JP4549791B2 - Short-circuit prevention device for low-voltage electric meters - Google Patents

Description

  The present invention relates to a short-circuit prevention tool for preventing a short-circuit accident in a terminal block when replacing a low-voltage electric meter such as a watt-hour meter.

  Low-voltage electric meters such as ordinary watt-hour meters and precision watt-hour meters are individually installed for each house or each office, and constantly measure the electric power supplied through the lead-in wires from the outside. Since the measured value is used for electricity trading, it must always be able to accurately measure the amount of electricity, and is usually tested for a certain period of time, for example, a period of less than 10 years for a normal electricity meter. It is exchanged for a new or maintenance item.

  This replacement is performed by removing all the wires connected to the power supply side terminal and load side terminal of the terminal block equipped with the low voltage electric meter. This is what is being done. For this reason, this replacement work is extremely dangerous, and the driver of the operator is required to loosen the terminal screw that presses the tip of the electric wire and remove the electric wire, especially at the power supply side terminal of the watt-hour meter. If the tip of a tool such as this slips and contacts the terminal screw of another adjacent electric wire, a short circuit accident may occur. Also, when connecting a wire by tightening a terminal screw to the power supply side terminal, the tip of the tool slips sideways when a terminal screw is tightened at the terminal adjacent to the terminal to which the wire is connected and another wire is connected. Then, there is a possibility that the same short-circuit accident may be caused by contacting the terminal screw just tightened. Such short-circuit accidents are often accompanied by injury to workers.

  In view of such circumstances, Japanese Patent Application Laid-Open No. 2002-55121 is a U-shaped frame body that includes a horizontally long main plate and side plates that are continuously provided downward from both ends thereof. Proposed is an inter-electrode insulation jig whose length spans the terminal box in the integrated watt-hour meter, and in which a plurality of window holes are formed in the main plate corresponding to the individual terminal portions (patent) Reference 1). When this inter-electrode insulation jig is attached to a watt-hour meter, each wire tightening part is individually partitioned by each window hole frame by positioning in the left-right direction, so the short-circuit accident as described above can be assured in advance. It is excellent in that it can be prevented. In the present specification, in the terminal block, each space surrounded by partition walls provided on both sides of each terminal screw is referred to as a “terminal portion”.

JP 2002-55121 A

  However, if the inter-electrode insulation jig is a watt hour meter provided in the same power feeding circuit, for example, a single-phase three-wire circuit, even if the watt hour meter has a different size, You can safely replace the watt-hour meter by installing it and positioning it in the left-right direction. However, you can replace the watt-hour meter installed in a circuit with a different power supply system such as a single-phase two-wire system. In order to do so, it was necessary to separately prepare an interelectrode insulating jig suitable for the power feeding method. Therefore, the operator has to carry a plurality of inter-electrode insulation jigs adapted to each power feeding method. In addition, since the inter-electrode insulation jig is a U-shaped frame as seen from the front and has a three-dimensional shape, there is a problem that a large storage space is required when carrying a plurality of these. It was.

  The present invention eliminates the problems of the prior art, and can reliably prevent erroneous connection and short-circuit accidents regardless of the power feeding method in replacement work of the low-voltage electric meter, and can be easily attached to the low-voltage electric meter and is portable. It aims at providing the short circuit prevention tool for low voltage | pressure electric meters which is excellent in and can be accommodated compactly.

  The above object is, according to the present invention, a short-circuit prevention tool for preventing a short-circuit accident at the time of replacement of a low-voltage electric meter provided with a terminal block in which a plurality of terminal portions are arranged in a row, wherein the plurality of terminals A strip-shaped transparent plate having at least one working opening having a size corresponding to one of the portions, and the strip-shaped transparent plate can be slid in the longitudinal direction along the row of the terminal portions. A low-voltage electric device, characterized in that the holding device further comprises mounting means for mounting the holding device at a predetermined position on the outer surface of the low-voltage electric meter. Achieved with instrumental short-circuit protection.

  According to the present invention, the transparent plate is provided with a working opening having a size corresponding to the size of one terminal portion, and when replacing the low-voltage electric meter, the electric wire is removed and connected using a tool such as a screwdriver. The work can be performed through the work opening, so that the worker can work while checking the connection position of the electric wire, and the adjacent terminal part is covered with the plate even when the tool slides sideways. Therefore, not only erroneous connection of electric wires but also the above-mentioned short circuit accident can be surely prevented.

