Power meter connection block

Abstract

To provide a watthour meter connection block capable of securing high safety and significantly reducing a load on an operator in connecting a voltmeter to a smart meter.SOLUTION: A watthour meter connection block (connection block 100) according to the present invention is a block for connecting three electric lines 302, 304 and 306 to a voltage line terminal, a ground line terminal and a voltage line terminal, respectively, and includes a base part 110 that is made of an insulating material, a mounting screw 120 that electrically connects the electric line to the ground line terminal by being tightened to a screw hole of the ground line terminal through an approximately central part of the base part, and two contact terminals 132 and 134 that are arranged on both sides of the mounting screw in the base part to electrically connect the two electric lines to the pair of voltage line terminals, respectively. A tip end of the mounting screw and the two contact terminals are projected in a back surface 110b of the base part, and only a head of the mounting screw is exposed in a front surface 110a of the base part.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a connection block for a watt-hour meter that connects a voltmeter to the terminal section of the watt-hour meter. [Background technology]

[0002] In order to ensure the quality of the power supply, electric utilities sometimes connect voltmeters to watt-hour meters installed at consumers' homes to measure the voltage of the power supplied to those homes. As a jig for connecting a measuring device such as a voltmeter to a consumer's watt-hour meter, for example, Patent Document 1 discloses a terminal jig for connecting a memory-type recorder (a voltage and current measuring meter) to the terminal section of a watt-hour meter.

[0003] The terminal jig of Patent Document 1 is composed of an insulating base plate that is detachably screwed to the terminal portion, and a leaf spring-like conductive lead plate that is attached to the surface of the base plate facing the terminal portion, has a protruding contact at its tip that elastically contacts the terminal portion, and is led out from the base plate with a lead wire extending from a memory recorder connected to its rear end. According to Patent Document 1, this configuration makes it possible to provide a terminal jig that can simplify connection to the terminal portion when measuring voltage and current with a watt-hour meter. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-271554 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, smart meters, which are digital watt-hour meters with communication functions, have become increasingly popular, replacing conventional analog watt-hour meters. However, no dedicated tool has yet been developed for connecting a voltmeter to a smart meter. For this reason, electrical insulation measures must be taken before connecting a voltmeter to a smart meter.

[0006] Furthermore, the connection point between the smart meter and the voltmeter is a live part through which low-voltage current flows. Therefore, if a terminal cover cannot be attached after the connection work, the connection point must be concealed (protected) with an insulating material such as a protective sheet. This type of connection and protection work must be performed with the utmost care, which places a heavy burden on the workers.

[0007] In view of these problems, the present invention aims to provide a connection block for a watt-hour meter that can ensure high safety when connecting a voltmeter to a smart meter and significantly reduce the burden on workers. [Means for solving the problem]

[0008] In order to solve the above problem, a typical configuration of a connection block for a watthour meter according to the present invention is a connection block for a watthour meter that connects a voltmeter to the terminal section of the watthour meter, in which a voltage line terminal, an earth line terminal, and a voltage line terminal are arranged in this order on the primary and secondary sides of the terminal section, and a screw hole is provided in the earth line terminal, and the connection block for a watthour meter is a block for connecting three electric wires to the voltage line terminal, the earth line terminal, and the voltage line terminal, respectively, and is characterized in that it has a base made of an insulating material, a mounting screw that passes through approximately the center of the base and is fastened to the screw hole in the earth line terminal to electrically connect the earth line terminal and the electric wires, and two contact terminals that are arranged on both sides of the mounting screw on the base and electrically connect a pair of voltage line terminals and each of the two electric wires, and the tip of the mounting screw and the two contact terminals protrude from the back surface of the base, and only the head of the mounting screw is exposed on the front surface of the base.

[0009] According to the above configuration, by fastening a mounting screw into a screw hole in the base of the watt-hour meter connection block (hereinafter referred to as the connection block) while the voltmeter wire is held in the base, the voltmeter wire is attached to the terminal of the watt-hour meter via the connection block, thereby connecting the terminal of the watt-hour meter and the voltmeter via the connection block.

[0010] At this time, the tip of the mounting screw and two contact terminals protrude from the back of the base, electrically connecting the terminal of the watt-hour meter and the voltmeter. In contrast, only the head of the mounting screw connected to the earth wire terminal is exposed on the surface of the base. In other words, the charged component (the conductive component connected to the voltage wire terminal) is not exposed on the surface of the base. This eliminates the risk of electric shock, ensuring high safety when connecting a voltmeter to a smart meter and significantly reducing the burden on workers.

[0011] The connection block for the electricity meter has a pillar portion that stands upright from the back surface of the base and supports the mounting screw and the two contact terminals on both sides of it so that they are close to the two voltage line terminals and earth line terminal of the terminal portion, and the gap between the pillar portions is preferably formed wider than the thickness of the partition between the voltage line terminals and earth line terminal of the terminal portion.

