Patent Application
20120169208
The embodiments described herein relate generally to power equipment protection devices and, more particularly, to apparatus for use in channeling exhaust gases and pressure away from a location of arc generation.
Known electric power circuits and switchgear generally have conductors that are separated by insulation, such as air, or gas or solid dielectrics. However, if the conductors are positioned too closely together, or if a voltage between the conductors exceeds the insulative properties of the insulation between the conductors, an arc can occur. The insulation between the conductors can become ionized, which makes the insulation conductive and enables formation of an arc flash.
An arc flash includes a rapid release of energy due to a fault between two phase conductors, between a phase conductor and a neutral conductor, or between a phase conductor and a ground point. Arc flash temperatures can reach or exceed 20,000° C., which can vaporize the conductors and adjacent equipment. Moreover, an arc flash can release significant energy in the form of heat, intense light, pressure waves, and/or sound waves, sufficient to damage the conductors and adjacent equipment. However, the current level of a fault that generates an arc flash is generally less than the current level of a short circuit, such that a circuit breaker may not trip or exhibits a delayed trip unless the circuit breaker is specifically designed to handle an arc fault condition.
Standard circuit protection devices, such as fuses and circuit breakers, generally do not react quickly enough to mitigate an arc flash. One known circuit protection device that exhibits a sufficiently rapid response is an electrical “crowbar,” which utilizes a mechanical and/or electro-mechanical process by intentionally creating an electrical “short circuit” to divert the electrical energy away from the arc flash point. Such an intentional short circuit fault is then cleared by tripping a fuse or a circuit breaker. However, the intentional short circuit fault created using a crowbar may allow significant levels of current to flow through adjacent electrical equipment, thereby still enabling damage to the equipment.
Another known circuit protection device that exhibits a sufficiently rapid response is an arc containment device, which creates a contained arc to divert the electrical energy away from the arc flash point. For example, some known devices generate an arc, such as a secondary arc flash, for use in dissipating energy associated with a primary arc flash detected on a circuit. At least some known arc containment devices include exhaust port that are positioned along a side surface to shorten an exhaust path away from the location where the contained arc is created and into the ambient. However, such venting schemes release hot gases at high pressure into an equipment enclosure, which can cause additional damage to other electronics modules within the same enclosure.
For at least the reasons stated above, a need exists for an arc containment device having an improved exhaust duct apparatus that directs exhaust gasses from an exhaust port on the arc containment device towards an optimized direction into an equipment enclosure.
Additionally, for at least the reasons stated above, a need exists for an arc containment device having an exhaust duct apparatus that is simple, robust, inexpensive, and without moving parts.
In one aspect, a device for diverting energy away from an arc flash occurring within an electrical power system is provided. The device includes an arc source configured to create a second arc flash, a plasma gun configured and disposed to inject plasma in proximity of said arc source in response to the arc flash, an arc containment device configured and disposed to house said arc source and said plasma gun, said arc containment device including an exhaust port configured to route exhaust gases out of said arc containment device in a first direction, and an exhaust duct configured to be operatively coupled in flow communication with said exhaust port, the exhaust duct comprising a substantially hollow tube including a first tube portion and a second tube portion, said first tube portion configured to be coupled in flow communication with said exhaust port, said second tube portion defining an exhaust vent and coupled in flow communication with said first tube portion to route the exhaust gases out of said arc containment device in a second direction.
In another aspect a method of manufacturing a device is provided. The method includes disposing an arc source configured to create a second arc flash, disposing a plasma gun configured to inject plasma in proximity of said arc source in response to the arc flash, disposing an arc containment device to house said arc source and said plasma gun, disposing an exhaust port in flow communication with the arc containment device, arranging the exhaust port to route exhaust gases out of the arc containment device in a first direction, and disposing an exhaust duct in flow communication with the exhaust port to route the exhaust gases out of the device in a second direction.
a is a partially exploded view of an alternative embodiment circuit protection system of
Exemplary embodiments of device and methods for use with a circuit protection system are described herein. These embodiments enhance the flow of exhaust gases, heat, and pressure out of the circuit protection system after an arc flash is generated. For example, the circuit protection system can receive a signal that indicates detection of a primary arc flash within a power system coupled to the circuit protection system. The circuit protection system can then generate a secondary arc flash to transfer the energy generated by the primary arc flash away from the power system. Moreover, these embodiments enhance the flow of exhaust gases, heat, and pressure out of a circuit protection device that is part of the circuit protection system. Routing the exhaust gases away from the circuit protection device, such as for example in a substantially vertical direction, protects the circuit protection system and any other electrical equipment that is positioned within an equipment enclosure from the flow of exhaust gases, heat, and pressure.