Further, in the short-circuit prevention device for a low-voltage electric meter according to the present invention, since the transparent plate body is slidably held by the guide means, each terminal portion of the terminal block can be seen through, and the terminal portion of the terminal block of the low-voltage electric meter By moving the transparent plate body along the row, the working opening can be easily positioned at a desired terminal portion, and as a result, it is not necessary to prepare a plurality of short-circuit prevention tools by a power feeding method.
Furthermore, since the transparent plate and the holder can be separated from each other, it is excellent in portability and can be stored compactly.

  Hereinafter, with reference to FIGS. 1-8, the short circuit prevention tool for low voltage | pressure electric meters of this invention is demonstrated in detail. In these drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description will be omitted below.

  FIG. 1 is a perspective view showing an example of an embodiment of a short-circuit prevention tool 1 according to the present invention. In this figure, the short-circuit prevention tool 1 includes a transparent plate 10 and a holder 20.

  The plate body 10 has a substantially rectangular strip shape and has working openings 11 penetrating the front and back. The thickness is not particularly limited and can be set as appropriate, but is usually 1 to 4 mm, preferably 2 to 3 mm. If it is less than the above range, there is a problem in strength such as damage caused by receiving external force in the stored state, and if it exceeds the above range, it is difficult for the operator to perform work such as removing the electric wire through this work opening. This is not preferable. Further, the length in the longitudinal direction and the width in the direction perpendicular to the longitudinal direction can be appropriately selected according to the size of the terminal block of the low-voltage electric meter to be used. Specifically, it may be larger than the size that covers a plurality of terminal portions that open toward the front from the terminal block, but preferably has a size that covers the surface of the terminal block completely. The material of the plate 10 may be a transparent electrically insulating material, and is preferably a hard material. By making the plate 10 transparent, it is possible to work while confirming the electric wires of each phase, so that there is an advantage that erroneous connection can be prevented. In addition, when the plate body 10 is slid and moved by a guide means 50 described later, the plate body 10 can be provided with a mark or the like that serves as a mark for the amount of movement. The plate body 10 may be provided with a knob 12 at a portion other than the work opening 11 so that the plate body 10 can be easily slid. The shape and size of the knob 12 are not particularly limited.

  The shape of the opening peripheral edge portion of the work opening 11 provided in the plate body 10 can be appropriately set, but it is preferable to have a shape corresponding to the shape of each terminal portion provided in parallel with the terminal block of the low-voltage electric meter, Usually, it is substantially rectangular. The size is a size corresponding to the size of one terminal portion. Actually, the terminal blocks of the watt-hour meter and other low-voltage electric meters are not all the same size, and the size and arrangement of the terminal portions may be slightly different depending on the producer of the low-voltage electric meter. Also, the size of each terminal portion varies depending on the maximum allowable current of the low voltage electric meter. Therefore, in consideration of the difference in the size of the terminal portion depending on the type of the electric meter, the size of the working opening is set to an average size of these, or any type such as a minimum one is used. It can be set according to the size of the terminal part.

  For example, as shown in FIG. 1, the working opening 11 may be provided in a region close to one end in the longitudinal direction of the plate body 10, but is not limited to the illustrated mode. May be provided. Further, the number of the openings 11 in the plate 10 is not limited to one and may be plural. When providing a plurality of openings, it is preferable that the interval between the adjacent openings 11 be separated by at least the length of the openings in the longitudinal direction of the plate body 10. For example, as shown in FIG. 2, one opening can be provided in each of the regions close to both ends (see FIGS. 2B and 2D), and can be further provided in the center (see FIG. 2). (See (c)). In this case, the individual openings may have different sizes. For example, in the case where the openings 11 are provided in regions close to both ends, respectively, taking into account the difference in the size of the terminal portion of the low-voltage electric meter, it corresponds to the maximum size and the minimum size of the terminal portion, respectively. It can be set to a size (see FIG. 5B). In addition, when the opening 11 is further provided in the center portion, the size of each opening 11 can be divided into three stages of large, medium and small. Moreover, this opening 11 can also be formed by notching from any one edge part of the longitudinal direction of the board 10 (refer the figure (c)). Even when the size of the terminal portion of the low-voltage electric meter is different by providing a plurality of openings 11 having different sizes in each plate 10 and changing the direction of the plate 10 left and right in reverse. A single plate 10 can be used. The opening 11 may be further provided with a window lid (not shown) that can be opened and closed.

