Claims:We claim:

1. A busway joint block assembly (100) in electrical power distribution, the busway joint block assembly (100) for connecting a plurality of feeder conductors (20), wherein each of the plurality of feeder conductors (20) having an incoming phase conductor (20A) and an outgoing phase conductor (20B), the busway joint block assembly (100) comprising:
a plurality of shorting plates (50) including a plurality of left shorting plates (50A) and a plurality of right shorting plates (50B) for clamping the plurality of feeder conductors (20) therebetween, each shorting plate (50) having a slot (40) configured at a centerthereon and a step profile(30) configured near the slot (40) thereon, thereby increasing thermal mass of the each shorting plate (50);
a plurality of insulation barriers (70) for placing the plurality of shorting plates (50) therein, each insulation barrier (70) having a slot (60) configured at a center thereon;
a joint bolt (80)passing through the slots (40)of the plurality of shorting plates (50) and the slots (60) of the plurality of insulation barriers (70), wherein the joint bolt (80) is tightened to clamp the plurality of shorting plates (50) with the plurality of feeder conductors (20); and
a joint nut (90) mounted on one end of the joint bolt (80)for tightly holding the busway joint block assembly (100);
wherein, due to increase of the thermal mass of the each shorting plate at joint section,current density in an area of the joint section on the each shorting plate is moderated, thereby improving thermal rating and short circuit performance of the busway joint block assembly (100).

2. The busway joint block assembly (100) as claimed in claim 1, wherein the step profile (30) of the each shorting plate (50) has more thickness in the joint section / bolting region.

3. The busway joint block assembly (100) as claimed in claim 1, wherein thickness of the step profile (30) of the each shorting plate (50) is kept such that a gap is maintained between the parallel shorting plates (50A, 50B).
, Description:Field of invention:

The present invention relates to buswaysin electrical power distribution and more particularly, to a busway joint block assembly in the electrical power distribution.

Backgroundof the invention:

The individual phases of busway in a uni-block joint are connected together with shorting plates on both sides of a conductor and in order to carry forward the continuity of current. In the assembly of the joint block, the shorting plates are held together by passing a joint bolt through slots provided in therein. The slots in the shorting plates result in lower cross-section to the current path at the slot cross over point. The current density gets increased due to lower thermal mass in the section where the joint bolt passes. High current densities in any joint sections effect in high temperature rise. The high temperature leads to deterioration of the conductor material at faster rate.

To increase thermal mass at localized area of a shorting plate, following alternate options can be considered:
a) Thickness of shorting plate needs to be increased uniformly
b) Width needs to be increased.

However, there are few drawbacks observed as follows, if any of theseother alternatives is selected to enhance thermal mass:
1. If the option (a) is selected, it will result in increased width of the joint
2. If the option (b) is selected, then entire width of busway increases.
3. Major changes in plastic components (insulation barrier) need to be carried out.
4. Major changes in bending tools of conductors are required.
5. Overall dimensions of the busway increases.

Accordingly, there is need of a busway joint block assembly in electrical power distribution having improved shorting plate that overcomes above mentioned drawbacks in the prior art.

Objects of the invention:

An object of the present invention is to increase thermal mass at localized area of a shorting plate of a busway joint block assembly in electrical power distribution.

Another object of the present invention is to moderate current density in the area of joint section on the shorting plate.

Yet, another object of the present invention is to improve the thermal rating and short time withstand performance of the busway joint block assembly.

Summary of the invention:

Accordingly, the present invention provides a busway joint block assembly in electrical power distribution. The busway joint block assembly is designed for connecting a plurality of feeder conductors. Each of the plurality of feeder conductors includes an incoming phase conductor and an outgoing phase conductor. The busway joint block assembly comprises of a plurality of shorting plates, a plurality of insulation barriers, a joint bolt and a joint nut.

The plurality of shorting plates includes a plurality of left shorting plates and a plurality of right shorting plates for clamping the plurality of feeder conductorstherebetween. Each shorting plate includes a slot configured at a center thereon. A step profile is configured near the slot on the each shorting plate. The step profile has more thickness in bolting region. Hence, the step profile increases thermal mass of the each shorting plate.Thickness of the step profile of the each shorting plate is kept such that a gap is maintained between the parallel shorting plates.

The plurality of insulation barriers is configured to place the plurality of shorting plates therein. Each insulation barrier includes a slot configured at a center thereon. The plurality of insulation barriers insulates the potentially live plurality of feeder conductors from adjacent phase and housing of the busway joint block assembly.

The joint bolt passes through the slots of the plurality of shorting plates and the slots of the plurality of insulation barriers. The joint bolt is tightened to clamp the plurality of shorting plates with the plurality of feeder conductors.The joint nut is mounted on one end of the joint bolt for tightly holding the busway joint block assembly.

