Abstract:
The present disclosure provides a method and system for mounting a current transformer in proximity to a circuit breaker of an electrical system. Generally, a plurality of current transformers (CTs) are provided to measure a plurality of branches from a main power supply and are accumulated on a sensor module. In at least one embodiment, the sensor module includes a molded polymer mounting support that can support the CTs. The polymer molded mounting support departs from the standard circuit board and is substantially less fragile. A wiring channel is provided within the sensor module so that CT output wiring can be safely routed to the output connector using as few as two soldered connections, rather than the typical six soldered connections required in existing branch monitoring systems. Multiple sensor modules can be stacked to allow continued alignment with the CTs and software/firmware/hardware can allow for any current polarity changes.

Description:
[0001]     This application claims the benefit of U.S. Provisional Patent Application No. 60/686,842 filed Jun. 2, 2005. 
     
    
     FIELD  
       [0002]     This disclosure relates to electrical power systems. More specifically, the disclosure relates to methods for power distribution and electrical protection for electrical power systems.  
       BACKGROUND  
       [0003]     In many premium power applications and power distribution systems, it is desirable to monitor individual branch circuit currents that distribute power from a main line to various circuit loads in an electrical system. An operator can be informed as to which connected loads are in operation, whether connected equipment is idling or fully operating, and whether any individual circuit is approaching overload and should be remedied.  
         [0004]     In collecting data from many scattered circuit loads, current transducers (CTs) are often mounted in the system to gather current flow information. A typical mount is within the circuit breaker panel enclosure, where multiple branches from circuit breakers in the panel can be conveniently monitored from a single location. Thus, a main power supply enters the circuit breaker panel and the power is split into multiple branches having circuit breakers protecting each branch. The CTs are mounted electrically downstream of the circuit breakers in a long circuit board placed adjacent the circuit breakers. In many industrial or data center applications, the connected loads are rarely turned off to be serviced or repaired. Consequently, the reliability of the CTs with their respective board must be very high, since the CTs are toroidal in nature and cannot be removed without disconnecting circuit wiring and interrupting critical power to loads.  
         [0005]     In application, relatively thick wire is fed from the electrical load into the circuit breaker panel, through the appropriate CT for a particular branch, and then into the contacts for the circuit breaker. However, there are several challenges. For example: 
        1. The standard 42-pole panel for circuit breakers has limited space within its housing, typically resulting in the CT board with the corresponding CTs being made long and thin and thereby mechanically weak. Stability and integrity of the system is compromised by the relative weakness of the CT board.     2. High voltage terminations at the individual circuit breaker outputs are very close to exposed current sensor soldered connections and thereby risk dangerous voltages entering the low-voltage control circuit wiring and destroying aspects of the electrical circuit and/or creating a safety hazard.     3. Typical CT boards require many extra soldered connections, directly lowering reliability and performance due to lack of mechanical strength.        
 
         [0009]     Branch circuit monitors to date, such as those disclosed in U.S. Pat. No. 6,330,516 and U.S. Pat. No. 6,809,509, have been built on printed circuit boards and thereby posses the disadvantages listed above. The circuit board is thin and tends to flex as thick branch circuit wires pass through the mounted CTs and can break the soldered connections, seriously impairing the performance of the branch circuit monitor.  
         [0010]     For example,  FIGS. 1A and 1B  are schematic front and end views, respectively, of a prior art arrangement. A circuit breaker panel  2  contains a circuit breaker assembly  4  having a plurality of circuit breakers  6 ,  8 . Conductive wires  10 ,  12  (relatively thick wires depending on the power requirements) feed power from the circuit breakers to loads  14 ,  16 . A circuit board  20  having CTs  22 ,  24  mounted thereon is used to measure current of the wires  10 ,  12  passing through the CTs  22 ,  24  between the circuit breakers and the loads. The CTs can eventually connect to an output connector  18  starting with an output wire  26  from the CT coil wire that is soldered to a pin  28  at a soldered connection  32 . The CT with the pin is assembled to the circuit board  20  by generally extending the pin  28  through a hole in the circuit board and soldering the pin to the circuit board at a soldered connection  34 . The soldered connection  34  is in turn connected to a circuit board line (not shown) formed on the circuit board  20  that leads to another soldered connection at the output connector  18 . A ribbon cable (not shown) can connect to the output connector  18  to carry output from the individual CTs to a monitoring system.  
         [0011]     Each CT conductive path to the output connector has therefore three soldered connections and each CT has two wires for a total of six soldered connections per CT. Generally, there are  21  CTs on a circuit board for  21  circuit breakers, resulting in at least  126  soldered connections per board. For the modem trend of a circuit breaker panel having  42  circuit breakers in line, there are  252  soldered connections for such a typical circuit board branch monitoring system.  
         [0012]     The bending stress  30  caused by pulling the thick wires  10 ,  12  through the CTs is concentrated on the CTs  22 ,  24  and its soldered connections, such as connection  28 , resulting in damage to the unit and therefore the system, more frequently than is desirable. Also, connections on the circuit board are exposed to dangerous voltages from the relatively close wires  10 ,  12 .  
