U.S. patent application number 15/078415 was filed with the patent office on 2017-09-28 for dielectric heat transfer windows, and systems and methods using the same.
This patent application is currently assigned to EATON CORPORATION. The applicant listed for this patent is EATON CORPORATION. Invention is credited to PETER JAMES FRITZ.
Application Number | 20170279252 15/078415 |
Document ID | / |
Family ID | 59886584 |
Filed Date | 2017-09-28 |
United States Patent
Application |
20170279252 |
Kind Code |
A1 |
FRITZ; PETER JAMES |
September 28, 2017 |
DIELECTRIC HEAT TRANSFER WINDOWS, AND SYSTEMS AND METHODS USING THE
SAME
Abstract
Devices, systems, and methods for dissipating heat from
electrical distribution assemblies and electrical switching devices
are described herein. In one non-limiting embodiment, a dielectric
material of relatively high thermal conductivity can be thermally
coupled to electrical switching devices to act as a dielectric heat
transfer window that dissipates heat. The dielectric heat transfer
window includes at least a first portion thermally coupled to a
heat generating component within an electrical switching device,
and a second portion disposed external to the electrical
distribution assembly or electrical switching device. Among other
benefits, this allows heat generated within the electrical
switching device to escape the interior of the electrical switching
device to an environment external to the electrical switching
device.
Inventors: |
FRITZ; PETER JAMES;
(WILLIAMSTON, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EATON CORPORATION |
Cleveland |
OH |
US |
|
|
Assignee: |
EATON CORPORATION
CLEVELAND
OH
|
Family ID: |
59886584 |
Appl. No.: |
15/078415 |
Filed: |
March 23, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02B 1/46 20130101; H01H
9/52 20130101; H02B 1/56 20130101; H01H 1/62 20130101 |
International
Class: |
H02B 1/56 20060101
H02B001/56; H02B 1/46 20060101 H02B001/46 |
Claims
1-17. (canceled)
18. The method of claim 20, wherein the source of heat is thermally
coupled to the ceramic element via a thermally conductive and
electrically insulating material.
19. (canceled)
20. A method of removing heat from an electrical switching device,
comprising: providing a source of electrically generated heat
within an electrical switching device; thermally coupling the
source of heat to a ceramic element; aligning at least a portion of
the ceramic element with an exterior surface of the electrical
switching device such that the portion forms part of the exterior
of the electrical switching device; electrically coupling the
electrical switching device to an electrical distribution assembly;
and aligning at least a portion of the ceramic element with an
exterior portion of the electrical distribution assembly such that
a portion forms part of the exterior of the electrical distribution
assembly.
21. The method of claim 18, wherein the thermally conductive and
electrically insulating material comprises a thermal interface
material.
22. The method of claim 18, wherein the thermally conductive and
electrically insulating material comprises poly-phenylene oxide or
an epoxy resin.
23. The method of claim 20, wherein the ceramic material comprises
boron nitride.
24. The method of claim 20, wherein the ceramic material comprises
aluminum nitride.
25. The method of claim 20, wherein the ceramic material comprises
aluminum oxide.
26. The method of claim 20, wherein the ceramic material comprises
a metallic compound.
27. A system for removing heat from an electrical distribution
assembly, comprising: an electrical distribution assembly
comprising a source of electrically generated heat; an electrical
switching device comprising a heat generating component, wherein
the electrical switching device is electrically coupled to the
electrical distribution assembly; and a thermally conductive
ceramic element coupled to the source of electrically generated
heat, the ceramic element comprising: a dielectric material; and at
least a first portion and a second portion, said first portion
being thermally coupled to the heat generating component, said
second portion being aligned with an exterior portion of the
electrical distribution assembly such that said second portion
forms part of the exterior of the electrical distribution
assembly.
28. The system of claim 27, wherein the ceramic element comprises
aluminum nitride.
29. The system of claim 27, wherein the ceramic element comprises
aluminum oxide.
30. The system of claim 27, wherein the ceramic element comprises a
metallic compound.
31. The system of claim 27, wherein the thermally conductive
ceramic element is coupled to the source of electrically generated
heat via a thermally conductive and electrically insulating
material.
32. The system of claim 31, wherein the thermally conductive and
electrically insulating material comprises a thermal interface
material.
33. The system of claim 31, wherein the thermally conductive and
electrically insulating material comprises poly-phenylene oxide or
an epoxy resin.
Description
BACKGROUND
[0001] Field
[0002] The disclosed concept relates generally to electrical power
systems and, more particularly, to electrical distribution
assemblies. The disclosed concept relates to dielectric materials
of high thermal conductivity that can be molded or assembled into
electrical distribution assemblies to act as heat transfer windows
that dissipate heat generated in and/or around electrical
distribution assemblies. The disclosed concept further relates to
methods for removing heat from an electrical switching device.
