JP5295167B2 - Electricity meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the burden of an operator who is engaged in a replacement work and enhance safety at the work. <P>SOLUTION: A watt-hour meter 100 comprises: a measuring part which is provided between first terminals connected to power sources and second terminals connected to loads and measures an integrated value of electric energy based on current which has flown from the power sources to the loads; and terminal screws 201 which are provided corresponding to the first and the second terminals, and fix electric wires 402, which are connected to the first and the second terminals, in a state of being in contact with the first and the second terminals. The terminal screws 201 are composed of a nonconductive material. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a watt-hour meter that integrates and measures electric power.

  The watt hour meter is an electric meter that measures the amount of power that has passed through the watt hour meter, and is called a meter or the like. In addition to measuring the amount of power that has passed through the watt hour meter, such a watt hour meter can be used for various measurement tasks such as voltage measurement and insulation resistance measurement of indoor electrical wiring using the watt hour meter terminal. Sometimes used.

  The watt hour meter includes a terminal to which an electric wire connected to the power supply side, an electric wire connected to the load side, and the like are connected. This terminal is accommodated in a case of a terminal box provided in the watt-hour meter. In the watt-hour meter, the above-described electric wires were inserted into the terminal box, and by tightening brass terminal screws provided on the case, the electric wires and the terminals were connected. . Moreover, in the watt hour meter, the electric wire connected to the watt hour meter can be removed by loosening the brass terminal screw.

  Conventionally, connection and removal of electric wires to and from such a watt hour meter are performed, for example, when a watt hour meter is newly installed, when a watt hour meter is replaced, or when an electric contract is abolished. In addition, in the past, most of the various work such as connection and removal of electric wires to such watt hour meters and measurement work such as voltage measurement and measurement of insulation resistance value of indoor electric wiring are in a state where electricity is applied ( It is carried out by hot-line work (without power outage).

  Specifically, for example, an amount of electric power having a structure in which a plurality of input terminals and a plurality of output terminals are provided at one end, and each terminal can be exposed by removing the danger prevention cover covering the surface. It is a tool used for a meter, and contains two bypass fittings made of a conductor in a non-contact state inside a horizontally long container body having an insulating structure as a whole. A contact pin to be brought into contact with one of the input terminals and one of the output terminals is connected, the tip of the contact pin protrudes to the back side of the container body, and a fixing pin hole is formed in a portion near both longitudinal ends of the container body. There was a technique (for example, refer to Patent Document 1 below).

JP 2009-150753 A

  However, since the conventional technique described above has performed various operations on the watt hour meter by tightening or loosening brass terminal screws provided on the case, the terminals are short-circuited via the terminal screws. There was a problem that there was something. When the terminals are short-circuited, an arc is generated and the watt hour meter is damaged, or the worker is burned by the generated arc, resulting in poor safety.

  The number of times (frequency) of various operations for the watt hour meter increases as the number of installed watt hour meters increases. Since the number of installed watt-hour meters is enormous, the number of times (frequency) of various operations on the watt-hour meter tends to increase. There has been a problem that the number (frequency) of occurrence of damage to the meter increases.

  As a countermeasure, in order to prevent short-circuit accidents during the various operations described above, in actual work, for example, the terminal part of the watt hour meter is covered with an insulating protective device (armor), and the terminal screw is turned. However, there is a problem in that various measures for the watt hour meter become complicated by taking such measures, and a long time is spent on the work.

  Furthermore, in the watt-hour meter, since the brass terminal screw is exposed to the outside, even when various operations are performed using the insulating protective equipment as described above, due to human error of the operator, etc. There was a problem that a short-circuit accident could occur accidentally.

  When the terminal part in the watt hour meter is short-circuited, the terminal screw and the watt hour meter main body are damaged, so that the watt hour meter itself needs to be replaced. In this case, a work for removing the damaged watt hour meter and a work for installing a new watt hour meter to be replaced are added separately from the original work. For this reason, there has been a problem that the labor cost of the worker for replacing the damaged watt hour meter and the equipment cost for the watt hour meter are unnecessarily high.

