JP2020112356A

JP2020112356A - Short-circuit prevention device

Info

Publication number: JP2020112356A
Application number: JP2019000973A
Authority: JP
Inventors: 冬彦阿曽; Fuyuhiko Aso; 貴光阿部; Takamitsu Abe; 俊也市川; Toshiya Ichikawa; 綾佳相山; Ayaka Aiyama
Original assignee: Nichia Corp; Yurtec Corp
Current assignee: Nichia Corp; Yurtec Corp
Priority date: 2019-01-08
Filing date: 2019-01-08
Publication date: 2020-07-27
Anticipated expiration: 2039-01-08
Also published as: JP6678968B1

Abstract

To provide a short-circuit prevention device capable of preventing a short circuit between different phases in a wire fixing screw or an electric wire in an electric wire insertion/removal work with respect to an electric power meter and applicable to electric power meters having different rated currents.SOLUTION: A short-circuit prevention device includes: a pair of clamping members that clamp both sides of an electric power meter; an adjusting member that adjusts the distance between the pair of clamping members according to the distance between both sides of the electric power meter; and a shielding member facing a partition wall between electric wire fixing screws of different phases adjacent to each other in the electric power meter, where the shielding member is movable in a distance direction between both sides of the electric power meter.SELECTED DRAWING: Figure 6

Description

本発明は、電力量計に対する電線挿抜作業において電線間の短絡を防止する短絡防止具に関するものである。 TECHNICAL FIELD The present invention relates to a short-circuit preventive tool for preventing a short circuit between electric wires during an electric wire insertion/removal operation for a watt hour meter.

電力量計の交換、点検、修理等のために電力量計に対して電線を挿入したり計器から電線を引き抜いたりする作業（以下、電線挿抜作業という）に際しては、電線固定用ネジ（以下、「ネジ」という）を締めたり緩めたりする。また、ネジは電線に直接接触しており充電状態にある。近年導入されたスマートメーターは異相端子間の仕切壁が低く、ネジを緩めていくとネジが仕切壁の高さを越えて突出してしまう恐れがあり、ネジからドライバーがずれた際のドライバーを介した異相間短絡、または電線を端子台に対し挿抜する際の電線とネジによる異相間短絡が発生する危険性があった。 When inserting, or pulling out the electric wire from or to the meter for replacement, inspection, repair, etc. of the watt-hour meter (hereinafter referred to as wire insertion/removal work), the wire fixing screw (hereinafter, Tighten or loosen the "screw"). Also, the screw is in direct contact with the electric wire and is in a charged state. The smart meter introduced in recent years has a low partition wall between terminals of different phases, and there is a risk of the screw protruding beyond the height of the partition wall as the screw is loosened. There was a risk of short circuit between different phases, or short circuit between different phases due to electric wires and screws when inserting and removing electric wires from the terminal block.

そこで、例えば特許文献１には、端子台を側面から挟むことができる挟持部と、端子間の界壁に対向できる絶縁性の歯部とを備える短絡防止具が提案されている。 Therefore, for example, Patent Document 1 proposes a short-circuit prevention tool including a sandwiching portion that can sandwich the terminal block from the side surface and an insulating tooth portion that can face the field wall between the terminals.

特開２０１７−０２０９７８JP, 2017-020978, A

しかしながら、上記従来の特許文献１のものは、定格電流の異なる（すなわち、端子配置あるいは計器幅の異なる）電力量計に対してはそれぞれ専用品を設計する必要があった。 However, in the above-mentioned conventional patent document 1, it is necessary to design dedicated products for watt-hour meters having different rated currents (that is, different terminal arrangements or meter widths).

本発明は上記課題に鑑みてなされたものであり、その目的とするところは、電力量計に対する電線挿抜作業において電線固定用ネジまたは電線における異相間短絡を防止することができ、定格電流の異なる電力量計にも適用可能である短絡防止具を提供することにある。 The present invention has been made in view of the above problems, and an object thereof is to prevent a short circuit between different phases in a wire fixing screw or a wire in a wire insertion/removal work for a watt hour meter, and a different rated current. It is to provide a short-circuit prevention tool that can be applied to an electric energy meter.

本発明のうち請求項１に記載の短絡防止具は、電力量計の両側部を挟持する一対の挟持部材と、前記電力量計の両側部間の距離に応じて前記一対の挟持部材間の距離を調整する調整部材と、前記電力量計の隣接する異相の電線固定用ネジ間の仕切壁に対向する遮蔽部材とを備え、前記遮蔽部材は、前記電力量計の両側部間の距離方向に移動自在であることを特徴とする。 The short-circuit prevention tool according to claim 1 of the present invention includes a pair of sandwiching members for sandwiching both side portions of the watt hour meter, and a pair of sandwiching members depending on a distance between both side portions of the watt hour meter. An adjusting member for adjusting the distance and a shield member facing the partition wall between the electric wire fixing screws of adjacent different phases of the watthour meter are provided, and the shield member is a distance direction between both sides of the watthour meter. It is characterized by being freely movable to.

本発明のうち請求項２に記載の短絡防止具は、前記一対の挟持部材が前記電力量計の第一凹部に係合することで、短絡防止具の略鉛直方向の移動が規制されることを特徴とする。 In the short-circuit prevention tool according to claim 2 of the present invention, the pair of holding members are engaged with the first recesses of the watt-hour meter so that the movement of the short-circuit prevention tool in the substantially vertical direction is restricted. Is characterized by.

本発明のうち請求項３に記載の短絡防止具は、前記電力量計の第二凹部に係合することで短絡防止具の略鉛直方向の移動が規制される、起伏自在なずれ止め部材を備えることを特徴とする。 The short-circuit prevention tool according to claim 3 of the present invention is an up-and-down shift preventive member for restricting movement of the short-circuit prevention tool in a substantially vertical direction by engaging with the second recess of the watt-hour meter. It is characterized by being provided.

本発明のうち請求項４に記載の短絡防止具は、前記電力量計の端子台の下端部に対向する隔壁を有することを特徴とする。 The short circuit preventer according to claim 4 of the present invention has a partition wall facing the lower end of the terminal block of the watthour meter.