         [0013]     Therefore, there remains a need for improvement in the method of mounting and monitoring branch distribution power in such power applications and related systems.  
       SUMMARY  
       [0014]     The present disclosure provides a method and system for mounting a current transformer in proximity to a circuit breaker of an electrical system. Generally, a plurality of current transformers (CTs) are provided to measure a plurality of branches&#39; power lines from a main power supply and are accumulated on a sensor module. In at least one embodiment, the sensor module includes a molded polymer mounting support that can hold the CTs. The polymer molded mounting support departs from the standard circuit board and is substantially more rugged. A wiring channel is provided within the sensor module so that CT output wiring can be safely routed to the output connector using as few as two soldered connections per CT, rather than the typical six soldered connections per CT required in existing branch monitoring systems. Independent of the number of connections, the disclosure advantageously provides a more rugged packaging and support arrangement than previously used. Multiple sensor modules can be stacked to allow continued alignment with the CTs and software/firmware/hardware can allow for any current polarity changes.  
         [0015]     The disclosure provides a sensor module for wiring in an electrical system, comprising: a first portion of material with a second portion of material being disposed at an angle to the first portion; at least one post coupled to the second portion, the post having an opening therethrough oriented at an angle to the second portion; and at least one current transformer coupled to the post, the current transformer having an aperture aligned with the post opening and the post adapted to insulate the current transformer from a wire passing through the post opening.  
         [0016]     The disclosure also provides a electrical system, comprising: an electrical panel; a plurality of circuit breakers coupled to the electrical panel at an incremental spacing relative to each other; and a first sensor module, comprising: a first flange and a web coupled to the first flange and having a lesser cross sectional thickness than the first flange, the web having a plurality of openings formed therethrough at an angle to the web, and a plurality of current transformers coupled to the web of the molded portion, the current transformers aligned with at least a portion of the circuit breakers at the incremental spacing to allow wiring to pass through the current transformers in alignment with the circuit breakers.  
         [0017]     The disclosure further provides a sensor module for wiring in an electrical system, comprising: a sensor support having a supporting surface and a second surface at an angle to the supporting surface and establishing a height above the supporting surface; at least one post laterally coupled to the sensor support along the height of the second surface, the post having an opening therethrough oriented at an angle to the second surface; and at least one current transformer coupled to the post, the current transformer having an aperture aligned with the post opening and the post adapted to insulate the current transformer from a wire passing through the post opening. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]     A more particular description, briefly summarized above, may be had by reference to the embodiments illustrated in the appended drawings, forming part of the present specification and described herein. It is to be noted, however, that the appended drawings illustrate only some embodiments described herein and are therefore not to be considered limiting of the disclosure&#39;s scope, in that there can be other equally effective embodiments.  
         [0019]      FIG. 1A  is a schematic front view of an exemplary prior art electrical branch monitoring system.  
         [0020]      FIG. 1B  is a schematic end view of the exemplary prior art electrical branch monitoring system of  FIG. 1A .  
         [0021]      FIG. 2  is a schematic front view of an exemplary embodiment of an electrical system having a monitoring system according to the present disclosure.  
         [0022]      FIG. 3  is a perspective schematic view of one embodiment of a sensor module as an exemplary sensor support.  
         [0023]      FIG. 4  is a cross sectional schematic view of the sensor module of  FIG. 2  with a post and a current transformer coupled thereto.  
         [0024]      FIG. 5  is a cross sectional schematic view of the sensor module of  FIG. 2  with a stepped post and a current transformer coupled thereto.  
         [0025]      FIG. 6  is a perspective schematic view of interfaced sensor modules between a plurality of circuit breakers and respectively electrical loads.  
         [0026]      FIG. 7  is a perspective schematic view of one embodiment of a circuit board as an exemplary sensor support. 
     
    
     DETAILED DESCRIPTION  
       [0027]      FIG. 2  is a schematic front view of an exemplary prior art electrical branch monitoring system. The electrical system  40  generally includes a circuit breaker panel  42  having an internal space that houses a circuit breaker assembly  44  mounted thereto. The circuit breaker assembly  44  includes one or more circuit breakers, such as circuit breakers  46 ,  48 ,  58 ,  60 , and  68 . Generally, the circuit breakers are aligned in pre-established spaces on a circuit breaker assembly. It is customary for the electrical circuit breaker assembly to have  21  spaces for circuit breakers in a vertical alignment. Sometimes the circuit breaker assembly has a similar arrangement to the side of an additional  21  possible spaces for other circuit breakers. Recently, some circuit breaker panels and associated circuit breaker assemblies have a vertical alignment of  42  circuit breakers for a more compact installation. The circuit breakers are generally numbered  1 - 21  or  1 - 42  on the panel to facilitate ready identification for maintenance, monitoring, or other functions. One or more electrical loads  54 ,  56 ,  98  are coupled to the circuit breakers through one or more wires  50 ,  52 ,  88 . The wires provide power to the electrical loads.  
