AND ASSOCIATED METHOD THEREFOR

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and claims the benefit of U.S.

Patent Application Serial No. 14/308,169, filed June 18, 2014, which is incorporated b reference herein.

BACKGROUND

Field

The disclosed concept relates generally to electrical switching apparatus and, more particularly, to circuit interrupters, such as, for example, circuit breakers. The disclosed concept also relates to jumpers for electrical switching apparatus. The disclosed concept further relates to methods of making jumpers. B ac kgrou nd In fopa ti on

Circuit breakers are typically available in one-, two-, three- and four- pole construction, although larger counts of poles are possible. It is known to connect multiple poles of circuit breakers in series to provide a high voltage for a low voltage switching and interruption device (e.g., without limitation, 750 VDC; 1000 VDC; 1.500 VAC), For a 1000 VDC application, for example, typically multiple circuit breakers are electrically tied together. Most known existing six-pole or eight-pole air circuit breakers are designed such that the poles are electrically connected internally in breaker structures in a predetermined manner.

It is known that to obtain higher interruption and voltage ratings, circuit breaker poles can be wired in series. Normally, cable or bus bars are electrically connected to the circuit breaker terminals, which can the current and remove a significant amount of the heat that is generated within the breaker. A conventional shorting strap, commonly referred to as a jumper, electrically connected between poles can cany the current, but does not remove much heat, resulting in relatively high temperature rises at the circuit breaker terminals. Commonly assigned United States Patent Application Publication ^' No. 2013/0213780 discloses an example jumper for electrically connecting electrical swi tching apparatus poles.

Consumer markets demand a circuit breaker jumper that both occupies relatively little space and operates at relativel low temperatures. The conventional tradeoff in jumper design, however, is between size and thermal performance (e.g., heat transfer). That is, to achieve lower operating temperatures, typically the size of the jumper must increase, and vice versa. Stated another way, jumper designs mast generally concede in one of these areas, or otherwise be cost-prohibitive.

There is room, therefore, fo improvement in electrical switching apparatus, such as circuit breakers, and in jumpers and associated methods therefor,

SUMMARY

These needs and others are met by embodiments of the disclosed concept, direct to a j umper and associated method for electrical switching apparatus, which among other benefits, provide both a current carrying functio and heat transfer function within relatively small available space.

In accordance with one aspect of the disclosed concept , a jumper is provided for an electrical switching apparatus. The electrical switching apparatus comprises a plurality of poles. Each of the poles comprises a terminal. The terminal of a first one of the poles is proximate the terminal of a second one of the pol es. The jumper comprises', a jumper member comprising an attachment portion and a heat sink portion,, the attachment portion being structured to electrically connect the terminal of the first one of the pole to the termina l of the second one of the poles, the heat sink portion comprising a plurality of spaced apart heat transfer members. The plurality of spaced apart heat transfer members are arranged in a plurality of rows and a plurality of columns.

The jumper member may further comprise a first side, a second side disposed opposite the first side, a first end. a second end disposed opposite the first end, a first edge, and a second edge disposed opposite the first edge. The attachment portion may include a first leg extending outwardly from the first end and a second leg extending outwardl from the first end opposite and spaced from the first leg. The plurality of rows and the plurality of columns may extend outwardly from the first side between the first edge and the second edge. Each of the heat transfer members may have a width, a height and a depth . The width may be the same for all of the heat, transfer members, the height may be the same for all of the heat transfer members, and the depth may be the same for all of the heat transfer members, Each one of the rows may be spaced apart the same distance from the other rows. Each one of the columns ma be spaced apart the same distance from the other columns.

As another aspect of the disclosed concept, an electrical switching apparatus comprises: a plurality of poles each comprising a terminal, the terminal of a first one of the poles being proximate the tenninal of a second one of the poles; and at least one jumper comprising: a jumper member comprising an attachment portion and a heat sink portion, the attachment portion electrically connecting the tenninal of the first one of the poles to the terminal of the second one of the poles, the heat sink portion comprising a plurality of spaced apart heat transfer members. Th plurality of spaced apart heat transfer members are arranged in a pl urality of rows and a plurality of columns.

The electrical switching apparatus may be a circuit breaker including plurality of jumpers. Each of the jumpers may electrically connect the terminals of a pair of the poles of the circuit breaker.

