JPH0435965Y2

JPH0435965Y2 -

Info

Publication number: JPH0435965Y2
Application number: JP11369290U
Authority: JP
Priority date: 1990-10-29
Filing date: 1990-10-29
Publication date: 1992-08-25
Also published as: JPH0378352U

Description

【考案の詳細な説明】［考案の技術分野］本考案は、ケーブルの短絡時許容電流の値を容
易かつ迅速に知り得るケーブル選定用スライドル
ールに関する。[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a slide rule for cable selection that allows the value of the short-circuit allowable current of a cable to be easily and quickly known.

［考案の技術的背景とその問題点］一般に、短絡時許容電流は、ケーブル線路の接
地事故電流あるいは短絡電流に耐え得るケーブル
導体を選定するために検討される。かかるケーブ
ルの短絡時許容電流は、導体抵抗、導体の熱容
量、短絡前の導体温度、短絡時最高許容導体温度
及び短絡持続時間から計算で求めるか、あるいは
予め算出されたものを表の形にまとめた数表を使
用して求められる。[Technical background of the invention and its problems] In general, allowable short-circuit current is studied in order to select a cable conductor that can withstand the grounding fault current or short-circuit current of the cable line. The allowable short-circuit current of such cables can be calculated from the conductor resistance, heat capacity of the conductor, conductor temperature before short-circuit, maximum allowable conductor temperature during short-circuit, and short-circuit duration, or the previously calculated values can be summarized in the form of a table. It can be found using a table of numbers.

しかしながら、かかる計算や数表を使用しての
ケーブルの短絡時許容電流の選定は、現場での選
定には不便であるという難点があつた。 However, selecting the cable's allowable short-circuit current using such calculations and numerical tables has the disadvantage that it is inconvenient for selection on site.

［考案の目的］本考案は上記の事情に基づきなされたもので、
携帯に便利でしかもケーブルの短絡時許容電流の
値を容易かつ迅速に知り得るケーブル選定用スラ
イドルールを得ることを目的としている。[Purpose of the invention] The invention was created based on the above circumstances.
The purpose of the present invention is to obtain a slide rule for cable selection that is convenient to carry and allows the user to easily and quickly know the value of the allowable current when a cable is short-circuited.

［考案の概要］本考案のケーブル選定用スライドルールは、一
方の円板の外周部近傍に、この円板と同心をなす
径の大きな円弧と小さな円弧およびそれらの両端
を結ぶ直線とから成る扇の地紙状の窓孔が設けら
れ、この窓孔の円弧の一方の辺にはこの辺に沿つ
て短絡時間を示す数字が、他方の辺にはこの辺に
沿つて係数を示す数字からそれぞれ記載され、前
記一方の円板に着脱自在且つ可回動に取り付けら
れる他方の円板には、前記一方の円板の窓孔の大
円弧の径よりも小径でかつ小円弧の径よりも大径
の円周にこの円周に沿つてケーブルの短絡時許容
電流の値及びケーブルの導体サイズを示す数字が
それぞれ記載されていることを特徴としている。[Summary of the invention] The slide rule for cable selection of this invention consists of a fan consisting of a large-diameter arc concentric with the disc, a small arc, and a straight line connecting both ends of the disc, near the outer periphery of one disc. A paper-like window hole is provided, and a number indicating the short circuit time is written along this side on one side of the circular arc of this window hole, and a number indicating the coefficient is written along this side on the other side. , the other disc detachably and rotatably attached to the one disc has a diameter smaller than the diameter of the large arc of the window hole of the one disc and larger than the diameter of the small arc. It is characterized in that numbers indicating the value of the allowable short-circuit current of the cable and the size of the conductor of the cable are written along the circumference, respectively.

［考案の実施例］以下、本考案を一実施例の図面に基づいて説明
する。第１図は、本考案のケーブル選定用スライ
ドルールを分解した状態で示す一方の円板の平面
図、第２図は、本考案のケーブル選定用スライド
ルールを分解した状態で示す他方の円板の平面
図、第３図は、第１図に示す一方の円板と第２図
に示す他方の円板とを組み合わせることにより得
られた本考案のケーブル選定用スライドルールの
一実施例の平面図である。[Embodiment of the invention] The invention will be described below based on the drawings of one embodiment. Fig. 1 is a plan view of one disc showing the slide rule for cable selection of the present invention in an exploded state, and Fig. 2 is a plan view of the other disc showing the slide rule for cable selection of the invention in an exploded state. FIG. 3 is a plan view of an embodiment of the slide rule for cable selection of the present invention obtained by combining one disk shown in FIG. 1 and the other disk shown in FIG. It is a diagram.