[0003] Background Information
[0004] Electrical distribution assemblies generally include
electrical switching devices. When current runs through an
electrical switching device, heat is generated by components of the
electrical switching device. As a result of this heat, the
temperature within and around the electrical switching device, and
more generally the electrical distribution assembly, tends to
increase. This heat, if it becomes excessive, can cause various
events to occur, including but not limited to damage to components,
other devices, premature activation of trip mechanisms, and other
malfunctions. In addition, electrical distribution assemblies and
electrical switching components therein may include other
circuitry, such as control circuitry, which further generate heat
within and around electrical distribution assemblies. Likewise, as
electrical distribution assemblies and electrical switching devices
therein are developed with greater complexity, the heat generated
throughout the electrical distribution assembly and electrical
components may increase. As a result of this potential increase in
heat, it may become somewhat difficult for the electrical
distribution assemblies and electrical switching devices to operate
within the given temperature ranges established by various safety
organizations as an industry standard. These codes include, but are
not limited to, the UL-67 safety codes, which include requirements
that temperatures within electrical distribution assemblies not
exceed 50 degrees centigrade over ambient.
[0005] Accordingly, it is desirable to couple thermally conductive
materials to various components of electrical distribution
assemblies and the electrical switching devices therein to transfer
heat away from those components. As such, electrical distribution
assemblies and electrical switching devices generally include at
least some thermally conductive materials coupled to various heat
generating components. However, due to cost constraints, potential
structural weakness, and various other inefficiencies related to
these thermally conductive materials, a better thermally conductive
material for performing the vital task of heat transfer is needed.
For example, thermal interface materials ("TIM"), poly-phenylene
oxide ("PPO"), and epoxy resin assemblies are known to be thermally
conductive and electrically insulating, and thus are used to
transfer heat from vulnerable components in an electrical
distribution assembly. However, PPO and epoxy resin insulation
products often lack the desirable strength to maintain structural
integrity under extreme conditions for desirable periods of time,
and as such have a tendency to break apart. Additionally, in some
instances relating to electrical distribution assemblies involving
electrical conductors, TIMs may provide insufficient thermal
conductivity unless they are of a sufficiently thermally conductive
variety that tends to be prohibitively expensive. For example, a
thermal coupling of certain TIMs to various materials generally
found within an electrical switching device may result in what is
called an "air gap," whereby a small space is present at the point
of coupling between the TIM and the material. This results in a
reduction of the thermal conductivity of the TIM, and thus reduces
the amount of heat that may be transferred away from the vulnerable
components. Additionally, TIMs generally are limited to a thermal
conductivity of roughly 1 W/(mK) before becoming prohibitively
expensive.
[0006] There is thus room for improvement in electrical power
systems, and in electrical distribution assemblies and the
components therein.
SUMMARY
[0007] These needs and others are met by aspects of the disclosed
concept, which are directed to dielectric heat transfer windows and
associated methods for reducing temperatures within and around
electrical distribution assemblies and electrical switching devices
therein.
[0008] In one aspect of the disclosed concept, a system for
removing heat from an electrical distribution assembly is provided.
The system includes an electrical distribution assembly, an
electrical switching device comprising a heat generating component,
and a thermally conductive ceramic element comprising a dielectric
material and at least a first portion and a second portion, said
first portion being thermally coupled to the heat generating
component, said second portion being external to the electrical
switching device, wherein the electrical distribution assembly is
electrically coupled to the electrical switching device, and
wherein the thermally conductive ceramic element is thermally
coupled to the electrical switching device.
[0009] In another aspect of the disclosed concept, an electrical
switching device is provided. The electrical switching device
comprises a heat generating component and a thermally conductive
ceramic element, comprising a dielectric material and at least a
first portion and a second portion, said first portion being
thermally coupled to the heat generating component, said second
portion being external to the electrical distribution assembly,
wherein the thermally conductive ceramic element is thermally
coupled to the electrical switching device.
[0010] In another aspect of the disclosed concept, a method of
removing heat from an electrical switching device is provided. The
method comprises providing a source of electrically generated heat
within an electrical switching device, thermally coupling the
source of heat to a ceramic element, and aligning at least a
portion of the ceramic element with an exterior surface of the
electrical switching device such that the portion forms part of the
exterior of the electrical switching device.
BRIEF DESCRIPTION OF DRAWINGS
[0011] A full understanding of the disclosed concept can be gained
from the following description of the preferred embodiments when
read in conjunction with the accompanying drawings.
