JPH1197087A - Auxiliary electrode for measuring earth resistance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide rich conductivity and good adhesiveness to the ground and also to easily and accurately measure earth resistance by taking chemical fiber plated with silver as a raw material, weaving it, and constituting a soft net. SOLUTION: A yarn (f) of chemical fiber (for instant, nylon) plated with silver, rich in conductivity, soft, and having high strength is woven into a net, and an earth resistance measuring auxiliary electrode P is manufactured. Since the silver-plated chemical fiber is expensive, it is preferable to use a net formed by combining and weaving chemical fiber plated with silver and chemical fiber not plated with silver (nylon, polypropylene, polyester, polyethylene, etc.), and the ratio of the plated yarn and the non-plated yarn is 1: 1 to 1: 2. The thickness of the yarn (f) for constituting the net is set in the range of 10 to 100 denier, the raschel weaving is preferable. In the size of a mesh (d), the length of one side is set to few mm, and the auxiliary electrode P has the suitable square shape and the length of one side in the range of 50 to 100 cm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a transformer, a lightning arrester,
The present invention relates to an auxiliary electrode suitable for use in measuring the ground resistance of a ground electrode provided on a steel tower, a power pole, or the like on which a high-voltage device or the like is mounted.

[0002]

2. Description of the Related Art Grounding work is required by law to prevent accidents due to earth leakage on power poles equipped with transformers, lightning arresters, high-voltage equipment, and the like. This grounding work is performed by embedding a grounding member at a predetermined depth around the pole position to form a grounding electrode, and connecting a grounding wire to the grounding pole.

Conventionally, this grounding member is buried in a grounding member, such as a metal rod, into the ground with a hammer, and the grounding resistance of the embedded grounding member is measured. Has passed.

The measurement of the ground resistance is generally performed by a method as shown in FIG. That is, the ground electrode 1 to be measured and the auxiliary electrodes (grounding rods) 2 and 3 are connected to the measuring instrument M via the lead wire 5, and a current (generally, alternating current is used) between the ground electrode 1 to be measured and the auxiliary electrode 3. And measure the resistance. In this case, the distance L between the measured ground electrode 1 and the auxiliary electrodes 2 and 3 is about 5 to 10 m. FIG. 5 illustrates this measurement principle. When the ground electrode 1 to be measured and the auxiliary electrode 3 are connected to a power supply 7 as shown in FIG. ). in this case,
If the distance between them is sufficiently long, the potential at the central portion becomes flat, so that the potential drop E ₁ due to the resistance R ₁ of the measured ground electrode 1 is obtained.
Potential drop E ₂ is to be clearly separated in the central portion and by the resistance R ₂ of the auxiliary electrode 3. Therefore, if another auxiliary electrode 2 is provided in this central portion and the potential difference E ₁ between the ground electrode 1 to be measured and the auxiliary electrode 2 in the central portion is measured, E ₁
= IR ₁ , R ₁ = E ₁ / I, and the ground resistance R ₁ of the measured ground electrode ₁ is obtained.

[0005]

As an auxiliary electrode for measuring the ground resistance, a metal rod having high conductivity is used. The metal rod is driven into the ground for measurement. In the case of debris, concrete, bedrock, etc., there is a problem that the measurement cannot be performed well because a grounding pole (grounding rod) made of a metal rod cannot be driven. For this reason, a method of placing a metal net on the ground surface, placing a grounding rod on the ground surface, and applying water on the ground rod to measure the ground rod is sometimes used.

However, the metal net has a large area,
Since it is hard and hard to deform, it is inconvenient for handling such as transportation and storage.In addition, it is difficult to make close contact with the ground, and the ground resistance of the auxiliary electrode becomes too large, so that accurate measurement values cannot be obtained. Was. Therefore, an object of the present invention is to provide an auxiliary electrode that can be properly grounded even on hard ground where a ground rod cannot be driven.

[0007]

In order to solve the above problems, the present invention employs the following configuration. That is, the auxiliary electrode for measuring ground resistance according to the present invention is characterized in that it is constituted by a flexible net woven from silver-plated chemical fiber as a material. Because silver-plated chemical fibers are expensive, it is actually economical to combine them with silver-plated chemical fibers and non-silver-plated chemical fibers to form a flexible net. preferable. Furthermore, the intersections where the fibers and the fibers in the net come into contact with each other are required to increase the adhesion between each other and reduce the electrical resistance as much as possible. In particular, it is preferable to adopt Raschel knitting in which the intersections of the vertical and horizontal yarns are complicatedly entangled. According to this knitting method, the intersection point is hard to shift and the strength is excellent. In addition, the net preferably has a moderately open stitch because it is flexible and has good adhesion to the ground.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below. This auxiliary electrode P for measuring ground resistance
Consists of a net that is very flexible under its own weight. The net is formed by knitting vertical and horizontal yarns (made of chemical fibers in the present invention) f,... By a known knitting method such as lace knitting, fish net knitting, Raschel knitting, etc. The size of the entanglement and the mesh d is such that the length of one side is about several mm. Note that the shape of the mesh d may be a polygon (triangle, quadrangle,...) Or another shape.

