Patent Application
20130146430
1. Field
The disclosed concept pertains generally to heat and corrosion protection devices and, more particularly, to devices used to protect circuit breaker terminals, terminal screw threads, connecting cables, and the like, from heat and corrosion caused by high temperature gases. The disclosed concept further pertains to circuit breakers. The disclosed concept also pertains to methods of protecting circuit breaker terminals, terminal screw threads, connecting cables, and the like.
2. Background Information
Circuit breakers function to interrupt the flow of electric current when an overload or short circuit is detected within a power circuit. When the circuit breaker interrupts the overload or short circuit current, an arc is generated, which creates exhaust gases of high temperature. These ionized exhaust gases can damage the terminal lug of the circuit breaker by causing corrosion. Additionally, the heated exhaust gases can damage the circuit breaker terminal lug by causing connecting cables to melt onto the terminal lug. Corrosion of the terminal lug coupled with melted cable material can damage terminal lug screw threads rendering the threads and terminal lug unusable.
When the cabling connected to a circuit breaker melts onto the terminal lug, such that removal thereof becomes difficult, it is standard practice to cut the damaged cabling. Additionally, when circuit breaker terminal lugs have degraded to such a degree that corrosion and cable melt have made the terminal lug and threads therein unusable, it is standard practice to replace the terminal lug, or in some cases, the entire circuit breaker. Information relevant to attempts to address these problems are found in U.S. Pat. No. 5,111,008. However, it is believed that the teachings found in this Patent suffer from the fact that it is not easily adaptable to interface between a commercial circuit breaker and its terminal lug.
Also, several manufacturers of industrial circuit breakers have produced “terminal shields”. These shields are not to be confused with the device to be described hereinbelow. In contrast to the device described by the disclosed concept, “terminal shields” lie between the internal phases of a circuit breaker and protect each phase from the arc of another phase. It is believed that such terminal shields fail to properly address or protect external circuit breaker terminal lugs and connecting cables from such arcing events.
Consequently, a need exists in the art for a method, apparatus, and device capable of preventing such terminal lug degradation or corrosion.
There is room for improvement in circuit breakers.
There is also room for improvement in circuit breaker terminal lugs.
There is further room for improvement in methods of protecting circuit breaker terminal lugs.
These needs and others are met by embodiments of the disclosed concept in which a circuit breaker terminal lug cover protects a circuit breaker terminal lug and a number of connecting cables from degradation or corrosion (e.g., without limitation, caused by heat and/or ionized exhaust gases).
In accordance with one aspect of the disclosed concept, a circuit breaker terminal lug cover is structured to mechanically secure to a circuit breaker terminal lug and protect the terminal lug from degradation or corrosion, the terminal lug includes a number of terminal lug screws capable of securing a number of cables to the circuit breaker. The terminal lug cover comprises: a plurality of sides structured to carry heat away from the terminal lug or deflect ionized gases away from the terminal lug, wherein at least one of the sides includes a number of securing members structured to mechanically secure the terminal lug cover to the circuit breaker terminal lug, and wherein one of the sides includes an access hole permitting access to the number of terminal lug screws.
As another aspect of the disclosed concept, a circuit breaker apparatus comprises: a circuit breaker comprising: a circuit breaker terminal lug including a number of terminal lug screws capable of securing a number of cables to the circuit breaker; and a circuit breaker terminal lug cover mechanically secured to the circuit breaker terminal lug in order to protect the terminal lug from degradation or corrosion, the terminal lug cover comprising: a plurality of sides structured to carry heat away from the terminal lug or deflect ionized gases away from the terminal lug, wherein at least one of the sides includes a number of securing members mechanically securing the terminal lug cover to the circuit breaker terminal lug, and wherein one of the sides includes an access hole permitting access to the number of terminal lug screws.
The plurality of sides may be a front side, a bottom side, and two opposing sides each of which is coupled to the front and bottom sides. The terminal lug cover may fit snugly on a front side, a bottom side, and two opposing sides of the terminal lug in order that physical contact between the terminal lug cover and the terminal lug permits the terminal lug cover to conduct heat away from the terminal lug and the number of cables or deflect ionized gases away from the terminal lug.
As another aspect of the disclosed concept, a method protects a circuit breaker terminal lug from degradation or corrosion. The circuit breaker terminal lug includes a number of terminal lug screws capable of securing a number of cables to a circuit breaker, and the circuit breaker includes a terminal lug. The method comprises: mechanically securing a circuit breaker terminal lug cover to the circuit breaker terminal lug in order to protect the terminal lug from degradation or corrosion; providing the circuit breaker terminal lug cover with a plurality of sides structured to carry heat away from the terminal lug or deflect ionized gases away from the terminal lug; including with at least one of the sides a number of securing members mechanically securing the terminal lug cover to the circuit breaker terminal lug; and providing one of the sides with an access hole permitting access to the number of terminal lug screws.
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 in which:
As employed herein, the term “number” shall mean one or an integer greater than one (i.e., a plurality).
As employed herein, the statement that two or more parts are “connected” or “coupled” or “affixed” together shall mean that the parts are joined together either directly or joined through one or more intermediate parts. Further, as employed herein, the statement that two or more parts are “attached” shall mean that the parts are joined together directly.