[0012] FIG. 1A is an illustrative schematic diagram presenting a
frontal view of an electrical distribution assembly in accordance
with an embodiment of the disclosed concept;
[0013] FIG. 1B is an illustrative schematic diagram presenting a
side cross sectional view of the electrical distribution assembly
as depicted in FIG. 1A;
[0014] FIG. 2 is an illustrative schematic diagram presenting a
side cross sectional view of an electrical distribution assembly
equipped with electrical switching devices in accordance with an
embodiment of the disclosed concept;
[0015] FIG. 3 is an illustrative schematic diagram presenting a top
view of an electrical switching device in accordance with an
embodiment of the disclosed concept;
[0016] FIG. 4 is an illustrative schematic diagram presenting a
side cross-sectional view of an electrical switching device in
accordance with an embodiment of the disclosed concept;
[0017] FIG. 5 is an illustrative schematic diagram presenting
another side cross-sectional view of an electrical switching device
in accordance with an embodiment of the disclosed concept;
[0018] FIG. 6 is another illustrative schematic diagram presenting
a top view of an electrical switching device in accordance with an
embodiment of the disclosed concept;
[0019] FIG. 7 is another illustrative schematic diagram presenting
a cross sectional side view of an electrical distribution assembly
in accordance with an embodiment of the disclosed concept; and
[0020] FIG. 8 is an illustrative flowchart of a method for removing
heat from an electrical switching device in accordance with an
embodiment of the disclosed concept.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The disclosed concept may take form in various components
and arrangements of components, and in various techniques, methods,
or procedures and arrangements of steps. The referenced drawings
are only for the purpose of illustrated embodiments, and are not to
be construed as limiting the present invention. Various inventive
features are described below that can each be used independently of
one another or in combination with other features.
[0022] Directional phrases used herein, such as, for example, left,
right, front, back, top, bottom, and derivatives thereof, relate to
the orientation of the elements shown in the drawings and are not
limiting upon the claims unless expressly recited therein.
[0023] As employed herein, the singular form of "a", "an", and
"the" include plural references unless the context clearly dictates
otherwise. Still further, as used herein, the term "number" shall
mean one or an integer greater than one (e.g., a plurality).
[0024] As employed herein, the terms "connected" or "coupled" shall
mean that two or more parts are joined together directly or joined
through one or more intermediate parts. Furthermore, the term
"attach" or "attached", as employed herein, shall mean that two or
more parts are joined together directly or through one or more
intermediate parts.
[0025] Further still, as employed herein, the terms "thermally
coupled" or "thermally connected" or "thermally attached" shall
mean that two or more parts are joined together directly or through
one or more intermediate parts such that heat may flow between the
two or more parts.
[0026] As employed herein, the terms "electrically coupled" or
"electrical communication" shall mean that two or more the parts or
components are joined together either directly or joined through
one or more intermediate parts such that electricity, current,
voltage, and/or energy is operable to flow from one part or
component to the other part or component, and vice versa.
[0027] FIG. 1A is an illustrative schematic diagram presenting a
frontal view of an electrical distribution assembly 100 in
accordance with an embodiment of the disclosed concept. In one
non-limiting embodiment, electrical distribution assembly 100
includes: a main circuit breaker 102 including a ceramic element
104, a switch 106, a hot wire 108, and a neutral ground 110
connected to main circuit breaker 102. Electrical distribution
assembly 100, in the illustrative embodiment, further includes a
branch circuit breaker 112 having a ceramic element 114, a switch
116, and a wire 118, which is connected to branch circuit breaker
112. Further still, electrical distribution assembly 100 includes a
cavity 120 located within electrical distribution assembly 100, and
bus bars 134 connected to branch circuit breaker 112.
[0028] In an illustrative embodiment, one or more of branch circuit
breakers 112A (12 branch circuit breakers 112A are shown in the
example of FIG. 1A) are included within electrical distribution
assembly 100, where each branch circuit breaker 112A is
substantially similar to branch circuit breaker 112, whereby each
branch circuit breaker 112A includes ceramic element 114 and switch
116, while also being connected to wires similar to 118 and to bus
bar 134. For ease of illustration and economy of disclosure, branch
circuit breakers 112A of FIG. 1A are drawn in a simplified
form.
[0029] In an embodiment of the disclosed concept, main circuit
breaker 102 includes at least one ceramic element 104 thermally
coupled to main circuit breaker 102. An electrical circuit is
generally formed by electrical current running from an external
power source into main circuit breaker 102 via hot wire 108,
through at least one electrical current carrying component, and out
of main circuit breaker 102 through bus bar 134. It will be
appreciated that when a current is running through an electrical
current carrying component, the temperature of the electrical
current carrying component increases. Accordingly, heat is
generated by the electrical current carrying component within main
circuit breaker 102. Upon the occurrence of an overload condition,
including but not limited to the event that the temperature of the
electrical current carrying component reaches a certain
predetermined level, a trip mechanism is activated, causing an
electrical current carrying component to mechanically break the
circuit and stop the current from running through main circuit
breaker 102, as signified when the switch 106 located on the
exterior of main circuit breaker 102 is in an "off" position. To
reduce the temperature in and around main circuit breaker 102,
ceramic element 104 is coupled to a heat generating component and
is structured to transfer heat away from a heat generating
component toward the surface of main circuit breaker 102, and
dissipate the heat into cavity 120 of electrical distribution
assembly 100.
