JP2765481B2 - Input side protection cover for high voltage load switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective cover for a fixed contact in a high-voltage load switch, and more particularly, to protection of an input-side blade-shaped fixed contact which is easy to mount and does not fall off easily. It is about the cover.

[0002]

2. Description of the Related Art In large-scale factories and buildings, power supply facilities (power receiving / returning facilities) are provided to receive and transform high-voltage power supplied from a power company or the like and supply operating power to various machines. ing. In the above-mentioned power supply equipment, an individual protection device is provided to distribute power from a high-voltage (for example, 3 KV) bus (busbar) received from the high-voltage lead-in point via the main cutoff device to a motor, a high-voltage advance capacitor, a transformer, and the like. A high-voltage load switch is used as the switch.

As shown in FIG. 3, the high-voltage load switch includes blade-shaped fixed contacts 20, 30 and a movable contact portion 40.
Consists of The blade-shaped fixed contacts 20, 30 are held in a state of being electrically insulated from the structure via the supporting insulators 26, 36, and are connected to their bases 23, 33, respectively, to connect the input side electrode 24, the output side electrode and the output side electrode. 34, the input side electrode 24 is connected to the bus 1 by the conducting wire 25, and the output side electrode 3
4 is connected to the load 2 by a conducting wire 35, respectively.

[0004] The movable contact portion 40 is provided with lip-shaped contacts 41a and 41b housed in a movable box 44 having rollers 45 via an insulator, and intermediate electrodes 42a and 42b respectively connected to the lip-shaped contacts 41a and 41b. And a switch 43 that performs the operation. The lip-shaped contacts 41a and 41b are made of a conductive material having high elasticity, and the movable contact portion 40 is moved forward or backward to connect the blade-shaped fixed contact 20 and the lip-shaped contact 41a, and the bus 1 and the load 2 respectively. Or open.

Various periodic inspections are required by law for electrical equipment, which is an electrical work. Among them, inspections performed while the high-voltage load switch is open include silent inspection and measurement inspection. In order to perform inspection work in an open state, it is necessary to take sufficient care and careful consideration so that workers do not touch live parts including the bus 1 to the input side of the high-voltage load switch. .

[0006]

Therefore, conventionally,
When working near high-voltage livelines, wear protective gear such as electric safety hats, high-pressure rubber gloves, and insulating clothing.
The live parts are covered or shielded with protective equipment such as protective sheets. In addition, the live wires of buses and high-voltage load switches have problems with insulation deterioration due to adhesion of metal powder to insulating members due to other work, and problems with dust adhering to conductive parts that cause poor contact. For this reason, it is preferable to attach a safer protective cover to prevent such adhesion at the live line portion.

[0007] However, in a relatively large-scale factory, the live parts of the high-voltage load switch requiring the above-mentioned protective cover may reach several hundreds. Therefore,
Since the time and labor required for attaching the protective cover or removing it for partial inspection is enormous, it is desired to have a protective cover that can be easily attached and detached in a short time. The present invention has been made in view of the above matters,
It is an object of the present invention to provide a safe input side protection cover for a high-voltage load switch that does not require any trouble in detaching and attaching and that does not easily fall off.

[0008]

In order to achieve the above-mentioned object, in order to facilitate the attachment and detachment, the cylinder is basically constituted by a cylindrical body having a hole for penetrating a supporting insulator, and the cylindrical body is pushed and expanded. A slit is provided in the upper longitudinal direction of the main body so that the main body can be attached to the blade-shaped fixed contact. That is, the present invention relates to a protective cover for a blade-like fixed contact having the support insulator 26 fixed to the upper surface of the base 23, and a through hole 10a for inserting the support insulator 26 into the center of a substantially cylindrical main body. A protective cover having a slit S in the upper longitudinal direction of the main body including the diameter line of the cylindrical insulator covering portion 13 forming the through hole 10a, and integrally forming the following parts a to e. is there. a. A cylindrical covering portion 11 for wrapping the input-side conductor portion 25 connected to the rear end of the base portion 23 in the blade-shaped fixed contact 20; b. The base 23 is connected to the cylindrical covering portion 11.
, A rectangular tubular covering portion 12 covering from the center to the electrode 24 at the base rear end, c. A cylindrical insulator covering portion 13 formed above the rectangular tubular covering portion 12, d. The fixed contact 2 is connected to the rectangular tubular
0 of the cutting edge base 2 3 flat cylindrical cover portion 14 surrounding the, e. The fixed contact 20 is connected to the flat
A flared covering portion 15 that surrounds the cutting edge 21 and the movable contact 41 that is thrown into the cutting edge 21.