請求項１に記載の発明によれば、短絡防止具が電力量計の両側部を挟持する一対の挟持部材と、一対の挟持部材間の距離を調整する調整部材と、電力量計の隣接する異相の電線固定用ネジ間の仕切壁に対向する遮蔽部材とを備え、遮蔽部材が、電力量計の両側部間の距離方向に移動自在であるので、挟持部材は両側部間の幅の異なる電力量計を挟持でき、また、遮蔽部材は端子配置の異なる電力量計においても、隣接する異相の電線固定用ネジ間の仕切壁に対向することができる。すなわち、定格電流の異なる電力量計に対する電線挿抜作業において、それぞれ専用品を必要とせず一台の短絡防止具で電線固定用ネジまたは電線における異相間短絡を防止できる。また、挟持部材が電力量計の両側部を挟持しているので、電力量計の両側部間の距離方向及び電力量計の奥行方向の短絡防止具のずれを防止できる。 According to the invention as set forth in claim 1, the short-circuit preventive device adjoins the pair of clamping members for clamping both sides of the watthour meter, the adjusting member for adjusting the distance between the pair of clamping members, and the watthour meter. Since the shielding member is provided with a shielding member facing the partition wall between the screws for fixing electric wires of different phases, and the shielding member is movable in the distance direction between both sides of the watt-hour meter, the sandwiching members have different widths between both sides. The watt-hour meter can be sandwiched, and the shielding member can face the partition wall between the electric wire fixing screws of different phases adjacent to each other even in the watt-hour meter having different terminal arrangements. That is, in the wire insertion/removal work with respect to the watt-hour meters having different rated currents, it is possible to prevent a short-circuit between different phases in the wire fixing screw or the wire with a single short-circuit preventive tool without requiring dedicated products. Further, since the sandwiching member sandwiches both side portions of the watt hour meter, it is possible to prevent the short circuit preventive tool from being displaced in the distance direction between both side portions of the watt hour meter and in the depth direction of the watt hour meter.

請求項２に記載の発明によれば、前記一対の挟持部材が前記電力量計の第一凹部に係合することで、短絡防止具の略鉛直方向の動きが規制されるので、電力量計に対する短絡防止具の略鉛直方向のずれや脱落を防止できる。 According to the invention as set forth in claim 2, since the pair of sandwiching members engage with the first concave portion of the watt-hour meter, the movement of the short-circuit prevention tool in the substantially vertical direction is restricted. It is possible to prevent the short circuit prevention tool from being displaced or dropped in the substantially vertical direction.

請求項３に記載の発明によれば、短絡防止具が、電力量計の第二凹部に係合することで短絡防止具の略鉛直方向の動きが規制される、起伏自在なずれ止め部材を備えていることで、電力量計に対する短絡防止具の略鉛直方向のずれや脱落を防止できる。 According to the invention as set forth in claim 3, the short-circuit prevention tool engages with the second recess of the watt-hour meter to restrict the movement of the short-circuit prevention tool in the substantially vertical direction. With the provision, it is possible to prevent the short-circuit prevention tool from slipping or falling off in the substantially vertical direction with respect to the watt-hour meter.

請求項４に記載の発明によれば、短絡防止具が、電力量計の端子台の下端部に対向する隔壁を有していることで、電線を電力量計の挿通孔に下方から挿入する際に、電線が端子台の前方へ入り込むことができないので、電線の導体部が電線固定用ネジに接触することによる異相間短絡を防止できる。 According to the invention described in claim 4, the short-circuit prevention tool has the partition wall facing the lower end portion of the terminal block of the watt-hour meter, so that the electric wire is inserted into the insertion hole of the watt-hour meter from below. At this time, since the electric wire cannot enter the front of the terminal block, it is possible to prevent a short circuit between different phases due to the conductor portion of the electric wire coming into contact with the screw for fixing the electric wire.

定格電流３０Ａの電力量計に取り付けた短絡防止具の、（ａ）前側上方から、（ｂ）前側下方から見た斜視図である。It is the perspective view which looked at the short circuit prevention tool attached to the electric power meter of 30 A of rated currents from the upper side of (a) front side, and (b) the lower side of front side. 定格電流３０Ａの電力量計に取り付けられる、ずれ止め部材が起立した状態の短絡防止具の、（ａ）平面図、（ｂ）正面図、（ｃ）側面図である。It is a (a) top view, a (b) front view, and a (c) side view of a short circuit preventive tool in the state where the anti-misalignment member stood attached to the watt-hour meter of rated current 30A. 定格電流３０Ａの電力量計に取り付けられる、ずれ止め部材が伏した状態の短絡防止具の、（ａ）平面図、（ｂ）正面図、（ｃ）側面図である。It is a (a) top view, a (b) front view, and a (c) side view of a short circuit preventive tool in a state where a slip prevention member was attached to a watt-hour meter with a rated current of 30A. 定格電流３０Ａの電力量計に取り付けられる、ずれ止め部材が起立した状態の短絡防止具の（ａ）前側上方から、（ｂ）後側上方から見た斜視図である。It is the perspective view seen from (a) front side upper part of the short-circuit prevention tool in the state where the anti-misalignment member stood attached to the watt-hour meter of rated current 30A, and (b) rear side upper part. 定格電流３０Ａの電力量計に取り付けられる、ずれ止め部材が伏した状態の短絡防止具の（ａ）前側上方から、（ｂ）後側上方から見た斜視図である。It is the perspective view seen from (a) front side upper part of the short-circuit prevention tool in the state where the slip prevention member was attached|attached to the electric energy meter of 30 A of rated currents, and (b) rear side upper part. 定格電流６０Ａの電力量計に取り付けた短絡防止具の、（ａ）前側上方から、（ｂ）前側下方から見た斜視図である。It is the perspective view which looked at the short circuit prevention tool attached to the electric power meter of 60 A of rated currents from the upper side of (a) front side, and the lower side of (b) front side. 定格電流６０Ａの電力量計に取り付けられる、ずれ止め部材が起立した状態の短絡防止具の（ａ）前側上方から、（ｂ）後側上方から見た斜視図である。It is the perspective view seen from (a) front side upper part of the short-circuit prevention tool in the state where the shift prevention member was erected attached to the watt-hour meter of rated current 60A, and (b) rear side upper part. 定格電流１２０Ａの電力量計に取り付けた短絡防止具の、（ａ）前側上方から、（ｂ）前側下方から見た斜視図である。It is the perspective view which looked at the short circuit prevention tool attached to the watt-hour meter of 120 A of rated currents from the upper side of (a) front side, and the lower side of (b) front side. 定格電流１２０Ａの電力量計に取り付けられる、ずれ止め部材が起立した状態の短絡防止具の（ａ）前側上方から、（ｂ）後側上方から見た斜視図である。It is the perspective view seen from (a) front side upper part of the short circuit preventive tool in the state where the shift prevention member was erected, which was attached to the watt-hour meter of rated current 120A, and was seen from (b) rear side upper part. 定格電流が（ａ）は１２０Ａ，（ｂ）は３０Ａ，（ｃ）は６０Ａの電力量計に取り付けた短絡防止具を下方から見た斜視図である。It is the perspective view which looked at the short circuit prevention tool attached to the electric energy meter whose rated current is (A) 120A, (b) 30A, and (C) 60A from the lower side. 定格電流が（ａ）及び（ｂ）は３０Ａ，（ｃ）及び（ｄ）は６０Ａ，（ｅ）及び（ｆ）は１２０Ａの電力量計の概形を示す正面図及び側面図である。It is the front view and side view which show the outline of a watt-hour meter whose rated current is (A) and (b) 30A, (c) and (d) 60A, (e) and (f) 120A.