[0030] As mentioned above, branch circuit breakers 112A are, in one
embodiment, substantially similar to branch circuit breaker 112,
and therefore include the components (e.g., ceramic element 114,
switch 116, wire 118, and bus bar 134). Similar to main breaker
102, an electrical circuit is generally formed in branch circuit
breaker 112 by electrical current running from bus bar 134, through
at least one electrical current carrying component housed within
branch circuit breaker 112, and out of the branch circuit breaker
via wire 118. When current is running through an electrical current
carrying component, the heat generated by various components that
the branch circuit breaker is comprised of increases, thereby
generating heat in and around branch circuit breaker 112. Upon the
occurrence of an overload condition, including but not limited to
the event that the temperature of the electrical current carrying
component reaches a certain predetermined level, a trip mechanism
is activated, causing an electrical current carrying component to
mechanically break the circuit and stop the current from running
through branch circuit breaker 112, as signified when switch 116
located on the exterior of branch circuit breaker 112 is in an
"off" position. To reduce the heat generated by various components
of branch circuit breaker 112, thereby preventing several
malfunctions to these components, ceramic element 114 is thermally
coupled to a heat generating component and is structured to
transfer heat away from an electrical current carrying component
toward the surface of branch circuit breaker 112, and to dissipate
said heat into cavity 120 of electrical distribution assembly
100.
[0031] FIG. 1B is an illustrative schematic diagram presenting a
cross sectional side view of electrical distribution assembly 100
as depicted in FIG. 1A. In one non-limiting embodiment of the
disclosed concept, electrical distribution assembly 100 is
substantially rectangular and may be any size capable of housing at
least one electrical switching device. Electrical distribution
assembly 100 may be capable of housing any number of electrical
switching devices and can be structured to provide an electrical
current to a device, building, or any other electrical system
requiring electricity (e.g., currents of less than 100 amperes, 125
amperes, 150 amperes, 200 amperes, or any current necessary to
power an electrical system). Although electrical distribution
assembly 100 is shown including both main circuit breaker 102 and
branch circuit breaker 112 persons of ordinary skill in the art
will recognize that electrical distribution assembly 100 may
alternatively include a single electrical switching device or
multiple electrical switching devices.
[0032] Main circuit breaker 102 in one non-limiting embodiment is
substantially rectangular and corresponds to any circuit breaker
suitable for acting as a disconnecting means to the entire power
load of the electrical distribution assembly. Main circuit breaker
102 may be suitable to connect to a single hot wire, two hot wires,
three hot wires, or any number of hot wires necessary to provide
desirable amount of electricity (e.g., a one-pole breaker, a
two-pole breaker, a three-pole breaker, etc.). Main breaker 102,
for example, may be a molded case circuit breaker, a miniature
circuit breaker, a fuse, or any type of switch gear or other
electrical switching device.
[0033] Main circuit breaker 102, in one embodiment, is thermally
coupled to ceramic element 104 in any suitable manner to facilitate
the dissipation of heat from within main circuit breaker 102 to an
environment external to main circuit breaker 102 via ceramic
element 104. For example, main circuit breaker 102 may be thermally
coupled to ceramic element 104 via molding, adhesion, latching, a
clinch joint, or any other suitable method known in the art for
thermal coupling.
[0034] Ceramic element 104, in one non-limiting embodiment,
includes a first portion and a second portion. The first portion of
ceramic element 104 is coupled to a heat generating component and
the second portion of ceramic element 104 is located in an
environment external to main circuit breaker 102. Ceramic element
104 is structured to act as a dielectric heat transfer window in
which heat generated by main circuit breaker 102 is dissipated into
an environment external to main circuit breaker 102. Ceramic
element 104, in one embodiment, is formed of a thermally conductive
dielectric material. Various types of thermally conductive
dielectric materials include, but are not limited to, boron
nitride, aluminum nitride, aluminum oxide, and/or poly-phenylene
oxide.
[0035] In one embodiment, electrical distribution assembly 100
includes branch circuit breaker 112 including ceramic element 114
for a dielectric heat transfer window and switch 116 for turning
the circuit within branch circuit breaker 112 on or off. Branch
circuit breaker 112 in one non-limiting embodiment is substantially
rectangular and includes any circuit breaker suitable for acting as
a disconnecting means to a circuit. Branch circuit breaker 112 is
structured to connect to a single hot wire, two hot wires, three
hot wires, or any number of hot wires necessary to provide a
desirable amount of electricity (e.g., a one-pole breaker, a
two-pole breaker, a three-pole breaker, etc.). In one embodiment,
branch circuit breaker 112 is a molded case circuit breaker, a
miniature circuit breaker, or a fuse, however persons of ordinary
skill in the art will recognize that any type of switch gear or
other electrical switching device may be used.
[0036] In one embodiment, the environment external to the
electrical switching device includes a cavity 120 located within
electrical distribution assembly 100. The cavity may be any length,
width, or depth suitable for heat to be transferred into.
Furthermore, the cavity may be closed, open, include vents, or be
otherwise structured to facilitate the dissipation of heat from the
electrical switching device.