The holder 20 includes a guide unit 50 and a mounting unit 40 connected to the guide unit 50. The guide means 50 is composed of a C-shaped member having a pair of opposing jaws, and more specifically, a slide guide plate 51 formed of a strip-shaped plate body, and both edges in the longitudinal direction of the slide guide plate 51 Slide frames 53 and 54 that are slightly erected from each of the sections, and slide frames 55 and 56 that are bent from the slide frames 53 and 54 and extend slightly parallel to the slide guide plate 51 toward each other. . The transparent plate 10 is inserted into the jaw, that is, the gap surrounded by the slide guide plate 51 and the slide frames 53, 55, 54, and 56, and both edges in the longitudinal direction are provided in the slide frames. While being held, it is slidably guided along the slide guide plate 51. The gap between the slide guide plate 51 and the slide frames 55 and 56, the shape of each slide frame, and the like are not particularly limited as long as they can be slidably guided by gripping both longitudinal edges of the transparent plate 10. The length of the guide means 50 in the longitudinal direction can be arbitrarily set. For example, as shown in FIG. 1, the length of the guide member 50 may be substantially the same as the entire length in the longitudinal direction of the plate member 10, or may be shorter or longer than that. It may be a thing.
The guide means 50 includes at least one surface of the slide guide plate 51 and each of the slide frames 53, 54, 55, and 56, the size of the terminal portion that varies depending on the type of the low-voltage electric meter, and the spacing between adjacent terminal portions. A mark related to can be attached. The method of attaching the mark is not particularly limited, and it can be performed using a known means such as a mark or engraving with oil-based ink.

  When using the guide means 50 that can completely grip the entire length of the plate body 10 in the longitudinal direction, it is necessary to provide an opening 52 in the slide guide plate 51. The size of the opening 52 provided in the slide guide plate 51 is not particularly limited as long as it is equal to or larger than the opening area of the work opening 11 provided in the plate body 10, and as shown in FIG. An opening having an opening area that is approximately half the area may be provided near the right end or the left end of the slide guide plate 51, and an opening having a larger opening area may be provided in the slide guide plate 51. The material of the guide means 50 is also preferably an electrically insulating material, and more preferably a transparent hard material.

  The mounting means 40 detachably mounts the holder 20 on a predetermined position on the outer surface of the low-voltage electric meter. The mounting means support piece 42 connected to the guide means 50 and the mounting fixed to the support piece 42. It consists of a tool 45. In the present specification, the term “joining” is used to include the case where the support piece 42 and the constituent member of the guide means 50 are joined and the case where both are integrated. is doing.

  The mounting tool support piece 42 and the guiding means 50 connected to the mounting tool support piece 42 are provided when the holding tool 20 is mounted at a predetermined position on the outer surface of the low-voltage electric meter with the mounting tool 45 fixed to the support piece 42. It is necessary to have a positional relationship in which the guide means 50 is arranged so as to cover the row of the terminal portions of the terminal block. Further, the connecting position of the support piece 42 to the guide means 50 needs to prevent the sliding movement of the plate member 10 in the guide means 50 from being hindered. Therefore, depending on the type of the mounting tool used and the mounting method of the holding tool using the same, the positional relationship between the mounting tool support piece and the guide means may change. Changes may be required.