As a further aspec t of the disclosed concept, a method of making a jumper comprises; extruding a jumper member from a single piece of electrically and thermally conductive material; and machining the jumper member to form an attachment portion and a beat sink portion comprising a plurality of spaced apart heat transfer members arranged in a plurality of rows and a plural ity of columns.

The method may further comprise drilling and threading the attachment portion. The method may also comprise coating a pluraiity of surfaces with an electrically insulating material.

BRIEF DESCRIPTION OF THE DRAWINGS

A full understanding of the disclosed concept can be gained from the following description of the preferred embodiments when read in conj unction with the accompanying drawings in which

Figure I is an isometric partially exploded view of a circuit breaker and. j umpers therefor, in accordance with an embodiment of the disclosed concept:

Figures 2 and 3 are front and back isometric views, respectively, of one of the jumpers of Figure I; Figures 4 and 5 are side elevation and top plan views, respectively, of the jumper of Figures 2 and 3;

Figure 6 is an isometric partially exploded view of a circuit breaker and jumpers therefor, in accordance with another embodiment of the disclosed concept;

Figures 7 and 8 are front and back isometric views, respectively, of one of the jumpers of Figure 6;

Figures 9 and 10 are side elevation and top plan views, respecti vely, of the jumper of Figures 7 and 8;

Figure 1 1 is a section view taken along line 1 1 1 1 f Figure 10;

Figure 12 is an isometric view of a j umper in accordance with another embodiment of the disclosed concept;

Figure 13 is a top plan view of the jumper of Figure 12;

Figure 14 is a section view taken along line 14—14 of Figure 13; and

Figure 15 is a section view taken along line 15— i 5 of Figure 13.

DESCRiPTlO OF THE PREFERRED EMBODIMENTS It will be appreciated that although the disclosed concept is shown and described in the examples herein in association with a four-pole circuit breaker, the disclosed concept is applicable to a wide range of electrical switching apparatus having any known or suitable plurality of poles.

As employed herein, the statement that two or more parts are

"connected" or "coupled" 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 "fastener" refers to any suitable connecting or tightening mechanism expressly including, hut not limited to, screws, bolts and the combinations of bolts and nuts (e.g., without limitation, lock nuts) and bolts, washers and nuts.

As employed herein, the term "number" shall mean one or an integer greater than one (i.e., a plurality). EXAMPLE 1.

Figure I shows an electrical switching apparatus 2 (e.g., without limitation, circuit breaker including a housing 4 and a plurality of poles 6,8,1.0,12 (four are shown) employing pair of jumpers 100, in accordance with a non-limiting embodiment of the disclosed concept. The jumper 100 is for electrical connection between a terminal 14 of one circuit breaker pole 6 and a terminal 16 of another circuit breaker pole 8.

In the example shown, the jumpers 100 are designed t be bolted to the circuit breaker terminals 14, 16. Portions (see, for example and without limitation, legs 142 and 144 of attachment portion 104, described hereinhekrw) may be threaded to further facilitate mechanically coupling and electrically connecting the jumpers 1 0 to the corresponding terminals 14,16.

In Figure I , the poles 6,8 further includ a number of connection members 20,22 (two are shown), which preferably cooperate with a corresponding numbe of suitable fasteners {not shown, but see fasteners 290 and 292 cooperating with connection member 20' of Figure 6),

It will be appreciated that, for ease of illustration, and economy of disclosure, only one jumper 100 will be described in detail herein.

EXAMPLE 2

Referring to Figures 2-4, the jumper 100 includes a jumper member

102 having an attachment, portion i04 and a heat sink portion 106. The attachment portion 1 4 is structured to electrically connect the terminal 14 of a corresponding first one of the circuit breaker poles 6 to the terminal 16 of another one of the circuit breaker poles 8, as previously discussed hereinabove with respect to Figure 1 . The heat sink portion i 06 includes a plurality of spaced apart heat transfer members 108. More specifically, all of the heat transfer members 108 are spaced apart from one another. The heat transfer members 108 are arranged in a plurality of rows 110 and a plurality of columns 120, as best shown in Figures 4 and 5.