[0037] Branch circuit breaker 112 is structured to be thermally
coupled to ceramic element 114 in any suitable manner to facilitate
the dissipation of heat from electrical switching device 112 to
cavity 120 via ceramic element 114. For example, the branch circuit
breaker may be structured to thermally couple to a ceramic element
via molding, adhesion, latching, a clinch joint, or any other
suitable method known in the art.
[0038] Ceramic element 114, in one non-limiting embodiment,
includes a first portion and a second portion. The first portion is
thermally coupled to a heat-generating component and the second
portion forms at least one surface of main breaker 112. Ceramic
element 114 is structured to act as a dielectric heat transfer
window in which heat is generated by branch circuit breaker 112 and
dissipated into cavity 120. Ceramic element 114 may include a
thermally conductive dielectric material. Various types of
thermally conductive dielectric materials include, but are not
limited to, boron nitride, aluminum nitride, aluminum oxide, and/or
poly-phenylene oxide.
[0039] FIG. 2 is an illustrative diagram presenting a side view of
an electrical distribution assembly 200 equipped with electrical
switching devices in accordance with an embodiment of the disclosed
concept. The electrical distribution assembly 200 includes a main
circuit breaker 202, a ceramic element 204, a switch 206, a hot
wire 208 and a neutral ground 210. Electrical distribution assembly
200 also includes one or more of branch circuit breakers 212 and
212A, each of which include a ceramic element 214 and a switch 216,
and are connected to a wire 218 and a bus bar 234. Although
electrical distribution assembly 200 includes both main breaker 202
and branch circuit breaker 212 in tandem persons of ordinary skill
in the art will recognize that this is merely a non-limiting
embodiment. In one embodiment, branch circuit breakers 212A are
substantially similar to branch circuit breaker 212, whereby each
branch circuit breaker 212A includes a ceramic element 214 and
switch 216, while being connected to wire 218 and bus bar 234.
[0040] In an embodiment of the disclosed concept, the main circuit
breaker 202 includes one or more of ceramic element 204 thermally
coupled to main circuit breaker 202. To prevent excessively high
temperatures and a resulting premature breaking of the current as
signified by the switch 206 being in an "off" position, ceramic
element 204 is thermally coupled to a heat generating component of
main circuit breaker 202, which, in one embodiment, is structured
to transfer heat away from main circuit breaker 202, through a
surface of electrical distribution assembly 200, and into an
environment external to electrical distribution assembly 200.
[0041] In one embodiment, ceramic element 204 includes at least a
first portion and a second portion. The first portion is coupled to
a heat-generating component located within main circuit breaker
202. The second portion is located external to main circuit breaker
202 and is structured to act as a dielectric heat transfer window
through which heat is transferred from within main circuit breaker
202 outward to an environment external to main circuit breaker 202.
In the illustrative embodiment, ceramic element 204 forms a surface
of electrical distribution assembly 200, thus preventing excessive
heat from being generated within electrical distribution assembly
200. In one non-limiting embodiment, ceramic element 204 is
structured to transfer heat from within main circuit breaker 202
through a rear or side opening in electrical distribution assembly
200. In an embodiment, ceramic element 204 extends along a length
of electrical circuit switching assembly 202 such that it is
structured to provide a maximum surface area to facilitate heat
transfer from within the electrical switching device to the
environment external to electrical distribution assembly 200.
[0042] Similarly, within electrical distribution assembly 200 is
branch circuit breaker 212 that includes ceramic element 214.
Branch circuit breaker 212 includes at least one heat-generating
component, however for simplicity, the at least one heat-generating
component is not shown. To prevent excessively high temperatures
and a resulting premature breaking of the current as signified by
switch 216 being in an "off" position, ceramic element 214 is
coupled to branch circuit breaker 212 so that it is structured to
transfer heat away from branch circuit breaker 212, through the
surface of electrical distribution assembly 200, and into an
environment external to electrical distribution assembly 200.
[0043] FIG. 3 is an illustrative schematic diagram presenting a top
view of an electrical switching device 302. Electrical switching
device 302 includes a ceramic element 304, a switch 306, a heat
generating component 308, and a case 322.
[0044] Ceramic element 304 is structured to have sufficient
thickness to maintain the structural integrity of electrical
switching device 302 and to protect electrical switching device 302
in the event of an explosion, overheating, malfunctions to other
components, or other undesirable conditions caused by excessive
heat. Further, to prevent a premature activation of a trip
mechanism as described above and signified by switch 306 being in
an "off" position, ceramic element 304, having a high thermal
conductivity, is thermally coupled to heat generating component 308
and as such is structured to transfer heat away from heat
generating component 308 and into an environment external to
electrical switching device 302. Although there are various other
components generally included in electrical switching device 302
and not shown in FIG. 3, it is understood that ceramic element 304
may be thermally coupled to any component capable of transferring
heat inside or outside of electrical switching device 302,
including but not limited to conductors, heat plates, inserts,
fins, metal blocks, and heat pipes.
