Patent Publication Number: US-2023146112-A1

Title: Electrical panelboard assembly including power distribution heatsink assembly, systems and methods

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 63/278,367, filed Nov. 11, 2021. The disclosure of the priority application in its entirety is hereby incorporated by reference into the presence application. 
    
    
     BACKGROUND 
     The field of the invention relates generally to electrical panelboard assemblies, and more particularly to panelboard assemblies for a harsh and/or hazardous environment. 
     During operation of panelboard assemblies, heat is generated. In some cases, the amount of heat generated may lead to electrical components within the panelboard assembly exceeding a desired temperature rise. If the temperature rise of electrical components within the panelboard assembly is not be kept below certain limits, the components may become damaged, or the panelboard assembly may not meet requirements for certifications and/or standards. 
     While known panelboard assemblies are satisfactory in some applications, they remain disadvantaged and improvements are desired. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Non-limiting and non-exhaustive embodiments are described with reference to the following Figures, wherein like reference numerals refer to like parts throughout the various drawings unless otherwise specified. 
         FIG.  1    is a schematic diagram of an exemplary panelboard assembly. 
         FIG.  2 A  is an exploded view of an exemplary embodiment of the panelboard assembly shown in  FIG.  1   . 
         FIG.  2 B  is a front view of the panelboard assembly shown in  FIG.  2 A  with the front cover removed. 
         FIG.  3 A  is a front view of a known panelboard assembly with the front cover removed. 
         FIG.  3 B  is a thermal image showing portions of the known panelboard assembly shown in  FIG.  3 A . 
         FIG.  3 C  is a thermal image showing other portions of the known panelboard assembly shown in  FIG.  3 A . 
         FIG.  4 A  is a perspective view of an exemplary power distribution heatsink assembly of the panelboard assembly shown in  FIG.  1   . 
         FIG.  4 B  is a top view of the power distribution heatsink assembly shown in  FIG.  4 A . 
         FIG.  5    is a perspective view of another exemplary power distribution heatsink assembly. 
         FIG.  6 A  is a perspective view of one more exemplary power distribution heatsink assembly. 
         FIG.  6 B  is a side view of the power distribution heatsink assembly shown in  FIG.  6 A . 
         FIG.  7    is a front perspective view of one more power distribution heatsink assembly. 
         FIG.  8    is a flow chart illustrating an exemplary method of assembling an electrical assembly using panelboard assemblies and power distribution heatsink assemblies shown in  FIGS.  1 - 7   . 
     
    
    
     DETAILED DESCRIPTION 
     The disclosure includes panelboard assemblies for a harsh and/or hazardous environment. A power distribution heatsink assembly is included in a panelboard assembly and is electrically connected to other components of the panelboard assembly to provide better dissipation of heat in the panelboard assembly than conventional heatsinks. Method aspects of assembling electrical assemblies will be in part apparent and in part explicitly discussed in the following description. 
     Electrical power systems sometimes operate within hazardous environments presenting a risk of explosion via ignition of a surrounding gas or vapor dusts, fibers, or flyings. Such hazardous environments may arise, for example without limitation, in petroleum refineries, petrochemical plants, grain silos, waste water treatment facilities and/or other industrial facilities, wherein volatile conditions are produced in the ambient environment and present a heightened risk of fire or explosion. A temporary or sustained presence of airborne ignitable gas, ignitable vapors, ignitable dust or otherwise flammable substances presents substantial concerns regarding safe and reliable operation of such facilities overall, including but not limited to safe operation of the electrical power system itself, which in some instances by virtue of conventional circuit protector devices may produce ignition sources in normal operation and in the presence of an electrical fault. As such, a number of standards have been promulgated relating to electrical product use in explosive environments to improve safety in hazardous locations in view of an assessed probability of explosion or fire risk. 
     For example, Underwriter&#39;s Laboratories (“UL”) standard UL 1203 sets forth Explosion-Proof and Dust-Ignition-Proof Electrical Equipment criteria for hazardous locations. Explosion-Proof and Dust-Ignition-Proof enclosures are available to enclose or contain electrical products. In combination with appropriate Explosion-Proof and Dust-Ignition-Proof enclosures, electrical equipment manufacturers may receive UL certification of compliance with the applicable rating standards for hazardous locations, and UL certification is an important aspect of a manufacturer&#39;s ability to successfully bring products to market in North America or any other market accepting of UL standard 1203. 
     The National Electric Code (NEC) generally classifies hazardous locations by class and division. Class I locations are those in which flammable vapors and gases may be present. Class II locations are those in which combustible dust may be found. Class III locations are those which are hazardous because of the presence of easily ignitable fibers or flyings. Considering Class I, Division 1 covers locations where flammable gases or vapors may exist under normal operating conditions, under frequent repair or maintenance operations, or where breakdown or faulty operation of process equipment might also cause simultaneous failure of electrical equipment. Division 1 presents a greater risk of explosion than, for example, Division 2 where flammable gases or vapors are normally handled either in a closed system, confined within suitable enclosures, or are normally prevented by positive mechanical ventilation. 