In other words, the heat transfer member 108 preferably comprise a plurality of spaced apart pin fins. Among other advantages, such a design allows for a more omni -directional method to dissipate heat. That is, conventional jumper designs (not shown) employ a plurality of elongated fins that extend in one direction the entire width of the jumper parallel to and spaced from one another . Such conventi onal elongated fins only work effectively if they are positioned (e.g., aligned) such that the air is free to move in the exact direction in which the fins are oriented. In other words, variety of different jumper designs must be created in which the elongated fins are disposed in different horizontal or vertical positions, depending on whether the circuit breaker is to be mounted horizontally or vertically. The "pin fin" concept of the disclosed jumper 2 addresses and overcomes this disadvantage by allowing free flow of air in m ultiple directions around and through the spaced apart rows 1 10 and columns 120 of heat transfer members 108 (e.g.. without limitation, pin fins). Thus, a single jumper design can be employed for a variety of different circuit breaker mounting configurations.

EXAMPLE 3

Continuing to refer to Figures 2-5, the jumper .member 102 of jumper 100 further includes first and second opposing sides 130, 132, first and second opposing ends 134,136, and first and second opposing edges 338, 140. The attachment portion 104 includes a first leg 142 extending outwardly from the first end 134, and a second leg 144 also extending outwardly from the first end 1.34 opposite and spaced from the first leg 142. as shown in Figures 2, 3 and 5, The plurality of rows 1 10 and the plural ity of columns 120 (both shown in Figure 5) extend outwardly from the first side 130 between the first and second edges 138,140, as best shown in Figure 5.

EXAMPLE 4

The heat sink portion 106 of the jumper member 102 of the jumper 100 preferably includes at least three rows 1 10 of heat transfer members 108 and at least three columns 120 of heat transfer members 108.

EXAMPLE 5

in the non-limiting example embodiment of Figures 1 -5, the jumper member 102 includes six rows 1 10 of heat transfer members 108 and three columns 120 of heat transfer members 108.

EXAMPLE 6

Preferably each one of the rows 0 is spaced apart the same distance 160 from the other rows 110, as best shown in Figure 5. See also rows 210 of jumper member 202, which are equally spaced a distance 260, as shown in Figure 10, and juniper member 302 of Figures 12-15 wherein the rows 310 of heat transfer members 308 are equally spaced a distance 360 (Figure 13).

EXAMPLE 7

Preferably each one of the columns 120 is spaced apart the same distance 1 2 from the other columns 120, as best shown in Figure 5. See also columns 220 of jumper member 202 of Figures 6-11. which are equally spaced a distance 262 (Figure 10), and columns 320 of jumper member 302 of Figures 12-15, which are equally spaced a distance 362 (Figure 13).

EXAMPLE 8

Referring to Figure 2, each of the heat transfer members 108 has a width 150, a height 152 and a depth 154, The width 150 is preferabty the same for all of the heat transfer members I CS, the height 152 i s preferably the same for al l of the heat transfer members 1 8, the depth 154 is preferably the same for all of the heat transfer member 108.

EXAMPLE 9

As best shown in Figure 3, the heat sink portion 106 of the jumper member 102 preferably further includes a pl urality of elongated fins 170, which extend outwardly from the second side 132 of the jumper member 102, as shown. Each of the elongated fins 170 preferably extends from the first edge 138 of the jumper member to the second edge 140 of the jumper member.

EXAMPLE 10

The jumper 100 (Figures 1-5), 200 (Figures 6-1 1), 300 (Figures 12-15) preferably comprises a jumper member 1.02 (Figures 1-5), 202 (Figures 6-1 1), 302 ( Figures 12-15) made from a single piece of electrically and thermally conductive material.

EXAMPLE I

in one non-limiting embodiment, the jumper members (e.g.,

102,202,302) are made from copper or aluminum (e.g., without limitation, 6063-T6 alunrituimY. EXAMPLE 12

Preferably, the jumper members (e.g., 102.202.302} are extruded from a single piece of such electrically and thermally conductive material, and are machined (e.g., without limitation, cross-hatch machined) to form the aforementioned heat sink members 108 (Figures 1 -5), 208 (Figures 6-1 1 ), 308 (Figures 12-15) of me heat sink portions 106 (Figures 1 -5). 206 (Figures 6-1 1 ), 306 (Figures 12-15) and attachment portions 104 (Figures 1 -5). 204 (Figures 6-1 1 ). 304 (Figures 12-15). That is, the j umper members (e.g., 102,202,302) are preferably extruded, cut, drilled and/or threaded, as necessary to provide a single piece electrically and thermally conductive member that both performs well thermally and maintains a small overall size, thereby satisfying market requirements regarding size, performance and cost.