[0045] In one embodiment, ceramic element 304 is molded into case
322 of electrical switching device 302. When electrical switching
device 302 is in operation, heat is generated by heat generating
component 308, and the heat is transferred to case 322. Heat is
then transferred to ceramic element 304, which acts as a heat
transfer window to dissipate heat outward from within electrical
switching device 302 to an environment external to electrical
switching device 302. Ceramic element 304 may include a thermally
conductive dielectric material. Various types of thermally
conductive dielectric materials include, but are not limited to,
boron nitride, aluminum nitride, aluminum oxide, and/or
poly-phenylene oxide.
[0046] In an embodiment of the disclosed concept, case 322 may be
formed from any suitable material to house electrical current
carrying component 308 and any other components of electrical
switching device 302. Various types of components include but are
not limited to, breaker contacts, trip actuators, electromagnetic
bars, wires, conductors, heat plates, inserts, fins, metal blocks,
and heat pipes. In one embodiment, case 322 is formed of any
suitable material including, but not limited to, metals, plastics,
poly-phenylene oxide, and/or a thermal interface material. In one
embodiment, ceramic element 304 is coupled to heat generating
component 308 via case 322. For example, case 322 may include a
thermally conductive material structured to transfer heat away from
heat generating component 308 and/or provide structural support to
electrical switching device 302.
[0047] FIG. 4 is an illustrative schematic diagram presenting a
side cross-sectional view of an electrical switching device 402 in
accordance with an embodiment of the disclosed concept. Electrical
switching device 402, in the embodiment, includes a ceramic element
404, a switch 406, an electrical current carrying component 408, a
case 422, a lever 424, a trip mechanism 426, a stationary contact
428, a movable contact 430, and an arc extinguisher 432. As current
carrying component 408 within the electrical distribution assembly
is in operation, a current runs through electrical current carrying
component 408, which generates heat. In the event of an overload
condition or short circuit, the trip bar activates, causing the
movable contact to separate from the stationary contact, thereby
breaking the circuit. For example, a broken circuit may be
represented by switch 406 being in an "off" position. Ceramic
element 404 is structured such that the heat travels from
electrical circuit carrying component 408, into molded case 422,
through ceramic element 404, and into an environment external to
electrical switching device 402.
[0048] In one embodiment, ceramic element 404 is a substantially
rectangular block that includes at least a first portion and a
second portion. The first portion is coupled to electrical current
carrying component 408. The second portion forms at least part of
the surface of electrical switching device 402 and is structured to
transfer heat from electrical switching device 402 to an
environment external to electrical switching device 402. The
distance between the first portion and second portion of ceramic
element 404 may be any distance suitable for heat transfer from
within electrical switching device 402 to an environment external
to electrical switching device 402. Ceramic element 402 may be
cubic, spherical, semi spherical, pyramidal, or any shape or
combination thereof suitable for providing a maximum surface area
of thermal coupling to electrical switching device 402. Ceramic
element 402 may be made of any grade of boron nitride, aluminum
nitride, aluminum oxide, or any other compound structured to have
sufficient strength provide structural support to electrical
switching device 402 and transfer heat from within electrical
switching device 402 to an environment external to electrical
switching device 402. For example, ceramic element 402 may be made
of the many grades of boron nitride that are commercially
available. In the illustrative embodiment, a first side of ceramic
element 404 is coupled to electrical circuit carrying component 408
via case 422. Ceramic element 404 is structured so as to not
interfere with the functioning of the other components of
electrical switching device 402. For example, when an overload or
short circuit occurs, trip mechanism 426 is activated, which causes
pull lever 424 to be pulled downward, thereby separating movable
contact 430 from stationary contact 428. Although there are various
other components generally included in electrical switching device
402, persons of ordinary skill in the art will recognize that
ceramic element 404 may be thermally coupled to any component
capable of generating heat inside or outside of an electrical
switching device, including but not limited to conductors, heat
plates, inserts, fins, metal blocks, and heat pipes.
[0049] In one embodiment, stationary contact 428 is electrically
coupled to movable contact 430. When contacts 428 and 430 are
separated while an electrical current is running between them, a
high power discharge of electricity may occur, forming an electric
arc between the now separated contacts. Electrical switching device
402, therefore, includes arc extinguisher 432 to contain and
extinguish the arc. Nevertheless, the arc generates a substantial
amount of heat and increases the risks of explosion, melting,
fires, malfunctions to other components, and other events.
Accordingly, ceramic elements 404 help to reduce the heat within
electrical switching device 402 by absorbing the heat from the arc
and dissipating the heat into an environment external to electrical
switching device 402.
[0050] FIG. 5 is an illustrative diagram presenting another side
cross sectional view of an electrical switching device 502 in
accordance with an embodiment of the disclosed concept. Electrical
switching device 502 includes a ceramic elements 504, a switch 506,
an electrical current carrying component 508, a lever 524, a trip
bar 526, a stationary contact 528, a movable contact 530, and an
arc extinguisher 532.