  The present invention provides a watt-hour meter capable of reducing the burden on an operator engaged in replacement work and improving safety during the replacement work in order to solve the above-described problems caused by the prior art. The purpose is to do.

  In order to solve the above-described problems and achieve the object, the watt-hour meter according to the present invention includes a first terminal connected to a power source, a second terminal connected to a load, and the first terminal. A measuring unit which is provided between the second terminal and measures the integrated value of the electric energy based on a current flowing from the power source to the load; and associates with the first terminal and the second terminal And a screw for fixing an electric wire connected to the first terminal and the second terminal in a state where the electric wire is in contact with the first terminal and the second terminal, The screw is formed using a non-conductive material.

  The watt-hour meter according to the present invention is characterized in that, in the above invention, the screw is formed using a ceramic material.

  Moreover, the watt hour meter concerning this invention is equipped with the terminal box provided with the some recessed part which can insert the said electric wire in said invention, The said 1st terminal and the said 2nd terminal are said recessed parts The screw is screwed into the terminal box from a direction intersecting with the insertion direction of the electric wire so that the tip is positioned in the recess.

  The watt-hour meter according to the present invention includes, in the above invention, an electric wire pressing member that is provided between the tip of the screw and the electric wire and is formed using a conductive material, and the screw is tightened. By doing so, the electric wire pressing member biases the electric wire pressing member in a direction in which the electric wire pressing member comes into contact with the electric wire.

  In the watt-hour meter according to the present invention, in the above invention, the electric wire pressing member includes a curved surface that is curved along the outer peripheral shape of the electric wire, and the curved surface is provided facing the electric wire. It is characterized by being.

  According to the watt-hour meter concerning this invention, while aiming at the reduction of the burden of the worker engaged in replacement work, there exists an effect that the improvement in the safety | security at the time of the said replacement work can be aimed at.

It is explanatory drawing which shows the external appearance of the watt-hour meter of embodiment concerning this invention. It is explanatory drawing which shows the external appearance structure of a connection terminal block. It is explanatory drawing which shows the internal structure of a connection terminal block. It is explanatory drawing which shows an example of the conventional electric energy meter. It is explanatory drawing which shows the connection method of the electric wire with respect to the watt-hour meter of embodiment concerning this invention.

  Exemplary embodiments of a watt-hour meter according to the present invention will be described below in detail with reference to the accompanying drawings.

(Embodiment)
(Appearance of electricity meter)
First, the external appearance of the watt hour meter according to the embodiment of the present invention will be described. The watt-hour meter according to the embodiment of the present invention may be an inductive watt-hour meter or an electronic watt-hour meter, and the configuration relating to the measurement of the power amount is not particularly limited. Absent. FIG. 1 is an explanatory diagram showing an external appearance of a watt-hour meter according to an embodiment of the present invention. In FIG. 1, the external appearance in the state which looked at the watt hour meter of embodiment concerning this invention from the front side is shown.

  Referring to FIG. 1, a watt hour meter 100 according to an embodiment of the present invention includes a main body 110 and a connection terminal block 120. The main body 110 includes a box-shaped housing 111. On the front side of the casing 111, a window portion 112 that can confirm the inside of the watt hour meter 100 is provided. A measuring unit and a display unit are provided inside the casing 111.

  The metering unit measures the integrated value of the amount of power supplied to the watt-hour meter 100. The display unit displays information regarding the integrated value of the electric energy measured by the measuring unit. The display content on the display unit can be viewed from the outside of the watt hour meter 100 through the window 112 when the watt hour meter 100 is viewed from the front. The configuration of the metering unit differs depending on whether the watt-hour meter 100 according to the embodiment of the present invention is, for example, an induction watt-hour meter or an electronic watt-hour meter.