The vertical and horizontal yarns are preferably highly conductive, and most preferably flexible and high-strength chemical fibers (eg, nylon) plated with silver. As the silver-plated chemical fiber, nylon fiber coated with silver is commercially available, and it is effective to use this. However, economically, it is preferable to use silver-plated chemical fibers and non-silver-plated chemical fibers (nylon, polypropylene, polyester, polyethylene, etc.) in an appropriate ratio. For example, a mixture of silver-plated nylon (hereinafter referred to as “plated yarn”) and non-plated chemical fiber (hereinafter referred to as “non-plated yarn”) in a ratio of about 1: 1 to 1: 2 is preferably used. be able to. Although it is possible to employ plating of another metal such as copper plating or nickel plating instead of silver plating, it is not preferable since it is practically unstable.

The thickness of the vertical and horizontal yarns f constituting the net is 10
It is preferably about 100 denier, but is not limited to this. Also, the shape and dimensions of the auxiliary electrode for measuring ground resistance made of a net may be appropriately determined according to the use conditions and the like. Usually, the length of one side is 50 to 10
A square of 0 cm would be appropriate.

The auxiliary electrode P for measuring the ground resistance is used by covering it on the ground G as shown in FIG. In this case, since the auxiliary electrode itself is made of a flexible net, it has good adhesion to the ground. When measuring the grounding resistance, a grounding terminal (E) is provided on the plating yarn constituting the net, and the lead wire 5
Alternatively, as shown in FIG. 3, a conventionally known grounding rod B may be placed on a net, and the lead wire 5 may be connected to the grounding rod. In addition, it is preferable to spray water on the net in order to reduce the grounding resistance. After the measurement is completed, the volume can be reduced by folding the flexible net into an appropriate size.

[0012]

EXAMPLE A silver-plated nylon fiber (trade name "X-static 3") manufactured by Sauquoit Co., USA was used as a plating thread.
0XS10 ") was combined with a non-plated yarn made of non-plated nylon fiber at a ratio of 1: 1 to produce a net as shown in FIG. 1 by Raschel knitting. This net has an electric resistance of 100Ω or less,
When an earth electrode was cut out into an m-square and used as an auxiliary electrode, and the earth resistance of the earth electrode to be measured was measured using a ground resistance meter 3235 manufactured by Yokogawa Electric Corporation, the earth resistance was successfully measured even on the rock. Was.

[0013]

As described above, the auxiliary electrode for measuring ground resistance according to the present invention is formed of a flexible net woven from silver-plated chemical fiber, and thus has high conductivity. In addition to this, it is possible to easily and accurately measure the ground resistance even in the ground where the adhesion to the ground is good and the auxiliary electrode composed of the conventional ground rod cannot be driven. Further, the auxiliary electrode made of the net is flexible and can be folded small when not in use, so that it is convenient for handling.

[Brief description of the drawings]

FIG. 1 is an external view illustrating an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part thereof.

FIG. 3 is an explanatory diagram of a method of use.

FIG. 4 is an explanatory diagram of a ground resistance measuring method.

FIG. 5 is an explanatory diagram showing the principle.

[Explanation of symbols]

 1 ground electrode to be measured 2, 3 auxiliary electrode 5 lead wire P auxiliary electrode f thread (chemical fiber) d mesh E ground terminal

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigeo Fukushima 507-1 Isa-machi, Isa-cho, Mine-shi, Yamaguchi Pref. (72) Inventor Makoto Takizawa 3-7-2 Nihonbashi Ningyocho, Chuo-ku, Tokyo Akihiro Trading Co., Ltd. (72) Inventor Noboru Kurosawa 1141 Ohara, Yabutsukahonmachi, Nitta-gun, Gunma Prefecture Kurosawa Race Co., Ltd.

Claims (3)

[Claims] 1. An auxiliary electrode for measuring ground resistance, comprising a flexible net woven from silver-plated chemical fibers. 2. An auxiliary electrode for measuring ground resistance, comprising a flexible net woven from a combination of silver-plated chemical fibers and non-silver-plated chemical fibers. 3. The auxiliary electrode for measuring ground resistance according to claim 1, wherein the net is woven by Raschel knitting.