[0051] In one embodiment, one or more of ceramic element 504 may be
included in electrical switching device 502 as needed such that
ceramic elements 504 fit around the various internal components in
electrical switching device 502. As a current runs through
electrical current carrying component 508, electrical current
carrying component 508 generates heat. Ceramic elements 504 are
structured such that current carrying components 508, and any
additional components generating heat within electrical switching
device 502 are exposed to a maximum surface area of ceramic
elements 504 as possible without ceramic elements 504 interfering
with the functions of the components of electrical switching device
502. Ceramic elements 504 are structured such that the heat
generated by electrical circuit carrying components 508 and other
internal components within electrical switching device 502 is
transferred to ceramic elements 504, whereby the heat is dissipated
into an environment external to electrical switching device 502.
Persons of ordinary skill in the art will recognize that ceramic
element 504 may be thermally coupled to any component capable of
generating heat inside or outside of electrical switching device
502, including but not limited to conductors, heat plates, inserts,
fins, metal blocks, and heat pipes.
[0052] FIG. 6 is an illustrative schematic diagram of an electrical
switching device 602 in accordance with an embodiment of the
disclosed concept. The electrical switching device 602 includes
ceramic elements 604, a switch 606, an electrical current carrying
component 608, and a case 622. Ceramic elements 604 each have a
first portion and a second portion. The first portions of ceramic
elements 604 are coupled to electrical current carrying component
608, and the second portions of ceramic elements 604 form a surface
of electrical switching device 602 such that ceramic elements 604
are structured to transfer heat from various components of
electrical switching device 602 to an environment external to
electrical switching device 602.
[0053] In one embodiment, ceramic elements 604 are directly coupled
to electrical current carrying component 608. However, ceramic
elements 604 may be coupled to electrical current carrying
component via case 622, a thermal interface material, or any
thermally conductive material. In a non-limiting embodiment,
electrical switching device 602 is substantially rectangular, and
ceramic elements 604 are also substantially rectangular and are
molded into case 622 such that ceramic elements 604 conform to the
shape of electrical switching device 602.
[0054] Electrical switching device 602 includes any device
structured to connect and disconnect an electrical current in a
distribution assembly. For example, the electrical switching device
602 may be switch gear, such as a main circuit breaker, a branch
circuit breaker, or a fuse. Electrical switching device 602 may
comprise any material known in the art, including poly-phenylene
oxide, a thermal interface material, or fiberglass.
[0055] In an embodiment of the disclosed concept, electrical
switching device may include a heat generating component. In an
embodiment of the disclosed concept, a heat generating component
may be a component that generates heat in and/or around electrical
switching device 602. In an embodiment of the disclosed concept, a
heat-generating component may be an electrical current carrying
component and comprise any material known in the art, including
silver tungsten, silver tungsten carbide, copper tungsten, silver
graphite, silver tungsten carbide graphite, or any other material
capable of carrying an electrical current. Furthermore, in an
embodiment of the disclosed concept, a heat generating component
may be any component capable of generating heat inside or outside
of electrical switching device 602, including but not limited to
conductors, heat plates, inserts, fins, metal blocks, and heat
pipes.
[0056] Ceramic elements 604, in a non-limiting embodiment, are
molded into electrical switching device 602 and as such can be any
shape suitable for optimal thermal coupling to electrical current
carrying component 608. In a non-limiting embodiment, ceramic
elements 604 comprise a thermally conductive material, dielectric
material. Ceramic element 604 may be made of any grade of boron
nitride, aluminum nitride, aluminum oxide, or any other thermally
conductive compound structured to have sufficient strength provide
structural support to electrical switching device 602 and transfer
heat from within electrical switching device 602 to an environment
external to electrical switching device 602. Ceramic elements 604
include a first portion and a second portion. The first portions
are thermally coupled to an electrical current carrying component
608 and structured to transfer heat away from the electrical
current carrying component 608 to an environment external to
electrical switching device 602. In an embodiment of the disclosed
concept, the first portion of the ceramic element 604 is structured
to maximize the surface area of the coupling between ceramic
element 604 and electrical current component 608. The dimensions of
ceramic elements 604 are structured such that the tensile strength
of ceramic elements 604 are capable of maintaining the structural
integrity of electrical switching device 602 in the event of fires,
explosions, or other undesirable events caused by excessive heat.
For example, ceramic element 604 is molded to conform to the shape
and structure of electrical switching device 602 and the surface
areas of ceramic elements 604 are such that it allows the first
portions of ceramic elements 604 to couple to heat generating
components and encapsulates at least a portion of a heat generating
component. The distance between the first portion and second
portion of ceramic element 604 may be any distance suitable for
heat transfer from electrical switching device 602 to an
environment external to electrical switching device 602. Ceramic
elements 604 may be cubic, spherical, semi spherical, pyramidal, or
any shape or combination thereof suitable for providing a maximum
surface area of thermal coupling to electrical switching device
602. Although there are various other components generally included
in electrical switching device 602 and not shown in FIG. 6, it is
understood that ceramic element 604 may be thermally coupled to any
component capable of generating heat inside or outside of
electrical switching device 602, including but not limited to
conductors, heat plates, inserts, fins, metal blocks, heat pipes,
arc extinguishers and control circuitry.
