JPS6050308B2 - How to detect abnormal heat generation locations - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for detecting a location where abnormal heat generation occurs.
The present invention relates to the same detection method performed using a thermal sensing electric wire having a structure in which a non-thermal sensing electric wire coated with E) or the like is added.

Conventional detection methods of this type use heat-sensing wires made by twisting a pair of heat-sensing wires whose insulators are coated with a material that easily melts, such as PE, so that stress is applied between the wires. This is commonly done.

For this reason, although it is possible to sense that abnormal heat generation has occurred due to a short circuit between lines due to heat, it is not possible to detect the location where the heat is generated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for detecting a location where abnormal heat generation occurs, which enables not only heat sensing but also detection of a heat generation location, in order to improve the above-mentioned drawbacks.

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

First, the heat-sensing wires used in this embodiment will be explained, and the piano wire 1 will be coated with a PE insulator 2 by extrusion to form the heat-sensing wires 6, 6'.

In order to apply stress between the wires, a pair of heat sensing wires 6, 6' are twisted together without twisting. As the non-thermal sensing electric wire 7, for example, a piano wire 1 coated with a cross-linked PE insulator 4 is repeatedly twisted together or longitudinally spliced during the above-mentioned pair twisting. After pressing and wrapping these with plastic tape, a PVC sheath 3 is covered. When using the heat sensing wire obtained in this way, PE is generated due to heat generation.
melts and the stress of the piano wire causes a short circuit between the wires, and heat generation can be detected.

At the same time, the location of heat generation can be detected using the non-thermal sensing wire and Murray loop.

(See FIG. 2.) A method of detecting a location where abnormal heat generation occurs will be explained with reference to FIG.

(1) Connect one end of the non-thermal sensing wire 7 and one end of one of the heat sensing wires 6.

(2) Connect the other ends of the non-thermal sensing wire 7 and the heat sensing wire 6 to the A and B ends of the Murray loop, respectively.

(3) The other heat sensing wire 6'' is connected to the power source E via the alarm device 9 in order to be used as a ground circuit in the event of a short circuit.

(4) At the location 8 where abnormal heat generation occurs, the heat sensing wire 6,
6" are short-circuited, current flows, and the alarm device 9 is activated. At the same time, the sliding resistance R is increased or decreased depending on the current direction of the galvanometer 10 to maintain balance, thereby reducing the distance to the point where the heat generation occurs. Measure. (Example) Using piano wires of the same size and twisting them at the same pitch, measure the interlocking and sliding resistance on a scale of 20 to 1000 to 20.

If the indicated value at equilibrium is a, then the distance X to the heat generating part is determined by the following formula. ±L(7T1.) (where L=line length (TrL)) 0=1000 The following can be considered as a modification of this invention.

(1) A heat sensing wire may be used in which one of the heat sensing wires is not coated with PE and is composed of one bare wire.

(2) The size and material of the conductor of the heat sensing wire and the non-thermal sensing wire may not be the same, but in this case, the resistance value must be corrected.

(3) This method can be applied not only to heat sensing, but also to detection of flooded positions, for example.

According to this invention, it is possible to detect the location where abnormal heat generation occurs, so it is possible to quickly detect the location where abnormal heat generation occurs in managing underground power transmission and distribution lines, and to greatly save labor in investigating the cause. becomes.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing one embodiment of a heat sensing electric wire used in the present invention.

Claims (1)

[Claims] 1. Lay a heat sensing wire in a predetermined location with a non-thermal sensing wire ¥7 coated with rubber, cross-linked polyethylene, etc., attached to a pair of heat sensing wires 6 and 6'. 7
One end of the heat sensing wire 6 is connected to one end of the heat sensing wire 6, and the other ends of the non-thermal sensing wire 7 and the heat sensing wire 6 are connected to the A and B ends of the Murray loop, respectively, and the other end of the heat sensing wire 6 is connected to one end of the heat sensing wire 6. The electric wire 6' is connected to the power source E via the alarm device 9, and at the same time as abnormal heat generation occurs, the pair of heat sensing electric wires 6, 6' are short-circuited at the relevant location to detect the abnormal heat generation and the abnormal heat generation location. A method for detecting a location where abnormal heat generation occurs, characterized by simultaneously detecting.