JPH0129970Y2 - - Google Patents

Description

[Detailed description of the invention] A. Industrial application field This invention relates to the improvement of a high-voltage cutout used to protect a pole-mounted transformer, and involves electrically insulating the arcing horn and the mounting bracket using an insulating support. The present invention relates to the structure of a high-voltage cutout for lightning protection that deals with contact voltage.

B. Prior Art In high-voltage distribution lines, a high-voltage cutout is connected to the primary side of a pole-mounted transformer for protection. In recent years, high-voltage cutouts for lightning protection have been used as part of lightning protection measures, especially in areas hit by lightning.

This high-voltage cut-out for lightning protection is equipped with a current-limiting (lightning-proof) element in the cut-out, and when a lightning surge invades, the discharge electrode of the current-limiting element on the charging side and the arcing horn on the opposite earth side. A flash fault is generated in the discharge gap formed between the cutout and the dual-purpose mounting bracket, and the resulting discharge current is sent to the ground through the cutout's mounting bracket and the support such as the steel tower to which the cutout is attached. This protects the transformer from insulation breakdown caused by lightning surges.

By the way, in the above case, the discharge current flows through the cut-out mounting bracket and the support such as the steel tower, so there is no risk of the worker touching the support (steel tower) while the discharge current is flowing. Then, the worker (human body) feels the potential difference between the contact part of the grounded support and the earth due to the gradient of the earth's potential, that is, the contact voltage Et between the hand touching the support and the foot on the earth. The voltage applied to the worker may cause the worker to receive an electrical shock.

C. Problems that the present proposal is intended to solve: Therefore, the present proposal prevents the generation of the above-mentioned contact voltage by electrically insulating the arcing horn and the mounting bracket with an insulating support. This is designed to eliminate the problem of shots.

D. Means for solving the problem To this end, in the present invention, the main body is attached to a support 4, such as a steel tower, which is installed on the ground and is itself in a grounded state, using the mounting bracket 3 attached to the main body 2, Furthermore, an insulating support 11 is attached to the mounting bracket 3, and the insulating support 11 is insulated to an extent that can prevent flashover between the plate-shaped mounting bracket 3 and the plate-shaped mounting bracket 3 caused by lightning surges. A discharge electrode 16 that maintains the distances l ₁ and l ₂ and attaches the plate-shaped arcing horn 12 on the earth side, and connects one end 12c of the attached arcing horn 12 to the current limiting element 19 on the cutout side.
The supporting member 4 is connected to the earth terminal 17 which is opposed to the discharge portion 16a of the
In the high-voltage cut-out for lightning protection to which a grounding wire 8 made of a covered wire that is grounded E ₂ separately from the grounding E ₁ is connected, the upper and lower parallel surfaces of the insulating support 11 are the mounting surfaces 11a, and 11a are formed with horizontally parallel guide protrusions 11b into which plate-shaped arcing horns 12 are fitted, and furthermore, bolts 1 are provided on each mounting surface 11a at asymmetrical positions in the front and rear.
This paper proposes a high-voltage cutout for lightning protection, which is characterized by having 4.

E. Function The mounting bracket 3 for attaching the cutout to a support (steel tower) is equipped with an insulating support stand 11, and an arcing horn 12 is attached to this support stand insulated from the mounting bracket. The arcing horn has one end facing the discharge electrode 16 on the cutout side through a predetermined discharge gap G, and a grounding wire 18 made of a covered wire is connected to a grounding terminal 17 provided on the arcing horn. With this structure, even if a flash fault occurs in the discharge gap due to the intrusion of a lightning surge, the discharge current will flow to the ground wire and not to the support (steel tower) to which the cutout is attached. Therefore, even if the worker touches the support, he or she will not receive an electrical shock due to the contact voltage and will be safe.

Example Examples of the present invention will be described below.