  When the watt-hour meter 100 according to the embodiment of the present invention is, for example, an induction watt-hour meter, the metering unit includes a rotating disk member formed using a metal material, a voltage coil, and a current coil. Prepare. The rotating disk member is formed in a disk shape using a metal material, and is provided so as to be rotatable about a rotation shaft provided at the center of the disk shape.

  The voltage coil is provided on one surface side of the rotating disk member, and is arranged so that the magnetic core coincides with the rotation center of the rotating disk member. The current coil is provided on the other surface side of the rotating disk member, and is arranged so that the magnetic core coincides with the rotation center of the rotating disk member.

  In the measuring unit, when electric power is supplied to the watt hour meter 100, the rotating disk member is penetrated between the voltage coil and the current coil based on the voltage applied to the voltage coil and the current applied to the current coil. Magnetic flux is generated. This magnetic flux moves around the rotation center of the rotating disk member, and a rotating magnetic field is generated by the movement of the magnetic flux.

  The rotating disk member rotates by a rotating torque obtained by using this rotating magnetic field. The metering unit in the inductive watt hour meter measures the integrated value of the amount of power supplied to the watt hour meter 100 based on the amount of rotation of the rotating disk member. The rotational torque is proportional to the power. Since the configuration of the metering unit in the inductive watt hour meter is a known technique, the description thereof is omitted.

  In addition, when the watt hour meter 100 according to the embodiment of the present invention is an electronic watt hour meter, for example, the metering unit calculates the voltage and current based on the power supplied to the watt hour meter 100. By multiplying and integrating the multiplication result, the integrated value of the electric energy supplied to the watt-hour meter 100 is measured. The metering unit in the electronic watt-hour meter includes an input conversion unit, a multiplication processing unit, and a frequency dividing circuit unit.

  The input conversion unit converts a voltage level and a current level in the supplied power into a voltage level and a current level of an electronic circuit configured between the first terminal and the second terminal. The multiplication processing unit generates a pulse signal proportional to the amount of supplied electric power by multiplication processing based on the voltage level and current level converted by the input conversion unit. The frequency dividing circuit unit converts the clock frequency of the pulse signal generated by the multiplication processing unit to a predetermined clock frequency lower than the clock frequency. Such a metering unit performs an integration process based on the pulse signal converted into a predetermined clock frequency by the frequency dividing circuit unit, and measures the integrated value of the electric energy.

  The metering unit in the electronic watt-hour meter uses a multiplication method such as a time-division multiplication method (analog multiplication) that performs pulse width modulation or a ΔΣ · A / D conversion multiplication method (digital multiplication) for multiplication. Weigh the total amount. The time division multiplication method (analog multiplication), the ΔΣ · A / D conversion multiplication method (digital multiplication), and the configuration of the measuring unit in the electronic watt-hour meter can be easily realized using various known techniques. Is omitted.

  The display unit includes a display screen and controls the display screen to display information related to the integrated value of the electric energy measured by the measuring unit. Specifically, the display unit displays a numerical value indicating an integrated value of the electric energy measured by the measuring unit. For example, the display unit can be a current character shape indicated by a number on a display screen formed by using a reel for a plurality of digits, to which numbers from 0 to 9 are assigned. In addition, the display unit may be a pointer shape that displays an integrated value of the measured electric energy with a pointer, for example. Moreover, a display part may show the integrated value of electric energy with the number of the digits of 0-9 displayed, for example using a liquid crystal display etc., for example.

(External structure of connection terminal block 120)
Next, the external structure of the connection terminal block 120 will be described. FIG. 2 is an explanatory view showing the external structure of the connection terminal block 120. In FIG. 2, the connection terminal block 120 includes first terminals 1S, 2S, and 3S and second terminals 1L, 2L, and 3L. In this embodiment, three first terminals 1S, 2S, and 3S and two second terminals 1L, 2L, and 3L are provided.

