WO2007097490A1

WO2007097490A1 - Bus duct with tube and bust duct system measurable the temperature

Info

Publication number: WO2007097490A1
Application number: PCT/KR2006/001259
Authority: WO
Inventors: Dongwook Kim; Seok Hyun Nam; Chan Yong Park; Sung Soo Huh; Sung Joo Bark
Original assignee: Ls Corp.
Priority date: 2006-02-23
Filing date: 2006-04-05
Publication date: 2007-08-30

Abstract

A bus duct (100) includes a case, a bus bar (107) installed in the case, and a tube (130) installed inside or outside the case. A bus duct system is capable of measuring distributed temperature, is formed by interconnecting a plurality of bus ducts (100) and a plurality of tubes (130) installed on the bus ducts (100), and includes an optical fiber (150) installed in the tubes (130). Thereby, the optical fiber (150) is easily installed in the tubes (130), which are provided inside or outside the bus ducts (100), so that the temperature at the areas where the connectors of each bus duct (100) and bus duct (100) are installed can be monitored in real time.

Description

BUS DUCT WITH TUBE AND BUS DUCT SYSTEM MEASURABLE THE TEMPERATURE

Technical Field

[1] The present invention relates, in general, to a bus duct for electric power distribution and a bus duct system in which the bus ducts are connected with each other, and more particularly, to a bus duct, on the inside or outside of which a tube for guiding an optical fiber is provided, thereby allowing the optical fiber to be easily installed in the tube as well as allowing the distributed temperature thereof to be measured, and to a bus duct system having the bus ducts connected with each other. Background Art

[2] Electric power distribution generally employs distribution based on an electric cable, but is based on a bus duct having a bus bar in multistory buildings or large-scale factories. The bus duct and the cable share a conductor and an insulator. In comparison with the cable, the bus duct can deliver a lot of electric current or power through the conductor, protect the conductor and the insulator using a metal duct, provide extension and removal, enable easy response to accidents when the accidents, and provide easy systematic management.

[3] FIG. 1 is a partially cut-away perspective view illustrating a conventional bus duct

10 having heterogeneous connectors. FIG. 2 is a partially cut-away perspective view illustrating a conventional bus duct 20 having homogeneous connectors. FIG. 3 is a partial perspective view illustrating a bus duct system in which bus ducts 10 having heterogeneous connectors are connected with each other. FIG. 4 is a partial perspective view illustrating a bus duct system in which bus ducts 20 having homogeneous connectors are connected with each other.

[4] As illustrated in FIG. 1, the bus duct 10 having heterogeneous connectors includes a top duct 11, a bottom duct 13, lateral ducts 15, a bus bar (not shown), which is installed in a space defined by the top duct 11, the bottom duct 13, and the lateral ducts 15 and delivers electric power, and male and female connectors 16a and 16b formed at opposite ends thereof.

[5] The bus ducts 10 having heterogeneous connectors, as illustrated in FIG. 1, are connected with each other in a manner such that the female connector 16b of any one thereof is connected with the male connector 16a of any other thereof, thereby forming the bus duct system illustrated in FIG. 3.

[6] In FIG. 1, among the reference numbers that have not yet been described, 18 indicates installation bolts, and 19 indicates reinforcement bolts. [7] Meanwhile, the bus ducts 20 having homogeneous connectors, as illustrated in FIG.

2, include a top duct 21, a bottom duct 23, lateral ducts 25, a bus bar (not shown), which is installed in a space defined by the top duct 21, the bottom duct 23, and the lateral ducts 25 and delivers electric power, and connectors 26 formed at opposite ends thereof.

[8] As illustrated in FIG. 4, the bus ducts 20 having homogeneous connectors are connected with each other via a connecting means 250, thereby forming a bus duct system.

[9] When the electric power is supplied through the bus duct system, the temperature is raised due to the resistance of the bus bar through which the electric current flows. In particular, the temperature is raised higher and higher by contact resistance at the joint where the bus ducts 10 or 20 are connected with each other. This increase in the temperature impedes the bus duct system, and entails the possibility that a fire may be caused. Therefore, it is necessary to measure and monitor the temperature of the bus duct system in real time. Disclosure of Invention Technical Problem

[10] However, because the bus duct 10 or 20 and the bus duct system having the bus ducts 10 or 20 are not provided with means for detecting temperature, the fire breaking cannot be effectively prevented. Although a means for detecting temperature should be installed in order to prevent fire breaking, such a means for detecting temperature cannot be easily installed.