         [0028]     The diagram illustrates one exemplary main power supply  100  providing power to the circuit breaker panel  42 . It is known to those with ordinary skill in the art that for different power requirements, such as 240 volts, that two power feeds are required with one neutral, and for a 3-phase power system, three power feeds are required with one neutral, and other arrangements. For multiple power feeds, multiple circuit breakers can be coupled together for each circuit breaker connected to separate power feeds for a given electrical load. Thus, the present disclosure contemplates such arrangements and is specifically included within the scope of the disclosure and the claims that follow.  
         [0029]     One or more sensor assemblies  61 ,  63 , such as sensor modules to be further described below, can be generally disposed between the circuit breakers and the loads. Other sensor assemblies can include circuit boards, as modified herein, and other structures (herein “sensor supports”) that can support one or more current transformers or other sensors attached thereto. Generally, the sensor assemblies  61 ,  63  will be mounted inside the circuit breaker panel  42  for safety, security, and protection of the sensor assemblies. The sensor assemblies can interface with each other in an interface area  66  described in more detail below. The sensor assemblies  61 ,  63  will generally include a plurality of circuit transformers (CTs), such as CTs  70 ,  72 ,  74 ,  78 . In general, a CT is a wire wound toroidal coil on a conductive or nonconductive core. While it is envisioned that current transformers will be the principle sensor used on a sensor assembly, other types of sensors, such as voltage, power and other sensors, are included, and thus the term current transformer is used broadly to include such sensors. The CTs can have an aperture formed within the CT through which a power wire, such as wire  50 , can be routed therethrough. The CTs can be specially coupled to the sensor assemblies as described below to reduce the bending stress caused by the wires  50 ,  52 ,  88 , passing through the apertures of the respective CTs. As described herein, at least one embodiment of the sensor assemblies  61 ,  63 , such as the sensor modules  62 ,  64 , avoids the prior art problems of relying upon the CTs to absorb the bending stress  30 , shown in  FIGS. 1A, 1B .  
         [0030]     Further, the sensor assemblies  61 ,  63  can include output connectors that can be coupled to a processor. For example, a first sensor assembly  61  can include a first output connector  80 . The connector can be a multi-pin connector, used in electronic connections, having as many as  50  pins or more, to which the various wires from the sensors can be connected. The connectors can be coupled to the sensor assemblies through the underside of the sensor assemblies so that a corresponding connector can be inserted from a backside of the breaker panel. The connector  80  is shown schematically in  FIG. 2  and is related to the position of an output connector block  81  shown in  FIG. 3  in one embodiment. Alternatively, the connector  80  can be positioned on the front of the sensor assembly, on an end, or at other orientations as may be convenient. The first output connector  80  can be coupled to a monitoring system  91 , having various components such as a processor  90 , through a cable  84 . In general, the output connector  80  will have output terminals for each of the CTs on the sensor assembly. Thus, cable  84  could be a ribbon cable, or other type of cable, such as an optical fiber cable, capable of discriminating between the outputs of different CTs. Similarly, a second sensor assembly  63  can likewise include an output connector  82  that can be electrically coupled to the monitoring system  91 , such as the processor  90 , through a cable  86 . The processor  90  can process the output from the CTs into various types of output, such as data, reports, or signals for further processing useful to the monitoring system and/or the operator. Furthermore, additional processors, such as processor  92 , can be coupled to the processor  90 . The processors  90  and/or  92  can include a data memory storage  94  and can be coupled to an output device  96 , such as a display, printer, transmitter, or other devices that can provide output in different formats.  
         [0031]     In a similar fashion, the main power supply  100  can be coupled with a main circuit breaker  102 . A main supply CT  104  can be coupled to the main power supply  100  to monitor aspects of the main power supply. In some embodiments, a voltmeter  106  can be coupled to one or more of the electrical conductors, such as the main power supply  100 .  