[0012] With this configuration, the connection block has an E-shaped cross section due to the base and the posts, and the contact terminals are covered by the posts, which more reliably prevents electric shock. Furthermore, because the bulkheads of the terminals are located in the gaps between the posts, the connection block protrudes less toward the front. This reduces the space occupied by the connection block inside the watt-hour meter, allowing for convenient installation of the terminal cover after the connection work. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a connection block for a watt-hour meter that can ensure high safety when connecting a voltmeter to a smart meter and significantly reduce the burden on workers. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram illustrating a watt-hour meter to which the watt-hour meter connection block according to the present embodiment is applied; [Figure 2] FIG. 2 is a diagram illustrating a connection block according to the present embodiment. [Figure 3] 10A and 10B are diagrams illustrating the attachment of the connection block of this embodiment to a watt-hour meter. [Figure 4] FIG. 2 is a schematic side view of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0015] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and, unless otherwise specified, do not limit the present invention. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown.

[0016] Fig. 1 is a diagram illustrating a watt-hour meter 200 to which a watt-hour meter connection block according to this embodiment (hereinafter referred to as connection block 100) is applied. Fig. 1 illustrates the watt-hour meter 200 with a cover 260 removed.

[0017] 1 is a digital smart meter and includes a metering unit 210, a terminal unit 220, a communication unit 250, and a cover 260. The metering unit 210 is connected to the terminal unit 220 and measures the power detected by the terminal unit 220. The communication unit 250 transmits the electricity usage data of the consumer measured by the metering unit 210 to the electric utility. The cover 260 is attached to the metering unit 210 and covers the terminal unit 220 connected to the metering unit 210 to shield it from the outside.

[0018] The terminal unit 220 has a total of six terminals: a primary terminal 230 for three-phase AC and a secondary terminal 240 for three-phase AC. The primary terminal 230 is made up of three terminals arranged in order: a voltage line terminal 232, a ground line terminal 234, and a voltage line terminal 236. The secondary terminal 240 is made up of three terminals arranged in order: a voltage line terminal 242, a ground line terminal 244, and a voltage line terminal 246. These terminals are provided with screw holes for attaching a bypass tool, and the screw holes formed in the ground line terminal 234 of the primary terminal 230 and the ground line terminal 244 of the secondary terminal 240 are labeled 238 and 248.

[0019] The connection block 100 of this embodiment is a jig for connecting the voltmeter 300 to the terminal section 220 (in this embodiment, the primary side terminal 230 is exemplified) of the watt-hour meter 200. In detail, the connection block 100 connects three electric wires 302, 304, and 306 connected to the voltmeter 300 to the voltage line terminal 232, the earth line terminal 234, and the voltage line terminal 236 of the primary side terminal 230, respectively.

[0020] FIG. 2 is a diagram illustrating the connection block 100 according to this embodiment. FIG. 2(a) is a perspective view of the front surface 110a of the connection block 100 observed from above. FIG. 2(b) is a perspective view of the back surface 110b of the connection block 100 observed from below. FIG. 3 is a diagram illustrating the attachment of the connection block 100 according to this embodiment to the electricity meter 200. FIG. 4 is a schematic side view of FIG. 1.

[0021] 2(a) and 2(b), the connection block 100 of this embodiment includes a base 110, a mounting screw 120, and two contact terminals 132 and 134. The base 110 is molded from an insulating material (e.g., resin) and is a member that integrally supports the mounting screw 120 and the two contact terminals 132 and 134 arranged on either side of it.

[0022] 2(b), three insertion holes 112a, 112b, and 112c are formed in the base 110. By inserting the ends of the electric wires 302, 304, and 306 into these insertion holes 112a, 112b, and 112c, respectively, the electric wires 302, 304, and 306 connected to the voltmeter 300 are held in the base 110 of the connection block 100. Inside the base 110, the contact terminal 132 and the electric wire 302 are connected. Similarly, the mounting screw 120 and the electric wire 304 are electrically connected, and the contact terminal 134 and the electric wire 306 are electrically connected.

[0023] 2, the mounting screw 120 penetrates substantially the center of the base 110 and is fastened to the screw hole 238 (see FIG. 1) of the earth wire terminal 234 of the primary side terminal 230 as shown in FIG. 3(a). As a result, the electric wire 304 is attached to the terminal portion 220 of the watt-hour meter 200 via the connection block 100, and the earth wire terminal 234 of the primary side terminal 230 and the electric wire 304 are electrically connected.

[0024] Furthermore, when the mounting screw 120 is tightened, the contact terminals 132 and 134 arranged on both sides of the mounting screw 120 are pressed against the voltage line terminals 232 and 236, establishing electrical continuity. This electrically connects the voltage line terminal 232 to the electric wire 302, and electrically connects the voltage line terminal 236 to the electric wire 306.

[0025] In this connection block 100 of this embodiment, only the head 122 of the mounting screw 120 is exposed on the front surface 110a of the base 110 as shown in Fig. 2(a). On the other hand, the tip 124 of the mounting screw 120 and two contact terminals 132 and 134 protrude from the back surface 110b of the base 110 as shown in Fig. 2(b).