The protective cover is made of a material having electrical characteristics such as large volume resistance and high dielectric strength, for example, polyethylene, polypropylene or soft polyvinyl chloride. Structurally, the slit is spread by hand. A member having flexibility for fitting and having a predetermined rigidity so as not to easily fall off is used. Further, since the protective cover is required to have a large volume resistance and a high dielectric strength, a material having a volume resistance of 10 ¹³ Ω · cm or more and a dielectric strength of 15 KV / mm or more is used. . The thickness is desirably 3 to 6 mm.

[0010]

As described above, since a cylindrical body having a through hole for the supporting insulator is provided substantially at the center and a slit in the longitudinal direction is provided at the upper part of the cylindrical body, the protective cover is mounted on the blade-shaped fixed contact. In this case, the tubular body is covered with the blade-shaped fixed contact while being expanded along the slit. The slit is automatically closed by the shape restoring force by covering the blade-shaped fixed contact and then releasing the pushed-out protective cover, thereby protecting the blade-shaped fixed contact in a state of being close to each part. This completely shuts off the input side of the high-voltage load switch from the outside, preventing the attachment of minute conductive members and dust,
High-voltage hot-line proximity work can also be performed more safely.

[0011]

Next, the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing one embodiment of the input side protection cover of the high voltage load switch of the present invention, and FIG. 2 is a perspective view when a movable contact portion is inserted into a fixed contact on the input side of the high voltage load switch. . First, the fixed contact that covers the protective cover will be described. As shown in FIG. 2, the fixed contact 20 has a support insulator 26 for attaching the fixed contact to a fixed frame (not shown) on a central upper surface of a blade-shaped base 23. An input electrode 24 is formed to connect the cutting edge 21 and a conductive wire portion 25 including a terminal to the other end.

Protective cover 1 for covering the fixed contact 20
Reference numeral 0 denotes an upper longitudinal direction of the cylindrical main body including a through hole 10a for inserting the support insulator 26 at the center of the substantially cylindrical main body, and including a diameter line of the insulator covering portion 13 forming the through hole 10a. And is formed of a soft plastic such as polyethylene, polypropylene or soft polyvinyl chloride (FIG. 2). That is, this protective cover 1
0 has the following parts a to e. a. A cylindrical covering portion 11 for wrapping the input-side conductor portion 25 connected to the rear end of the base portion 23 in the blade-shaped fixed contact 20; b. The base 23 is connected to the cylindrical covering portion 11.
, A rectangular tubular covering portion 12 covering from the center to the electrode 24 at the base rear end, c. A cylindrical insulator covering portion 13 formed above the rectangular tubular covering portion 12, d. The fixed contact 2 is connected to the rectangular tubular
0 of the cutting edge base 2 3 flat cylindrical cover portion 14 surrounding the, e. The fixed contact 20 is connected to the flat
A flared covering portion 15 that surrounds the cutting edge 21 and the movable contact 41 that is thrown into the cutting edge 21.

The flared covering portion 15 wraps around the cutting edge 21 of the blade-shaped fixed contact 20. When the lip-shaped movable contact 41 is inserted to form a contact state as shown in FIG. The contact 41 is formed in a divergent shape so as to be easily inserted, and has a shape that is longer than the cutting edge 21 and sufficiently covers the same. Also, slit S
Is provided so as to connect from the upper end point 16 of the cylindrical covering portion 11 to the point 17 of the insulator covering portion 13 and from the point 18 of the insulator covering portion 13 to the point 19 of the flared covering portion 15.