     The International Electrotechnical Commission (IEC) likewise categorizes hazardous locations into Class I, Zone 0, 1, or 2 representing locations in which flammable gases or vapors are or may be airborne in an amount sufficient to produce explosive or ignitable mixtures. As defined in the IEC, a Class I, Zone 0 location is a location in which ignitable concentrations of flammable gases or vapors are present continuously or for long periods of time. A Class I, Zone 1 location is a location in which ignitable concentrations of flammable gases or vapors are likely to exist because of repair or maintenance operations or because of leakage or possible release of ignitable concentrations of flammable gases or vapors, or is a location that is adjacent to a Class I, Zone 0 location from which ignitable concentrations of vapors could be communicated. 
     Given that electrical devices, such as those described below, may be ignition sources in certain circumstances, explosion-proof, flame-proof, or ignition proof enclosures are conventionally provided in NEC Division 1 or 2 locations and/or IEC Zone 1 or 2 locations to house electrical devices that pose ignition risk. The terms “explosion-proof” or “flame-proof” in this context, refer to enclosures that are designed to be capable of containing an internal explosion of a specified flammable vapor-air mixture. 
     In addition to hazardous locations discussed above, so-called harsh locations also require specific focus in the design of panelboard assemblies used therewith. Harsh locations may entail corrosive elements and the like in the atmosphere that are not necessarily explosive and/or are subject to temperature cycling, pressure cycling, shock and/or mechanical vibration forces that are typically not present in non-harsh operating environments. Of course, some locations in which panelboard assemblies are desirably employed are both harsh and hazardous by nature, and are therefore designed for various operating conditions, for which typical panelboard assemblies for other uses are unsatisfactory. 
     In a harsh and/or hazardous environment, a temperature rise of a panelboard assembly during operation needs to be managed to be a level required by standards for the harsh and/or hazardous environment such that the panelboard assembly does not pose as a fire or explosion hazard. Systems, assemblies, and methods described herein provide panelboard assemblies that are safely operable and meet requirements on temperature rises for the harsh and/or hazardous environment, especially when a high amperage current, such as 225 Amperes (A) or above, flows through the panelboard assembly. The panelboard assembly described herein includes a power distribution heatsink assembly that is electrically connected to components of the panelboard assembly to increase heat dissipation. The power distribution heatsink assembly may also serve as a power distribution block in the panelboard assembly. 
       FIG.  1    is a schematic diagram of an exemplary panelboard assembly  100 . In the exemplary embodiment, panelboard assembly  100  includes a core assembly  107 . Core assembly  107  includes a main breaker assembly  102  and a branch breaker assembly  104 . Core assembly  107  may include other components such as a contactor assembly (not shown). Core assembly  107  may further include a line side terminal  108 , which is configured to be electrically connected to a power supply  110 . Power supply  110  may be an alternating current (AC) power supply such as a three-phase AC power supply, or a direct current (DC) power supply. Main breaker assembly  102  is electrically connected to line side terminal  108  and configured to switch the entire panelboard assembly  100  on or off as needed, irrespective of any secondary circuit breaker or switch associated with branch breaker assembly  104 . 
     In the contemplated embodiment, main breaker assembly  102  is electrically connected to branch breaker assembly  104 , which is configured to control one or more loads  112 . Branch breaker assembly  104  includes one or more branch circuit breakers  114  (shown in  FIGS.  2 A and  2 B  described later). Branch circuit breaker  114  is electrically connected to one or more loads  112  and is configured to individually switch the connected loads  112  on or off. 
     In the exemplary embodiment, panelboard assembly  100  further includes a power distribution heatsink assembly  106 . Power distribution heatsink assembly  106  is electrically connected to core assembly  107  or other components of panelboard assembly  100 . For example, power distribution heatsink assembly  106  is electrically connected to main breaker assembly  102 . In another example, power distribution heatsink assembly  106  is electrically connected to branch breaker assembly  104 . Power distribution heatsink assembly  106  may be electrically connected between main breaker assembly  102  and branch breaker assembly  104 . In some embodiments, power distribution heatsink assembly  106  is electrically connected to other components in panelboard assembly  100  than main breaker assembly  102  and branch breaker assembly  104 . Alternatively, power distribution heatsink assembly  106  is electrically connected to any component(s) in panelboard assembly  100 , including components other than main breaker assembly  102  and branch breaker assembly  104 , as well as main breaker assembly  102  and/or branch breaker assembly  104 . The number of power distribution heatsink assemblies  106  included in panelboard assembly  100  is not limited to one. Any number of power distribution heatsink assemblies  106  may be included in panelboard assembly  100 , based on needs for heat dissipation. 