以下、本発明の実施の形態を図面に基づいて説明する。以下の好ましい実施形態の説明は例示に過ぎず、本発明、その適用物あるいはその用途を制限することを意図するものではない。ここでは、本発明の短絡防止具３が電力量計１の端子台１０に対し、正面から取り付けられる場合を示す。図１は、定格電流３０Ａの電力量計１に取付けた短絡防止具３の、（ａ）電力量計１から電線を取り外した状態において前側上方から見た斜視図、（ｂ）電力量計１に対し電線が取り付けられた状態において前側下方から見た斜視図である。図２は、定格電流３０Ａの電力量計１に取り付けられる、ずれ止め部材３１２が起立した状態の短絡防止具３の、（ａ）平面図、（ｂ）正面図、（ｃ）側面図である。図３は、定格電流３０Ａの電力量計１に取り付けられる、ずれ止め部材３１２が伏した状態の短絡防止具３の、（ａ）平面図、（ｂ）正面図、（ｃ）側面図である。図４は、定格電流３０Ａの電力量計１に取り付けられる、ずれ止め部材３１２が起立した状態の短絡防止具３の（ａ）前側上方から、（ｂ）後側上方から見た斜視図である。図５は、定格電流３０Ａの電力量計１に取り付けられる、ずれ止め部材３１２が伏した状態の短絡防止具３の（ａ）前側上方から、（ｂ）後側上方から見た斜視図である。図６は、定格電流６０Ａの電力量計１に取り付けた短絡防止具３の、（ａ）電力量計１から電線を取り外した状態において前側上方から見た斜視図、（ｂ）電力量計１に対し電線が取り付けられた状態において前側下方から見た斜視図である。図７は、定格電流６０Ａの電力量計１に取り付けられる、ずれ止め部材３１２が起立した状態の短絡防止具３の（ａ）前側上方から、（ｂ）後側上方から見た斜視図である。図８は、定格電流１２０Ａの電力量計１に取り付けた短絡防止具３の、（ａ）電力量計１から電線を取り外した状態において前側上方から見た斜視図、（ｂ）電力量計１に対し電線が取り付けられた状態において前側下方から見た斜視図である。図９は、定格電流１２０Ａの電力量計１に取り付けられる、ずれ止め部材３１２が起立した状態の短絡防止具３の（ａ）前側上方から、（ｂ）後側上方から見た斜視図である。図１０は、定格電流が（ａ）は１２０Ａ，（ｂ）は３０Ａ，（ｃ）は６０Ａの電力量計１に取り付けた短絡防止具３を下方から見た斜視図である。図１１は、定格電流が（ａ）及び（ｂ）は３０Ａ，（ｃ）及び（ｄ）は６０Ａ，（ｅ）及び（ｆ）は１２０Ａの電力量計１の概形を示す正面図及び側面図である。なお、以下の説明において前後方向及び左右方向とは、図１、図６及び図８に示す通りとする。 Embodiments of the present invention will be described below with reference to the drawings. The following description of the preferred embodiments is merely an example, and is not intended to limit the present invention, its application, or its use. Here, the case where the short-circuit prevention tool 3 of the present invention is attached to the terminal block 10 of the watt-hour meter 1 from the front is shown. FIG. 1 is a perspective view of a short-circuit preventive tool 3 attached to a watt-hour meter 1 having a rated current of 30 A as seen from the upper front side in a state in which an electric wire is removed from the watt-hour meter 1, (b) watt-hour meter 1 4 is a perspective view seen from the lower front side in a state in which an electric wire is attached. FIG. 2 is a (a) plan view, a (b) front view, and a (c) side view of the short-circuit preventive tool 3 attached to the watt-hour meter 1 having a rated current of 30 A and in which the shift preventing member 312 is erected. .. FIG. 3 is a plan view (a), a front view (b), and a side view (c) of the short-circuit prevention tool 3 attached to the watt-hour meter 1 having a rated current of 30 A and in which the shift preventing member 312 is down. .. FIG. 4 is a perspective view of the short-circuit preventive tool 3 attached to the watt-hour meter 1 having a rated current of 30 A, in which the shift-preventing member 312 is upright, as viewed from above (a) front side and (b) above rear side. .. FIG. 5 is a perspective view of the short-circuit prevention tool 3 attached to the watt-hour meter 1 having a rated current of 30 A, in which the anti-misalignment member 312 is down, as viewed from above (a) front side and from above (b) rear side. .. FIG. 6 is a perspective view of the short-circuit prevention tool 3 attached to the watt-hour meter 1 having a rated current of 60 A as seen from the front upper side in a state where the electric wire is removed from the watt-hour meter 1, (b) the watt-hour meter 1 4 is a perspective view seen from the lower front side in a state in which an electric wire is attached. FIG. 7 is a perspective view of the short-circuit prevention tool 3 attached to the watt-hour meter 1 having a rated current of 60 A, in which the anti-misalignment member 312 is erected, as viewed from above (a) front side and from above (b) rear side. .. FIG. 8 is a perspective view of the short-circuit prevention tool 3 attached to the watt-hour meter 1 having a rated current of 120 A, viewed from the upper front side in the state in which the electric wire is removed from the watt-hour meter 1, (b) the watt-hour meter 1 4 is a perspective view seen from the lower front side in a state in which an electric wire is attached. FIG. 9 is a perspective view of the short-circuit prevention tool 3 attached to the watt-hour meter 1 having a rated current of 120 A, in which the anti-misalignment member 312 is erected, as viewed from above (a) front side and from above (b) rear side. .. FIG. 10 is a perspective view of the short-circuit prevention tool 3 attached to the watt-hour meter 1 having a rated current (a) of 120 A, (b) of 30 A, and (c) of 60 A as viewed from below. FIG. 11 is a front view and a side view showing an outline of the watt-hour meter 1 having rated currents (a) and (b) of 30 A, (c) and (d) of 60 A, and (e) and (f) of 120 A. It is a figure. In the following description, the front-rear direction and the left-right direction are as shown in FIGS. 1, 6 and 8.