  The first terminals 1S, 2S, and 3S are each connected to a power source. The power source is a power supply source for the watt hour meter 100, and the first terminals 1S, 2S, and 3S in this embodiment are connected to a power distribution line or a distribution line connected to a power transmission line. The second terminals 1L, 2L, 3L are each connected to a load. The load can be an electrical device that uses the power passed through the watt hour meter 100 or a facility that uses electricity.

  Inside the watt hour meter 100, first terminals 1S, 2S, and 3S that are on the power source side when the watt hour meter 100 is installed, and a second terminal that is on the load side when the watt hour meter 100 is installed. A measuring unit is provided between 1L, 2L, and 3L. The first terminals 1S, 2S, and 3S and the second terminals 1L, 2L, and 3L are electrically connected to each other via a measuring unit.

  The metering unit measures the amount of power supplied from the power source side and supplied to the load side via the watt-hour meter 100. The measuring unit has a different measuring method depending on whether the watt hour meter 100 is an inductive watt hour meter or an electronic watt hour meter. In either case, the voltage value and current in the power supplied to the watt hour meter 100 are different. The amount of power can be measured based on the value.

  The electricity meter 100 may include a communication terminal. The communication terminal is a terminal provided for transmitting a pulse signal each time a certain amount of electric power is reached. By providing this communication terminal, the amount of electric power can be confirmed even in a remote place. A communication line is fixed to each communication terminal using a screw or the like. About the communication terminal in the watt-hour meter 100 and the communication method using the said communication terminal, since it is easily realizable using well-known various techniques, description is abbreviate | omitted.

(Internal structure of connection terminal block 120)
Next, the internal structure of the connection terminal block 120 will be described. FIG. 3 is an explanatory diagram showing the internal structure of the connection terminal block 120. In FIG. 3, the AA cross section in FIG. 2 is shown. In this embodiment, only the second terminal 3L is shown, and the structure of the other terminals (first terminals 1S, 2S, 3S and second terminals 1L, 2L) provided in the watt-hour meter 100 is as follows. Since it is the same as the structure of the second terminal 3L, illustration is omitted.

In FIG. 3, a power supply-side electric wire can be fixed to each of the first terminals 1 </ b> S, 2 </ b> S, and 3 </ b> S included in the connection terminal block 120 with a terminal screw 201. In addition, an electric wire connected to the load side can be fixed to each of the second terminals 1L, 2L, and 3L included in the connection terminal block 120 with a terminal screw 201.

  The terminal screw 201 is screwed into a screw hole 302 provided in the terminal box (terminal block cover) 301. The screw hole 302 passes through the terminal box 301 along the thickness direction of the terminal box 301. The connection terminal block 120 includes an electric wire insertion portion 303 into which an electric wire is inserted. The electric wire insertion portion 303 includes an opening portion 303a having an opening diameter larger than the diameter of the electric wire, and an electric wire insertion hole portion 303b that accommodates the electric wire inserted into the electric wire insertion portion 303.

  The electric wire insertion portion 303 is provided for each of the first terminals 1S, 2S, 3S and the second terminals 1L, 2L, 3L, and the electric wire insertion holes 303b in the electric wire insertion portions 303 are insulated from each other. ing. The terminal screw 201 penetrates the terminal box 301 by being screwed into the screw hole 302, and the tip is positioned in the wire insertion hole 303 b in the wire insertion portion 303.

  A ring-shaped member 304 made of brass is provided inside the wire insertion hole 303b. Thereby, the inner side (inner peripheral surface) of the wire insertion hole 303b has conductivity. The brass ring-shaped member 304 includes a hole (not shown) that allows the terminal screw 201 to pass therethrough in the screw hole 302.