     As used herein, a power distribution heatsink assembly is electrically connected when an end of a heatsink of the power distribution heatsink assembly is electrically connected to at least one other component of the panelboard assembly. The power distribution heatsink assembly, however, may or may not form an electrical circuit with other components of the panelboard assembly when the power distribution heatsink assembly is electrically connected to other components in the panelboard assembly. In some embodiments, power distribution heatsink assembly  106  is connected to other components at only one point of electrical contact and does not form a circuit or a complete loop with other components. In other embodiments, power distribution heatsink assembly  106  are connected to other components at more than one point of electrical contact and form a circuit or a complete loop with other components with current flowing through the points of electrical contacts. 
     In contemplated embodiments, panelboard assembly  100  is adapted for use in a harsh and/or hazardous environment such as for lighting, motor applications, and other power system needs. Panelboard assembly  100  may also be used, however, in a non-hazardous environment as desired. 
       FIGS.  2 A and  2 B  show an exemplary embodiment of panelboard assembly  100 .  FIG.  2 A  is an exploded view of panelboard assembly  100 .  FIG.  2 B  is a front view of panelboard assembly  100  with a front cover of enclosure  130  removed. Panelboard assembly  100  may include a mounting board  116 , on which electrical elements of panelboard assembly  100  such as main breaker assembly  102  and branch breaker assembly  104  are mounted. In the exemplary embodiment, panelboard assembly  100  may be divided into a main panel  118  and a branch panel  120 . Main panel  118  may include main breaker assembly  102 . Branch panel  120  may include branch breaker assembly  104 . Panelboard assembly  100  may further include a main panel dead front  122 . Main panel dead front  122  may be used to cover at least a portion of main panel  118 . Main panel dead front  122  may further include one or more slots  124  that allow access to main breaker assembly  102  to switch main breaker assembly  102  on or off. Panelboard assembly  100  may also include a branch panel dead front  126  for covering at least a portion of branch panel  120 . Branch panel dead front  126  may also include one or more slots  124  for access to branch breaker assembly  104 . Panelboard assembly  100  may further include a power distribution block (not shown) that is electrically connected to both main breaker assembly  102  and branch breaker assembly  104 . 
     In the exemplary embodiment, panelboard assembly  100  may further include an enclosure  130  that is used to enclose core assembly  107  such as main panel  118  and branch panel  120 . Enclosure  130  also encloses main panel dead front  122  and branch panel dead front  126  if main panel dead front  122  and branch panel dead front  126  are used. 
     In the exemplary embodiment, panelboard assembly  100  further includes power distribution heatsink assembly  106 . Power distribution heatsink assembly  106  is electrically connected to core assembly  107  such as main breaker assembly  102 , branch breaker assembly  104 , or any other component of panelboard assembly  100 . In the depicted embodiment, power distribution heatsink assembly  106  is electrically connected between main breaker assembly  102  and branch breaker assembly  104  and also serves as a power distribution block of the panelboard assembly  100 , where power distribution heatsink assembly  106  is used to distribute electrical power from an input power source to devices downstream. 
     Power distribution heatsink assembly  106  may be positioned at any location interior of enclosure  130 . For example, power distribution heatsink assembly  106  is mounted on an interior wall  132  of enclosure  130 . In one example, power distribution heatsink assembly  106  is mounted on a side wall  134  of enclosure  130  or a bottom wall  136  of enclosure  130 . Power distribution heatsink assembly  106  may be positioned proximate main breaker assembly  102 . In one example, power distribution heatsink assembly  106  is positioned with a closer distance from main breaker assembly than from other components of core assembly  107  such as branch breaker assembly  104 . In some embodiments, power distribution heatsink assembly  106  is mounted on mounting board  116 . In one example, power distribution heatsink assembly  106  is mounted on a side  143  of mounting board  116  opposite the side  139  where core assembly  107  is mounted. 
     In some embodiments, a portion of power distribution heatsink assembly  106  is positioned exterior of enclosure  130 . For example, a portion of power distribution heatsink assembly  106  extends out of a top wall  138  or side wall  134  of enclosure  130 , dissipating heat out of enclosure  130 . 
     In the exemplary embodiment, panelboard assembly  100  is configured to be electrically connected to a three-phase AC power supply. Connection to a three-phase AC power supply is used only as an example herein. Panelboard assembly  100  may be connected to AC power supplies of other distribution configurations or a DC power supply. In the exemplary embodiment shown in  FIGS.  2 A and  2 B , power distribution heatsink assembly  106  is electrically connected between main breaker assembly  102  and branch breaker assembly  104 , also serving as a power distribution block of panelboard assembly  100 . 
