Claims: WE CLAIM:
1. An electrical distribution equipment comprising:

a substantially rectangular busbar (1), substantially curved at the edges;

characterized in that the busbar having an inner insulating sheath (2) adhered to the outer surface of the busbar in a manner that the inner insulating sheath essentially encloses the busbar (1) at the curved edges and an outer insulating sheath (3) circumferentially encloses the busbar so as to cover the busbar and the inner insulating sheath along the length of the busbar such that the outer surface of the equipment is not contoured.

2. The electric distribution equipment as claimed in claim 1, wherein the inner insulating sheath (2) has a high dielectric strength material which has a high tearing and shearing resistance.

3. The electric distribution equipment as claimed in claim 2, wherein the inner insulating sheath (2) is made of adhesive backed PET or electrostatic spray coating or varnishing.

4. The electric distribution equipment as claimed in claim 1, wherein the outer insulating sheath (3) has a high melt flow index.

5. The electric distribution equipment as claimed in claim 4, wherein the outer insulating sheath (3) is made of extruded vinyl, or electro static spray coating or heat-shrinkable tube insulation.

6. The electric distribution equipment as claimed in any one of the preceding claims, wherein the dielectric strength of the inner insulating sheath (2) is equivalent or higher than that of the outer surrounding layer of insulating sheath (3).

7. An air-gap free sandwich busduct construction comprising a plurality of electrical distribution equipment as claimed in any one of the preceding claims.

8. A method of insulating an electrical busbar (1) having a substantially rectangular shape with substantially curve at the edges, comprising:

applying an inner insulating sheath (2) to the electrical busbar (1) at the substantially curved edges, along the length of the busbar, where in the inner insulating sheath has a layer of adhesive attached thereto; and
applying an outer insulating sheath (3), along the length of the busbar, to circumscribe the busbar with inner insulating sheath attached thereto;
wherein the busbar is cleaned before applying the inner insulating sheath (2).
9. The method as claimed in claim 8, wherein the inner insulating sheath (2) has a high dielectric strength material which has a high tearing and shearing resistance.

10. The method as claimed in claim 9, wherein the inner insulating sheath (2) is made of adhesive backed PET or electrostatic spray coating or varnishing.

11. The method as claimed in claim 8, wherein the outer insulating sheath (3) has a high melt flow index.

12. The method as claimed in claim 11, wherein the outer insulating sheath (3) is made of extruded vinyl, or electro static spray coating or heat-shrinkable tube insulation.

13. The method as claimed in any one of the preceding claims, wherein the dielectric strength of the inner insulating sheath is equivalent or higher than that of the outer surrounding layer of insulating sheath.

Dated this 31st day of March 2018

Abhishek Sen
Of S. MAJUMDAR & CO.
(Applicant’s Agent)

, Description:FIELD OF INVENTION
The present invention relates to electric power distribution systems in general, and more particularly, to an insulation system for busways.

BACKGROUND

In a typical edgewise construction of busways, the weight of the busbars is borne by the edges of the busbars. The area at the tips of the busbars is minimal and holds the least amount of insulation. The stress concentration at the edges is thus the highest and dielectric failures are often observed at these locations. The invention at hand shows means of strengthening the insulation at these areas.
In the general art, there are several insulation techniques which augment the insulation by means of sheathing or creating a redundant layer of insulation. These techniques however fail to address the problem of non-uniformity of thickness.
Reference has been made to US3550269, relating to a means of overcoming stresses on the edges of busbars by having a hollow cylindrical bus bar and surrounding it with an insulation after which it is sent to be compressed into a flat form. During the flattening process the uniformity of the inner hollow bar is lost and thus, air gaps may be created in between the busbars and insulation after compression which will in turn lower the electrical and mechanical characteristics of the busbars.
Reference has been made to US3956574 disclosing use of U-shaped insulators on the edges as well as flat shaped insulators on the top and bottom to prevent sticking of the busbars with each other and the housing which causes damage to the primary insulator. Failure of the primary insulation will lead to busduct section being damaged and irreparably broken.

Yet another reference has been made to US8258404 discloses applying insulating sheaths with corrugations at parts of the busbars with bends as opposed to conventional tape or epoxy extrusion based insulation. The method in question is in practice as it eliminates the need to cut insulation at bends or require the usage of insulating tape. This in turn minimizes the amount of air gaps in the busbar. While the patent explains ways to conform to bent busbars.
Thus there is a need for an improved insulated busbar wherein the insulation presents a way to augment the dielectric strength at the edges yet maintain a uniform thickness of insulation over the conductor and busways with an air-gap free construction.
SUMMARY OF THE INVENTION
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the present invention. It is not intended to identify the key/critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concept of the invention in a simplified form as a prelude to a more detailed description of the invention presented later.
An object of the present invention is to provide a busbar with augmented insulation at the edges which can be formed or bent.
An object of the present invention is to provide means to augment the insulation at the edges at the same time form insulated busbars which can be stacked together tightly without airgaps.
In accordance with an aspect of the present disclosure, is to provide an electrical distribution equipment comprising a substantially rectangular busbar, substantially curved at the edges, characterized in that the busbar having an inner insulating sheath adhered to the outer surface of the busbar in a manner that the inner insulating sheath essentially encloses the busbar at the curved edges and an outer insulating sheath circumferentially encloses the busbar so as to cover the busbar and the inner insulating sheath along the length of the busbar such that the outer surface of the equipment is not contoured.