[11] Accordingly, the present invention has been made in an effort to solve the problems occurring in the related art, and an object of the present invention is to provide a bus duct, on the inside or outside of which a tube for guiding an optical fiber is provided, thereby allowing the optical fiber to be easily installed inside or outside the bus duct merely by interconnecting the bus ducts, and to a bus duct system allowing distributed temperature to be measured. Technical Solution

[12] In order to achieve the above object, according to one aspect of the present invention, there is provided a bus duct, which includes a case, a bus bar installed in the case, and a tube installed inside or outside the case.

[13] According to another aspect of the present invention, the bus duct further includes an installation means outside the bus duct, wherein the tube is guided by the installation means and is installed outside the bus duct.

[14] According to another aspect of the present invention, the tube is attached to the case. [15] According to another aspect of the present invention, the installation means is installed using reinforcement bolts or assembly bolts. [16] According to another aspect of the present invention, the installation means includes a main body that is provided with a fixing hole and at least a tube guide on a side of the main body, wherein the tube guide is provided with tube guide hole or tube guide recess. [17] According to another aspect of the present invention, the installation means includes tube guides on opposite sides of the main body, wherein the tube guides are provided with tube guide hole or recess. [18] According to another aspect of the present invention, the installation means includes first and second main bodies, each of which is provided with a fixing hole, and at least a tube guide, which is provided with at least one tube guide recess on a side of each of the first and second main bodies. [19] According to another aspect of the present invention, the first and second main bodies are bent at a predetermined angle. [20] According to another aspect of the present invention, the tube is formed in a dual layer. [21] According to another aspect of the present invention, the dual layer includes an inner layer having a lubricant component and an outer layer provided on the outer surface of the inner layer and formed of polymer. [22] According to another aspect of the present invention, the lubricant component of the inner layer includes silicon. [23] According to another aspect of the present invention, the tube is formed in a single layer of polymer having a lubricant component. [24] According to another aspect of the present invention, the inner layer or the single layer has a static friction coefficient ranging from 0.05 to 0.20. [25] According to another aspect of the present invention, the thickness of the inner layer and the outer layer each is 0.8 mm or less. [26] According to another aspect of the present invention, the tensile strength of the inner layer or the single layer is 240kg/cm or more. [27] According to another aspect of the present invention, either one of the inner layer and the single layer includes siloxane in an amount ranging from about 0.1 wt% to about 5 wt%. [28] According to another aspect of the present invention, there is provided a bus duct system, which is capable of being used to measure distributed temperature and is formed by interconnecting the bus ducts. Here, the tube of any one of the interconnected bus ducts is connected with the tube of an adjacent bus duct, either directly or by way of a connector tube, and the tube is provided with an optical fiber therein. [29] According to another aspect of the present invention, the tube or the connector tube has a portion wound one or two turns to form a circular shape. [30] According to another aspect of the present invention, the tube and an adjacent tube are connected by a connector, or the tube and the connector tube are connected by a connector. [31] According to another aspect of the present invention, the tube and the connector tube are each provided with a male thread on one end thereof, and the connector is a tube on opposite ends of which female threads are formed. [32] According to another aspect of the present invention, the tube and the connector tube are each provided with a flange on one end thereof, and the connector is provided with wings that have at least one threaded hole and are fastened with at least a screw. [33] According to another aspect of the present invention, the tube and the connector tube are each provided with a flange on one end thereof, the connector is provided with a connecting fastener, and the tube and the connector tube are fastened using the connecting fastener. [34] According to another aspect of the present invention, the tube and the connector tube are each provided with a male thread on one end thereof, and the connector is a tube on opposite ends of which nuts are formed and fastened to the male threads. [35] According to another aspect of the present invention, the tube and the connector tube are each provided with a male thread on one end thereof, and the connector is provided with female threads and wings having at least a threaded hole. [36] According to another aspect of the present invention, the tube and the connector tube are each inserted into an intermediate tube, and the connector is installed to enclose the intermediate tube and is provided with wings that have at least a threaded hole and are fastened by at least a screw. [37] According to another aspect of the present invention, the tube and the connector tube are each provided with a flange on one end thereof, and the connector is provided with fitting tubes that are provided with a flange and are fitted into opposite ends of the connector. [38] According to another aspect of the present invention, the connector is provided with at least a flexible bellows. [39] According to another aspect of the present invention, the bus ducts of the bus duct system are interconnected by a connecting means, and the connecting means is provided with a protrusion. [40] According to another aspect of the present invention, the optical fiber is installed in the tube in an air-blown fiber (ABF) method. [41] According to another aspect of the present invention, there is provided a method of installing a bus duct system capable of measuring distributed temperature. The method includes the steps of installing at least one bus duct having a case, a bus bar installed in the case, and a tube which is installed inside or outside the case in the lengthwise direction of the bus duct, and installing an optical fiber in the tube using the air pressure.