       FIGS.  3 A- 3 C  show a front view of a known panelboard assembly  300  with the front cover removed ( FIG.  3 A ) and thermal images of portions of panelboard assembly  300  during operation ( FIGS.  3 B and  3 C ). Known panelboard assembly  300  includes a main breaker assembly  302 , a branch breaker assembly  304 , and a power distribution block  306  positioned and electrically connected between main breaker assembly  302  and branch breaker assembly  304 .  FIG.  3 B  is a thermal image taken at a location between main breaker assembly  302  and power distribution block  306 .  FIG.  3 C  is a thermal image taken at a location where main breaker assembly exits panelboard assembly  300  to be connected to a power supply. The lighter portions of  FIGS.  3 B and  3 C  represent areas of relatively high temperatures (e.g. the location indicated by  312  in  FIGS.  3 B and  3 C ), and the darker portions of  FIGS.  3 B and  3 C  represent areas of relatively cool temperatures (e.g. the location indicated by  314  in  FIGS.  3 B and  3 C ). As shown, the lightest portions  312  are near the locations of terminals  310  of main breaker assembly  302  or power distribution block  306 , especially near terminals  310  of main breaker assembly  302 . That is, the greatest amount of heat is at areas near the terminals  310  of panelboard assembly  300 . 
     In a panelboard assembly, heat is generated during operation, especially at terminals, where conductors are connected to components of the panelboard assembly. Conductors, breakers, and breaker assemblies are typically insulated, especially for a harsh and/or hazardous environment such that any arcing or sparking does not escape into air inside or outside of the enclosure, which may contain flammable or ignitable substances, and become a fire hazard. Therefore, heat is trapped inside the conductors, breakers, and breaker assemblies. If the heat is not dissipated from the electrical components, the components may become damaged or the temperature may rise high enough to pose as fire hazard, which is especially dangerous in a harsh and/or hazardous environment. 
     Additionally, in order for a panelboard assembly to meet certain certifications such as UL or IEC as described above, the maximum temperature rise of electrical components within a panelboard assembly should remain below a specified temperature rise. For example, maximum temperature rise of electrical components of a panelboard assembly should be 60° C. or less when the panelboard assembly is in operation. Difficulty in meeting the requirement increases when the current rating increases, especially when the current rating is 225 A or above. Known panelboard assemblies that meet the standard are relatively large when the panelboard assembly is rated at 225 A or greater. e.g., when operating at 225 A or greater, known A-size to G-size panelboard assemblies do not meet this requirement, while an H-size panelboard assembly, which is larger than A-size to G-size panelboard assemblies, may meet this requirement. An H-size panelboard assembly includes over 60 circuit breakers and has a height of over 6 feet (1.83 meters), which is bulky and expensive, and typically is not desirable to customers. 
     Accordingly, there is a need for a device that is used to help dissipate heat produced in a panelboard assembly, allowing a reduced-sized high-amperage panelboard assembly to be used to provide high amperage current. As used herein, a high-amperage panelboard assembly refers to a panelboard assembly that meets standards for panelboards to be used in a harsh and hazardous environment while operating at 225 A or above. 
       FIGS.  4 A and  4 B  show an exemplary embodiment of power distribution heatsink assembly  106 .  FIG.  4 A  is a top perspective view of power distribution heatsink assembly  106 .  FIG.  4 B  is a top view of power distribution heatsink assembly  106 . In the exemplary embodiment, power distribution heatsink assembly  106  includes heatsinks  402 . In the depicted embodiment, power distribution heatsink assembly  106  includes three heatsinks  402 , e.g., one for each phase of three-phase AC power. In some embodiments, power distribution heatsink assembly  106  includes four heatsinks  402 , e.g., one for each of three phases of three-phase AC power and one for the neutral line or neutral conductor. In other embodiments, power distribution heatsink assembly  106  includes one heatsink  402  for DC power. The number of heatsinks  402  may be in other numbers such as two. The configured electrical connection of heatsinks  402  may be in other configurations such as being configured to be connected to slip-phase power. Heatsink  402  is fabricated from electrically conductive material such as metal like copper, copper alloy, aluminum, aluminum alloy, or nickel-plated aluminum or aluminum alloy to reduce corrosion. Heatsink  402  has a first end  406  and an opposing second end  408  ( FIG.  4 B ), and a body  407  extending between first end  406  and second end  408 . Heatsink  402  may further include fins  422  extending from body  407 . Heatsink  402  further includes apertures  414  at first end  406  and/or second end  408 . Apertures  414  are sized to receive conductors  140  ( FIG.  2 B ) therein and provide points of electrical connection at which power distribution heatsink assembly  106  is electrically connected to other components of panelboard assembly  100 . 