図１１（ａ），（ｃ），（ｅ）に示すように、電力量計１は、その下端部において端子台１０を有している。定格電流３０Ａの電力量計１は４つの端子部１１を有し、定格電流６０Ａの電力量計１及び定格電流１２０Ａの電力量計１は６つの端子部１１を有していて、それぞれ端子部１１の配置間隔が異なっている。
定格電流３０Ａの場合、図１（ｂ）に示すように、左右方向に間隔を空けて並ぶ４本の電線２ａ〜２ｄはそれぞれ、複数の導電性の線材が撚り合わされた導体部（図示しない）と、導体部を被覆する絶縁性の被覆２２とを有していて、導体部の上端部は電力量計１下面の挿通孔１６から端子台１０内部へと挿入された後、電線固定用ネジ１２によって端子部１１に固定される。電線２ａ及び２ｄ，２ｂ及び２ｃにはそれぞれ同相の電圧が供給されている。隣接する電線固定用ネジ１２の間には仕切壁１３が設けられているが、仕切壁１３の高さは、電線固定用ネジ１２を緩めたときに電線固定用ネジ１２の頭部が仕切壁１３の前端面から突出する高さである。また、定格電流６０Ａの場合は、図６（ｂ）に示すように、６本の電線２ｅ〜ｊのうち、電線２ｅ及び２ｊ，２ｆ及び２ｉ，２ｇ及び２ｈにはそれぞれ同相の電圧が供給されている。そして同様に、定格電流１２０Ａの場合は図８（ｂ）に示すように、６本の電線２ｋ〜２ｐのうち、電線２ｋ及び２ｐ，２ｌ及び２ｏ，２ｍ及び２ｎにはそれぞれ同相の電圧が供給されている。
電力量計１の形状については、定格電流３０Ａの場合は、端子台１０の略中央部において、略直方体状の凹部（第二凹部）１５を有している。定格電流６０Ａ及び１２０Ａの場合は、端子台１０の両側部に略直方体状の切欠部（第一凹部）１４を有している。 As shown in FIGS. 11A, 11</b>C, and 11</b>E, the watt-hour meter 1 has a terminal block 10 at its lower end. The watt-hour meter 1 having a rated current of 30 A has four terminal portions 11, and the watt-hour meter 1 having a rated current of 60 A and the watt-hour meter 1 having a rated current of 120 A have six terminal portions 11, each of which has a terminal portion. The arrangement intervals of 11 are different.
In the case of the rated current of 30 A, as shown in FIG. 1B, each of the four electric wires 2a to 2d arranged side by side in the left-right direction is a conductor portion (not shown) in which a plurality of conductive wires are twisted together. And an insulating coating 22 for covering the conductor portion, and the upper end portion of the conductor portion is inserted into the terminal block 10 through the insertion hole 16 on the lower surface of the watt-hour meter 1 and then the wire fixing screw is provided. It is fixed to the terminal portion 11 by 12. In-phase voltages are supplied to the electric wires 2a and 2d, 2b and 2c, respectively. A partition wall 13 is provided between adjacent electric wire fixing screws 12, but the height of the partition wall 13 is such that when the electric wire fixing screw 12 is loosened, the head of the electric wire fixing screw 12 is a partition wall. 13 is a height protruding from the front end surface of 13. Further, in the case of the rated current of 60 A, as shown in FIG. 6B, the in-phase voltage is supplied to the electric wires 2e and 2j, 2f and 2i, 2g and 2h among the six electric wires 2e to j. ing. Similarly, in the case of the rated current of 120 A, as shown in FIG. 8B, among the six electric wires 2k to 2p, the same phase voltage is supplied to the electric wires 2k and 2p, 2l and 2o, 2m and 2n, respectively. Has been done.
Regarding the shape of the watt-hour meter 1, when the rated current is 30 A, the terminal block 10 has a substantially rectangular parallelepiped recess (second recess) 15. For rated currents of 60 A and 120 A, the rectangular parallelepiped notch (first recess) 14 is provided on both sides of the terminal block 10.

短絡防止具３は、図１乃至図１０に示すように、本体部３１と、電力量計１の両側部を挟持する一対の挟持部材３３，３３と、本体部３１から引き出される量により電力量計１の幅に応じて挟持部材３３，３３間の距離を調整する調整部材３２と、電力量計１の隣接する異相の電線固定用ネジ１２間の仕切壁１３に対向する、２つの遮蔽部材３４，３４を備えている。 As shown in FIG. 1 to FIG. 10, the short-circuit prevention tool 3 includes a main body portion 31, a pair of holding members 33, 33 for holding both side portions of the watt hour meter 1, and an amount of electric power drawn from the main body portion 31. An adjusting member 32 that adjusts the distance between the sandwiching members 33, 33 according to the width of the total 1 and two shield members that face the partition wall 13 between the electric wire fixing screws 12 of the different phases of the electric energy meter 1 that are adjacent to each other. 34, 34 are provided.