Advantageous Effects

[42] According to the present invention, in the bus duct including a tube having mechanical strength, as well as in the bus duct system formed by interconnecting the bus ducts capable of installing the optical fiber in the tube in a short time, an optical fiber can be conveniently installed in the bus duct system in a short time using a system (e.g. a system in which the optical fiber is rapidly transported in the tube using air pressure). Thereby, the surface temperatures of the bus duct and the connecting means of the bus duct, the temperature of the bus bar, and the external surrounding temperature can be monitored through the optical fiber in real time.

[43] Further, in the case of this system, however narrow the space in a previously installed bus duct line may be, the optical fiber can be installed as long as a space through which the tube can pass exists, thereby allowing the temperature to be detected at various positions. Brief Description of the Drawings

[44] FIG. 1 is a partially cut-away perspective view illustrating a conventional bus duct having heterogeneous connectors;

[45] FIG. 2 is a partially cut-away perspective view illustrating a conventional bus duct having homogeneous connectors;

[46] FIG. 3 is a partial perspective view illustrating a bus duct system in which bus ducts having heterogeneous connectors are connected with each other;

[47] FIG. 4 is a partial perspective view illustrating a bus duct system in which bus ducts having homogeneous connectors are connected with each other;

[48] FIG. 5 is a perspective view illustrating a bus duct capable of measuring the temperature in accordance with an exemplary embodiment of the present invention;

[49] FIG. 6 is a sectional view taken along line A-A of FIG. 5;

[50] FIG. 7 is a sectional view illustrating a modification of the bus duct illustrated in

FIG. 5;

[51] FIG. 8 is an enlarged perspective view illustrating an installation means in the bus duct of FIG. 5;

[52] FIG. 9 is a sectional view taken along line A-A of the installation means of FIG. 8;

[53] FIG. 10 is a perspective view illustrating another example of the installation means of FIG. 8;

[54] FIG. 11 is a sectional view taken along line A-A of the installation means of FIG. 10; [55] FIG. 12 is a perspective view illustrating a modification of an installation means assembled to a bus duct having a tube in accordance with an exemplary embodiment of the present invention; [56] FIG. 13 is a perspective view illustrating another example of the installation means of FIG. 12; [57] FIG. 14 is a perspective view illustrating another modification of an installation means assembled to a bus duct having a tube in accordance with an exemplary embodiment of the present invention; [58] FIG. 15 is a perspective view illustrating another example of the installation means of FIG. 14; [59] FIG. 16 is a perspective view illustrating yet another modification of an installation means assembled to a bus duct having a tube in accordance with an exemplary embodiment of the present invention; [60] FIG. 17 is a perspective view illustrating another example of the installation means of FIG. 16; [61] FIG. 18 is a partially cut-away perspective view schematically illustrating a bus duct having a tube in accordance with an exemplary embodiment of the present invention;

[62] FIG. 19 is a sectional view taken along line A-A of FIG. 18;

[63] FIG. 20 is a sectional view illustrating a tube installed on a bus duct in accordance with an embodiment of the present invention; [64] FIG. 21 is a sectional view illustrating a modification of a tube installed on a bus duct in accordance with an embodiment of the present invention; [65] FIG. 22 is a partial side view illustrating a bus duct system interconnecting bus ducts, each of which has a tube, in accordance with the present invention; [66] FIG. 23 is a partial side view illustrating a modification of the bus duct system of

FIG. 22; [67] FIG. 24 is a perspective view illustrating another connection of a tube in a bus duct having a tube in accordance with the present invention; [68] FIG. 25 illustrating only the tube of FIG. 24;

[69] FIGS. 26 through 33 are perspective views illustrating connection of a tube;

[70] FIG. 34 is a schematic sectional view illustrating a connector having a bellows; and

[71] FIG. 35 is a schematic sectional view illustrating a bus duct according to the present invention, in which an optical fiber is installed in a tube.