     In the exemplary embodiment, power distribution heatsink assembly  106  includes an isolator  404 . Isolator  404  is fabricated from electrically nonconductive material or electrical insulator, such as plastic, epoxy or phenolic plastic, fiberglass, and/or ceramic. Isolator  404  electrically separates heatsinks  402 . For example, if three heatsinks  402  are each electrically connected to separate phases of three-phase AC power, isolator  404  separates heatsinks  402  to prevent short circuiting between phases. Isolator  404  includes a base  416 . Isolator  404  further includes a divider  418  that project from base  416  and separate adjacent heatsinks  402 . Divider  418  provides electrical insulation between adjacent heatsinks  402 . Isolator may include apertures  420 , which may be used to, for example, mount power distribution heatsink assembly  106  onto panelboard assembly  100  such as enclosure  130  or mounting board  116 . 
     In operation, power distribution heatsink assembly  106  is electrically connected to a component of panelboard assembly  100  such that power distribution heatsink assembly  106  is in the electrical path of panelboard assembly  100 . In some embodiments, power distribution heatsink assembly  106  is a part of the circuit formed by other components of panelboard assembly  100 , where both first and second ends  406 ,  408  of heatsinks  402  are electrically connected to the circuit such that electricity flows from another component of panelboard assembly  100  at one end  406 ,  408  of heatsink  402  to the other end  406 ,  408  of heatsink  402 . In other embodiments, power distribution heatsink assembly  106  is electrically connected to other components of panelboard assembly  100 , but does not form a circuit or a complete loop with other components of panelboard assembly  100 . For example, first ends  406  of heatsinks  402  of power distribution heatsink assembly  106  are electrically connected to the electrical circuit or in the electrical path of the electrical circuit, but second ends  408  of heatsinks  402  are not electrically connected to the electrical circuit such as being electrically freestanding. In any configurations, because heatsink is directly connected to conductors  140 , heat is directly transmitted from conductors  140  to heatsink  402  and dissipated through heatsink  402 , reducing the temperature rise of panelboard assembly  100 . 
       FIG.  5    shows another exemplary embodiment of a power distribution heatsink assembly  106 . The exemplary embodiment of power distribution heatsink assembly  106  shown in  FIG.  5    is similar to the exemplary embodiment of power distribution heatsink assembly  106  shown in  FIGS.  4 A and  4 B  except that heatsinks  402  shown in  FIG.  5    includes a different number of fins  422  and a different orientation of fins  422 . In the exemplary embodiment shown in  FIG.  5   , power distribution heatsink assembly  106  includes three heatsinks  402  that each include eight fins  422  with a major axis of each fin  422  being orthogonal to the major axis of the heatsinks  402 . In other embodiments, however, power distribution heatsink assembly  106  may include any number of heatsinks  402  having any number of fins  422  in any orientation such that power distribution heatsink assembly  106  may function as described herein. Power distribution heatsink assembly  106  may include any number of isolators  404  having any shape and orientation such that power distribution heatsink assembly  106  may function as described herein. 
       FIGS.  6 A and  6 B  show one more exemplary embodiment of power distribution heatsink assembly  106 .  FIG.  6 A  is a perspective view of power distribution heatsink assembly  106 .  FIG.  6 B  is a side view of power distribution heatsink assembly  106 . In the exemplary embodiment, power distribution heatsink assembly  106  includes heatsinks  402 - s  and isolator  404 - s . Different from power distribution heatsink assembly  106  shown in  FIGS.  4 A,  4 B, and  5   , isolator  404 - s  includes a stepped structure that provides mechanical support and electrical isolation or insulation of heatsinks  402 - s . Isolator  404 - s  includes steps  610 . Each step  610  is positioned away from other steps  610 . Steps  610  provides structural support to one of first end  406  or second end  408  of heatsinks  402 - s.    
     In the exemplary embodiment, each heatsink  402 - s  spans between isolators  404 - s , such that each first end  406  of heatsinks  402 - s  is attached to the same isolator  404 - s  and each second end  408  of heatsinks  402 - s  is attached to the same isolator  404 - s . Each first end  406  and second end  408  of heatsink  402 - s  is attached to isolator  404 - s  at a corresponding step. Step  610  may include a groove  614  sized to receive heatsink  402 - s  therein at end  406 ,  408 . Heatsink  402 - s  may be coupled to step  610  via, for example, adhesive or friction force between step  610  and heatsink  402 - s.    
     In the exemplary embodiment, first end  406  of heatsink  402 - s  includes an aperture  414 . Aperture  414  is sized to receive conductor  140  therethrough and used to electrically connect power distribution heatsink assembly  106  with other components of panelboard assembly  100 . Power distribution heatsink assembly  106  does not form a circuit with other components of panelboard assembly  100 . That is, first ends  406  of heatsinks  402 - s  are electrically connected to an electrical circuit of panelboard assembly  100 , but second ends  408  of heatsinks  402 - s  are not electrically connected to the electrical circuit of panelboard assembly  100  (i.e. second ends  408  are freestanding and include no electrical connection). As a result, current does not flow through second end  408  and down to other components of panelboard assembly  100 . 