本体部３１は、端子台１０の電線固定用ネジ１２の上方、すなわち端子台の上端部付近に対向する上辺部３１０と、端子台１０の電線固定用ネジ１２の下方、すなわち端子台の下端部付近に対向する下辺部（隔壁）３１７と、上辺部３１０と下辺部３１７それぞれの右端を略コの字状に連結する連結部３１８から構成されていて、ポリカーボネイト等の絶縁性及び耐久性の高い材質で形成されていることが好ましい。上辺部３１０の左右方向略中央部には、定格電流３０Ａの電力量計１の凹部１５に係合する起伏可能なずれ止め部材３１２が設けられている。ずれ止め部材３１２は、略平板状のアーム部３１３と係合部３１４がそれぞれの一端において略直角に連結された形状であり、アーム部３１３の他端は上辺部３１０の左右方向略中央部において、上下方向に起伏可能に軸支されている。ずれ止め部材３１２が伏した状態において、係合部３１４は、定格電流３０Ａの電力量計１の凹部１５に挿入された状態となり、これにより、短絡防止具３の上下方向の移動が規制される。ずれ止め部材３１２が起立した状態において、下辺部３１７の下面には、後方へと水平に伸びて形成された凸部３１７ａが設けられている。図１０に示すように、凸部３１７ａの後端面と端子台１０下端部の前端面は略面一であり、また、下辺部３１７の左右両端部の後面と端子台１０下端部との隙間Ｇ１の前後径は、電線２ａ〜２ｐの外径よりも狭い。上辺部３１０と下辺部３１７には、調整部材３２を挿通するための、左端において開口した中空部３１０ａ，３１７ｂが長手方向に沿って設けられている。 The main body portion 31 includes an upper side portion 310 facing above the electric wire fixing screw 12 of the terminal block 10, that is, near the upper end portion of the terminal block, and below the electric wire fixing screw 12 of the terminal block 10, that is, a lower end portion of the terminal block. It is composed of a lower side portion (partition wall) 317 facing in the vicinity and a connecting portion 318 that connects the right ends of the upper side portion 310 and the lower side portion 317 in a substantially U shape, and has high insulation and durability such as polycarbonate. It is preferably made of a material. At a substantially central portion in the left-right direction of the upper side portion 310, an undulating shift preventing member 312 that engages with the concave portion 15 of the watt-hour meter 1 having a rated current of 30 A is provided. The shift preventing member 312 has a shape in which a substantially flat plate-shaped arm portion 313 and an engaging portion 314 are connected to each other at substantially right angles, and the other end of the arm portion 313 is substantially at the center in the left-right direction of the upper side portion 310. , Is rotatably supported up and down. In the state in which the shift prevention member 312 is down, the engagement portion 314 is in a state of being inserted into the recessed portion 15 of the watt-hour meter 1 having a rated current of 30 A, whereby the vertical movement of the short-circuit prevention tool 3 is restricted. .. In the state in which the shift preventing member 312 is erected, the lower surface of the lower side portion 317 is provided with a convex portion 317a that extends horizontally toward the rear. As shown in FIG. 10, the rear end surface of the convex portion 317a and the front end surface of the lower end portion of the terminal block 10 are substantially flush with each other, and a gap G1 between the rear surface of the left and right end portions of the lower side portion 317 and the lower end portion of the terminal block 10 is formed. The front and rear diameters of are smaller than the outer diameters of the electric wires 2a to 2p. Hollow portions 310a and 317b opened at the left end for inserting the adjusting member 32 are provided in the upper side portion 310 and the lower side portion 317 along the longitudinal direction.

調整部材３２は、ポリカーボネイト等の耐久性の高い材質で形成されていることが好ましく、本体部３１の上辺部３１０及び下辺部３１７の中空部３１０ａ，３１７ｂにそれぞれ摺動可能に挿通されている上アーム３２０及び下アーム（隔壁）３２１と、それらの左端部間に連結されている調整バー３２２とを有しており、本体部３１から引き出し自在に設けられている。図１０に示すように、下アーム３２１の後端面と端子台１０下端部との隙間Ｇ２の前後径は、電線２ａ〜２ｐの外径よりも狭い。そして、本体部３１の上辺部３１０の前面左端には調整部材固定ネジ３１１が設けられており、調整部材固定ネジ３１１を締結することで、本体部３１に対する調整部材３２の位置が固定される。また、図６及び図８に示すように、調整部材３２，上アーム３２０及び下アーム３２１の前面には、各電力量計１に対応する調整部材３２の位置を示す目印線３２３が表示されている。これにより、作業者が調整部材３２の位置を迷いなく設定でき、作業性が向上する。 The adjusting member 32 is preferably formed of a highly durable material such as polycarbonate, and is slidably inserted into the hollow portions 310a and 317b of the upper side portion 310 and the lower side portion 317 of the main body 31, respectively. It has an arm 320 and a lower arm (partition wall) 321, and an adjustment bar 322 connected between the left end portions thereof, and is provided so as to be freely drawn from the main body portion 31. As shown in FIG. 10, the front-rear diameter of the gap G2 between the rear end surface of the lower arm 321 and the lower end of the terminal block 10 is smaller than the outer diameters of the electric wires 2a to 2p. An adjusting member fixing screw 311 is provided on the front left end of the upper side portion 310 of the main body 31, and the position of the adjusting member 32 with respect to the main body 31 is fixed by fastening the adjusting member fixing screw 311. Further, as shown in FIGS. 6 and 8, on the front surfaces of the adjusting member 32, the upper arm 320, and the lower arm 321, a mark line 323 indicating the position of the adjusting member 32 corresponding to each watt hour meter 1 is displayed. There is. Thereby, the operator can set the position of the adjusting member 32 without hesitation, and the workability is improved.

本体部３１の連結部３１８及び調整バー３２２の背面においては、電力量計１の両側部を挟持するための挟持部材３３，３３が、それぞれ同じ高さに位置する軸部において回転可能に軸支されていて、電力量計１の種類に応じて回転させた状態で用いられる。挟持部材３３は略直方体形状であり、ゴム等の摩擦係数の大きい材質で形成されていることが好ましい。挟持部材３３の軸部を挟んで一方側の係合部３３１の高さｈ１と他方側の係合部３３２の高さｈ２、及びそれぞれの位置は、それぞれ定格電流６０Ａ，１２０Ａの電力量計１の切欠部１４に嵌まり込む寸法及び位置となっている。また、挟持部材３３は、定格電流３０Ａの電力量計１の両側面に当接する当接面３３３を有する。そして、本体部３１及び調整部材３２の前面には、図１，図６及び図８に示すように、各電力量計１に対応する挟持部材３３の上下端の位置を示す目印線３１９，３２４が表示されている。これにより、作業者が挟持部材３３の向きを迷いなく設定でき、作業性が向上する。 On the back surfaces of the connecting portion 318 of the main body 31 and the adjusting bar 322, holding members 33, 33 for holding both sides of the watt-hour meter 1 are rotatably supported by shafts located at the same height. The electric power meter 1 is used in a rotated state according to the type. The sandwiching member 33 has a substantially rectangular parallelepiped shape, and is preferably formed of a material having a large friction coefficient such as rubber. The height h1 of the engaging portion 331 on the one side and the height h2 of the engaging portion 332 on the other side with respect to the shaft portion of the holding member 33, and the respective positions, are the watt hour meter 1 of rated currents 60A and 120A, respectively. The size and position are such that they fit into the notch portion 14. Further, the sandwiching member 33 has contact surfaces 333 that contact both side surfaces of the watthour meter 1 having a rated current of 30A. Then, on the front surfaces of the main body 31 and the adjusting member 32, as shown in FIGS. 1, 6 and 8, mark lines 319, 324 indicating the positions of the upper and lower ends of the sandwiching member 33 corresponding to each watt hour meter 1. Is displayed. Thereby, the operator can set the orientation of the holding member 33 without hesitation, and the workability is improved.