[72] *Description of Reference Numbers of Main Parts in the Drawings*

[73] 100: bus duct 101: top duct

[74] 103: bottom duct 105: lateral duct [75] 106: connector 107: bus bar

[76] 108: assembly bolt 109: reinforcement bolt

[77] 120: installation means 130: tube

[78] 300: connector tube 310: connector

[79] 310e: bellows

Best Mode for Carrying Out the Invention

[80] Reference will now be made in greater detail to an exemplary embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.

[81] The present invention will be described in connection with, but is not limited to, a bus duct having homogeneous connectors. Therefore, it will be obvious that the present invention can also be readily applied to a bus duct having heterogeneous connectors.

[82] FIG. 5 is a perspective view illustrating a bus duct having a tube in accordance with an exemplary embodiment of the present invention. FIG. 6 is a sectional view taken along line A-A of FIG. 5. FIG. 7 is a sectional view illustrating a modification of the bus duct illustrated in FIG. 5.

[83] As illustrated in FIGS. 5 and 6, the bus duct 100 according to an exemplary embodiment of the present invention includes a top duct 101, a bottom duct 103, lateral ducts 105, a bus bar 107, which is installed in a space defined by the top duct 101, the bottom duct 103, and the lateral ducts 105, and delivers electric power, and connectors 106 formed on opposite ends.

[84] In FIGS. 5 and 6, the external ducts constituting the bus duct 100 are shown as the top duct 101, the bottom duct 103, and the lateral ducts 105. However, the external ducts may be integrated. Hereinafter, the integrally formed top duct 101, bottom duct 103, and lateral ducts 105 are referred to as a "case."

[85] The case, which is integrally formed by the top duct 101, the bottom duct 103, and the lateral ducts 105, is generally formed to have, but is not limited to, a quadrangular cross section. Therefore, according to the environment in which the bus duct 100 is installed, the case may be formed to have various shapes, such as a trapezoidal shape, a circular shape, and so on.

[86] In FIGS. 5 and 6, regarding the reference numbers that have not yet been described,

109 indicates reinforcement bolts for still more firmly holding the bus bar 107, 120 indicates means for installing a tube, and 130 indicates a tube in which an optical fiber is installed.

[87] In FIGS. 5 and 6, the tube 130 is installed on the case by, but is not limited to, the installation means 120 fixed by the reinforcement bolts 109. Therefore, it will be understood that the tube 130 may be directly installed on the case by adhesives. In the case in which the tube is installed by the installation means 120, the installation means 120 may be installed at various positions of the case by means of the reinforcement bolts 109, as well as separate installation bolts 108, as illustrated in FIG. 7.

[88] FIGS. 8 through 17 illustrate an example of the installation means 120 installed on the bus duct 100.

[89] As illustrated in FIGS. 8, 9, 10 and 11, the installation means 120 includes a main body 121 that is provided with a fixing hole 122, and at least a tube guide 123 on a side of the main body 121, through which the tube 130 is guided. As illustrated in FIGS. 10 and 11, the tube guides 123 can be partly opened on opposite sides of the main body 121 contacting the bus duct 100 such that the tube 130 is in direct contact with one lateral duct of the bus duct.

[90] In FIGS. 8, 9, 10 and 11, with respect to the reference numbers that have not yet been described, 125 indicates a tube guide recess or hole that is formed in the tube guide 123 so as to allow the tube 130 to be positioned therein. In the case of the tube guide hole 125, it can be formed as a hole through which the tube 130 passes. In the case of the tube guide recess 125, it can be formed as a concave recess in the longitudinal direction of the tube 130.

[91] As illustrated in FIGS. 12 and 14, the main body can be divided into a first main body 121a and a second main body 121b, and then the tube guide(s) 123 can be formed to have tube guide recess(es) 126 on at least a side of each of the first and second main bodies 121a and 121b.

[92] As illustrated in FIG. 14, the tube guides 123 can be provided with a plurality of tube guide recesses 126. As illustrated in FIG. 16, the first and second main bodies 121a and 121b can be bent at a predetermined angle according to the position where the installation means 120 is installed, and then the fixing holes 122 can be formed at the bent portions of the first and second main bodies 121a and 121b.