In order to cover the above-mentioned protective cover 10 on the blade-shaped fixed contact 20, flexibility is required because the slit S needs to be inserted while being spread by hand. Structural strength and rigidity are required to prevent the part from turning over, coming off or falling off.
It is molded from polyethylene, polypropylene, or a soft polyvinyl chloride member satisfying the range of 0.05 to 150 kg / mm ^2, and the thickness is desirably 3 to 6 mm. Thickness 3
If it is less than 6 mm, sufficient strength cannot be obtained, and if it is 6 mm or more, attaching and detaching of the cover becomes difficult. In addition, the electrical characteristics of the protective cover are required to have a large volume resistance and a high dielectric strength, so that the volume resistance is 10 ¹³ Ω · cm or more and the dielectric strength is 1
The value of 5 KV / mm or more is satisfied.

[0015]

According to the present invention, a substantially cylindrical main body has a through-hole at the center thereof for inserting a supporting insulator on the fixed contact side, and includes a diameter line of the insulator covering portion forming the through-hole. Since the upper part of the cylindrical body has a slit in the longitudinal direction, the cylindrical body is pushed along the slit and placed on the blade-shaped fixed contact, and then the protective cover that has been expanded is released to release the shape restoring force. , The slit is automatically closed, so that the blade-like fixed contact can be easily attached. In addition, since the protective cover is attached in a state of being close to each part of the blade-shaped fixed contact, the input side of the high-voltage load switch is completely shut off from the outside, and adhesion of minute conductive members and dust is prevented. At the same time, high-voltage live-line proximity work can be performed more safely. Further, since the protective cover is formed of a soft plastic such as polyethylene, polypropylene or soft polyvinyl chloride, it can be easily attached or detached by pushing and spreading, and the efficiency of the attaching / detaching operation can be improved. further,
Since it is not a simple cylindrical structure but has a shape with ingress and egress along with the actual shape and has a thickness of 3 to 6 mm, it has strength and rigidity as a structure, and there is no possibility of falling off or falling off by hitting a person or an object.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an input-side protection cover of a high-voltage load switch of the present invention.

FIG. 2 is a perspective view when a movable contact portion is inserted into a fixed contact on the input side of a high-voltage load switch.

FIG. 3 is a schematic side view schematically showing the high-voltage load switch of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bus 2 Load 10 Protective cover 11 Cylindrical covering 12 Square tubular covering 13 Cylindrical insulator covering 14 Flat tubular covering 15 End-expanding covering S Slit 20 Blade-like fixed contact 21 Cutting edge 22 Cutting edge base Reference Signs List 23 Base 24 Input side electrode 25 Conductor 26 Support insulator 40 Movable contact part 41 Movable contact 41a, 41b Lip contact

Claims (3)

(57) [Claims] 1. A protective cover for a blade-shaped fixed contact element (20) having a support insulator (26) fixed to an upper surface of a base (23), wherein a through-hole (10a) for inserting the support insulator (26) is provided at the center of a substantially cylindrical main body. Polyethylene or polypropylene having a slit S in the upper longitudinal direction of the main body including the diameter line of the cylindrical insulator covering portion 13 forming the through hole 10a, and integrally forming the following parts a to e. Or input side protection cover of high-voltage load switch made of soft PVC. a. A cylindrical covering portion 11 for wrapping the input-side conductor portion 25 connected to the rear end of the base portion 23 in the blade-shaped fixed contact 20; b. The base 23 is connected to the cylindrical covering portion 11.
, A rectangular tubular covering portion 12 covering from the center to the electrode 24 at the base rear end, c. A cylindrical insulator covering portion 13 formed above the rectangular tubular covering portion 12, d. The fixed contact 2 is connected to the rectangular tubular
0 of the cutting edge base 2 3 flat cylindrical cover portion 14 surrounding the, e. The fixed contact 20 is connected to the flat
A flared covering portion 15 that surrounds the cutting edge 21 and the movable contact 41 that is thrown into the cutting edge 21. 2. The protective cover has a volume resistance of 10 ¹³ Ω.
The input-side protection cover of the high-voltage load switch according to claim 1, wherein the input-side protection cover is formed of a material having a size of not less than cm. 3. The input-side protection cover for a high-voltage load switch according to claim 1, wherein the thickness of the protection cover is 3 to 6 mm.