         [0032]     For some embodiments, where the circuit breaker assembly  44  includes circuit breakers  1 - 21 , the first sensor assembly  61  can be used with its similar arrangement of  21  CTs. In other circuit breaker assemblies that have a greater number of circuit breakers  1 - 42 , a plurality of sensor assemblies can be used, such as the embodiment illustrated in  FIG. 2 . The sensor assemblies  61 ,  63  can be interchangeable in that they each have a similar profile and can interchange with each other. Each sensor assembly could include at least 21 CTs so that together they can serve the  42  circuit breakers. The present disclosure solves at least two challenges in so doing. First, at least one of the sensor assemblies can be inverted for the two interchangeable sensor assemblies to interface, i.e., rotated so that its bottom is the top and top is the bottom in an end-to-end fashion, such as illustrated in  FIG. 2 . Thus, the CTs on sensor assembly  61  would number  1 - 21  from the top of the sensor assembly as viewed from the perspective to  FIG. 2  to the bottom (i.e., from the output connector  82 ) while the inverted sensor assembly, such as sensor assembly  63 , would number  21 - 1  from the top to the bottom, where the CT would start near the output connectors on each sensor assembly. Software, firmware, and/or hardware coupled to the output of the CTs would have conflicting identities of two sets of 1-21 CTs, as well as one of the sets being in a reversed number sequence. Further, if the inverted CT is measuring current, the current flowing through the CTs of the sensor assembly  63  would be a reverse current (i.e., negative) compared to a normal flow of current (i.e., positive) flowing through the CTs of the sensor assembly  61 . The present disclosure can use the negative current advantageously using the software, firmware, and/or hardware the correct the CTs identities and to make adjustments for the inverted sensor support. Generally, when the monitoring system senses a reversed current, such as through the CTs of the inverted sensor assembly  63 , the system recognizes the negative current as an inverted sensor assembly and can remaps the identities of the CTs to correspond to the correct circuit breakers. In the illustration of  FIG. 2 , the first CT of the sensor assembly  63  would become CT  42  to corresponding to the circuit breaker  60 . Similarly, the 21 st  CT of the sensor assembly  63 , that is CT  78 , would be mapped to the 22 nd  circuit breaker, that is circuit breaker  68 , and become the 22 nd  CT to the monitoring system. Thus, CTs  21 - 1  would be re-identified as CTs  22 - 42 , respectively, for the inverted sensor assembly to correspond with the circuit breakers  22 - 42 . The software, firmware, and/or hardware of the present disclosure can perform such re-identification automatically.  
         [0033]     In a similar fashion, individual CTs can indicate a reversal of current, generally inadvertently. For example, a sensor assembly could inadvertently have one or more CTs reversed during assembly and not discovered until the system is installed and operational. Likewise, one or more of the CTs can fail and need a secondary CT coupled to the respective power wire. The secondary CT could be installed inappropriately and indicate a reversed current. Thus, in a similar manner, the system can recognize the negative current as an inverted CT and translate the current as a positive current in conjunction with the other CTs associated with the sensor assembly or the system.  
         [0034]     The second challenge solved by the present disclosure is in maintaining the spacing between the CTs and corresponding circuit breakers in the interface area  66 . For example, the circuit breakers  58  and  68  are generally at fixed spacing intervals, dictated by the structure, the rails, and other pre-assembled aspects of the circuit breaker assembly  44 . The close proximity of the spacing between the circuit breakers  58 ,  68  has heretofore been problematic in abutting two prior art assemblies such the circuit boards in the patents described in the Background. The abutment would cause a misalignment between the respective CT and its circuit breaker in the interface area, causing stress on the CT and the problems described above.  
         [0035]     The present disclosure also solves this difficulty by overlapping at least one and generally two openings formed between the sensor assemblies and the respective circuit breaker(s). For example, the circuit breaker  58  could be the 21 st  circuit breaker in-the circuit breaker assembly  44  and the circuit breaker  68  could be the 22 nd  circuit breaker in the circuit breaker assembly  44 . Thus, both circuit breakers  58 ,  68  would be in proximity to the interface area  66  between the two sensor assemblies  61 ,  63 . The CT  74  having an aperture  76  coupled to the second sensor assembly  63  can be aligned with the corresponding opening  75  formed in the first sensor assembly  61  where both the aperture and the opening can align with circuit breaker  58 . Similarly, the CT  78  (e.g., the 21 st  CT of the second sensor assembly  63 ) when inverted, could align with a corresponding opening  79  formed in the first sensor assembly  61  and the 22 nd  circuit breaker  68 . The alignment between the CTs and the interface includes one or more CTs in the interface area that overlap with a corresponding opening in the adjacent sensor assembly and allows wires to pass in alignment between the corresponding circuit breaker through the sensor assembly, and to the load. For example, a wire  88  coupled to the circuit breaker  68  could pass through the CT  78  and a corresponding opening  79  in the other sensor assembly and onto an electrical load  98 . The CTs and openings can be on one sensor assembly, or on both sensor assemblies in the 21 st  position of each sensor support.  
         [0036]     Further, the disclosure can provide for those instances where a CT for a given wire fails to function. The present disclosure provides an alternative to disassembling the system  40  and the particular sensor assembly with a defective CT. The disclosure can provide a secondary CT and exclude an output of a CT coupled to the sensor assembly that otherwise would be used to monitor the conditions for that branch circuit. The software, firmware, or hardware can detect when abnormal conditions exists by for example, comparing with stored historical data or noting values lower or higher than predetermined values, and other metrics. The system can trigger an alarm, make adjustments, or otherwise alert an operator. For example, a CT  160  coupled to a sensor assembly could normally be used to monitor the conditions of branch wire  158 . If CT  160  fails, the processor  90  can provide an output indicating the condition. A secondary CT  162  can be coupled for example by clamping the CT to the wire  158  without having to disconnect the wire  158 . The CT  162  can be independently coupled to the monitoring system, such as to the processor  90  or a connector for the sensor assembly. The monitoring system  91  can exclude the output, automatically or selectively, from the defective CT  160  and use the output from the secondary CT  162  in substitution thereof and independent of the CT  160 .  