[93] As illustrated in FIGS. 13, 15 and 17, one main body can be formed by narrowing the entry of the tube guide recess 126 so as to allow the tube 130 to be inserted into the entry of the tube guide recess 126.

[94] FIG. 18 is a perspective view illustrating a bus duct 100, on the inside of which a tube is provided, in accordance with a second exemplary embodiment of the present invention. FIG. 19 is a sectional view taken along line A-A of FIG. 18.

[95] As illustrated in FIGS. 18 and 19, the bus duct 100, having a tube in accordance with the present invention, includes a bus bar 207 installed in a case, and connectors 106 is formed on opposite ends thereof.

[96] A space into which the tube can be inserted is provided between the case and the bus bar 107, and the tube 130 is guided into the space. Thereby, the tube 130 is installed in the bus duct.

[97] Thus, the tube 130 is not exposed to the outside, and is preferably formed of an insulating material because it is installed at the top or bottom space of the bus bar 107 and at the top of each connector 106, at which a metal conductor of the bus bar is exposed. Because the tube has stability at high temperature, when the electric current flows as well as guides an optical fiber therein, it is preferably formed of a material having high mechanical strength. In order to facilitate connecting the tubes 130 when the bus ducts 100 are connected with each other, the tube 130 is preferably installed such that it can be moved in the lengthwise direction of the bus duct 100.

[98] In FIG. 19, the tube 130 is installed at the left top of the bus bar 107, but the present invention is not limited thereto. Therefore, the tube 130 may be installed at various positions, such as the middle top, the middle bottom, the right bottom, the left middle, etc. of the bus bar 107.

[99] FIGS. 20 and 21 are sectional views illustrating a tube 130 installed in a bus duct

100.

[100] As illustrated in FIGS. 20 and 21, the tube 130, in which an optical fiber is installed, can be formed in a single layer or in a dual layer having an outer layer 131 and an inner layer 133.

[101] Because the tube 130 is installed inside or outside the bus duct 100, it is difficult to secure sufficient space for installation of the tube 130 if the diameter of the tube 130 is too large, whereas the optical fiber cannot be easily installed in the tube 130 if the diameter of the tube 130 is too small. Further, if the tube 130 is too thin, the tube 130 is easily deformed or damaged. For these reasons, the tube 130 should meet predetermined size and strength threshold values.

[102] First, the tube 130 having the dual layer will be described. The outer layer 131 of the tube 130 is a layer contacting the outside, and preferably has a tensile strength of 240kg/cm or more, not only to protect the inner layer 133 and the installed optical fiber from external shocks and forces but also to prevent the thickness thereof from being increased. When the tube has this tensile strength, the thickness of the outer layer 131 can be less than 0.8 mm.

[103] In order to form a tube having this strength and thickness, the outer layer 133 of the tube is preferably formed of polymer, for instance high-density polyethylene.

[104] The inner layer 133, which is integrally formed with and in the outer layer 131, can be formed of the same material as the outer layer 131, namely high-density polyethylene. The inner layer 133 preferably has a lubricating component in order to minimize friction against the optical fiber 150 when the optical fiber is installed in the tube 130 using, for instance, compressed air. The lubricant component can employ silicon. In addition, in order to further increase the lubricant property of the inner layer 133 and integration with respect to the outer layer 131, the inner layer 133 preferably contains siloxane, which preferably has a content between about 0.1 wt% and about 5 wt%, and more preferably between about 0.2 wt% and about 0.3 wt%. The inner layer 133, containing siloxane, has a static friction coefficient of about 0.1. The static friction coefficient of the inner layer 133, which is in contact with the optical fiber 150, is preferably within a range from about 0.05 to about 0.2.

[105] When the tube 130 is formed in the single layer, as illustrated in FIG. 21, the single layer of the tube 130 preferably has both a predetermined tensile strength equal to or greater than that of the outer layer 131, and a lubricant property like that of the inner layer 133.

[106] The single layer is preferably formed of a polymer, for instance high-density polyethylene. The tube 130 preferably has a lubricant component in order to minimize friction against the optical fiber 150 when the optical fiber is installed in the tube 130 using compressed air. The lubricant component can employ silicon. In addition, in order to further increase the lubricant property of the tube 130, the tube 130 preferably contains siloxane, which is preferably present in an amount between about 0.1 wt% and about 5 wt%, and more preferably between about 0.2 wt% and about 0.3 wt%.