In the embodiment of FIG. 1, the holder 20 is mounted on the lower surface of the protruding meter body of the low-voltage electric meter via the mounting tool 45, and guide means is provided so as to cover the row of terminal portions of the terminal block on the lower side of the meter. 50 is arranged. Therefore, the support piece 42 needs to be arranged at an angle with respect to the slide guide plate 51 constituting the guide means 50, specifically, an angle of 80 to 100 degrees, preferably 85 to 95 degrees. Preferably, the guide means 50 is connected to the bent portions of the slide frames 53 and 55 so as to be substantially perpendicular. In the case of the figure, the support piece 42 has an integral structure with the slide frame 53 erected from the edge of the slide guide plate 51, but is not limited to the example shown in the figure, and the support piece 42 of a similar shape prepared separately is used. The end may be joined to the bent portion or the outer surface of the slide frame 53. When the separately prepared support piece 42 is joined to the bent portion or the like, the support piece 42 and the guide means 50 can be made detachable by using known means, or the joined portion can be formed to be bendable. By making it detachable or bendable in this way, the short-circuit prevention tool 1 of the present invention can be accommodated in a more compact manner. Further, the number of support pieces connected to the guide means 50 is not limited to one, but may be two or more and may be appropriately arranged on slide frames or the like at both edges of the guide means 50.
In the case of this figure, the support piece 42 has a convex plane whose end on the side connected to the guide means 50 is equal to the entire length in the longitudinal direction of the guide means 50, but is not limited to the example shown in the figure. The guide means 50 may have a side length equal to or shorter than the entire length in the longitudinal direction, and may have a plane such as a substantially triangular shape or a substantially rectangular shape with the side as the end. In the case of using a support piece having a plane such as a substantially triangular shape with a short side length, it is preferable that the support piece is arranged at the center in the longitudinal direction of the slide frame 53 or the like.

The mounting tool 45 is not particularly limited as long as it can hold the weight of the holder 20 and the transparent plate 10 sufficiently when mounted on the outer surface of the low-voltage electric meter, and has electrical insulation properties. (See FIG. 1), various bands such as rubber bands, PP bands, cloth bands, polyester bands (see FIGS. 6 and 7), or ones having a hook attached to one end of an elastic linear body (see FIG. 8), etc. It can be used suitably. Moreover, a magnet can also be used when the low voltage | pressure electric meter exterior is metal and the meter itself does not cause a malfunction by the influence of a magnetic field.

  The mounting tool 45 may be fixed to the support piece 42 by a known method such as adhesion so as not to be separated from the mounting tool support piece 42 in advance, but is preferably detachable from the support piece 42. It is good to be fixed to. Specifically, as shown in FIG. 1, when a suction cup is used as the mounting tool 45, a mounting portion 41 that protrudes perpendicularly to the surface from the center on the back surface side is a gourd type provided on the support piece 42. The suction cup can be fixed to the support piece 42 by inserting the large diameter hole in the opening 43 and moving the attachment portion 41 to the small diameter hole. The fixing method is not limited to this, and either one of the mounting tool 45 or the mounting tool support piece 42 is provided with a screw hole, and the other is provided with a screw-like protrusion that fits the screw hole, thereby preventing the short circuit of the present invention. When the tool 1 is used, the mounting tool 45 may be fixed to the support piece 42 by screwing the screw-like protrusions into the screw holes.

  When a suction cup or a magnet is used as the mounting tool 45, the attachment part 41 protruding to the back surface side can have a structure as shown in FIG. 3, for example. The mounting portion 41 shown in the figure is obtained by passing a plurality of cylindrical rings 412, 412,... Having the same outer diameter and thickness through a shaft 411 protruding perpendicularly to the surface from the center on the back side of the suction cup. Thus, a cap 413 having the same outer diameter as the plurality of cylindrical rings is screwed into a threaded portion provided at the tip of the shaft 411. The shaft 411 may be the same material as the suction cup or a different material fixed to the suction cup using a means such as bonding or adhesion, or may be integrally formed with the suction cup 45. As the individual cylindrical rings 412 and caps 413, those obtained by molding an electrically insulating material can be suitably used. The total thickness of the individual cylindrical rings is preferably smaller than the length of the shaft 411 excluding the threaded portion by the thickness of the mounting tool support piece 42, as shown in FIG. Further, by changing the number of cylindrical rings 412 fitted between the back surface of the suction cup and the support piece 42, the mounting means can be fixed by changing the distance between the two. Thus, for example, in the drawing showing the use state of the short-circuit prevention device of the present invention of FIG. 5, even when the distance between the meter body 101 and the terminal portion 102 of the low-voltage electric meter 100 is large, the support piece 42 and the low-voltage electric meter The distance from the outer surface of the main body 101 can be adjusted, and as a result, the work opening 11 of the transparent plate 10 held by the holder 20 can be positioned in the vertical direction along the surface of the terminal block. In addition, as long as such positioning is possible, it is not limited to the above cylindrical ring or cap, and other members may be used.