EXAMPLE 13

The j umper member 102,202,302 preferably further includes a plurality of surfaces coated with an electrically insulating material 180,280,380, as partially shown in simplified form in Figures 3, 8 and 12, respectively. For example and without limitation, such portions can be painted black for enhanced thermal performance.

EXAMPLE 14

Figures 6 and 7-1 1 show another circuit breaker 2' and jumpers 200 (two are shown) therefor, in accordance with another non-limiting alternative example embodiment of the disclosed concept. The circuit breaker 2' includes a housing 4' and four poles ό',Β', Ι Ο',12'. Each pole ό',δ' includes a corresponding terminal 14', 16·'.

Jumper 200 electrically connects terminal 1 ' of circuit breaker pole 6' to term inal 16' of circui t breaker pole 8'. More specifically, a fastener 290 extends through le 242 of extension portion 204 through terminal 14' and threads into the corresponding portion of connection member 20'. Similarly., fastener 292 extends through terminal 16' and leg 244 of the attachment portion 204 to threadingly engage another corresponding portion of the connection member 20 ^* . In this manner, the j umper 200 is mechanically coupled securely to the terminals 14', 16' ^" of the circuit breaker 2'. EXAMPLE 15

Continuing to refer to Figures 6-1 1 , the jumper 200 may employ a jumper member 202 having a. heat sink portion 206 with four rows 210 and three columns 220 of beat transfer members 208, as shown.

The width 250, height 252 and depth 254 of each of the heat transfer members 208 (e.g., without limitation, pin fins) may be the same for all of the heat transfer members 208.

The jumper member 202 may include a plurality of elongated fins 270 extending outwardly from the second side 232 of the j umper member 202 between the first and second edges 238,232, as best shown in Figure 8,

EXAMPLE

Figures 12-15 show another juniper 300 in accordance with a further non-limiting alternative example embodiment in accordance with the disclosed concept. The jumper member 302 of Figures 12- 15 includes three rows 310 and three columns 320 of heat transfer members 308 (e.g., without limitation, pin fins).

As shown in Figure 12, each of heat transfer members 308 has a width 350, a height 352, and a depth 354. In the example shown, the dimensions of these parameters are the same for six of the heat transfer members 308. However, the height 352 of the other three heat transfer members 308 (see, for example, the last row 310 of heat transfer members 308 disposed at the second end 336) is different. More specifically, whereas the other six heat transfer members 308 have a height 352 (e.g., thickness) that varies (e.g. , tapers), the last row 3 10 of heat sink members 308, disposed at the second end 336 of the jumper member 302, ail have a constant (e.g., non-tapering) height 352 (e.g., thickness). This will be turther appreciated with reference to the section views of Figures 14 and 15,

It will also be appreciated that, unlike the aforementioned jumper members 102 (Figures 1 -5) and 202 (Figures 6-1 1 ), in the example embodiment of Figures 12-15, the second side 332 of the jumper member 302 does not include any elongated fins,

It will be appreciated that the jumpers 1 0,200,300 could have any known or suitable alternative configuration (not shown) consisting of a plurality of rows 1 10,210,310 and columns 120,220,320 of spaced apart heat transfer members 108,208 ,308 (e.g., without limitation, pin fms), in order to provide a jumper 100,200,300 with enhanced thermal performance (e.g., heat transfer) while

maintaining a small overall size. In this manner, a single, relatively low cost jumper 100,200,300 can be made and employed in a wide variety of different electrical switching apparatus applications (e.g.. without limitation, horizontally and or vertically mounted circuit breakers 2,2'). The spaced apart rows 1 10,210,310 and columns 120,220,320 of heat transfer members 108.208.308 establish effective airflow and. therefore, heat dissipation. This, in combination with the single piece electrically and thermally conductive material (e.g., without limitation, copper; aluminum) construction of the jumper 100,200,300 pro vide for a effective yet relati ely small and inexpensive design.

While specific embodiments of the disclosed concept have been described in detail, it will be appreciated by those skilled in the ait 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.