         [0037]      FIG. 3  is a perspective schematic view of one embodiment of a sensor module as an exemplary sensor assembly. The sensor assemblies  61 ,  63 , described in  FIG. 2 , can comprise sensor modules  62 ,  64 . In general, the term “sensor module” herein will include a sensor assembly having a relatively significant height from a plane upon which it is mounted in contrast to a circuit board with a relatively insignificant height above its plane of mounting. The sensor module generally has a sufficient height such that a wire from a circuit breaker can pass laterally (i.e., sideways) through the sensor module in contrast to the wire passing above it, as in prior efforts, measured from a plane on which the sensor module is mounted. The sensor module can advantageously be molded substantially as a unit or can be assembled from preformed sections.  
         [0038]     The sensor module, such as the first sensor module  62 , also shown in  FIG. 2 , is illustrated on its side to show the various portions thereof For illustrative purposes and to provide a context to the figure, the wire  50 , also shown in  FIG. 2 , is shown passing through the first CT  70 , although certainly other orientations are possible. In general, the sensor module includes a first surface  108  that can provide a supporting surface for the module on a structure to which it is coupled. A second surface  109  is formed at an angle to the first surface to establish a height above the first surface for the sensor module. Advantageously, the height is of a dimension such that the wire  50  from a circuit breaker (shown in  FIG. 6 ) mounted adjacent the sensor module can pass laterally through the sensor module in alignment with the circuit breaker, as described herein. Related structures such as a post with an opening, described below, can be laterally coupled to the second surface along its height and reduce or avoid the bending stresses from the wire passing therethrough. This structure is in contrast to prior efforts, using for example circuit boards of relatively insignificant height, resulting in such bending stresses.  
         [0039]     The module can include a first portion  110  that is sufficiently wide to mount to a structure, such as the circuit breaker panel  42 , shown in  FIG. 2 . The first portion can establish the supporting surface  108 . One or more mounts  130 , in at least one embodiment, can extend outwardly from the first portion of  110  as a tab with a mounting opening form and therethrough to further allow coupling of the first portion  110  to the panel  44 . Other methods of mounting the sensor module such as retainers, adhesive, or other methods are contemplated. The sensor module  62  further includes a second portion  114  disposed at an angle to the first portion  110 . The second portion can establish the second surface  109 . In at least one embodiment for commercial efficiency, the second portion  114  can have a thinner cross-sectional area compared to the first portion  110  in the same direction. For example, and without limitation, the first portion  110  can include a flange having a greater width than height and the second portion  114  could be a web having a greater height than width. The flange provides a quantity of bending stiffness to the web across its smaller cross sectional dimension (i.e., thickness  166  shown in  FIG. 4 ) and the web provides a quantity of bending stiffness to the flange across its smaller cross sectional dimension (i.e., thickness  168  shown in  FIG. 4 ) when the flange and web are coupled together. In at least some embodiments, the sensor module  62  can further include a third portion  112 . The third portion  112  can be similarly shaped as the first portion  110  and can also be a flange, although other shapes are contemplated. The sensor module further includes an output connector block  81  with an opening  81 A, the block being coupled to the sensor module  62  to allow an output connector  80 , shown in  FIG. 2 , to be assembled thereto.  
         [0040]     The sensor module can further include a recessed portion  116 . In at least one embodiment, the recessed portion  116  is adapted to allow an adjacent sensor module to be coupled thereto to form the interface area  66 . Thus, the recessed portion  116  is generally symmetrical with the recessed portion of an adjacent module. Further, the sensor modules can be made interchangeable with each other, so that they can be inverted and still function in the intended manner as described herein.  
         [0041]     The sensor module material can be any suitable material and if molded will be generally a polymer compound that can withstand some stresses. Advantageously, at least a portion of the sensor module is nonconductive. Exemplary materials for the sensor module are polymers, like polyesters, such as polyethylene terephthalate (“PET”), including PET (FR530), and polybutylene terephthalate (“PBT”), including PBT (4130). PBT is especially preferred since it is highly temperature resistant. Both materials are Underwriters Laboratories (UL) listed materials. Other structural materials, conductive and nonconductive can be used.  