  FIG. 5 is a diagram showing a use state of the short-circuit prevention tool 1 of the present invention in the replacement work of the low-voltage electric meter. Here, the code | symbol 100 is a single-phase three-wire type normal electric energy meter installed in each house of a common house or an apartment house as an example of a low voltage | pressure electric meter. The ordinary watt-hour meter 100 includes a meter body housed in a case 101 and a terminal box 102 provided below the meter body. In replacing the watt hour meter, first, a cover (not shown) on the surface of the terminal box is removed to expose a terminal block in which a plurality of terminal portions are arranged in parallel. This terminal block is provided with three terminal portions for each of a normal power supply side terminal and a load side terminal. The terminal portions of the power supply side terminals are arranged in the order of voltage line, neutral line, and voltage line, and the electric wires 103a, 103c, and 103b covered with insulating materials of different colors from outside correspond to these. Each is connected. The load side terminals are also arranged in the same manner as the terminal portions of the power source side terminals, and the electric wires 104a, 104c and 104b covered with insulating materials of different colors are connected to each other.

  First, a suction cup is attached to the mounting tool support piece 42 of the holder 20, and the suction means is pressed against a predetermined position on the outer surface of the lower side of the case 101 of the normal watt hour meter so that the guide means 50 is connected to the normal watt hour meter. The holding tool 20 is attached so as to cover the terminal block. At this time, the transparent plate 10 may be held in advance by the holder 20 or may be held after the holder 20 is attached. Moreover, the working opening 11 of the transparent plate 10 can be positioned in the vertical direction along the surface of the terminal block using the above method. Next, by using the knob 12 provided on the surface of the transparent plate 10 held by the holder 20, the plate 10 is moved in the longitudinal direction thereof, so that the terminal of the voltage line 103 a among the power supply side terminals. The working opening 11 is positioned in the part. This positioning may be performed by marks such as engravings attached to the guide means 50 and the plate 10. A screwdriver is inserted from the work opening 11 toward the screw head of the terminal screw in the terminal portion, and the connected electric wire is removed from the lower side of the terminal block 102 by loosening the terminal screw. An insulating cap is put on the tip of the removed electric wire. Next, the plate body 10 is moved again in the horizontal direction using the knob 12, the working opening 11 is positioned at the terminal portion of the other voltage line 103b, and the electric wire is removed by the same operation. Similarly, the position of the opening 11 of the plate 10 is adjusted to the terminal portion of the remaining neutral wire 103c, and the same operation is repeated. Thus, after all the electric wires connected to the power supply side terminal are removed, the electric wires 104a, 104b, and 104c connected to the load side terminal are respectively removed. Thereafter, the ordinary watt-hour meter 100 is removed from its mounting base (not shown) and replaced with a new meter that has been certified. In this new instrument, first, the electric wires 104a, 104b, and 104c are connected to the load side terminal as if attached before the replacement. Next, the short-circuit prevention tool 1 of the present invention is mounted again on the new instrument in the same manner as described above, and the work opening 11 of the plate 10 is positioned in the terminal portion for connecting the voltage line 103a of the power supply side terminal. Thereafter, the terminal screw of the terminal part is loosened, and the electric wire 103a with the insulating cap removed from the tip is connected to the terminal part. The same operation is repeated for the other voltage line 103b and neutral line 103c. Thus, even when the driver is slid in the terminal block during the exchange work of the watt hour meter, the terminal portion adjacent to the terminal portion related to the removal or connection of the electric wire is covered with the transparent plate 10, A short circuit accident can be reliably prevented. Further, since the plate body 10 is transparent, each phase can be confirmed by seeing through the opening 22 provided in the slide guide plate 51 of the guide means 50 and the transparent slide guide plate 51. Absent.

  FIG. 6 shows another example of the embodiment of the short-circuit prevention device of the present invention. In this embodiment, the overall length in the longitudinal direction of the guiding means 50 is shorter than that in the embodiment of FIG. 1, and as a result, the overall length in the longitudinal direction of the plate 10 is longer. In addition, an elongated hole 43 formed by cutting out from the end opposite to the bent portion is provided at a substantially central portion of the support piece 42. A rubber band is used as the mounting tool 45, and the rubber band is provided with the same mounting tool 41 as in the example of FIG. 1, and the mounting tool 41 is fitted into the elongated hole 43 and the rubber band. Is fixed to the support piece 42. Other configurations are the same as those of the embodiment of FIG.