[0026] That is, in the connection block 100 of this embodiment, when attached to the terminal portion 220 of the watt-hour meter 200, the conductive members (charged members) connected to the contact terminals 132 and 134 are not exposed on the surface 110a of the base 110. Furthermore, the work of attaching the connection block 100 to the watt-hour meter 200 only requires fastening the mounting screw 120 to the ground wire terminal 234, so there is no need to touch the charged members. This eliminates the risk of electric shock and ensures high safety when connecting the voltmeter 300 to the watt-hour meter 200, which is a smart meter. This makes it possible to significantly reduce the burden (stress) on the worker.

[0027] 2, in the connection block 100 of this embodiment, pillars 114, 116, and 118 extend upright from the back surface 110b of the connection block 100. The pillars support the mounting screw 120 and the two contact terminals 132 and 134 on either side of the mounting screw 120, respectively, so that the mounting screw 120 is close to the two voltage line terminals 232 and 236 and the ground line terminal 234 of the terminal section 220. As a result, the cross section of the connection block 100 is E-shaped, formed by the base 110 and the pillars 114-118. With this configuration, the contact terminals 132 and 134 of the connection block 100 are covered by the pillars 114 and 118 except for the portions that come into contact with the voltage line terminals 232 and 236. This more reliably prevents electric shock.

[0028] As shown in FIG. 3(b), the gaps G1 and G2 between the pillar portions 114-118 of the connection block 100 are formed wider than the thicknesses T1 and T2 of the partition walls 222 and 224 between the voltage line terminals 232 and 236 and the earth line terminal 234 of the terminal portion 220.

[0029] With the above configuration, the partition walls 222 and 224 of the terminal portion 220 can be positioned in the gaps G1 and G2 between the columns 114 and 118, reducing the amount of protrusion (overhang) toward the front of the connection block 100. Therefore, as shown in FIG. 4, the space occupied by the connection block 100 in the watt-hour meter 200 can be reduced, making it possible to attach the terminal cover 260 after the connection work. This allows the voltage line terminals 232, 236, 242, and 246 to be safely covered, eliminating the need to cover the terminal portion 220 with a protective sheet made of insulating material. This also reduces the burden on workers.

[0030] 4, whether or not the cover 260 can be closed with the connection block 100 attached depends on the thickness of the connection block 100 (the sum of the thickness of the base 110 and the height of the posts 114, 116, and 118). However, according to the configuration of the present invention, the contact terminals 132 and 134 and the wires 302 and 306 are simply connected internally as shown in FIG. 2, so the thickness of the connection block 100 can be easily reduced.

[0031] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these examples. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that these modifications and alterations also fall within the technical scope of the present invention. [Industrial Applicability]

[0032] The present invention can be used as a connection block for a watt-hour meter that connects a voltmeter to the terminal portion of the watt-hour meter. [Explanation of symbols]

[0033] 100...Connection block, 110...Base, 110a...Surface, 110b...Back, 112a...Insertion hole, 112b...Insertion hole, 112c...Insertion hole, 114...Column portion, 116...Column portion, 118...Column portion, 120...Mounting screw, 122...Head, 124...Tip, 132...Contact terminal, 134...Contact terminal, 200...Watt-hour meter, 210...Measuring portion, 220...Terminal portion, 222... Partition wall, 224...partition wall, 230...primary side terminal, 232...voltage line terminal, 234...earth line terminal, 236...voltage line terminal, 238...screw hole, 240...secondary side terminal, 242...voltage line terminal, 244...earth line terminal, 246...voltage line terminal, 248...screw hole, 250...communication unit, 260...cover, 300...voltmeter, 302...electric wire, 304...electric wire, 306...electric wire

Claims

1. A watt-hour meter connection block for connecting a voltmeter to a terminal portion of a watt-hour meter, The terminal unit has a voltage line terminal, a ground line terminal, and a voltage line terminal arranged in this order on the primary side and the secondary side, The earth wire terminal is provided with a screw hole, The watt-hour meter connection block is a block for connecting three electric wires to the voltage line terminal, the earth line terminal, and the voltage line terminal, respectively; A base made of an insulating material; a mounting screw that penetrates substantially the center of the base and is fastened to the screw hole of the ground wire terminal to electrically connect the ground wire terminal and the electric wire; the base portion has two contact terminals disposed on both sides of the mounting screw and electrically connecting the pair of voltage line terminals to the two electric wires, the tip of the mounting screw and the two contact terminals protrude from the rear surface of the base; 13. A connection block for an electricity meter, comprising: a base portion having a first end and a second end; a base portion and a second end;

2. The connection block for the watt-hour meter has a column portion that stands upright from the back surface of the base portion and supports the mounting screw and the two contact terminals on both sides of the mounting screw so that they are close to the two voltage line terminals and the earth line terminal of the terminal portion, 2. The connection block for an electricity meter according to claim 1, wherein the gap between the pillars is formed wider than a thickness of a partition wall between the voltage line terminal and the earth line terminal of the terminal portion.

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