FIG. 1 shows a box-shaped high-voltage cutout 1 for lightning protection, which is attached to a support 4 via a mounting bracket 3 provided on the back surface 2a of the main body 2. This support 4 consists of steel towers, poles, etc. that are installed on the ground and are themselves grounded as shown in Figure ₁ , and this cutout is attached to (connected to) the angles 4a, armrests 4b, etc. Use it by attaching it to the Further, the above-mentioned mounting bracket 3 consists of a mounting part 3a and a support part 3b, which are integrally connected by a bolt 5 and a nut 6.
The support portion 3b is fastened to a bolt 7 fixed to the back surface 2a of the main body 2 by a nut 8.
Reference numerals 9 and 10 indicate auxiliary bolts and nuts for angle mounting provided on the mounting portion. Reference numeral 11 denotes an insulating support made of synthetic resin or porcelain and formed into a substantially rectangular parallelepiped, and upper and lower mounting surfaces 11 are symmetrically formed.
One mounting surface of (a) is attached to the support part 3b of the mounting bracket 3, and the ground side arcing horn 12 is attached to the other mounting surface of the attached support base. An appropriate insulation distance l ₁ , l ₂ is set between the metal fitting 3 and the arcing horn 12 so that insulation is maintained even when lightning surges enter.
is formed. The insulating support base 11 has upper and lower mounting surfaces 11 formed in parallel as shown in the figure.
In addition to a, each mounting surface is provided with a bolt 14 fixed upright with an adhesive 13 and a nut 15 mounted on the bolt, and a pair of guides formed on both sides of the mounting surface. If the mounting bracket 3 and arcing horn 12 are to be mounted on the mounting surface of the support base, insert the bolts into the mounting holes 3c and 12a of the mounting bracket and the arcing horn, and then The nut 15 is tightened and installed with the respective side surfaces 3d and 12b engaged with the guide protrusions 11b, that is, positioned so as to be inserted between the guide protrusions. The guide protrusions formed on the mounting surface of the insulating support base are shaped to match the shapes of the support fittings and arcing horn that are attached to the respective mounting surfaces, that is, the thickness and width of these. If both are made to have the same thickness and width, the shapes of the upper and lower mounting surfaces will be symmetrical, and the insulating support can be mounted on either of the upper or lower mounting surfaces. Reference numeral 12 denotes an arcing horn mounted on an insulated support as described above, and one end 12c of the arcing horn is connected to the discharge part 1 of the discharge electrode 16 to the current limiting element 19 provided on the main body side.
6a through a discharge gap G, and the grounding terminal 17 integrally provided at the other end 12d is grounded by a grounding wire 18 made of a coated wire so as not to contact the support 4, and is _an arcing horn. 12 and the ground _E1 of the support 4 are grounded separately. The mounting hole 12a of the horn is formed into an elongated hole so that the horn can slide back and forth while guiding the guide protrusion 11b and the bolt 14, thereby allowing the discharge gap G to be adjusted. Further, 19 is a current-limiting element with voltage non-linearity, which is built in the housing part 2b of the main body and one end of which is connected to the charging side of a fixed electrode (not particularly shown), etc.; 20 is a current-limiting element that is connected to the other end of the current-limiting element and is connected to the lower side. A discharge electrode in which a pointed discharge part 16a protruding from the ground side faces the arcing horn on the ground side via a discharge gap G, and 21 is made of rubber or synthetic resin that covers the outer periphery of the discharge electrode except for the current limiting element and the discharge part. Insulator, 22
Reference numeral 23 denotes an adhesive for fixing the current limiting element to the housing of the main body, and 23 denotes a cap-shaped insulating cover made of rubber or the like, which is applied to the lower end opening 2c of the housing so as to exclude the discharge part 16a of the discharge electrode. , 23a indicate discharge holes of the insulating cover which are located in the discharge section and whose tips protrude downward.

In the above configuration, if a lightning surge enters the cutout and a flash fault occurs in the discharge gap G between the cutout's discharge electrode and the arcing horn, the discharge current at that time will be reduced from the current limiting element 19 to the discharge electrode 16. -Discharge gap G-Arching horn 12
It flows along the path of - ground terminal 17 - ground wire 18 .
Further, the follow-on arc caused by the commercial frequency caused by the flash fault is blocked by the current limiting element 19 built into the main body.
That is, since the arcing horn 12 is insulated from the mounting bracket 3 by the insulating support base 11, the discharge current does not flow into the mounting bracket 3 and the support 4 (steel tower) to which the cutout is attached.