         [0042]     One or more CT posts for supporting the CTs can be coupled to the sensor module  62 . In at least one embodiment, the posts are formed integrally therewith during a molding process. The posts, such as  118 , have an opening  150  formed to allow the wire, such as wire  50 , to be inserted therethrough. In general, the opening  150  will be aligned at an angle to the second portion  114 . When assembled, such as shown in  FIG. 2 , the opening  150  will be aligned with its respective circuit breaker to allow the wire to be inserted through the opening and aligned with the corresponding circuit breaker. Thus, the height of the opening  150  above the first portion  110  in general will correspond to the height of the circuit breaker, such as circuit breaker  46 , above the height of the panel  42  when the sensor module  62  is mounted to the panel  42 . In at least one embodiment, the sensor module  62  can have  22  posts coupled thereto. The posts can allow for the customary  21  circuit breakers with the 22 nd  post to be used in conjunction with an adjacent sensor module. More specifically,  21  posts in the sensor module  62  could have CTs (shown in  FIGS. 4, 5 ) mounted thereto. In the embodiment shown in  FIG. 3 , the CTs could be disposed on any post between post  70  to post  126  for any correspond circuit breakers in the circuit breaker panel. Post  124  could be used to overlap with a CT mounted on a post of an adjacent sensor module (shown in  FIG. 6 ) in the corresponding position as post  126  is on the first sensor module  62 . Thus, an overlapping post  124  having an opening  125  has a general utility of allowing wire coming through a corresponding CT on an adjacent module through the opening  125  that can continue to the corresponding electrical load, such as shown in  FIG. 2 .  
         [0043]     The posts can generally be aligned at a consistent vertical height to correspond to the height of the circuit breakers. Further, the spacing between the posts, such as posts  118 ,  120 , are generally at the same spacing as the circuit breakers in the circuit breaker panel to maintain an alignment with the wires passing therethrough to the circuit breakers. The alignment helps reduce stresses on the wiring that in turn reduces stresses on the sensor module and circuit breakers. However, the general diameter of a CT is larger than can be accommodated with the restricted spacing between the posts. Thus, the CTs can be assembled to the sensor module in an alternating fashion as shown in  FIGS. 4, 5  described below. To assist in accommodating the alternating arrangement, a step  122  can be formed or otherwise coupled on one or more posts to restrict the axial (i.e. lateral relative to the second portion  114 ) movement of the CT along the length of the post. For example, post  120  can be coupled with a step  122 . Advantageously, the steps are included on alternating posts to assist in appropriate placing of the CTs for the particular post. In the interface area  66 , the step can be provided by surface  128  to restrict the axial movement of the CT along the axis of the post.  
         [0044]      FIG. 4  is a cross sectional schematic view of the sensor module of  FIG. 3  with a post and a current transformer coupled thereto. The cross section is shown through the post  118  of  FIG. 3  and through a portion of  FIG. 6  with the addition of a CT and relevant wiring. The sensor module  62  generally includes a first portion  110 , such as a flange, a second portion  114 , such as a web, and in some embodiments, a third portion  112 , such as an additional flange. In general, the first portion  110  can provide a mounting surface to some support structure, such as the circuit breaker panel  42 , shown in  FIG. 2 . One or more mounts  130  can facilitate the mounting of the sensor panel  62  to a support structure. The shape of the sensor module  62  can vary significantly in size, height, orientation, relative widths, and thicknesses, and the illustration is only exemplary. In general, however, the sensor module will have a first portion of some dimensions and a second portion of some dimensions coupled to the first portion at some angle thereto so that an opening  150  formed through the second portion  114  can be adapted to align with the corresponding circuit breaker (shown in  FIGS. 2, 6 ). This “height” above a plane on which the sensor module is mounted that is sufficiently high to allow the CTs to be laterally coupled thereto reduces the bending stresses on the CTs in contrast to bending stresses on the CTs mounted as shown in  FIG. 1B . The post  118  can be formed integrally with the sensor module, such as by molding therewith, or otherwise coupled to the sensor module  62  and in general could be formed with the second portion  114 . Importantly, the post  118  can absorb bending stress  146  caused by the wire  52  bending or otherwise attempting to misalign the opening  150  with the sensor module  62 . Further, the posts transfer bending stresses from wires passing through the posts to the second portion  114  coupled with the posts, so that the second portion incurs stress in a shear stress mode that would tend to otherwise tear the second portion material. A shear stress mode can be structurally accommodated by the thickness of the second portion sufficient to resist tearing from the bending stresses. Thus, the connections of the CT to the sensor module are generally not unduly stressed, absent a catastrophic failure of the coupling portion of the sensor module, such as the posts with the CTs separating from the sensor module.  
         [0045]     A CT  72  can be disposed about the post  118 . In at least one embodiment, the CT  72  will be disposed around the post  118 , so that the wire  52  is not in direct contact with the CT  72 , that is, the post  118  provides a buffer structure between the CT  72  and any wire disposed through the opening  150 . Thus, the CT  78  disposed distally from the wire  52  is generally not exposed to undue stress  146  as in prior efforts. If the post  118  does not have a step, as described in  FIG. 3 , then the CT will generally be disposed in proximity to the second portion  114 .  