第１図及び第２図において、一方の円板１及び
他方の円板２は同一直径であり、両者の円板１，
２はその等の中心において着脱自在且つ可回動に
結合される。しかして、一方の円板１の外周部近
傍の表面には、この円板１と同心をなす径の大き
な円弧（以下「大円弧」という。）３ａと小さな
円弧（以下「小円弧」という。）３ｂ及びそれら
の両端を結ぶ直線３ｃ，３ｄとから成る扇の地紙
状の窓孔３が設けられており、この窓孔３の例え
ば大円弧３ａの辺にはこの辺に沿つて短絡時間
（秒）を示す数字４が記載され、また小円弧３ｂ
の辺にはこの辺に沿つて係数を示す数字５がそれ
ぞれ記載されている。なおこの係数はケーブル絶
縁体の材料によつて決定されるもので、例えばケ
ーブル絶縁体の材料がビニルの場合は例えば1.5、
またケーブル絶縁体の材料が架橋ポリエチレンの
場合は例えば2.0とされている。 In FIGS. 1 and 2, one disc 1 and the other disc 2 have the same diameter, and both discs 1,
2 are detachably and rotatably connected at their centers. Thus, on the surface of one of the disks 1 near the outer periphery, there is a circular arc 3a with a large diameter (hereinafter referred to as "large circular arc") concentric with this disk 1 and a small circular arc (hereinafter referred to as "small circular arc"). ) 3b and straight lines 3c and 3d connecting both ends thereof, a fan-like paper-like window hole 3 is provided, and a short circuit time ( The number 4 indicating the second) is written, and the small arc 3b
The number 5 indicating the coefficient is written along this side. Note that this coefficient is determined by the material of the cable insulator; for example, if the cable insulator material is vinyl, it is 1.5,
For example, if the cable insulation material is crosslinked polyethylene, the value is 2.0.

他方の円板２の表面には、一方の円板１の窓孔
３の大円弧３ａの径よりやや小径の円６（以下
「大円」という。）と小円弧３ｂの径よりやや大径
の円７（以下「小円」という。）とが同心状に設
けられ、大円６にはこの円周６に沿つてケーブル
の導体サイズ（mm²）を示す数字８が記載され、ま
た小円７にはこの円周７に沿つて短絡時許容電流
値（kA）を示す数字９がそれぞれ記載されてい
る。なお、前記の短絡時許容電流値は、600Vビ
ニル絶縁ビニルシースケーブル（以下「VVケー
ブル」という。）の短絡前の導体温度を60℃、短
絡時の導体最高温度を120℃とした場合の値を示
している。 On the surface of the other disc 2, there is a circle 6 (hereinafter referred to as "large circle") with a diameter slightly smaller than the diameter of the large arc 3a of the window hole 3 of the one disc 1, and a circle 6 with a diameter slightly larger than the diameter of the small arc 3b. A circle 7 (hereinafter referred to as "small circle") is provided concentrically, and a number 8 indicating the cable conductor size (mm ² ) is written on the large circle 6 along the circumference 6, and a small circle 7 is provided along the circumference 6. Along the circumference of the circle 7, a number 9 indicating the allowable current value (kA) at the time of short circuit is written. The above allowable current value during short circuit is the value when the conductor temperature of 600V vinyl insulated vinyl sheath cable (hereinafter referred to as "VV cable") before short circuit is 60℃, and the maximum conductor temperature during short circuit is 120℃. It shows.