Fig. 3 shows an embodiment of the present invention when applied to a cylindrical high-pressure cutout, in which the cutout 1 is connected to a support 4 (actually connected to a support It is used by being attached to the attached armrest 4a)). In addition, the insulating support base 11 has one mounting surface 11a attached to the lower mounting portion 3b of the mounting bracket 3, and the other mounting surface 11a.
The arcing horn 12 is attached to and used in this embodiment, and since the mounting bracket and the arcing horn have the same thickness and width, the shapes of the upper and lower mounting surfaces of the insulating support are symmetrical. Can be mounted on any mounting surface. 24 is a fuse cylinder stored and held in the main body, 25 is a fuse, 26 is a lower fixed electrode connected to one end of the current limiting element 19, 27 is a synthetic resin lower cover fixed to the lower end opening of the main body, 28 is a lower cover 29 is an engagement piece; 30 is a string connecting the seal plug and the lower cover; 31 is a lower outlet wire;
2 indicates a lead portion.

Note that members having the same or equivalent functions as those of the box-shaped cutout of the above embodiment will be designated by the same reference numerals, and a description thereof will be omitted.

G. Effects of the Proposal As described above, in the high-voltage cut-out of the present proposal, the arcing horn installed in the cut-out is insulated from the mounting bracket and the support by an insulating support, and thereby the discharge current at the time of a flash is reduced from the mounting bracket and the support. This prevents the discharge current from flowing to the support, and at the same time allows the discharge current to flow directly to the ground via the covered wire grounding wire that connects the arcing horn.
Unlike in the past, no contact voltage is generated in the mounting bracket and the support, and it is possible to reliably prevent electrical shock problems caused by the voltage on the operator.

In addition, when installing the above-mentioned insulated support base, which insulates between the mounting bracket and support and the arcing horn to prevent discharge current from flowing through them, the mounting position and mounting direction are restricted. In this way, bolts equipped with nuts are fixed to the upper and lower mounting surfaces of the support base, and guide protrusions that engage with the mounting bracket and arcing horn are formed, allowing for accurate mounting and eliminating unnecessary installation. Since the arcing horn and the discharge electrode do not move, the discharge gap between the arcing horn and the discharge electrode is kept constant, and stable discharge characteristics can be expected.
Since both mounting surfaces 11a are symmetrical, either an arcing horn or a mounting bracket can be mounted, and there is no fear of incorrect mounting.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the present invention. Figure 1 is an installation diagram of a box-shaped high-voltage cutout for lightning protection with the main part partially broken, and Figure 2 is a Longitudinal sectional view, b is a side view, c is a plan view, 3rd
The figure shows how the cylindrical cutout for lightning protection is installed, with the main part partially broken. 1...High pressure cutout, 2...Main body, 3...Mounting bracket, 3c...Mounting hole, 3d...Side surface, 4...Support, 1
DESCRIPTION OF SYMBOLS 1...Insulating support base, 11a...Mounting surface, 11b...Guide protrusion, 12...Arching horn, 12b...Side surface, 12c...One end, 12d...Other end, 14...Volt, 15...Nut, 16...Discharge electrode, 16a...Discharge Part, 17...Earth terminal, 18...Grounding wire, 19...
Current-limiting element, _E1 ...grounding, _E2 ...grounding, G...discharge gap, _l1 ...insulation distance, _l2 ...insulation distance.

Claims (1)

[Scope of utility model registration request] The main body is attached to a support 4, such as a steel tower, which is installed on the ground and is itself in a grounded state, using a mounting bracket 3 attached to the main body 2. Furthermore, an insulating support 11 is attached to the mounting bracket 3, and the same is used. The insulating support base 11 is provided with a plate-shaped earth side with insulation distances l ₁ and l ₂ maintained to the extent that flash shorting can be prevented between the plate-shaped mounting bracket 3 and the plate-shaped mounting bracket 3 due to the intrusion of lightning surges. The arcing horn 12 is attached, and one end 12c of the attached arcing horn 12 is made to face the discharge part 16a of the discharge electrode 16 connected to the current limiting element 19 on the cutout side via a predetermined discharge gap G. Earth terminal 17 integrated with horn 12
In the high-voltage cutout for lightning protection to which a grounding wire 8 made of a covered wire that is grounded _E2 separately from the grounding E1 of the support ₄ is connected, the upper and lower parallel surfaces of the insulating support base 11 are used as mounting surfaces 11a, Further, on both sides of each mounting surface 11a, horizontally parallel guide protrusions 11b into which plate-shaped arcing horns 12 are fitted are formed, and furthermore, bolts 14 are erected and fixed to each mounting surface 11a at asymmetrical positions in the front and back. High-voltage cutout for lightning protection.