本体部３１の上辺部３１０と下辺部３１７の間には、左右に摺動可能な絶縁性の遮蔽部材３４，３４が計２つ設けられている。遮蔽部材３４は、４枚の略長方形状の板体３４ａ〜３４ｄによって上下左右を枠組みされた形状であり、左右の板体３４ｂ及び３４ｃの後端は端子台１０の仕切壁１３の前面に略当接していて、前端は電線固定用ネジ１２を緩めた際にも電線固定用ネジ１２の頭が前方に突出しない程度である。上面及び下面の板体３４ａ及び３４ｄは、それぞれ上辺部３１０と下辺部３１７に摺動可能に連結されている。これにより、左右の板体３４ｂ及び３４ｃは、互いの間隔を保ったまま、電力量計１の種類（つまり端子部１１の配置）に応じて隣接する異相の電線固定用ネジ１２の間の仕切壁１３に対向する位置へと移動させた状態で用いられる。なお、上面の板体３４ａの略中央部には略円形の貫通孔３４１が設けられていて、各電力量計１の異相の電線固定用ネジ１２の間の仕切壁１３に対向する位置において、上辺部３１０の下面に設けられたボールプランジャ３１６に係合することで、遮蔽部材３４，３４の位置決めが容易になされ、かつ、遮蔽部材３４，３４は左右方向に一定以上の外力が働かなければ左右に動くことがない。また、図１，図６及び図８に示すように、本体部３１の前面には、各電力量計１に対応する遮蔽部材３４，３４の位置を示す目印線３１５が表示されている。これにより、作業者が遮蔽部材３４，３４の位置を迷いなく設定でき、作業性が向上する。 Between the upper side portion 310 and the lower side portion 317 of the main body portion 31, there are provided a total of two insulating shield members 34, 34 that are slidable left and right. The shielding member 34 has a shape framed in the vertical and horizontal directions by four substantially rectangular plate members 34 a to 34 d, and the rear ends of the left and right plate members 34 b and 34 c are substantially in front of the partition wall 13 of the terminal block 10. The front end is such that the head of the wire fixing screw 12 does not project forward even when the wire fixing screw 12 is loosened. The plate bodies 34a and 34d on the upper surface and the lower surface are slidably connected to the upper side portion 310 and the lower side portion 317, respectively. As a result, the left and right plate bodies 34b and 34c are separated from each other between the adjacent wire fixing screws 12 of different phases according to the type of the watt-hour meter 1 (that is, the arrangement of the terminal portion 11) while keeping the space between them. It is used after being moved to a position facing the wall 13. In addition, a substantially circular through hole 341 is provided in a substantially central portion of the plate body 34a on the upper surface, and at a position facing the partition wall 13 between the different-phase electric wire fixing screws 12 of each watthour meter 1, By engaging with the ball plunger 316 provided on the lower surface of the upper side portion 310, the shielding members 34, 34 can be easily positioned, and the shielding members 34, 34 must be subjected to an external force above a certain level in the left-right direction. Does not move left or right. Further, as shown in FIGS. 1, 6 and 8, on the front surface of the main body portion 31, mark lines 315 indicating the positions of the shielding members 34, 34 corresponding to the watt-hour meters 1 are displayed. As a result, the operator can set the positions of the shielding members 34, 34 without hesitation, and the workability is improved.