     In the depicted embodiment, power distribution heatsink assembly  106  includes four heatsinks  402 - s  and two isolators  404 - s . Alternatively, power distribution heatsink assembly  106  includes one isolator  404 - s , which includes a stepped structure that spans from first end  406  to send end  408  of heatsink  402 - s . Power distribution heatsink assembly  106  may include any number of isolators  404 - s  having any suitable shape and any number of heatsinks  402 - s  having any suitable shape and in any suitable configuration such that power distribution heatsink assembly  106  may function as described herein. 
       FIG.  7    shows one more exemplary embodiment of power distribution heatsink assembly  106 . In the exemplary embodiment, power distribution heatsink assembly  106  includes heatsink  402 - d  and isolator  404 - d . Heatsink  402 - d  has a first end  406  and a second end  408 . Heatsink  402 - d  directly extends from a terminal  710 - h  of main breaker assembly  102  and is electrically connected to terminal  710 - h  at first end  406 . At terminals  710 - n , conductors  140  are electrically connected to core assembly  107  (shown in  FIG.  2 A ). Alternatively, power distribution heatsink assembly  106  may be directly connected to a terminal of other components of panelboard assembly  100 , such as a terminal of branch breaker assembly  104 . Heatsink  402 - d  forms an “L” shape to increase a surface area of heatsink  402 - d  to enhance heat dissipation. Isolator  404 - d  includes first end  720  and second end  722 . Second end  408  of heatsink  402  is attached to first end  720  of isolator  404 - d . Second end  722  of isolator  404  is mounted to enclosure  130 , such as a wall  132 , of panelboard assembly  100 . Power distribution heatsink assembly  106  does not form an electrical circuit with other components of panelboard assembly, where current does not flow through second end  408  of heatsink  402 -d and down to other components of panelboard assembly  100 . In one test, the temperature rise of terminal  710 - h  where power distribution heatsink assembly  106  is installed is approximately 15° C. less than other terminals  710 - n  that do not have power distribution heatsink assembly  106  installed. 
     In the exemplary embodiment, heatsink  402 - d  extends directly from terminal  710 - h  by being directly attached to terminal  710 - h . In some embodiments, heatsink  402 - d  extends from a conductor  140  to be electrically connected to terminal  710 - h.    
     When heatsink  402  does not form a circuit with other components of panelboard assembly  100  (see  FIGS.  6 A,  6 B, and  7   ), because heatsink  402  of power distribution heatsink assembly  106  is electrically connected to other components of panelboard assembly  100  by being in an electrical path of panelboard assembly  100 , heatsink  402  has electrical potential at the non-electrically connected end. Isolator  404  electrically insulates heatsink  402 . For example, isolator  404  insulates heatsink from enclosure  130  when enclosure is fabricated from electrically-conductive material such as metal, to prevent enclosure  130  from having electrical potential. 
     In some embodiments, power distribution heatsink assembly  106  shown in  FIGS.  6 A- 7    further include fins (fins not shown in  FIGS.  6 A,  6 B, and  7   ) extending from heatsink body  407 . Fins are used to increase heat dissipation. 
     Heatsinks  402  and/or fins  422  of power distribution heatsink assembly  106  are shown as planar for illustration purpose only. Heatsinks may be in other shapes such as oval or irregular shapes or may be curved or in any three-dimensional (3D) shapes. 
     Referring back to  FIGS.  2 A and  2 B , in some embodiments, power distribution heatsink assembly  106  is located entirely within enclosure  130 . Because locations near terminals  710  of main breaker assembly  102  have the most heat in panelboard assembly  100 , power distribution heatsink assembly  106  is positioned proximate terminals  710  of main breaker assembly  102 . In other embodiments, part of power distribution heatsink assembly is within enclosure  130  and part of power distribution heatsink assembly  106  is external to enclosure  130 . For example, heatsink  402  may extend through enclosure  130  and dissipate heat out of enclosure  130 . An external part of heatsink  402  may be positioned on a top  141  or on a side  142  of enclosure  130  (see  FIG.  2 A ). Heatsink  402  may be surrounded or separated from enclosure  130  by isolator  404  at the intersection of heatsink  402  with enclosure  130  to prevent enclosure  130  from having electrical potential. Alternatively, another enclosure may be provided to enclose power distribution heatsink assembly  106  and enclosure  130  and to shield panelboard assembly  100 . Having power distribution heatsink assembly  106  located partially outside of enclosure  130  increases heat dissipation. 
