JP4078955B2 - Multiphase current transformer for distribution board - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a through-type multiphase current transformer incorporated in a distribution board.
[0002]
An example of a conventional multiphase current transformer for a distribution board is shown in FIG. 4 of JP-A-7-229927.
In recent years, as shown in FIG. 6 of Japanese Patent Laid-Open No. 9-298026, for example, neutral wires are arranged one step higher in the arrangement of bus bars in a single-phase three-wire distribution board, and the connection conductors between the bus bars are connected. Ensuring the insulation distance and simplifying the connection of the branch breaker terminal to the stepped structure are implemented.
[0003]
[Patent Document 1]
JP-A-7-229927 (FIG. 4)
[Patent Document 2]
JP-A-9-298026 (FIG. 6)
[0004]
[Problems to be solved by the invention]
In the above-mentioned conventional multiphase current transformer for distribution board, the through hole of the primary conductor is provided at the same height in parallel so that the bus bar and the cable can be inserted, so this multiphase current transformer is connected to the circuit breaker. When installing on the load side, it is necessary to bend the bus bar after passing through the multiphase current transformer in the distribution board where the neutral wire bus bar is arranged one step higher. Since the branch circuit breaker cannot be installed at the bent portion, there is a problem that the vertical dimension of the distribution board becomes large because of unnecessary space.
[0005]
The present invention has been made in order to solve such a problem, and a multiphase in which the vertical dimension of the distribution board can be used effectively without a bent portion forming a step in the primary conductor interfering with the installation of the branch circuit breaker. The purpose is to provide a current transformer .
[0006]
[Means for Solving the Problems]
The multiphase current transformer for a distribution board according to the present invention is provided with three through holes through which a primary conductor passes between two opposing faces of a six-sided solid in parallel, and through-type current transformer elements in the through holes at both ends. The central through-hole is an enlarged through-hole enlarged in the upward direction orthogonal to the parallel direction, and a bent portion that forms a step in the primary conductor is provided in the enlarged through-hole.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a perspective view of a multiphase current transformer showing Embodiment 1 of the present invention, FIG. 2 is a plan view of a distribution board in which the multiphase current transformer of the present invention is installed, and FIG. 3 is a line of FIG. FIG. 4 is a sectional view taken along line BB in FIG. 2. FIG. 5 is a cross-sectional view of another connection example in a distribution board using the multiphase current transformer of the present invention.
In FIG. 1, a multiphase current transformer 1 whose outer shell is made of an insulating resin is provided with a through hole 2 through which a primary conductor is inserted. Three-phase three-wire type or single-phase three-wire type current measurement is possible with two current transformer elements, and current measurement of all lines is possible from the vector composition relationship. This multi-phase current transformer 1 is wound around the annular core. Two sets of current transformer elements 3 with lines are arranged on both sides, the central hole of the annular core becomes the through hole 2, and no current transformer element is arranged in the central enlarged through hole 2a.
Therefore, the lower part of the enlarged through-hole 2a is enlarged upward by a circular arc, and the upper part is formed in a long D-shaped section with a straight line.
And the terminal 4 which leads to the secondary winding of the current transformer element 3 is provided in the outer shell surface which consists of insulating resin. In addition, there are provided mounting legs 5 and test seal holes 6 formed by projecting the insulating resin itself.
[0008]
An example of mounting the multiphase current transformer of the present invention in the distribution board will be described with reference to FIGS. The primary conductor of the multiphase current transformer 1 is a bus bar 11, and the neutral wire bus bar 11 a of the three bus bars is arranged one step higher.
In order to arrange the neutral wire bus bar 11a one step higher, it is connected to the terminal 10a of the circuit breaker 10 through the conductive spacer 12 of the step size, inserted through the enlarged portion on the upper side of the enlarged through hole 2a, and branched off. It is extended to the connection position with the container 13. The bus bar 11 other than the neutral wire is inserted into the through hole 2 and extended to the connection position with the branch breaker 13 at the same height.
[0009]
Since the neutral bus bar 11a arranged one step higher can be inserted through the enlarged through hole 2a as it is and a step can be obtained at the position of the terminal 10a of the circuit breaker 10, the space for forming the step can be saved. Since the bus bar 11 and the neutral wire bus bar 11a are arranged in steps corresponding to the step of the input terminal of the branch circuit breaker 13, between the branch conductor 14 to the input terminal of the branch circuit breaker 13 and the bus bars 11, 11a. Insulation distance can be secured and the branch conductors 14 can be connected linearly.
[0010]
Further, when the bus bar 11 is not stepped, the bus bar 11 can be inserted into the opening of the enlarged through hole 2a having the same height as the other through holes 2, so that the multiphase current transformer 1 is not limited by the bus bar arrangement form. Can be shared.
[0011]
Further, as shown in FIG. 5, the connecting conductor 15 to the neutral wire bus bar 11a arranged one step higher is used as the primary conductor of the multiphase current transformer 1, and the bent portion forming the step is positioned in the enlarged through hole 2a. Thus, the space occupied by the bent portion can be reduced, so that the number of branch circuit breakers 13 installed in the distribution board can be increased or the distribution board itself can be made smaller than the conventional one.