  When the short-circuit prevention tool of this embodiment is used, for example, for the watt-hour meter replacement work similar to that shown in FIG. 5, first, a rubber band is hung vertically on the case 101 of the meter body 100 to 20 is attached to the instrument body 100. At this time, the distance between the plate 10 and the surface of the terminal block 102 can be adjusted by changing the fixing position of the rubber band attachment portion 41 in the elongated hole 43. Further, the holder 20 can be positioned along the row of the terminal portions of the terminal block 102 by shifting the rubber band hung on the case 101 to the left and right. In this case, the guide means 50 of the holder 20 is arranged close to the load side terminal side so as not to cover each terminal portion on the power source side, or the outermost side on the power source side or load side at both ends of the terminal block. It is preferable to arrange the terminal portion so as not to cover it. By arranging the guide means 50 in this way, the plate body 10 can be slid in the left-right direction along the row of the terminal portions of the terminal block 102, and the same operation as described above can be performed. It is possible to safely remove the electric wire from the power supply side terminal and prevent the electric wire from being connected to the terminal after replacing the instrument. Also in this embodiment, since the plate 10 is transparent, it goes without saying that there is no problem of erroneous connection of electric wires.

  FIG. 7 shows still another embodiment of the short-circuit prevention device of the present invention. Unlike the embodiment shown in FIG. 6, the guide means 50 has only a slide frame 53 erected from one edge in the longitudinal direction of the slide guide plate 51 and a slide frame 55 bent from this. However, the slide frames 54 and 56 facing these are not provided. Instead, a slide movement restricting means 57 including a projection 571 protruding from the surface of the slide guide plate 51 and a cap 572 covering the tip of the slide guide plate 51 is provided in a region near the edge opposite to the slide frame 53 of the slide guide plate 51. ing. When using the short-circuit prevention tool 1, the plate body 10 having the long holes 13 and 13 at the center is gripped by the jaw portion composed of the slide frames 53 and 55 and the protrusion 571 is fitted into the long hole 13. The cap 572 is placed on the tip of the protrusion 571 protruding from the surface of the plate 10. The opening 43 for fixing the mounting tool 45 provided at the center of the mounting tool support piece 42 is provided toward the end of the support piece 42 from the large-diameter hole provided on the slide frame 55 side and the hole. It is composed of a long hole. When the mounting tool 45 is fixed to the support piece 42, the mounting tool 45 is pulled up after the mounting portion 41 of the mounting tool 45 is inserted through the large-diameter hole. Similar to the above, the distance between the surface of the low voltage electric meter terminal block and the transparent plate 10 can be adjusted by adjusting the fixing position of the mounting tool 45 within the range of the elongated hole. In the figure, a PP band 451 with a stopper 452 is used as the mounting tool 45. The mounting tool 45 is also preferably one having electrical insulation. The stopper 452 is preferably made of plastic that is usually used for bundling packages.

  When the short-circuit prevention tool 1 shown in FIG. 7 is attached to the ordinary watt-hour meter 100 shown in FIG. 5, for example, a band 451 is hung perpendicularly to the case, and the band 451 is tightened by a stopper 452 to attach the short-circuit prevention tool 1 to the above case. Fix to 101. The fixing position and usage method of the short-circuit prevention tool 1 are the same as those of the embodiment shown in FIG. Also in this embodiment, the same effect as the short-circuit prevention tool of the embodiment shown in FIGS. 1 and 6 can be obtained.

  FIG. 8 is a view showing still another embodiment of the short-circuit preventing device for a low-voltage electric meter according to the present invention. The mounting means 40 in this embodiment includes mounting tool support pieces 42, 42, 42, 42 provided so as to project outward in the vicinity of both ends of the slide frames 53 and 54 of the guide means 50, and these The mounting piece 45 is fixed through an opening provided at a substantially central portion of each support piece 42. The mounting tool support pieces 42, 42 provided on the slide frame 54 and the mounting means fixing pieces 42, 42 provided on the slide frame 53 are symmetrical with respect to the center in the longitudinal direction of the guide means 50. ing. As the mounting tool 45, one having a hook 453 attached to one end of a rubber thread 454 as an elastic body, and fixing the other end of the rubber thread 454 through the opening 43, each mounting tool support piece 42. Can be attached to each. Other configurations such as the plate 10 and the guide means are the same as those in the embodiment of FIG.