As employed herein, the term “circuit breaker” shall mean any electrical switch or circuit interrupter that interrupts the flow of electrical current in an electrical circuit upon the existence or occurrence of specified number of electrical/mechanical fault conditions, and that permits the flow of electric current in the electrical circuit under other conditions.
As employed herein, the term “circuit breaker terminal” shall mean a component of a circuit breaker that permits a number of cables of a circuit to connect to the circuit breaker.
As employed herein, the term “circuit breaker terminal lug” or “terminal lug” shall mean a physical component of a circuit breaker having a circuit breaker terminal
As employed herein, the term “hole” shall mean an opening through something; an area where something is missing; or an aperture through something.
As employed herein, the term “access hole” shall mean a hole through or in something to access something else.
As employed herein, the term “screw” shall mean a simple machine of the inclined plane type consisting of a spirally grooved solid cylinder structured to fit into a correspondingly grooved hollow cylinder; a nail-shaped or rod-shaped piece with a spiral groove structured to fit into a correspondingly grooved hollow material by rotating; or a threaded or spirally grooved fastener structured to fit into a correspondingly threaded or spirally grooved terminal lug by rotating.
As employed herein, the term “cable” shall mean a circuit conductor having a number of individual electrical conductors.
The disclosed concept provides advantageous apparatus and devices for protecting circuit breakers from failure, degradation, corrosion, and eventual replacement due to excessive heat resulting from ionized gases released during arcing events. The circuit breaker terminal lug covers described herein prolong the operational lifetime of circuit breakers, and their connecting components. Using the apparatus and devices according to the disclosed concept, thermal energy and/or ionized exhaust gasses are efficiently and effectively conducted away from or deflected away from the circuit breaker and its connecting cables.
As shown in
The terminal lug 2 can be made of copper, aluminum or any other suitable conductor for a circuit, such as a power circuit.
The terminal lug cover 1 can be made of a suitable thermoplastic material (e.g., without limitation, LEXAN® 500 10% glass filled V0 rated).
The terminal lug cover 1 advantageously couples to a portion of the terminal lug 2 external to the circuit breaker 3. The terminal lug 2 is removable from the circuit breaker 3. The upper (with respect to
The disclosed terminal lug cover 1 protects the terminal lug 2 against relatively high temperature exhaust gasses after the circuit breaker 3 has interrupted the corresponding circuit (not shown). The terminal lug cover 1 protects against erosion of the terminals of the terminal lugs 2 from melted terminal material caused by high temperature gases exiting the circuit breaker 3. Since terminals and lug screw threads can otherwise be damaged to a point where the cabling would need to be cut in order to change out the product, the disclosed solution can help avoid potentially costly repairs, beyond a simple circuit breaker replacement.
The disclosed terminal lug cover 1 assembles to the profile of the circuit breaker terminal lug 2, with securing clips 8 and/or 9 to hold the cover in position. The cover 1 allows access to a number of the circuit breaker terminal lug screws 5 in order to connect cabling. The cover 1 then deflects ionized gases away from the body of the terminal lug 2.
In view of what is described above, one skilled in the art will understand that the embodiments of the assembly thus far described comprise the circuit breaker 3, the circuit breaker terminal lug 2, and the terminal lug cover 1. One embodiment of the disclosed concept utilizes a terminal lug cover, such as 1, having four sides 10,11,12,13 with the lower (with respect to
One skilled in the art may find advantages by using a mechanism different than the securing clips 8 and/or 9 to fasten the terminal lug cover 1 to the terminal lugs 2. One skilled in the art may also find advantages by using a different type of hole than the circular hole 6 on the front (with respect to
According to several embodiments, the disclosed concept will extend the life of circuit breaker terminal lugs and connecting cables (not shown) by protecting against degradation and/or corrosion from heat, ionized exhaust gasses or connecting cable melt. These advantageous characteristics of the terminal lug cover 1 will result in substantial cost savings in circuit breaker maintenance.
What has been shown is the circuit breaker terminal lug cover 1. While the terminal lug cover 1 has been described through specific embodiments and applications thereof, it is understood that numerous modifications and variations could be made thereto by those skilled in the art without departing from the spirit and scope of the disclosed concept. It is therefore understood that within the scope of the claims, the disclosed concept may be practiced otherwise than specifically described herein.
Accordingly, it is to be understood that the disclosed concept is not to be limited by the specific illustrated embodiments, but only by the scope of the appended claims. The description may provide examples of similar features as are recited in the claims, but it should not be assumed that such similar features are identical to those in the claims unless such identity is essential to comprehend the scope of the claim. In some instances, the intended distinction between claim features and description features is underscored by using slightly different terminology.
The disclosed concept is described in association with a molded case circuit breaker, although the disclosed concept is applicable to a wide range of circuit breakers.
While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the disclosed concept which is to be given the full breadth of the claims appended and any and all equivalents thereof.
This application claims the benefit of U.S. Patent Application Ser. No. 61/569,726, filed Dec. 12, 2011, which is incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 61569726 | Dec 2011 | US |