  A wire pressing metal fitting 305 is provided in the wire insertion hole 303b. In this embodiment, an electric wire pressing member can be realized by the electric wire pressing metal 305. The wire pressing metal 305 is formed using a conductive material such as a metal material and has a flat plate shape.

  The wire pressing metal 305 is preferably curved along the outer peripheral surface of the wire inserted into the wire insertion hole 303b. The wire pressing metal 305 is movable in the wire insertion hole 303b along the screwing direction of the terminal screw 201 with respect to the terminal box 301 (the vertical direction in FIG. 3).

  In the wire insertion hole 303 b, the wire holding metal fitting 305 is placed on the other end of the terminal screw 201 screwed into the screw hole 302, with one side facing the wire inserted into the wire insertion hole 303 b. It is provided with the surface sides facing each other. When the terminal screw 201 screwed into the screw hole 302 is tightened in a state where the electric wire is inserted into the electric wire insertion hole 303 b, the electric wire pressing metal 305 is inserted into the electric wire insertion hole by the tip of the terminal screw 201. It is urged toward the electric wire inserted into the portion 303b and pressed against the electric wire. The brass ring-shaped member 304 and the wire pressing metal 305 are electrically connected to the measuring unit.

  The terminal screw 201 is formed using a ceramic material. Ceramics (ceramics) are sintered bodies that are baked and hardened by heat treatment at a high temperature and that have a metal oxide as a basic component, and have insulating properties (non-conductive properties). Further, the terminal screw 201 has a hardness capable of pressing the wire pressing metal fitting 305 against the electric wire without being deformed when screwed into the screw hole and tightened.

  Further, the terminal screw 201 is turned using a tool such as a screwdriver when connecting the electric wire to the first terminals 1S, 2S, and 3S and the second terminals 1L, 2L, and 3L. For this reason, the terminal screw 201 is formed using a material having higher hardness than the driver for turning the terminal screw 201 so that the terminal screw 201 is not deformed by the driver for turning the terminal screw 201.

  In the watt-hour meter 100, the terminal screw 201 is not limited to being formed using a ceramic material. The terminal screw 201 only needs to be formed using a material having insulating (non-conductive) and predetermined hardness. The terminal screw 201 may be formed using, for example, a plastic material having a predetermined hardness instead of the ceramic material. By using a ceramic material, it is possible to provide a terminal screw 201 having higher hardness and superior heat resistance than using a plastic material.

  In FIG. 3, reference numeral 310 denotes a measurement hole into which a measurement terminal (not shown) provided in the measuring instrument is inserted in various measurement operations such as voltage measurement and measurement of the insulation resistance value of indoor electric wiring. Shows the part. By inserting the measurement terminal into the measurement hole 310, the measurement terminal and the wire pressing metal 305 are electrically connected. Thereby, the measurement part in the watt-hour meter 100 and the measurement terminal can be electrically connected.

(Conventional electricity meter)
Next, a conventional watt-hour meter will be described. FIG. 4 is an explanatory diagram showing an example of a conventional watt-hour meter. In FIG. 4, the cross section of the connection terminal block in the conventional watt-hour meter is shown. In FIG. 4, the same parts as those of the watt-hour meter 100 according to the embodiment of the present invention are denoted by the same reference numerals, and description thereof is omitted.

  In FIG. 4, a conventional watt-hour meter 400 is provided with a brass terminal screw 401 in place of the ceramic terminal screw 201 as compared with the watt-hour meter 100 according to the embodiment of the present invention. Since the terminal screw 401 is made of brass, it has conductivity. Moreover, the conventional watt-hour meter 400 does not include the wire pressing metal fitting 305 as compared with the watt-hour meter 100 according to the embodiment of the present invention, and the tip of the terminal screw 401 has a wire insertion hole 303b. It was set as the structure which contact | abuts directly on the outer peripheral surface of the electric wire 402 inserted in the inside.