[107] FIG. 22 is a side view illustrating a bus duct system having the bus ducts 100, on the outside of each of which the tube is provided, as illustrated in FIG. 5. FIG. 23 is a side view illustrating a modification of FIG. 22. FIG. 24 is a side view illustrating a bus duct system having the bus ducts 100, on the inside of each of which the tube is provided. FIG. 25 is a partial perspective view schematically illustrating only the tube of FIG. 24.

[108] As illustrated in FIGS. 22 and 23, bus ducts 100, on the outside of each of which the tube is provided, are connected with each other, thereby forming a bus duct system. When the bus ducts 100 are connected with each other, the tubes 130 to be interconnected can be connected with each other using a connector tube 300. As illustrated in FIGS. 23, 24 and 25, so that the temperature at the connector can be reliably detected, the tube is preferably wound one or more turns around the connector in a circular shape.

[109] In this connection, the bus ducts 100 and 100 can be directly connected with each other without a connecting means 250. The tubes 130 and 130 can be directly connected with each other without the connector tube 300. However, according to the type of connectors 106 of the bus duct 100, the bus ducts 100 and 100 can be connected with each other via the connecting means 250.

[110] As described above, a protrusion 251 can be formed at the connecting means 250 such that the connector tube 300, wound one or two turns around the outer surface of the connecting means 250, is fitted around the protrusion. [111] FIGS. 26 through 33 are perspective views illustrating modifications in which a tube 130 and a tube 130 are connected in the case of directly connecting the tube 130 and the tube 130, or in the case of connecting the tube 130 and the tube 130 by way of a connector tube 300.

[112] The tube 130 and the tube 130 or the tube 130 and the connector tube 300

(hereinafter, referred to as "the tube 130 and the tube 130 or 300") are connected with each other as follows.

[113] As illustrated in FIG. 26, the tube 130 and the tube 130 or 300 are formed with male threads 130c and 300c on the outer surfaces of the ends thereof, a tubular connector

310 is formed with female threads 310c on the inner surfaces of the opposite ends thereof, and then the tube 130 and the tube 130 or 300 are screwed into the tubular connector 310, so that the tube 130 and the tube 130 or 300 can be connected with each other.

[114] As illustrated in FIG. 27, the tube 130 and the tube 130 or 300 are formed with flanges 130d and 300d on the ends thereof, the connector 310 is formed with wings

311 having at least one threaded hole 311a, the flanges 130d and 300d are positioned to be in contact with each other and are enclosed by the connector 310, and then the wings 311 of the connector 310 are fastened by at least one screw 313, so that the tube 130 and the tube 130 or 300 can be connected with each other.

[115] As illustrated in FIG. 28, the tube 130 and the tube 130 or 300 are formed with flanges 130d and 300d on the ends thereof, the connector 310 is provided with a connecting fastener 315, the flanges 130d and 300d are positioned so that they are in contact with each other and are enclosed by the connector 310, and then the tube 130 and the tube 130 or 300 are fastened by the connecting fastener 315, so that tube 130 and the tube 130 or 300 can be connected with each other.

[116] As illustrated in FIG. 29, the tube 130 and the tube 130 or 300 are formed with male threads 130c and 300c on the outer surfaces of the ends thereof, a tubular connector 310 is provided with female-threaded nuts 317 on the opposite ends thereof, and then the tube 130 and the tube 130 or 300 are screwed onto the nuts 317, so that the tube 130 and the tube 130 or 300 can be connected with each other.

[117] As illustrated in FIG. 30, the tube 130 and the tube 130 or 300 are formed with male threads 130c and 300c on the outer surfaces of the ends thereof, a tubular connector 310 is formed with female threads 310c on the inner surfaces of the opposite ends thereof and is provided with wings 311 having at least one threaded hole 311a, and then the male threads 130c and 300c are screwed onto the female threads 310c, and the wings 311 are fastened by at least one screw 313 through the threaded hole 31 Ia, so that the tube 130 and the tube 130 or 300 can be more firmly connected with each other. [118] As illustrated in FIGS. 31 and 32, an intermediate tube 320 is additionally provided between the tube 130 and the tube 130 or 300, the ends of the tube 130 and the tube 130 or 300 are first inserted into the intermediate tube 320, a connector 310 formed with wings 311 having at least one threaded hole 31 Ia is disposed on the outer surface of the intermediate tube 320, and then the wings 311 are fastened by at least one screw 313 through the threaded hole 31 Ia, so that the tube 130 and the tube 130 or 300 can be connected with each other.