次に、本考案にかかるケーブル選定用スライド
ルールを用いて、導体サイズが14mm²で短絡時間が
１秒の場合の600V VVケーブルの短絡時許容電
流の値を知る方法について述べる。先ず、第２図
に示す他方の円板２の上に第１図に示す一方の円
板１をその等の中心において着脱自在且つ可回動
に結合して第３図に示すケーブル選定用スライド
ルールを得る。しかして、一方の円板１もしくは
他方の円板２を回転させて他方の円板２の大円６
に記載された数字「14」の目盛りと一方の円板１
の大円弧３ａに記載された数字「１」の目盛りと
を一致させる。そして小円弧３ｂに記載された数
字「1.5」の目盛りに対応する小円７の目盛りか
ら略「1.2」が得られ、この数字から導体サイズ
が14mm²で短絡時間が１秒の場合の600V VVケー
ブルの短絡時許容電流の値が略1.2kAであること
を知ることができる。同様にして短絡時間が0.5
秒の場合は一方の円板１もしくは他方の円板２を
回転させて大円６の「14」の目盛りと大円弧３ａ
の「0.5」の目盛りとを一致させ、小円弧３ｂの
「1.5」の目盛りに対応する小円７の目盛りから略
「2.0」が得られる。なお、ケーブル絶縁体の材料
が架橋ポリエチレンの場合は、小円弧３ｂに記載
された数字「2.0」の目盛りに対応する小円７の
目盛りから略「1.7」が得られ、この数字から導
体サイズ14mm²で短絡時間が１秒の場合の600V
架橋ポリエチレン絶縁ビニルシースケーブルの短
絡時許容電流が略1.7kAであることを知ることが
できる。 Next, we will explain how to find out the allowable short-circuit current value of a 600V VV cable when the conductor size is 14 mm ² and the short-circuit time is 1 second using the slide rule for cable selection according to the present invention. First, one disk 1 shown in FIG. 1 is removably and rotatably coupled at the center of the other disk 2 shown in FIG. 2 to form the cable selection slide shown in FIG. 3. Get the rules. Thus, by rotating one disk 1 or the other disk 2, the large circle 6 of the other disk 2 is rotated.
The scale with the number "14" written on it and the disc 1 on one side
Match the scale of the number "1" written on the large arc 3a. Then, approximately "1.2" is obtained from the scale of the small circle 7 corresponding to the scale of the number "1.5" written on the small arc 3b, and from this number, 600V VV is obtained when the conductor size is 14 mm ² and the short circuit time is 1 second. It can be seen that the allowable current value during short circuit of the cable is approximately 1.2kA. Similarly, short circuit time is 0.5
In the case of seconds, rotate one disk 1 or the other disk 2 to match the "14" scale of the great circle 6 and the great arc 3a.
, and approximately "2.0" is obtained from the scale of the small circle 7 corresponding to the "1.5" scale of the small arc 3b. If the material of the cable insulator is cross-linked polyethylene, approximately "1.7" is obtained from the scale of the small circle 7 corresponding to the scale of the number "2.0" written on the small arc 3b, and from this number the conductor size is 14 mm. 600V when the short circuit time is 1 second at ²
It can be seen that the allowable current of the cross-linked polyethylene insulated vinyl sheath cable during short circuit is approximately 1.7 kA.

しかして、本考案においては他方の円板２を着
脱自在としておき、使用電圧が600V以外の電圧
についての第２図と同様の記載を施した他の円板
（不図示）を複数種類準備しておくことにより、
多種多様のケーブルの短絡時許容電流の値を容易
に知ることができる。 Therefore, in the present invention, the other disc 2 is made detachable, and multiple types of other discs (not shown) are prepared with descriptions similar to those in Fig. 2 for voltages other than 600V. By keeping
You can easily find out the allowable short-circuit current values of a wide variety of cables.

［考案の効果］上記から明らかなように、本考案のケーブル選
定用スライドルールによれば、一方の円板もしく
は他方の円板を回転することによりケーブルの種
別及び又はケーブルの使用電圧に対応したケーブ
ルサイズごとの短絡時許容電流を容易且つ迅速に
知ることができる。また、本考案のスライドルー
ルは携帯が容易であるから、現場における使用に
最適であり、現場の作業管理上きわめて有益であ
る。[Effect of the invention] As is clear from the above, according to the slide rule for cable selection of the invention, by rotating one disc or the other disc, it is possible to select a cable that corresponds to the type of cable and/or the working voltage of the cable. Allowable short circuit current for each cable size can be easily and quickly determined. Furthermore, since the slide rule of the present invention is easily portable, it is ideal for use in the field, and is extremely useful for work management in the field.

[Brief explanation of the drawing]

第１図は本考案のケーブル選択用スライドルー
ルの一実施例を分解状態で示す一方の円板の平面
図、第２図は他方の円板の平面図、第３図は本考
案のケーブル選択用スライドルールの一実施例を
示す平面図である。１……一方の円板、２……他方の円板、３……
窓孔、６……大円、７……小円。 Fig. 1 is a plan view of one disk showing an embodiment of the slide rule for cable selection of the present invention in an exploded state, Fig. 2 is a plan view of the other disk, and Fig. 3 is a plan view of the cable selection of the present invention. FIG. 3 is a plan view showing an example of a slide rule for use in the present invention. 1...One disk, 2...The other disk, 3...
Window hole, 6...large circle, 7...small circle.

Claims

[Scope of utility model registration request]

A fan-like paper-like window hole is provided near the outer periphery of one of the disks, and consists of a large-diameter circular arc concentric with the disk, a small circular arc, and a straight line connecting both ends of the circular arc. On one side of the arc, a number indicating the short circuit time is written along this side, and on the other side, a number indicating the coefficient is written along this side,
The other disc, which is detachably and rotatably attached to the one disc, has a circle having a diameter smaller than the diameter of the large arc of the window hole of the one disc and larger than the diameter of the small arc. A slide rule for cable selection, characterized in that numbers indicating the allowable current value during short circuit of the cable and the cable conductor size are written along the circumference, respectively.