  When the short-circuit preventing tool 1 of this embodiment is used for exchanging the ordinary watt hour meter 100 shown in FIG. 5, for example, the hooks 453 and 453 on the slide frame 53 side are connected to the meter body 101 of the ordinary watt hour meter 100. The holder 20 can be mounted by engaging with the mounting brackets 105 (the brackets on the left side are not shown) on both sides, and the two hooks on the slide frame 54 side are suspended. If possible, the hooks 453 and 453 on the slide frame 54 side may be locked to the lower end of the mounting base (not shown) of the ordinary watt-hour meter. The subsequent operations such as position adjustment of the work opening 11 of the plate 10 are the same as described above. Even when this short-circuit prevention tool 1 is used, the same effects as those of the above embodiments can be obtained.

  In addition, as an application of this short circuit prevention tool 1, it can be used suitably also in the case of the removal and connection operation | work of the electric wire in the terminal block for exclusive use provided in the switchboard in a factory, or the inside of a control panel. That is, the four hooks of the short-circuit prevention device 1 are respectively locked to the surrounding electric wires that are unrelated to the above-mentioned work, thereby fixing the short-circuit prevention device and preventing the short-circuit accident while removing and connecting the wires. It can be performed.

  The short-circuit prevention device of the present invention can be easily mounted on a low-voltage electric meter, and can reliably prevent misconnection and short-circuit accidents at the time of removal and connection of electric wires in the terminal block equipped with the low-voltage electric meter. And is compact and can be stored in a compact manner, and is particularly suitable when an operator concentrates and replaces a large number of low-voltage electric meters in a short time.

It is a perspective view which shows an example of embodiment of the short circuit prevention tool for low voltage | pressure electric meters of this invention. It is a figure which shows arrangement | positioning of the opening provided in the transparent board which comprises the short circuit prevention tool for low voltage | pressure electric meters of this invention. It is a figure which shows the attachment part of the mounting tool which comprises the short circuit prevention tool for low voltage | pressure electric meters of this invention. It is a figure which shows the attachment state to the mounting tool support piece of the mounting tool which comprises the short circuit prevention tool for low voltage | pressure electric meters of this invention. It is a perspective view which shows the use condition of the short circuit prevention tool for low voltage | pressure electric meters of this invention. It is a perspective view which shows another embodiment of the short circuit prevention tool for low voltage | pressure electric meters of this invention. It is a perspective view which shows another embodiment of the short circuit prevention tool for low voltage | pressure electric meters of this invention. It is a perspective view which shows another embodiment of the short circuit prevention tool for low voltage | pressure electric meters of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Short-circuit prevention tool 10 for low voltage | pressure electric meters A strip-shaped transparent board 11 Work opening 20 Holder 40 Mounting means 41 Mounting part 42 Mounting tool support piece 45 Mounting tool 50 Guide means 51 Slide guide plate 52 Opening 53 Slide frame 54 Slide frame 55 Slide frame 56 Slide frame 57 Slide movement limiting means

Claims (6)

  A short-circuit prevention tool for preventing a short-circuit accident at the time of replacement of a low-voltage electric meter provided with a terminal block in which a plurality of terminal portions are arranged in a line, the size corresponding to one of the plurality of terminal portions A strip-shaped transparent plate having at least one working opening, and a holder having guide means for guiding the strip-shaped transparent plate along the row of the terminal portions so as to be slidable in the longitudinal direction thereof The holding tool further comprises mounting means for mounting the holder at a predetermined position on the outer surface of the low-voltage electric meter.   The short-circuit prevention tool for low-voltage electric meters according to claim 1, wherein the working opening is provided in a region near one end in the longitudinal direction of the transparent plate.   2. The short-circuit prevention tool for a low-voltage electric meter according to claim 1, wherein each of the work openings is provided in a region close to both ends in the longitudinal direction of the transparent plate.   4. The short-circuit prevention tool for a low-voltage electric meter according to claim 2, wherein the work opening is further provided in a central region in the longitudinal direction of the transparent plate.   The short-circuit preventing tool for a low-voltage electric meter according to claim 1, wherein the mounting means includes an elastic body with a suction cup, a magnet, a band, or a hook. The short-circuit prevention tool for a low-voltage electric meter according to claim 1, wherein the guide means further includes means for restricting sliding movement of the transparent plate.

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