[119] As illustrated in FIG. 33, a connector 310 is provided with fitting tubes 319 on the opposite ends thereof, and the ends of the tube 130 and the tube 130 or 300 are force- fitted into the connector 310 by way of the fitting tubes 319, so that the tube 130 and the tube 130 or 300 can be connected with each other.

[120] When the tube 130 and the tube 130 are directly connected with each other without the connector tube 300, or with a connector tube 300 having a linear shape, the connector 310 is preferably provided with a bellows 310e in order to accommodate heat expansion, as illustrated in FIG. 34.

[121] The bus ducts 100 having the above-described tube are connected to form the bus duct system, and the optical fiber, which enables detection of the temperature of the bus duct 100 are installed in the tube 130 on the inside or outside of the bus duct 100. Thereby, the temperature of each position of the bus duct system is measured.

[122] The method of installing the optical fiber in the tube 130 generally employs an air- blown fiber (ABF) method, in which a guide head (not shown) is fixed to one end of the optical fiber, the optical fiber and its guide head are inserted into the tube 130, and then the guide head is guided into and installed in the tube 130 using high-pressure air.

[123] FIG. 35 illustrates a method of installing an optical fiber in a tube 130. As illustrated in FIG. 5, the tube 130 is installed outside the bus duct 100 by using the installation means 120 or by being directly adhered to the case of the bus duct 100. As illustrated in FIG. 18, the tube 130 is installed inside the bus duct 100.

[124] As illustrated in FIGS. 22, 23 and 24, the plurality of bus ducts 100, each of which is provided with the tube 130, are interconnected and installed at a desired position, and then the optical fiber 150 is installed in the tube 130 by injecting compressed air into the tube 130. More specifically, the head 400 is mounted on the end of the optical fiber 150, and the optical fiber 150 having the head 400 is inserted into the tube 130 to a predetermined depth. Then, the compressed air is injected at the end of the tube 130. Thereby, the optical fiber 150 is installed in the tube 130.

[125] In the drawings and specification, typical exemplary embodiments of the invention have been disclosed, and although specific terms are employed, they are used in a generic and descriptive sense only and are not for the purposes of limitation, the scope of the invention being set forth in the following claims. Industrial Applicability Ultimately, the temperature of the bus duct line, through which the electric current is delivered, is measured and monitored, so that an accident can be prevented in advance, and an accident location can be rapidly discovered and coped with. Further, the surrounding temperature is monitored, so that the incidence of fires can be monito red.

Claims

[I] A bus duct (100) comprising: a case; a bus bar (107) installed in the case; and a tube (130) installed inside or outside the case. [2] The bus duct (100) as set forth in claim 1, further comprising an installation means (120) outside the bus duct (100), wherein the tube (130) is guided by the installation means (120) and is installed outside the bus duct (100). [3] The bus duct (100) as set forth in claim 1, wherein the tube (130) is attached to the case. [4] The bus duct (100) as set forth in claim 2, wherein the installation means (120) is installed using reinforcement bolts (109) or assembly bolts (108). [5] The bus duct (100) as set forth in claim 4, wherein the installation means (120) includes a main body (121), which is provided with a fixing hole (122), and at least one tube guide (123) on one side of the main body (121), through which the tube (130) is guided. [6] The bus duct (100) as set forth in claim 5, wherein the installation means (120) includes a tube guide (123), which is provided with tube guide holes or recesses

(125) on opposite sides of the main body (121). [7] The bus duct (100) as set forth in claim 4, wherein the installation means (120) includes first and second main bodies (121a and 121b), each of which is provided with a fixing hole (122), and at least one tube guide (123), which is provided with at least one tube guide recess (126) on one side of each of the first and second main bodies (121a and 121b). [8] The bus duct (100) as set forth in claim 7, wherein the first and second main bodies (121a and 121b) are bent at a predetermined angle. [9] The bus duct (100) as set forth in claim 1, wherein the tube (130) is formed in a dual layer. [10] The bus duct (100) as set forth in claim 9, wherein the dual layer includes an inner layer having a lubricant component and an outer layer provided on an outer surface of the inner layer and formed of a polymer.

