit  112  houses the electrical contacts of the first breaker  100  and the moving components that couple electrical contacts with the mechanism within the housing  108 . The breaking unit  112  may comprise an extinguishing mechanism for extinguishing any arcing between the electrical contacts when the first breaker  100  is actuated to the open position. For example, the extinguishing mechanism may be a SF 6  puffer design, a SF 6  self-blast design or other types of known extinguishing mechanisms. In one embodiment, the breaking unit  112  comprises an upstream breaking portion  114  and a downstream breaking portion  116 . Optionally, the upstream and downstream breaking portions  114 ,  116  are substantially co-axially aligned with each other along a common longitudinal axis (shown as broken line “Z” in  FIG. 5 ) that is substantially perpendicular to the support insulator  110 . This embodiment of the first breaker  100  may also be referred to as a “T breaker”. Each of the breaking portions  114 ,  116  are made of porcelain, or a composite material, and filled with pressurized SF 6  gas. Because the terminals  115 ,  117  are positioned on either end of the breaking unit  112 , the breaking unit  112  can become live and subject to voltage and current when the first breaker  100  is closed and electrically connected with the conductor  20 . 
         [0051]      FIG. 6  depicts a step of electrically connecting the first breaker  100  to the conductor  20 . This step is preceded by a step of confirming that the first breaker is in the open position. In  FIG. 6 , the first breaker  100  is in an open position and it does not conduct electric current. A conductive connection jumper or wire  118  is connected to the upstream terminal  115  of the first breaker  100  and to the conductor  20 , upstream of the upstream end  22 A of the jumper  22 . Another conductive connection jumper cable or wire  119  is connected to the downstream terminal  117  and the conductor  20 , downstream of the downstream end  22 B of the jumper  22 . The conductive connection wires  118 ,  119  may also be rated to handle the voltage and current load within the section  10 . For example, the gauge of conductive connection wires  118 ,  119  may be the same as the jumper  22 . 
         [0052]      FIG. 7  depicts a step of actuating the first breaker  100  to the closed position. In the closed position, electric current can be conducted through the first breaker  100 . Together, the conductive connection wires  118 ,  119  and the first breaker  100  define a second alternate circuit  128 . The second alternate circuit  128  has an upstream end  128 A and a downstream end  128 B. The second alternate circuit  128  is parallel to the first alternate circuit  28  and thus at least a portion of the current load in the system  10  diverts through the second alternate circuit and around the first alternate circuit  28  and the inline opener  24 . 
         [0053]      FIG. 8  depicts a step of disconnecting the jumper  22  from the conductor  20  so that the current load within the section  10  flows through the second alternate circuit  128 .  FIG. 9  depicts a step of actuating the first breaker  100  back into the open position. This step generates a de-energized portion  21  of the conductor  20  that is downstream of the first breaker  100 .  FIG. 10  depicts a step of disconnecting the conductive connection wires  118 ,  119  from the conductor  20  and moving the first breaker  100  into a position that is away from the conductor  20 . For example as illustrated the first breaker  100  may be moved completely away from section  10 . 
         [0054]    The first breaker  100  is rated to meet the voltage and current specifications of the system  1000 . In one embodiment, the first breaker  100  is selected from known circuit breakers such as, but not limited to, magnetic breakers, thermal magnetic breakers, and live tank breakers, such as sulfur hexafluoride (SF 6 ) breakers all of which provide intentional actuation between the open and closed positions, as would be appreciated by one skilled in the art. As seen in  FIG. 9  by way of example, a power cord  108   a  runs through travelers  108   e  on the boom  101  from the actuating mechanism in boom-mounted control box  108  to a circuit breaker open/close control box  108   b  at the ground level. The control box  108   b  may for example be mounted on a support truck (not shown). Another power cord  108   c  runs between the circuit breaker open/close control box  108   b  and a generator  108   d  similarly located on or near the ground level, for example on the support truck, etc. 
         [0055]      FIG. 11  depicts another embodiment of the present invention that utilizes a second breaker  200 , better seen in  FIG. 16 , instead of the first breaker  100 .  FIG. 11  depicts the section  10  with the same features described above regarding  FIG. 5  with the difference between  FIG. 5  and  FIG. 11  being the use of the second breaker  200 .  FIG. 11  depicts the second breaker  200  mounted on the support base  106  upon the boom  101 . The second breaker  200  can be actuated between a closed position and an open position. When in the closed position the first breaker  200  comprises electrical contacts that are in direct contact with each other and can conduct the electric current that is flowing through the section  10  without generating unacceptable amounts of resistance or heat. When in the open position, the electrical contacts within the second breaker  200  are physically separated and any arcing therebetween has been suppressed so that the second breaker  200  acts as an electrical insulator that does not conduct electric current. 
         [0056]    One embodiment of the second breaker  200 , which is shown in a corresponding magnified view in  FIG. 16 , comprises a housing  208 , a support insulator  210 , a breaking unit  212  with a primary terminal  215 ,  217  at each end of the breaking unit  112  (see  FIG. 16 ). This embodiment of the second breaker  200  may also be referred to as an “I breaker”. The features of the second breaker  200  perform the same functions as those described above regarding the first breaker  100 . For example, the housing  208  houses a mechanism for actuating the second breaker  200  between the open and closed positions. The support insulator  210  insulates the breaking unit  212  from ground. The breaking unit  212  houses the electrical contacts and the mechanical components that couple the electrical contacts with the mechanism within the housing  208 . As with the breaking unit  112 , the breaking unit  212  may comprise an extinguishing mechanism for extinguishing any arcing between the electrical contacts when the second breaker  200  is actuated to the open position. For example, the extinguishing mechanism may be a SF 6  puffer design, a SF 6  self-blast design or other types of known extinguishing mechanisms. 
         [0057]    As depicted in  FIG. 11 , the second breaker  200  is electrically connected to the conductor  20  on either side of the jumper  22  by conductive connection wires  216 ,  218 . The second breaker  200  is in the open position in  FIG. 11 . 
         [0058]      FIG. 12  depicts a step of actuating the second breaker  200  to the closed position, which creates a third alternate circuit  228 . The third alternate circuit  228  has an upstream end  228 A and a downstream end  228 B. The third alternate circuit  228  is parallel to the first alternate circuit  28  and a portion of the current load in the system  10  diverts around the first alternate circuit  28  and the inline opener  24 . 
         [0059]      FIG. 13  depicts a step of disconnecting the jumper  22  from the conductor  20 . The second breaker  200  is still in the closed position so that the current load within the section  10  flows through the third alternate circuit  228 . 
         [0060]      FIG. 14  depicts a step of actuating the second breaker  200  to the open position. This stops the conduction of the current load through the second breaker  200  resulting in the de-energized portion  21  of the conductor  20  downstream of the second breaker  200 . As described above regarding the first breaker  100 , the second breaker can then be disconnected from the conductor  20  and moved to a position that is away from the conductor  20 . This leaves the section  10  with a portion of live conductor  20  and a de-energized portion  21 . 
         [0061]    While the above disclosure describes certain examples of the present invention, various modifications to the described examples will also be apparent to those skilled in the art. The scope of the claims should not be limited by the examples provided above; rather, the scope of the claims should be given the broadest interpretation that is consistent with the disclosure as a whole.