[0057] The environment external to electrical switching device 602
may correspond to any suitable environment, such as, for example, a
cavity within an electrical distribution assembly. As another
example, the environment may be a vent built into an distribution
assembly for the ventilation of heat. As still another example, the
environment is external to an electrical distribution assembly, or
the environment may be open space.
[0058] FIG. 7 is an illustrative schematic diagram presenting a
cross sectional side view of an electrical distribution assembly
700 in accordance with an embodiment of the disclosed concept. FIG.
7 is substantially identical to FIG. 1B, such that for each element
in 1B labeled 1XX, the similar element in FIG. 7 is labeled 7XX.
For example, main circuit breaker 102 in FIG. 1B is labeled as main
circuit breaker 702 in FIG. 7. Electrical distribution assembly 700
includes: a main circuit breaker 702 including a ceramic element
704, a switch 706, a hot wire 708 and a neutral ground 710
connected to main circuit breaker 702, a branch circuit breaker 712
having a ceramic element 714, a switch 716, and a wire 718
connected to branch circuit breaker 712, and bus bars 734 connected
to branch circuit breaker 712. In addition, FIG. 7 also shows
cavity 725, a trim assembly 736 and a door 738.
[0059] In a non-limiting embodiment, cavity 725 exists between trim
assembly 736 and door 738. Trim assembly 736 is mechanically
coupled to the walls of electrical distribution assembly such that
it encloses wires, circuit breakers, bus bars, and other internal
components of electrical distribution assembly 700 and acts as a
barrier between these internal components and the environment
external to electrical distribution assembly 700. Trim assembly 736
includes several openings. Main circuit breaker 702 and branch
circuit breakers 712 each extend from a wall of electrical
distribution assembly 700 through the openings in trim assembly
736. The openings in trim assembly 736 act to hold circuit breakers
702 and 712 in place, particularly when a user is moving switches
706 and 716 into the "on" or "off" positions. Accordingly, switches
706 and 716, as well as ceramic elements 704 and 714 are located at
least in part within cavity 725. As such, heat is able to dissipate
from circuit breakers 702 and 712 into cavity 725 via ceramic
elements 704 and 714.
[0060] Door 738 functions to open and close so as to allow access
to circuit breakers 702 and 712. Further, when heat dissipates into
cavity 725, cavity 725 increases in heat. As such, door 738 opens
so that heat further dissipates into the outside environment
external to electrical distribution assembly 700 in order to more
efficiently remove heat from electrical distribution assembly
700.
[0061] FIG. 8 is an illustrative flowchart of a process for
removing heat from an electrical switching device in accordance
with an embodiment of the disclosed concept. Process 800 begins, in
one embodiment, at step 802. At step 802, a source of electrically
generated heat within an electrical switching device is provided.
For example, the source of heat may be any component or device
associated with the electrical switching device.
[0062] At step 804, the source of heat is thermally coupled to a
ceramic element. The thermal coupling made be performed via a
procedure or many procedures, including, but not limited to,
molding, adhesion, latching, a clinch joint, a thermal interface
material such as a thermal adhesive, or any other suitable method
known in the art for thermal coupling.
[0063] At step 806, at least a portion of the ceramic element is
aligned with an exterior surface of the electrical switching device
such that the portion forms part of the exterior of the electrical
switching device. In one embodiment, the electrical switching
device is electrically coupled to the electrical distribution
assembly. Additionally, a portion of the ceramic element is aligned
with an exterior surface of the electrical distribution assembly
such that the portion forms part of the exterior of the electrical
distribution assembly.
[0064] In the claims, any reference signs placed between
parentheses shall not be construed as limiting the claim. The word
"comprising" or "including" does not exclude the presence of
elements or steps other than those listed in a claim. In a device
claim enumerating several means, several of these means may be
embodied by one and the same item of hardware. The word "a" or "an"
preceding an element does not exclude the presence of a plurality
of such elements. In any device claim enumerating several means,
several of these means may be embodied by one and the same item of
hardware. The mere fact that certain elements are recited in
mutually different dependent claims does not indicate that these
elements cannot be used in combination.
[0065] Although the disclosed concept has been described in detail
for the purpose of illustration based on what is currently
considered to be the most practical and preferred embodiments, it
is to be understood that such detail is solely for that purpose and
that the disclosed concept is not limited to the disclosed
embodiments, but, on the contrary, is intended to cover
modifications and equivalent arrangements that are within the
spirit and scope of the appended claims. For example, it is to be
understood that the disclosed concept contemplates that, to the
extent possible, one or more features of any embodiment can be
combined with one or more features of any other embodiment.
* * * * *