         [0046]     Generally, the CT has a pair of output wires  136  to provide an output signal to the monitoring system, shown in  FIG. 2 . In at least one embodiment, the output wires  136  can be directly coupled to an output connector  80  without intermediate soldering connections other than at the output connector. Thus, the typical  126  soldering connections for  21  CTs found in prior art can be reduced to  42  soldering connections, a 67% decrease in soldering connections. It is believed that this reduction will result in inherently less failures. To facilitate the output wires  136  for each CT traveling to the connector  80 , a wire channel  134  can be formed in the sensor module  62 . For convenience, the wire channel  134  can be formed in the first portion  110 . The number of output wires in the channel will vary depending upon the particular entry of the respective CT to the wire channel. In general, the maximum expected number of output wires in the wire channel will be about  42  to correspond to two output wires for  21  CTs, in at least one embodiment. Further, the wire channel  134  can be filled with an insulative material to seal the output wire from the CTs in the wire channel. Thus, the present disclosure provides an increased safety margin over prior art by maintaining the wire  52  carrying the power to the electrical load away from both the CT by way of the post  118  and the output wire  136  from the CT to a separate and in some cases sealed wire channel  134 , with an attendant reduction in the number of solder connections and failure rates.  
         [0047]      FIG. 5  is a cross sectional schematic view of the sensor module of  FIG. 3  with a stepped post and a current transformer coupled thereto.  FIG. 5  is illustrative of the cross section of the sensor module shown in  FIG. 3  and  FIG. 6  passing through a stepped post  120 , having a step  122 , with the addition of a CT and relevant wiring. Similar to the description regarding  FIG. 4 , the sensor module  62  includes the first portion  110 , the second portion  114 , and a third portion  112 , in at least some embodiments. A post  120  is generally coupled to the second portion  114 , where the post  120  has an opening formed therethrough that is generally aligned with a circuit breaker, such as the circuit breakers shown in  FIGS. 2, 6 . The post  120  can include a step  122 . In some embodiments, the step can be formed integrally with the post  120  and in other embodiments, the step can simply be a cylinder or other geometric shaped component inserted at least partially around, over, attached to, or otherwise coupled with the post  120 . In general, the step  122  will restrict the movement of a CT, such as CT  70 , coupled to the post  120  in a direction along the axis of the opening through the post. The offset distance caused by the step  122  away from the second portion  114  on the post  120  can correspond to and allow for close spacing of the post  118 , described in  FIG. 4 , and its respective CT  72  to maintain an axial alignment with circuit breakers at their close spacing. Output wires  132  extending from the CT  70  can be routed to and through the wiring channel  134  (shown in  FIG. 4 ) that in at least one embodiment can be formed in the first portion  110 . In this embodiment, similar to the embodiment shown in  FIG. 4 , the post  120  can isolate the CT  70  from the wire passing through the post  120 . The isolation can occur electrically as well as mechanically, such that a bending stress  146  caused by the wire is generally absorbed by the post  120  and not the CT  70 . Thus, the CT  70  and its output wires  132  are generally protected and subject to less system failure. The sensor module further includes an output connector block  81  with an opening  81 A, the block being coupled to the sensor module  62  to allow an output connector  80 , shown in  FIG. 2 , to be assembled thereto.  
         [0048]      FIG. 6  is a perspective schematic view of interfaced sensor modules between a plurality of circuit breakers and respective electrical loads. A first sensor module  62  can interface with a second sensor module  64 . The second sensor module  64  can be interchangeable with the first sensor module  62 . Each module can include an output connector  80 ,  82 , respectively. The second sensor module generally will have a similar structure to the first sensor module so that it includes a first portion  110 A, a second portion  114 A, and a third portion  112 A. Generally, the first and third portions will be a flange having a wider base than height and the second portion  114 A will be a web having a larger height than width (i.e., thickness of the section). The first, second, and third portions can be molded as an integral unit in at least some embodiments. Further, the second sensor module will generally have a plurality of posts as has been described above and can be coupled to a support structure by, for example, coupling the first portion  110 A to an electrical panel, shown in  FIG. 2 , and in some embodiments facilitated by a mount  130 A.  
         [0049]     The first sensor module  62  can include a recessed portion  116  that can be coupled to a corresponding recessed portion  116 A of the second sensor module  64  in the interface area  66 .  
         [0050]     One or more circuit breakers  58 ,  68 ,  108  can be disposed in the electrical system  40 . Generally, the circuit breakers will be disposed at a fixed relative spacing or an increment thereof The spacing is generally determined by the factory-installed rails  138  and the spacing between the rails. The rails form a supporting surface for the circuit breakers to be inserted and generally clipped on or screwed thereto. For example, the rail  138  to which the circuit breaker  58  can be coupled thereto, is spaced at a unit spacing  142  from an adjacent rail  140  to which the circuit breaker  68  is coupled thereto. The electrical system may not require a circuit breaker to be coupled to rail  148  and may skip an interval to a rail  152  disposed at a spacing  144 , incremental to the spacing  142 . Generally and without limitation, the incremental spacing will occur in integers, such as one spacing, two spacings, and so forth, although fractional increments can be used ,such as one-half and one-third spacings. The circuit breaker  108  coupled to the rail  152  can connect to a wire passing through the second sensor module for an electrical load  154 . A wire  88  can be disposed between the circuit breaker  68  and a load  98 . Similarly, a wire can be disposed between the circuit breaker  58  and a load  156 . Generally, each wire will pass through a corresponding CT mounted in either the first sensor module  62  or the second sensor module  64 . In the interface area  66 , the wire could and generally does pass through both recessed portions of the sensor modules  62 ,  64 . For example, in at least one embodiment, post  124 A,  126 A formed in the recessed portion  116 A of the second sensor module  64  could be aligned with and overlap corresponding posts on the recessed portion  116  of the first sensor module  62 , as described in reference to  FIG. 3 .  