次に、本発明の短絡防止具３を用いた電力量計１の交換作業の方法及び、本発明の作用効果について説明する。まずは、定格電流３０Ａの電力量計１の交換方法について述べる。
交換作業の準備として、まず、調整部材３２を左右に摺動させることで、図１に示す本体部３１から引き出されていない位置へと動かした後、調整部材固定ネジ３１１を締めることにより、本体部３１に対する調整部材３２の位置を固定する。次に、挟持部材３３が図５に示す向きとなるよう回転させる。このとき、挟持部材３３，３３の当接面３３３，３３３間の距離は、電力量計１の両側部間の距離よりも僅かに短くなっている。これにより、短絡防止具３を電力量計１へ取り付ける際には、挟持部材３３を電力量計１に対しその両側部を挟む状態まで押し込むことで、挟持部材３３が、その弾性によって電力量計１の両側部を強固に挟み込み互いに固定された状態とすることができる。そして、２つの遮蔽部材３４，３４を目印線に従って図１に示す位置まで摺動させ、ボールプランジャ３１６で位置決めする。以上で準備が完了する。
次に、電線２ａ〜２ｄから取り外す対象の電力量計１に対し、前方から挟持部材３３を電力量計１の両側部を挟んだ状態まで押し込むことで、挟持部材３３がその弾性によって電力量計１の両側部を強固に挟み込んだ状態とする。以上で電力量計１への短絡防止具３の装着が完了し、あとはドライバーを用いて電線固定用ネジ１２を緩め、電線２ａ〜２ｄを取り外せばよい。このとき、電線固定用ネジ１２の頭は遮蔽部材３４，３４の前面よりも前側に露出することがない。そして、新しい電力量計１を電線２ａ〜２ｄに取り付ける際には、以上と同様にして短絡防止具３を取り付けた電力量計１に対し、電線２ａ〜２ｄを端子付近まで挿入し、電線固定用ネジ１２で締結固定すればよい。
次いで、定格電流６０Ａの電力量計１の交換方法について述べる。基本的な方法は上記の定格電流３０Ａの電力量計１に対するものと同じであるが、以下の点で相違する。図６及び図７に示すように、ずれ止め部材３１２は使用しないため、交換作業の準備段階から完了まで起立した状態としておく。準備段階において、調整部材３２は、６０Ａの目印線３２３まで引き出した状態で調整部材固定ネジ３１１により固定する。また挟持部材３３は軸部３３０が上側となるように回転させておく。このとき、挟持部材３３，３３の係合部３３１，３３１間の距離は、電力量計１の切欠部１４，１４間の距離よりも僅かに短くなっている。これにより、短絡防止具３を電力量計１へ取り付ける際には、挟持部材３３の係合部３３１，３３１を電力量計１に対しその両側部を挟んだ状態まで押し込むことで、挟持部材３３が、その弾性によって電力量計１の両側部を強固に挟み込み互いに固定された状態とすることができる。
また、定格電流１２０Ａの電力量計１については、図８及び図９に示すように、ずれ止め部材３１２は使用しないため、交換作業の準備段階から完了まで起立した状態としておく。準備段階において、調整部材３２は、１２０Ａの目印線３２３まで引き出した状態で調整部材固定ネジ３１１により固定する。また挟持部材３３は軸が下側となるように回転させておく。このとき、挟持部材３３，３３の係合部３３２，３３２間の距離は、電力量計１の切欠部１４，１４間の距離よりも僅かに短くなっている。これにより、短絡防止具３を電力量計１へ取り付ける際には、挟持部材３３の係合部３３２，３３２を電力量計１に対しその両側部を挟んだ状態まで押し込むことで、挟持部材３３が、その弾性によって電力量計１の両側部を強固に挟み込み互いに固定された状態とすることができる。 Next, a method for replacing the watt-hour meter 1 using the short-circuit prevention tool 3 of the present invention and the function and effect of the present invention will be described. First, a method of replacing the watt-hour meter 1 having a rated current of 30 A will be described.
As a preparation for the replacement work, first, the adjustment member 32 is slid to the left and right to move the adjustment member 32 to a position where it is not pulled out from the main body portion 31 shown in FIG. 1, and then the adjustment member fixing screw 311 is tightened. The position of the adjusting member 32 with respect to the portion 31 is fixed. Next, the holding member 33 is rotated so as to be in the direction shown in FIG. At this time, the distance between the contact surfaces 333, 333 of the sandwiching members 33, 33 is slightly shorter than the distance between both sides of the watthour meter 1. Thus, when the short-circuit prevention tool 3 is attached to the watt-hour meter 1, the holding member 33 is pushed into the watt-hour meter 1 until both sides thereof are held, so that the holding member 33 is elastic. Both side portions of 1 can be firmly sandwiched and fixed to each other. Then, the two shielding members 34, 34 are slid to the position shown in FIG. 1 along the marking lines, and the ball plunger 316 positions them. The preparation is complete.
Next, the clamping member 33 is pushed into the electric power meter 1 to be removed from the electric wires 2a to 2d from the front until the both sides of the electric energy meter 1 are sandwiched, so that the elastic force of the clamping member 33 causes the electric power meter to operate. Both sides of 1 are firmly sandwiched. With the above, the mounting of the short-circuit prevention tool 3 on the watt-hour meter 1 is completed, and then the screw 12 for fixing the electric wire may be loosened using a screwdriver to remove the electric wires 2a to 2d. At this time, the head of the wire fixing screw 12 is not exposed to the front side of the front surface of the shielding members 34, 34. When attaching the new watt-hour meter 1 to the electric wires 2a to 2d, insert the electric wires 2a to 2d into the vicinity of the terminals in the electric power meter 1 to which the short-circuit prevention tool 3 is attached in the same manner as above, and fix the electric wires. It suffices to fasten and fix with the screw 12 for use.
Next, a method for replacing the watt-hour meter 1 having a rated current of 60 A will be described. The basic method is the same as that for the watt-hour meter 1 having the rated current of 30 A described above, but is different in the following points. As shown in FIGS. 6 and 7, since the shift preventing member 312 is not used, it is kept upright from the preparation stage to the completion of the replacement work. In the preparation stage, the adjusting member 32 is fixed by the adjusting member fixing screw 311 while being pulled out to the mark line 323 of 60A. The holding member 33 is rotated so that the shaft portion 330 is on the upper side. At this time, the distance between the engaging portions 331 and 331 of the sandwiching members 33 and 33 is slightly shorter than the distance between the notches 14 and 14 of the watthour meter 1. Thus, when the short-circuit prevention tool 3 is attached to the watt-hour meter 1, the engaging portions 331 and 331 of the holding member 33 are pushed into the watt-hour meter 1 until both sides thereof are held, thereby holding the holding member 33. However, due to its elasticity, both sides of the watt-hour meter 1 can be firmly sandwiched and fixed to each other.
Further, as for the watt-hour meter 1 having a rated current of 120 A, as shown in FIGS. 8 and 9, since the shift prevention member 312 is not used, it is kept standing from the preparation stage to the completion of the replacement work. In the preparation stage, the adjusting member 32 is fixed by the adjusting member fixing screw 311 while being pulled out to the mark line 323 of 120A. Further, the holding member 33 is rotated so that the shaft is on the lower side. At this time, the distance between the engaging portions 332 and 332 of the sandwiching members 33 and 33 is slightly shorter than the distance between the notches 14 and 14 of the watthour meter 1. Thus, when the short-circuit prevention tool 3 is attached to the watt-hour meter 1, the engaging members 332 and 332 of the holding member 33 are pushed into the watt-hour meter 1 until both sides thereof are held, thereby holding the holding member 33. However, due to its elasticity, both sides of the watt-hour meter 1 can be firmly sandwiched and fixed to each other.

このように構成した短絡防止具３によれば、電力量計１の両側部を挟持する一対の挟持部材３３と、一対の挟持部材３３間の距離を調整する調整部材３２と、電力量計１の隣接する異相の電線固定用ネジ１２間の仕切壁１３に対向する遮蔽部材３４，３４とを備え、遮蔽部材３４，３４が、電力量計１の両側部間の距離方向に移動自在であるので、挟持部材３３は両側部間の幅の異なる電力量計１を挟持でき、また、遮蔽部材３４，３４は端子配置の異なる電力量計１においても、隣接する異相の電線固定用ネジ１２間の仕切壁１３に対向することができる。すなわち、定格電流の異なる電力量計１に対する電線挿抜作業において、それぞれ専用品を必要とせず一台の短絡防止具３で電線固定用ネジ１２または電線２ａ〜２ｄ、２ｅ〜２ｊ、２ｋ〜２ｐにおける異相間短絡を防止できる。また、挟持部材３３が電力量計１の両側部を挟持しているので、電力量計１の両側部間の距離方向及び電力量計１の奥行方向の短絡防止具３のずれを防止できる。 According to the short-circuit prevention tool 3 configured in this way, the pair of clamping members 33 that clamps both sides of the watt-hour meter 1, the adjustment member 32 that adjusts the distance between the pair of clamping members 33, and the watt-hour meter 1 And shielding members 34, 34 facing the partition wall 13 between the adjacent electric wire fixing screws 12 of different phases, and the shielding members 34, 34 are movable in the distance direction between the both sides of the watt hour meter 1. Therefore, the sandwiching member 33 can sandwich the watt-hour meter 1 having different widths between the both sides, and the shielding members 34, 34 are provided between the adjacent wire fixing screws 12 of different phases even in the watt-hour meter 1 having different terminal arrangements. It can face the partition wall 13. That is, in the wire insertion/removal work for the watt-hour meters 1 having different rated currents, the wire fixing screw 12 or the wires 2a to 2d, 2e to 2j, and 2k to 2p are not required by the single short-circuit preventive tool 3 each requiring a dedicated product. Short circuit between different phases can be prevented. Further, since the sandwiching member 33 sandwiches both side portions of the watt-hour meter 1, it is possible to prevent the short circuit preventive tool 3 from being displaced in the distance direction between both side portions of the watt-hour meter 1 and in the depth direction of the watt-hour meter 1.