In accordance with another aspect of the present disclosure, is to provide a method of insulating an electrical busbar having a substantially rectangular shape with substantially curve at the edges, comprising applying an inner insulating sheath to the electrical busbar at the substantially curved edges, along the length of the busbar, where in the inner insulating sheath has a layer of adhesive attached thereto; and applying an outer insulating sheath along the length of the busbar, to circumscribe the busbar with inner insulating sheath attached thereto; wherein the busbar is cleaned before applying the inner insulating sheath.

Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The above and other aspects, features and advantages of the embodiments of the present disclosure will be more apparent in the following description taken in conjunction with the accompanying drawings, in which:
Figure 1 illustrates a lateral view of a busbar in accordance to the invention.
Figure 2 illustrates a lateral view of a busbar with inner insulating sheath in accordance to the invention.
Figure 3 illustrates lateral view of an insulated busbar in accordance to the invention.
Figure 4 illustrates the process of applying an inner insulating sheath a busbar is followed manually before feeding into the extrusion mould in accordance to the invention.
Figure 5 illustrates the inner insulating sheath is applied in a continuous manner before feeding the busbar into the extrusion mould in accordance to the invention.
Figure 6 illustrates a plan view of the busbar with insulation sheath at the edges entering the mould for being coated with the secondary layer of insulation in accordance to the invention.
Figure 7 illustrates lateral view of an air-gap free sandwich busduct construction comprising of a plurality of insulated busbars in accordance to the invention.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.

DETAILED DESCRIPTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.
It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.
All terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments belong. Further, the meaning of terms or words used in the specification and the claims should not be limited to the literal or commonly employed sense, but should be construed in accordance with the spirit of the disclosure to most properly describe the present disclosure.
The terminology used herein is for the purpose of describing particular various embodiments only and is not intended to be limiting of various embodiments. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising" used herein specify the presence of stated features, integers, steps, operations, members, components, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, members, components, and/or groups thereof. Also, Expressions such as "at least one of," when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.
The present disclosure will now be described more fully with reference to the accompanying drawings, in which various embodiments of the present disclosure are shown. The present disclosure may, however, be embodied in many different forms and should not be construed as being limited to the various embodiments set forth herein, rather, these various embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the present disclosure. Furthermore, a detailed description of other parts will not be provided not to make the present disclosure unclear. Like reference numerals in the drawings refer to like elements throughout.
The subject invention lies in providing a hybrid insulation system for busways and process of manufacturing thereof.
An embodiment of the present invention describes an electrical distribution equipment comprising a substantially rectangular busbar (1), substantially curved at the edges. The busbar has an inner insulating sheath adhered to the outer surface in a manner that the inner insulating sheath essentially encloses the busbar at the curved edges. Further an outer insulating sheath (3) circumferentially in provided such that it encloses the busbar so as to cover it and the inner insulating sheath along the length of the busbar such that the outer surface of the equipment is not contoured. The inner insulating sheath (2) has a high dielectric strength material which has a high tearing and shearing resistance and is made of adhesive backed PET or electrostatic spray coating or varnishing. The outer insulating sheath (3) has a high melt flow index and is made of extruded vinyl, or electro static spray coating or heat-shrinkable tube insulation.
Another embodiment of the present invention describes a method of insulating an electrical busbar (1) having a substantially rectangular shape with substantially curve at the edges. The method comprises applying an inner insulating sheath (2) to the electrical busbar (1) at the substantially curved edges, along the length of the busbar, where in the inner insulating sheath has a layer of adhesive attached thereto and applying an outer insulating sheath (3) along the length of the busbar, to circumscribe the busbar with inner insulating sheath attached thereto, wherein the busbar is cleaned before applying the inner insulating sheath (2).
In another embodiment, the dielectric strength of the inner insulating sheath (2) is equivalent or higher than that of the outer surrounding layer of insulating sheath (3).
In another embodiment, an air-gap free sandwich busduct construction comprising of a plurality of insulated busbars (7) such that the busbar sides are completely parallel for the busbars to be stacked tightly over their width.
In an exemplary implementation of the present invention, the electrical distribution equipment consists of busbars (1), extruded outer insulating sheath (3), and inner insulating sheath (2). The insulating sheath (2) has an adhesive backing that is used for taping with the edges of the busbar (1). After taping the edges, the busbar (1) passes through an extrusion machine (6) wherein the extruded outer insulating sheath (3) forms a layer of insulating over the taped busbars.
The extrusion machine (6) consists of a mould with a female cavity in the shape of the busbars and concentric in alignment with the geometry of the busbar. These busbars are then cooled by forced convention for the outer extruded insulation to cure quickly.
In an embodiment of the present invention, the busbar (1) is first cleaned by means of a buffing machine or cloth. The inner insulating sheath (2) is then applied at the edges as shown in figure 2. The edge insulated busbar is then fed into the extrusion mould where a layer of extruded insulating sheath (3) is formed as shown in figure 3.
In one embodiment of the invention the taping process is followed manually as shown in figure 4 before feeding into the extrusion mould.
In another embodiment of the invention the inner insulating sheath (2) is applied in a continuous manner before feeding the busbar into the extrusion mould as shown in fig 5.
The insulated busbar (7) is shown in figure 6 has an outer periphery which is continuous and multiple busbars can be stacked against each other inside an enclosure to make an air-gap free sandwich busway construction.
Some of the non-limiting advantages of the present invention are:
a) Augmented dielectric strength at the edges.
b) Ability to maintain an air-gap free sandwich construction.
c) An insulated busbar which can be bent after insulation application.

Although insulation systems for busways and process of manufacturing thereof has been described in language specific to structural features, it is to be understood that the embodiments disclosed in the above section are not necessarily limited to the specific methods or devices described herein. Rather, the specific features are disclosed as examples of implementations of insulation systems for busways and process of manufacturing thereof.