An arc triggering device such as a plasma gun 282 is disposed proximate the arc source electrode gap 284, for example centrally disposed with respect to the arc source electrodes 216, and configured to ionize a portion of the space in the arc source electrode gap 284. In one embodiment, the plasma gun 282 injects plasma as an arc mitigation technique, to create a secondary arcing fault in response a signal indicative of a primary arc flash within the power system coupled to the circuit protection system 106. In an embodiment, the plasma gun 282 is covered by a plasma gun cover 218 (
Conductor cover 212 includes a plurality of mounting apertures (not shown) that are each sized to receive a respective fastening mechanism therein to couple conductor cover 212 to a support such as a conductor base 210. Moreover, conductor cover 212 includes an edge portion 220 having a plurality of recesses 222 formed therein (
Top cover 202 includes a top surface 242, a lip 244, and a side surface 246 extending between top surface 242 and lip 244. Lip 244 is sized to overlay exhaust manifold posts 232 (
Moreover, as shown in
In an exemplary embodiment, shock shield 206 includes a top surface 226 and a side surface 228. A plurality of exhaust vents 230 are formed in top and side surfaces 226 and 228. Exhaust manifold 204 is sized to cover shock shield 206. Exhaust manifold 204 includes a plurality of posts 232 (
In an exemplary embodiment, and as shown in
Furthermore, arc containment device 200 includes one or more non-conductive exhaust ducts 322 positioned on the periphery of top cover 202. In an exemplary embodiment, as illustrated in
During operation, controller 300 receives a signal from, for example, electronics modules 104 (
The secondary arc flash also creates exhaust gases. The exhaust gases are channeled through exhaust vents 230 of shock shield 206. The exhaust gases are also channeled through exhaust vents 236 (
While each exhaust duct 322 is shown in the Figures, by way of example and not limitation, as having a generally triangular cross-section, it is contemplated that each exhaust duct 322 may comprise a pipe, tube, or channel having any generally convenient cross-section. Each exhaust duct 322 may be oriented and arranged to direct the exhaust gases in any desired predetermined direction. Likewise, while the embodiments in the Figures, by way of example and not limitation, illustrate two exhaust ports 350, it will be understood that any number of exhaust ports may be formed as described, and arranged in flow communication with the exhaust path 240. Likewise, while the embodiments in the Figures, by way of example and not limitation, illustrate two exhaust ducts 322 connected in flow communication with corresponding exhaust ports 350, it will be understood that any number of exhaust ducts 322 may be provided in an embodiment. In an embodiment, as shown in
While the embodiments in the Figures, by way of example and not limitation, illustrate each exhaust duct 322 being formed of two separate components, it will be understood, that in an embodiment, each exhaust duct 322 may be unitary, or as any desired number of components coupled together.
A plurality of first primary electrical connectors 312 are coupled to arc containment device 200 to electrically connect arc containment device 200 to a plurality of conductors (not shown) of a circuit (not shown) that is being monitored and/or protected by arc containment device 200. Moreover, controller 300 (
Exemplary embodiments of apparatus for use in devices for protection of power distribution equipment are described above in detail. The systems, methods, and apparatus are not limited to the specific embodiments described herein but, rather, operations of the methods and/or components of the system and/or apparatus may be utilized independently and separately from other operations and/or components described herein. Further, the described operations and/or components may also be defined in, or used in combination with, other systems, methods, and/or apparatus, and are not limited to practice with only the systems, methods, and storage media as described herein.
Although the present invention is described in connection with an exemplary circuit protection environment, embodiments of the invention are operational with numerous other general purpose or special purpose circuit protection environments or configurations. The circuit protection environment is not intended to suggest any limitation as to the scope of use or functionality of any aspect of the invention. Moreover, the circuit protection environment should not be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment.
The order of execution or performance of the operations in the embodiments of the invention illustrated and described herein is not essential, unless otherwise specified. That is, the operations may be performed in any order, unless otherwise specified, and embodiments of the invention may include additional or fewer operations than those disclosed herein. For example, it is contemplated that executing or performing a particular operation before, contemporaneously with, or after another operation is within the scope of aspects of the invention.
When introducing elements of aspects of the invention or embodiments thereof, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
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 language of the claims.