     In some embodiments, power distribution heatsink assembly  106  is modular where one or more power distribution heatsink assemblies  106  may be electrically connected at any suitable location to other components of panelboard assembly  100  and may be replaced or exchanged with other modules of power distribution heatsink assembly  106 . 
     The above examples of the location of electrical connection and physical location of power distribution heatsink assembly  106  are presented in the context of only one power distribution heatsink assembly  106  being present. However, there may be any suitable number of power distribution heatsink assemblies  106  having any location of electrical connection and any physical location such that panelboard assembly  100  may function as described herein. 
       FIG.  8    is a flow chart of an exemplary method  800  of assembling an electrical assembly for a harsh and/or hazardous environment. In the exemplary embodiment, method  800  includes providing  802  a core assembly of a panelboard assembly. A core assembly may be any of the core assemblies  107  described above. Method  800  also includes providing  806  a power distribution heatsink assembly  106 . A power distribution heatsink assembly  106  may be any of the power distribution heatsink assemblies  106  described above. Further, method  800  includes electrically connecting  810  a first end of the heatsink assembly to the core assembly. For example, power distribution heatsink assembly  106  may be electrically connected to a main breaker assembly  102 , a branch breaker assembly  104 , or other components of panelboard assembly  100 . Power distribution heatsink assemblies  106  may or may not form an electrical circuit with core assembly  107  or other components of panelboard assembly  100 . 
     The benefits and advantages of the inventive concepts are now believed to have been amply illustrated in relation to the exemplary embodiments disclosed. 
     At least one technical effect of the systems, assemblies, and methods described herein includes (a) heatsinks that reduce temperature rise in a high-amperage panelboard assembly by electrically connecting to a component of the panelboard assembly; and (b) power distribution heatsink assemblies that serve functions of heatsinks as well as power distribution blocks. 
     An embodiment of a panelboard assembly for a harsh and/or hazardous environment is disclosed. The panelboard assembly includes a core assembly. The core assembly includes a main breaker assembly configured to be electrically connected to a power supply, and a branch breaker assembly electrically connected to the main breaker assembly and configured to be electrically connected to one or more loads, and a power distribution heatsink assembly. The power distribution heatsink assembly includes an electrically-conductive heatsink having a first end and an opposing second end, the first end electrically connected to the core assembly and an electrically-nonconductive isolator electrically insulating the heatsink. 
     Optionally, the power distribution heatsink assembly is electrically connected to the main breaker assembly at the first end and electrically connected to the branch breaker assembly at the second end. The power distribution heatsink assembly is positioned proximate a terminal of the main breaker assembly. The heatsink defines an aperture at the first end, and the aperture is sized to receive a conductor of the core assembly. The power distribution heatsink assembly further includes a first heatsink and a second heatsink, the isolator positioned between the first heatsink and the second heatsink. The power distribution heatsink assembly further includes a first heatsink and a second heatsink, and the isolator further includes a first step and a second step spaced apart from one another, wherein the first heatsink is positioned on the first step and the second heatsink is positioned on the second step. The heatsink extends from a terminal of the core assembly. The power distribution heatsink assembly further includes a first heatsink electrically connected to a conductor of a first phase and a second heatsink electrically connected to at least one of a conductor of a second phase or a neutral conductor. The heatsink further includes a heatsink body extending between the first end and the second end and a plurality of fins extending from the heatsink body. The power distribution heatsink assembly is modular. The panelboard assembly further includes a mounting board having a first side and a second side opposite the first side, wherein the core assembly is mounted on the first side, and the power distribution heatsink assembly is mounted on the second side. The panelboard assembly further includes an enclosure surrounding the core assembly, wherein a portion of the heatsink is positioned exterior of the enclosure. The panelboard assembly further includes an enclosure surrounding the core assembly, wherein the power distribution heatsink assembly is mounted on an interior wall of the enclosure. The first end and the second end of the heatsink do not define a closed electrical loop with the core assembly. 
     An embodiment of a power distribution heatsink assembly of a panelboard assembly for a harsh and/or hazardous environment is disclosed. The panelboard assembly includes a core assembly. The core assembly includes a main breaker assembly and a branch breaker assembly. The power distribution heatsink assembly includes an electrically-conductive heatsink having a first end and an opposing second end, the first end configured to be electrically connected to the core assembly and an electrically-nonconductive isolator electrically insulating the heatsink. 
     Optionally, the power distribution heatsink assembly further includes a first heatsink and a second heatsink, the isolator positioned between the first heatsink and the second heatsink. The power distribution heatsink assembly further includes a first heatsink and a second heatsink, and the isolator further includes a first step and a second step spaced apart from one another, wherein the first heatsink is positioned on the first step and the second heatsink is positioned on the second step. The heatsink defines a first aperture at the first end, the first aperture sized to receive a first conductor of the core assembly. The heatsink defines a second aperture at the second end, the second aperture sized to receive a second conductor of the core assembly. The heatsink is sized to extend from a terminal of the core assembly. 
