JPS6111926Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grounding switch housed within a closed switchboard.

Closed switchboards generally house disconnectors, voltage transformers, meter current transformers, etc., but earthing switches can also be included. . One terminal of this grounding switch is connected between the load and the disconnector, and the other terminal is connected to the ground.As a general rule, it is closed only after the disconnector is opened. It functions to make maintenance and inspection of the load safe by placing it in the area.

By the way, high-voltage charging parts in electrical equipment housed in a closed switchboard must be surrounded with an insulating material or coated with an insulating material as much as possible. This is because if a foreign object or a small animal that has entered the closed switchboard comes into contact with these high-voltage charging parts, there is a risk that a serious accident will be induced. For this reason, although high-voltage charging parts and high-voltage busbars in many electrical devices have been appropriately insulated, the reality is that no such treatment has been applied to grounding switches.

FIG. 1 shows the general configuration of the grounding switch. According to this, the base plate (insulator)
A fixed contact piece 3 is mounted on the base plate 1 via an insulator 2, while a rotary support member 7,
A movable contact piece 4 is rotatably mounted via a rotating shaft (ground conductor) 6. By operating a drive lever (not shown) fixed to the rotating shaft 6, the movable contact piece 4 moves toward the fixed contact piece 3 and can be brought into contact with the fixed contact piece 3. Note that the other end of the fixed contact piece 3 is configured as a power supply terminal.

As can be seen from the above explanation, the grounding switch has a movable part, but at least the part where the fixed contact piece makes contact with the movable contact piece cannot be insulated, so the live part is exposed to the outside as it is. It is. In this case, it is clear that exposing the charging part not only causes the above-mentioned problems, but also that if the charging operation is performed by mistake, a discharge phenomenon will occur immediately before the charging operation. It is clear that a discharge phenomenon occurs in the air inside a closed switchboard, which is not desirable. Furthermore, in the conventional three-phase grounding switch, insulation between phases is performed in the air, so a large insulation distance between phases must be taken, and when constructed in one piece, the whole switch becomes large. There is.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a miniaturized grounding switch whose live parts are not exposed and which does not cause a discharge phenomenon in the air even if it is accidentally turned on.

For this purpose, the present invention constitutes a grounding switch using a vacuum switch, the main body of the switch is surrounded by an insulating frame, and the terminals as live parts exposed to the outside are covered with an insulating cover. It is characterized by

The present invention will be explained below.

Figures 2a and 2b show the left side and partially broken front view. As shown in the figure, each vacuum switch compatible with three phases includes a vacuum switch main body 10, a fixed lead 1
2 and a movable lead 11, the vacuum switch 1
A fixed contact (not shown) attached to the tip of the fixed lead 12 and a movable contact (not shown) attached to the tip of the movable lead 11 are housed inside the terminal 0 so that they can be brought into contact and separated. That is, by driving the movable lead 11 up and down, these contacts can be brought into contact and separated. When a grounding switch is constructed using a vacuum switch, there is no room for air discharge to occur.

A three-phase vacuum switch is constructed individually using an insulating frame 14 that also serves as interphase insulation, with a fixed lead 12 and a part of the movable lead 11 left outside, a front insulating plate 16, and a mounting frame (grounded metal) 15. Although they are spatially separated, the separation is performed in close proximity. This is because the size can be reduced if the vacuum switches are placed close to each other. By the way, a part of the fixed lead 12 protrudes upward through the upper part of the insulating frame 14, and since this protruding part is used as a high voltage application terminal, this part must be appropriately insulated for interphase insulation. . The insulation treatment in this case requires complete insulation treatment while a high voltage is applied. In this example, this process is performed using a two-part insulating cover 19. After appropriately connecting a conductor to be connected (not shown) whose tip is bare to the protruding part, a two-piece insulating cover 19 is used to completely insulate the entire protruding part and the connection part. It is an insulating coating. The mode of insulation treatment is not limited to this, but it is sufficient that appropriate insulation treatment is performed at least while the conductor to be connected is connected.

On the other hand, the movable lead 11 is electrically connected to the mounting frame 15 in an appropriate manner, and is always kept in a grounded state by grounding the ground terminal 18 to the earth, but the part protruding downward from the mounting frame 15 is used for opening and closing operations.
Although the detailed operation mechanism is not shown, when the operation lever 20 is operated to the ON or OFF position, the movable reed 11
The mounting legs 13 are provided so that the entire earth switch can be housed and mounted inside a closed switchboard.

As explained above, the present invention configures the main body of a three-phase grounding switch as a vacuum switch, and then surrounds the outer periphery of the vacuum switch with an insulator that also functions as interphase insulation. The high voltage application side terminal that partially protrudes outside the object is insulated by an insulating cover, and a ground metal that surrounds the vacuum switch together with the above insulator and is provided in common to the three phases. A movable terminal on the ground side is appropriately electrically connected to the plate, and the movable terminal on the ground side, which partially protrudes to the outside from the ground metal plate, is driven for all three phases at once by a switchgear provided in common for the three phases. It was designed so that Therefore, according to the present invention,
There is no chance of air discharge occurring, the live parts are reliably insulated, and three-phase vacuum switches are placed close together and drive all three phases at once, so the overall configuration can be reduced. There is.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a general configuration of a grounding switch according to the prior art, and FIGS. 2a and 2b are views showing a left side and a partially cutaway front view of an example of the grounding switch according to the present invention. 10... Vacuum switch body, 11... Movable lead, 12... Fixed lead, 14... Insulating frame, 15... Mounting frame (ground metal), 17... Switch operating device.

Claims (1)

[Scope of utility model registration request] The main body of the three-phase earthing switch is configured as a vacuum switch, and the outer periphery of the switch is surrounded by an insulator that also serves as interphase insulation, and the high voltage application side terminal partially protrudes outside of the insulator. While being insulated by an insulating cover, the movable terminal on the ground side is appropriately electrically connected to a grounding metal plate that surrounds the vacuum switch together with the above insulator and is provided in common to the three phases. A grounding switch characterized in that a grounding side movable terminal partially protruding from the metal plate is driven by a switching device commonly provided for three phases.