[0012]
Embodiment 2. FIG.
6 is an exploded perspective view of a multiphase current transformer showing Embodiment 2 of the present invention, and FIG. 7 is a cross-sectional view of the multiphase current transformer of Embodiment 2. FIG. In the figure, the same reference numerals as those in the first embodiment are omitted.
The second embodiment is a multi-phase current transformer equipped with a terminal block that holds a connection conductor as a penetrating primary conductor, and ensures stable fixation of the bus bar and interphase insulation at the connection portion between the connection conductor and the bus bar.
[0013]
The terminal block 16 is provided with an insertion protrusion 16a fitted into the through hole 2, and the insertion protrusion 16a is provided with an insertion hole 16b through which the bar conductor 17 is inserted and fixed. The insertion protrusion 16c inserted into the enlarged through hole 2a is provided with a second insertion hole 16d through which the connection conductor 15 is inserted and an insertion hole 16e through which the bar conductor 17 can be inserted. And the base along the connection conductor 15 is provided, and the neutral wire bus bar 11a is screwed and fixed.
Further, the bar conductor 17 can be attached to the insertion protrusion 16c.
[0014]
In order to make the connection height position the same when the bus bar 11 is directly connected to the terminal 10a of the circuit breaker 10 and when the bus bar 11 is connected via the bar conductor 17, the thickness of the bar conductor 17 is corrected. There are enough steps to do it. The terminal block 16 to which the bar conductor 17 and the connection conductor 15 are attached is mounted on the multiphase current transformer 1 and fixed by screws 18 to be integrated.
[0015]
By connecting the multiphase current transformer 1 equipped with the terminal block 16 equipped with the connection conductor 15 and the bar conductor 17 to the circuit breaker 10, a bent portion forming a step is arranged in the enlarged through hole 2a. Thus, the space occupied by the bent portion in the distribution board can be reduced. And the connection part of the connection conductor 15 and the bar conductor 17, and the neutral wire bus bar 11a and the bus bar 11 is reliably insulated between phases by the insulating wall 16f.
[0016]
In the above description, the neutral wire bus bar 11a is disposed one step higher. However, if the connection conductor 15 of the insertion protrusion 16c is replaced with the bar conductor 17, the three bus bars 11 can be disposed at the same height. Applicable. The insulating wall 16f is effective for interphase insulation in this arrangement.
If the terminal block 16 is removed, the cable can be inserted into the through hole 2 and the enlarged through hole 2a.
[0017]
【The invention's effect】
According to the multiphase current transformer for distribution board of the present invention, as described above, the central through hole is an enlarged through hole enlarged in the orthogonally upward direction, and the bent portion forming the step in the primary conductor is the enlarged through hole. Because the vertical part of the distribution board can be used effectively without the bent part interfering with the installation of the branch circuit breaker, the number of branch circuit breakers installed in the distribution board compared to conventional ones The distribution board itself can be made smaller.
[Brief description of the drawings]
FIG. 1 is a perspective view of a multiphase current transformer according to Embodiment 1 of the present invention.
FIG. 2 is a plan view inside the distribution board in which the multiphase current transformer according to Embodiment 1 of the present invention is installed.
3 is a cross-sectional view taken along line AA in FIG.
4 is a cross-sectional view taken along line BB in FIG.
FIG. 5 is a cross-sectional view of another connection example in the distribution board using the multiphase current transformer of Embodiment 1 of the present invention.
FIG. 6 is an exploded perspective view of a multiphase current transformer showing Embodiment 2 of the present invention.
FIG. 7 is a sectional view inside a distribution board in which a multiphase current transformer according to Embodiment 2 of the present invention is installed.
[Explanation of symbols]
1 multiphase current transformer, 2 through hole, 2a enlarged through hole,
3 current transformer element, 10 circuit breaker, 10a terminal,
11 Busbar, 11a Neutral wire busbar,
13 branch circuit breaker, 15 connecting conductor, 16 terminal block,
16a, 16c insertion protrusion, 16b, 16e insertion hole,
16d second insertion hole, 16f insulating wall, 17 bar conductor,

Claims (4)

A distribution board in which three through holes through which a primary conductor passes are provided in parallel between two opposing faces of a substantially six-dimensional solid, and through-type current transformer elements are respectively arranged in the through holes at both ends. In the multiphase current transformer for use, a central through hole is an enlarged through hole enlarged in an upward direction orthogonal to the parallel direction, and a bent portion that forms a step in the primary conductor is provided in the enlarged through hole. A multiphase current transformer for distribution boards. 2. The multiphase current transformer for a distribution board according to claim 1, wherein the enlarged through hole has a D-shaped cross section and is expanded in a direction of a straight side of the D character. A terminal block to be mounted on the surface provided with the through hole, an insertion hole through which the primary bar conductor provided in the insertion protrusion inserted from the terminal block into the through hole, and an enlarged through hole in the center are inserted. 3. A multiphase for a distribution board according to claim 1, wherein a second insertion hole through which a connecting conductor having a step difference from the primary bar conductor is provided in an enlarged portion of the insertion protrusion. Current transformer. 4. A multiphase current transformer for a distribution board according to claim 3, wherein an interphase insulating wall is provided on the side of the terminal block to which the bus bar is connected.

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