     While exemplary embodiments of components, assemblies and systems are described, variations of the components, assemblies and systems are possible to achieve similar advantages and effects. Specifically, the shape and the geometry of the components and assemblies, and the relative locations of the components in the assembly, may be varied from that described and depicted without departing from inventive concepts described. Also, in certain embodiments, certain components in the assemblies described may be omitted to accommodate particular types of panelboard assemblies, or the needs of particular installations, while still providing cost effective panelboard assemblies for electrical wiring or cabling. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. 
     Aspects of the Disclosure 
     1. A panelboard assembly for a harsh and/or hazardous environment, comprising: a core assembly comprising:
         a main breaker assembly configured to be electrically connected to a power supply; and   a branch breaker assembly electrically connected to the main breaker assembly and configured to be electrically connected to one or more loads; and   a power distribution heatsink assembly comprising:
           an electrically-conductive heatsink having a first end and an opposing second end, the first end electrically connected to the core assembly; and   an electrically-nonconductive isolator electrically insulating the heatsink.   
               

     2. The panelboard assembly of aspect 1, wherein the power distribution heatsink assembly is electrically connected to the main breaker assembly at the first end and electrically connected to the branch breaker assembly at the second end. 
     3. The panelboard assembly of aspect 1, wherein the power distribution heatsink assembly is positioned proximate a terminal of the main breaker assembly. 
     4. The panelboard assembly of aspect 1, wherein the heatsink defines an aperture at the first end, and the aperture is sized to receive a conductor of the core assembly. 
     5. The panelboard assembly of aspect 1, wherein the power distribution heatsink assembly further comprises a first heatsink and a second heatsink, the isolator positioned between the first heatsink and the second heatsink. 
     6. The panelboard assembly of aspect 1, wherein the power distribution heatsink assembly further comprises a first heatsink and a second heatsink, and the isolator further comprises a first step and a second step spaced apart from one another, wherein the first heatsink is positioned on the first step and the second heatsink is positioned on the second step. 
     7. The panelboard assembly of aspect 1, wherein the heatsink extends from a terminal of the core assembly. 
     8. The panelboard assembly of aspect 1, wherein the power distribution heatsink assembly further comprises:
         a first heatsink electrically connected to a conductor of a first phase; and   a second heatsink electrically connected to at least one of a conductor of a second phase or a neutral conductor.       

     9. The panelboard assembly of aspect 1, wherein the heatsink further comprises a heatsink body extending between the first end and the second end and a plurality of fins extending from the heatsink body. 
     10. The panelboard assembly of aspect 1, wherein the power distribution heatsink assembly is modular. 
     11. The panelboard assembly of aspect 1, further comprising a mounting board having a first side and a second side opposite the first side, wherein the core assembly is mounted on the first side, and the power distribution heatsink assembly is mounted on the second side. 
     12. The panelboard assembly of aspect 1, further comprising an enclosure surrounding the core assembly, wherein a portion of the heatsink is positioned exterior of the enclosure. 
     13. The panelboard assembly of aspect 1, further comprising an enclosure surrounding the core assembly, wherein the power distribution heatsink assembly is mounted on an interior wall of the enclosure. 
     14. The panelboard assembly of aspect 1, wherein the first end and the second end of the heatsink do not define a closed electrical loop with the core assembly. 
     15. A power distribution heatsink assembly of a panelboard assembly for a harsh and/or hazardous environment, the panelboard assembly including a core assembly that includes a main breaker assembly and a branch breaker assembly, the power distribution heatsink assembly comprising:
         an electrically-conductive heatsink having a first end and an opposing second end, the first end configured to be electrically connected to the core assembly; and   an electrically-nonconductive isolator electrically insulating the heatsink.       

     16. The power distribution heatsink assembly of aspect 15, wherein the power distribution heatsink assembly further comprises a first heatsink and a second heatsink, the isolator positioned between the first heatsink and the second heatsink. 
     17. The power distribution heatsink assembly of aspect 15, wherein the power distribution heatsink assembly further comprises a first heatsink and a second heatsink, and the isolator further comprises a first step and a second step spaced apart from one another, wherein the first heatsink is positioned on the first step and the second heatsink is positioned on the second step. 
     18. The power distribution heatsink assembly of aspect 15, wherein the heatsink defines a first aperture at the first end, the first aperture sized to receive a first conductor of the core assembly. 
     19. The power distribution heatsink assembly of aspect 18, wherein the heatsink defines a second aperture at the second end, the second aperture sized to receive a second conductor of the core assembly. 
     20. The power distribution heatsink assembly of aspect 15, wherein the heatsink is sized to extend from a terminal of the core assembly.