         [0051]     In at least one exemplary embodiment and without limitation, it is expected that the sensor modules would include  22  posts with the first  21  posts having CTs mounted thereon starting from the output connector on the end. The 22 nd  post of each module would overlap with the corresponding 21 st  CT of the other module. For example, a CT mounted on the post  126 A of the second sensor module  64  would generally align with an opening through a post  126  (shown in  FIG. 3 ) of the first sensor module  62 . Likewise, the post  124 A with its corresponding opening of the second sensor module  64  would align with the post  126  (shown in  FIG. 3 ) and a CT mounted thereon of the first sensor module  62  in an overlapping fashion so that the wires from the circuit breakers to the respective loads could pass through both sensor modules in the interface area  66  and maintain alignment with the spacing  142  if circuit breakers were present in both locations.  
         [0052]     While  FIGS. 3-6  illustrate a non-limiting embodiment of the sensor module, the sensor assembly broadly described in  FIG. 2  can include circuit boards and other structures that support the current transformers attached thereto.  
         [0053]      FIG. 7  is a perspective schematic view of one embodiment of a circuit board as an exemplary sensor support, having certain aspects taught in this disclosure. A circuit board  176  can include one or more CTs  74 ,  78  coupled thereto. The CTs can be coupled to the circuit board by soldering, fastening, forming, or other means. As described above, a plurality of circuit boards can be disposed adjacent each other in an end to end fashion to provide additional capacity for servicing a larger number of circuit breakers than individual circuit boards.  
         [0054]     To solve the above referenced issue of alignment between the closely spaced circuit breakers  58 ,  68  and the CTs on the circuit boards at the ends of the circuit boards, an interface area  66  can be formed between the adjacent circuit boards  176 ,  178 . The first circuit board  176  can include a recessed portion  116  and the second circuit board  178  can include a recessed portion  116 A, similar to the recessed portions described above in reference to the sensor modules in  FIGS. 3-6 . The recessed portions can be substantially symmetrical between the circuit boards to allow interchangeability when inverting one or more of the circuit boards. The CTs  74 ,  78  can be mounted laterally relative to their respective recessed portions  116 ,  116 A of their circuit boards. When the circuit boards  176 ,  178  are mounted adjacent each other end-to-end, the recessed portions  116 ,  116 A can be laterally aligned in the interface area  66  in a side-by-side fashion and allow the CTs  74 ,  78  to maintain a relative alignment with the circuit breakers  58 ,  68 . The CTs can be mounted laterally offset from each other on the circuit board to allow a closer axial spacing  170  between adjacent axes  172 ,  174  passing through the apertures than if mounted without the offset. Such alignment would otherwise be unavailable as in prior efforts because the dimensions of the CTs have not allowed sufficiently close spacing as the dimensions of the circuit breakers. Wires  78 ,  108  passing through CTs  74 ,  78 , respectively, can be routed from the circuit breakers through the CTs  74 ,  78  in relative alignment and lessen associated bending stresses that otherwise can cause failures in the system.  
         [0055]     Various basics of the invention have been explained herein. The various techniques and devices disclosed represent a portion of that which those skilled in the art would readily understand from the teachings of this application. Variations are possible and contemplated and are limited only by the claims. Details for the implementation thereof can be added by those with ordinary skill in the art. Such details may be added to the disclosure in another application based on this provisional application and it is believed that the inclusion of such details does not add new subject matter to the application. The accompanying figures may contain additional information not specifically discussed in the text and such information may be described in a later application without adding new subject matter. Additionally, various combinations and permutations of all elements or applications can be created and presented. All can be done to optimize performance in a specific application.  
         [0056]     The various steps described herein can be combined with other steps, can occur in a variety of sequences unless otherwise specifically limited, various steps can be interlineated with the stated steps, and the stated steps can be split into multiple steps. Unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, should be understood to imply the inclusion of at least the stated element or step or group of elements or steps or equivalents thereof, and not the exclusion of any other element or step or group of elements or steps or equivalents thereof Further, any documents to which reference is made in the application for this patent as well as all references listed in any list of references filed with the application are hereby incorporated by reference. However, to the extent statements might be considered inconsistent with the patenting of this invention such statements are expressly not to be considered as made by the applicant(s).  
         [0057]     Also, any directions such as “top,” “bottom,” “left,” “right,” “upper,” “lower,” and other directions and orientations are described herein for clarity in reference to the figures and are not to be limiting of the actual device or system or use of the device or system. The device or system may be used in a number of directions and orientations.