[I I] The bus duct (100) as set forth in claim 10, wherein the lubricant component of the inner layer includes silicon.

[12] The bus duct (100) as set forth in claim 1, wherein the tube is formed in a single layer of polymer having a lubricant component. [13] The bus duct (100) as set forth in any one of claims 10, 11 and 12, wherein any one of the inner layer and the single layer has a static friction coefficient ranging from 0.05 to 0.20.

[14] The bus duct (100) as set forth in claims 10 or 11, wherein the inner layer and the outer layer each have a thickness of 0.8 mm or less.

[15] The bus duct (100) as set forth in any one of claims 10, 11 and 12, wherein any one of the inner layer and the single layer has a tensile strength of 240kg/cm or more.

[16] The bus duct (100) as set forth in any one of claims 10, 11 and 12, wherein any one of the inner layer and the single layer includes siloxane, ranging from about 0.1 wt% to about 5 wt%.

[17] A bus duct system that is capable of measuring distributed temperature and is formed by interconnecting the bus ducts (100) set forth in any one of claims 1 through 16, wherein the tube (130) of any one of the interconnected bus ducts (100) is connected with the tube (130) of the adjacent bus duct (100), either directly or by way of a connector tube (300), and the tube (130) is provided therein with an optical fiber (150).

[18] The bus duct system as set forth in claim 17, wherein the tube (130) or the connector tube (300) has a portion that is wound one or two turns in a circular shape.

[19] The bus duct system as set forth in claim 17, wherein the tube (130) and the tube

(130), or the tube (130) and the connector tube (300), are connected by a connector (310).

[20] The bus duct system as set forth in claim 19, wherein the tube (130) and the connector tube (300) are each provided with a male thread (130c or 300c) at one end thereof, and the connector (310) is a tube, at opposite ends of which female threads (310c) are formed.

[21] The bus duct system as set forth in claim 19, wherein the tube (130) and the connector tube (300) are each provided with a flange (130d or 300d) at one end thereof, and the connector (310) is provided with wings (311) that have at least one threaded hole (31 Ia) and are fastened by at least one screw (313).

[22] The bus duct system as set forth in claim 19, wherein the tube (130) and the connector tube (300) are each provided with a flange (130d or 300d) at one end thereof, the connector (310) is provided with a connecting fastener (315), and the tube (130) and the connector tube (300) are fastened by the connecting fastener (315).

[23] The bus duct system as set forth in claim 19, wherein the tube (130) and the connector tube (300) are each provided with a male thread (130c or 300c) at one end thereof, and the connector (310) is a tube at opposite ends of which nuts (317) are formed and fastened to the male threads (130c or 300c). [24] The bus duct system as set forth in claim 19, wherein the tube (130) and the connector tube (300) are each provided with a male thread (130c or 300c) at one end thereof, and the connector (310) is provided with female threads (310c) and wings (311) having at least one threaded hole (31 Ia).

[25] The bus duct system as set forth in claim 19, wherein the tube (130) and the connector tube (300) are each inserted into an intermediate tube (320), and the connector (310) is installed to enclose the intermediate tube (320), and is provided with wings (311) that have at least one threaded hole (31 Ia) and are fastened by at least one screw (313).

[26] The bus duct system as set forth in claim 19, wherein the tube (130) and the connector tube (300) are each provided with a flange (130d or 300d) at one end thereof, and the connector (310) is provided with fitting tubes (319) that are fitted into opposite ends of the connector (310).

[27] The bus duct system as set forth in any one of claims 19 through 26, wherein the connector (310) is provided with at least one flexible bellows (310e).

[28] The bus duct system as set forth in claim 17, wherein the bus ducts (100) of the bus duct system are interconnected by a connecting means (250), and the connecting means (250) is provided with a protrusion (251).

[29] The bus duct system as set forth in claim 17, wherein the optical fiber is installed in the tube (130) by an air-blown fiber (ABF) method.

[30] A method of installing a bus duct system capable of measuring distributed temperature, the method comprising the steps of: installing at least one bus duct (100) having a case, a bus bar (107) installed in the case, and a tube (130) installed inside or outside the case in a lengthwise direction of the bus duct (100) and using air pressure; and installing an optical fiber (150) in the tube (130) using the air pressure.