  That is, in the conventional watt-hour meter 400, the terminal screw 401 having conductivity is exposed to the outside, and the work is performed by bringing a metal driver or the like into contact with the terminal screw 401. For this reason, the adjacent terminal screws 401 may be short-circuited via the driver. Further, in the conventional watt-hour meter 400, a conductive foreign material is fitted between the terminal screw 401 and the screw hole 302, and a short circuit may occur due to the foreign material.

  Further, in the conventional watt-hour meter 400, the electric wire 402 inserted into the electric wire insertion hole 303b is urged to come into contact with the brass ring-shaped member 304 by the tip of the brass terminal screw 401. It was supposed to be configured. For this reason, when the terminal screw 401 screwed into the screw hole 302 is tightened, the force acts locally on the electric wire 402. As a result, there has been a problem that the electric wire 402 is likely to deteriorate when it is used for a long time or when the electric wire 402 is repeatedly removed and connected. In response to such a problem, the watt-hour meter 100 according to the embodiment of the present invention has the following effects.

(Wire connection method)
Below, the connection method of the electric wire 402 with respect to the watt-hour meter 100 of embodiment concerning this invention is demonstrated. FIG. 5 is an explanatory diagram showing a method of connecting the electric wire 402 to the watt hour meter 100 according to the embodiment of the present invention.

  In FIG. 5, when connecting the electric wire 402 to the watt-hour meter 100 according to the embodiment of the present invention, the tip of the electric wire 402 to be connected is connected to the wire insertion hole 303 in the corresponding electric wire insertion portion 303. Insert into the part 303b. The tip end of the electric wire 402 to be connected is inserted into a position (one side opposite to the tip end of the terminal screw 201) facing the one surface side of the wire pressing metal fitting 305.

  At the tip of the electric wire 402 to be connected, the insulating coating is removed and the conductive core wire is exposed. The conductive core wire is exposed in the insertion direction of the electric wire 402 with respect to the electric wire insertion hole 303b, with a length that is approximately the same as the length of the electric wire holding fitting 305, or slightly shorter than the length of the electric wire holding fitting 305. It is preferable.

  Next, using a tool such as a screwdriver, the terminal screw 201 screwed into the screw hole 302 is rotated in the tightening direction. As a result, the wire pressing metal 305 is pushed by the tip of the terminal screw 201 that enters the inside of the terminal box 301, and moves in a direction in which the wire pressing metal 305 contacts the wire 402. The terminal screw 201 is such that even when the electric wire 402 is pulled with a certain force, the electric wire 402 inserted into the electric wire insertion hole 303b in the electric wire insertion portion 303 does not come out of the electric wire insertion hole 303b. It is preferable to tighten until it is pressed by the wire pressing metal fitting 305.

  Since the wire holding metal fitting 305 is formed using a conductive material, the electric wire holding metal fitting 305 is pressed against the electric wire 402 inserted into the electric wire insertion hole 303b in the electric wire insertion portion 303. 402 and the electric wire pressing metal 305 are electrically connected. Since the wire pressing metal 305 contacts the electric wire 402 on the surface, the electric wire 402 and the electric wire pressing metal 305 can be reliably brought into contact with each other, and the electric wire 402 and the measuring unit can be reliably electrically connected.

  Further, the wire holding metal 305 is further tightened with the terminal screw 201 screwed into the screw hole 302 with the terminal screw 201 screwed into the screw hole 302 being in contact with the electric wire 402. Then, the contacting electric wire 402 is pressed against the ring-shaped member 304 made of brass. The electric wire 402 is brought into surface (or line) contact with the ring-shaped member 304 made of brass by being urged by the electric wire pressing metal 305 on the surface. Thereby, the electric wire 402 and the ring-shaped member 304 made of brass can be reliably brought into contact, and the electric wire 402 and the measuring portion can be reliably electrically connected.