また、前記一対の挟持部材３３が前記電力量計１の切欠部１４に係合していること、または、電力量計１の凹部１５に係合することで短絡防止具３の略鉛直方向の動きが規制される起伏自在なずれ止め部材３１２を備えていることにより、短絡防止具３の略鉛直方向の動きが規制されるので、電力量計１に対する短絡防止具３の略鉛直方向のずれや脱落を防止できる。 Further, the pair of clamping members 33 are engaged with the cutout portion 14 of the watt-hour meter 1 or are engaged with the recessed portion 15 of the watt-hour meter 1 so that the short-circuit prevention tool 3 can move in a substantially vertical direction. Since the movement of the short-circuit prevention tool 3 in the substantially vertical direction is regulated by the provision of the up-and-down movable stopper member 312 whose movement is regulated, the short-circuit prevention tool 3 shifts in the substantially vertical direction with respect to the watt-hour meter 1. Can be prevented from falling off.

そして、凸部３１７ａの後端面と端子台１０下端部の前端面が略面一であり、また、下辺部３１７の左右両端部の後面と端子台１０下端部との隙間Ｇ１の前後径及び、下アーム３２１の後端面と端子台１０下端部との隙間Ｇ２の前後径が電線２ａ〜２ｐの外径よりも狭いため、電線２ａ〜２ｑを電力量計１の挿通孔１６に下方から挿入する際に、電線２ａ〜２ｑが端子台１０の前方の空間へと入り込むことができないので、電線の導体部が電線固定用ネジ１２に接触することによる異相間短絡を防止できる。 The rear end surface of the convex portion 317a and the front end surface of the lower end portion of the terminal block 10 are substantially flush with each other, and the front-rear diameter of the gap G1 between the rear surface of the left and right end portions of the lower side portion 317 and the lower end portion of the terminal block 10, and Since the front-back diameter of the gap G2 between the rear end surface of the lower arm 321 and the lower end of the terminal block 10 is smaller than the outer diameter of the electric wires 2a to 2p, the electric wires 2a to 2q are inserted into the insertion hole 16 of the watt-hour meter 1 from below. At this time, since the wires 2a to 2q cannot enter the space in front of the terminal block 10, it is possible to prevent a short circuit between different phases due to the conductor portion of the wire coming into contact with the wire fixing screw 12.

本発明は、上記の実施形態に限らず本発明の要旨を逸脱しない範囲で変形可能であり、短絡防止具の各部の形状、大きさ、厚さ等は適宜変更できる。例えば、遮蔽部材の形状は平板を組み合わせた形状でなくともよく、孔の開いた直方体状等、隣り合う電線の間を仕切ることのできる形状であればよい。 The present invention is not limited to the above-described embodiment and can be modified without departing from the gist of the present invention, and the shape, size, thickness and the like of each part of the short-circuit prevention tool can be appropriately changed. For example, the shape of the shielding member does not have to be a shape obtained by combining flat plates, and may be any shape that can partition adjacent electric wires, such as a rectangular parallelepiped shape with holes.

１電力量計
１２電線固定用ネジ
１３仕切壁
１４切欠部（第一凹部）
１５凹部（第二凹部）
３１２ずれ止め部材
３１７下辺部（隔壁）
３２調整部材
３２１下アーム（隔壁）
３３挟持部材
３４遮蔽部材 1 electricity meter
12 Screws for fixing electric wires
13 partition walls
14 Notch (first recess)
15 recess (second recess)
312 Locking member
317 Lower side (partition wall)
32 Adjustment member
321 Lower arm (partition wall)
33 Clamping member
34 Shielding member

本発明のうち請求項１に記載の短絡防止具は、電力量計の両側部を挟持する一対の挟持部材と、前記電力量計の両側部間の距離に応じて前記一対の挟持部材間の距離を調整する調整部材と、前記電力量計の隣接する異相の電線固定用ネジ間の仕切壁に対向する遮蔽部材とを備え、前記遮蔽部材は、前記電力量計の両側部間の距離方向に移動自在であり、前記調整部材には、各電力量計に対応する調整部材の位置を示す目印線が表示されてあることを特徴とする。

The short-circuit prevention tool according to claim 1 of the present invention includes a pair of sandwiching members for sandwiching both side portions of the watt hour meter, and a pair of sandwiching members depending on a distance between both side portions of the watt hour meter. An adjusting member for adjusting the distance and a shield member facing the partition wall between the electric wire fixing screws of adjacent different phases of the watthour meter are provided, and the shield member is a distance direction between both sides of the watthour meter. The adjustment member is marked with a mark line indicating the position of the adjustment member corresponding to each watt hour meter .

Claims

A pair of sandwiching members for sandwiching both side portions of the watt hour meter, an adjusting member for adjusting a distance between the pair of sandwiching members according to a distance between both side portions of the watt hour meter, and the watt hour meter adjacent to each other. A short-circuit prevention tool comprising: a shield member facing a partition wall between electric wire fixing screws of different phases, wherein the shield member is movable in a distance direction between both sides of the watt-hour meter.

The short-circuit prevention tool according to claim 1, wherein movement of the short-circuit prevention tool in a substantially vertical direction is restricted by engaging the pair of holding members with the first recess of the watt-hour meter.

The short-circuit prevention tool according to claim 1 or 2, further comprising: an up-and-down shift preventing member that restricts movement of the short-circuit prevention tool in a substantially vertical direction by engaging with the second recess of the watt-hour meter. ..

The short-circuit prevention tool according to claim 1, further comprising a partition wall facing a lower end portion of the terminal block of the watt-hour meter.