By adding the step profile on the each shorting plate, the thermal mass of the each shorting plate at the joint section increases. Hence, reduction in the current density at the joint section (nearly 30% reduction) is achieved. Thus, thermal rating and enhancing short circuit performance of the busway joint block assembly is improved.

Brief description of the drawings:

Figure 1 showsvarious views of a shorting plate of a busway joint block assembly in electrical power distribution in accordance with a prior art;

Figure 2 shows various views of a shorting plate of a busway joint block assembly in the electrical power distribution in accordance with a present invention;

Figure 3 shows an exploded view of single phase joint in the busway joint block assembly in the electrical power distribution in accordance with a present invention;

Figure 4 shows a side view of the single phase joint in the busway joint block assembly in the electrical power distribution in accordance with a present invention;

Figure 5 shows a side view of the busway joint block assembly in the electrical power distribution in accordance with a present invention;

Figure 6 shows a current density plot (A/m2) for the shorting plate in accordance with a prior art; and

Figure 7 shows a current density plot (A/m2) for the shorting plate in accordance with a present invention.

Detailed description of the embodiments of the invention:

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiments.

The present invention provides a busway joint block assembly in electrical power distribution.The present invention provides increase in thermal mass in clamping section of a shorting plate of the busway joint block assembly. By adding the step profile of the shorting plate in the busway joint block assembly, current density at localized area of the joint section reduces. Hence, thermal performance and short circuit rating is enhanced without modifying busway design.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures. These reference numbers are shown in bracket in the following description.

Referring to figure 1, a shorting plate (10) of a busway joint block assembly in electrical power distribution in accordance with a prior art is shown.

Referring to figures 2 to 5, a busway joint block assembly (100) in accordance with the present invention is shown. The busway joint block assembly (100) is designed for connecting a plurality of feederconductors (20).Each of the plurality of feeder conductors (20) includes an incoming phase conductor (20A) and an outgoing phase conductor (20B). The busway joint block assembly (100) (refer figure 5)comprises of a plurality of shorting plates (50), a plurality of insulation barriers (70), a joint bolt (80) and a joint nut (90).

The plurality of shorting plates (50) (refer figures 3 to 5) includes a plurality of left shorting plates (50A) and a plurality of right shorting plates (50B) for clamping the plurality of feeder conductors (20) therebetween. Each shorting plate (50) includes a slot (40) configured at a center(not numbered) thereon. A step profile (30)(refer figure 2) is configured near the slot (40) on the each shorting plate (50). The step profile (30) has more thickness in the joint section/bolting region. Hence, the step profile (30) increases thermal mass of the each shorting plate (50). In an embodiment, thickness of the step profile (30) of the each shorting plate (50) is kept such that a gap (not numbered) is maintained between the parallel shorting plates (50A, 50B).

The plurality of insulation barriers (70) (refer figure 3) is configured to place the plurality of shorting plates (50) therein. Each insulation barrier (70) includes a slot (60) configured at a center(not numbered) thereon. The plurality of insulation barriers (70) insulates the potentially live plurality of feeder conductors (20) from adjacent phase and housing of the busway joint block assembly (100). A single phase joint in the busway joint block assembly (100) is shown in the figure 4.

The joint bolt (80) (refer figure 5) passes through the slots (40) of the plurality of shorting plates (50) and the slots(60) of the plurality of insulation barriers (70). The joint bolt (80) is tightened to clamp the plurality of shorting plates (50) with the plurality of feeder conductors (20).

The joint nut (90) (refer figure 5) is mounted on one end of the joint bolt (80) for tightly holding the busway joint block assembly (100).

By adding the step profile (30) on the each shorting plate (50) in the busway joint block assembly (100), the thermal mass of the each shorting plate (50) at the joint section increases. Hence, reduction in the current density at the joint section (nearly 30% reduction) is achieved. Referring to the figure 6, the current density (A/m2) for the shorting plate (10) without step profile increases due to a slot (not numbered) provided for passage of a joint boltin accordance with a prior art. However, referring to the figure 7, the current density (A/m2)for the shorting plate (50) with the step profile (30) remains the same as the current density of the feeder conductor (50)in accordance with a present invention. Thus, thermal rating and short circuit performance of the busway joint block assembly (100) is improved.The shorting plate (50) is adapted in existing joint block assembly without change in other components and overall dimensions of the busway. This invention requires no changes in other components of the busway.

Advantages of the invention:

1. The current density at joint section is reduced due to the step profile (30) at the bolting region on the each shorting plate (50).
2. The busway joint block assembly (100) for improved thermal performance
3. Short circuit performanceis enhanced
4. There is no increase in dimensions of the busway joint block assembly (100).

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.