  As described above, the watt-hour meter 100 according to this embodiment includes the first terminals 1S, 2S, and 3S connected to the power source, the second terminals 1L, 2L, and 3L connected to the load, A measuring unit that is provided between the first terminal 1S, 2S, 3S and the second terminal 1L, 2L, 3L, and that measures the integrated value of the electric energy based on the current flowing from the power source to the load; An electric wire 402 provided in association with each of the terminals 1S, 2S, 3S and the second terminals 1L, 2L, 3L and connected to the first terminals 1S, 2S, 3S and the second terminals 1L, 2L, 3L. A terminal screw 201 that realizes a screw for fixing the electric wire 402 in contact with the first terminal 1S, 2S, 3S and the second terminal 1L, 2L, 3L, and the terminal screw 201 is non-conductive. It is characterized by being formed using a functional material .

  According to the watt-hour meter 100 of this embodiment, the exchange (including installation and removal) of the watt-hour meter 100 can be performed without touching the charged portion. As a result, it is possible to reduce the burden on the worker engaged in the replacement work of the watt-hour meter 100, and to improve the safety during the replacement work.

  Moreover, the watt-hour meter 100 of this embodiment is characterized in that the terminal screw 201 is formed using a ceramic material. According to the watt-hour meter 100 of this embodiment, the insulation of the terminal screw 201 can be ensured and the strength of the terminal screw 201 can be ensured. Thus, for example, when used outdoors, it is possible to suppress deterioration due to wind and rain and deterioration of the watt hour meter due to deterioration of the terminal screw as compared with a conventional metal terminal screw.

  The watt-hour meter 100 of this embodiment includes a terminal box 301 provided with a wire insertion hole 303b that realizes a plurality of recesses into which the wire 402 can be inserted, and includes first terminals 1S, 2S, 3S and the second terminals 1L, 2L, and 3L are provided in the wire insertion hole 303b, and the terminal screw 201 intersects the insertion direction of the electric wire 402 so that the tip is positioned in the wire insertion hole 303b. It is characterized by being screwed into the terminal box 301 from the direction in which it is made.

  In addition, the watt-hour meter 100 of this embodiment includes a wire pressing metal fitting 305 that is provided between the tip of the terminal screw 201 and the electric wire 402 and realizes a wire pressing member formed using a conductive material. When the terminal screw 201 is tightened, the wire pressing metal 305 is biased in a direction in which the electric wire pressing metal 305 contacts the electric wire 402.

  According to the watt-hour meter 100 of this embodiment, the electric wire 402 can be securely fixed and the electrical connection is reliably performed as compared with the case where the electric wire 402 is fixed by the tip of the terminal screw 201. be able to.

  In the watt-hour meter 100 of this embodiment, the electric wire pressing metal 305 is provided with a curved surface that is curved along the outer peripheral shape of the electric wire 402, and the curved surface is opposed to the electric wire 402. It is characterized by that. According to the watt-hour meter 100 of this embodiment, the electrical connection between the electric wire pressing metal 305 and the electric wire 402 inserted into the electric wire insertion hole 303b can be reliably performed.

  As described above, the watt-hour meter according to the present invention is useful for a watt-hour meter that accumulates and measures electric power, and in particular, reduces the burden on an operator engaged in replacement work and increases safety during the replacement work. Suitable for conscious watt-hour meter.

DESCRIPTION OF SYMBOLS 100 Electricity meter 120 Connection terminal block 201 Terminal screw 301 Terminal box 303b Wire insertion hole 305 Wire clamp 1S, 2S, 3S First terminal 1L, 2L, 3L Second terminal

Claims (3)

A first terminal connected to a power source;
A second terminal connected to the load;
A measuring unit that is provided between the first terminal and the second terminal and measures an integrated value of electric energy based on a current flowing from the power source to the load;
An electric wire provided in association with each of the first terminal and the second terminal and connected to the first terminal and the second terminal is connected to the first terminal and the second terminal. A plurality of screws formed using a non-conductive material to be fixed to each terminal in contact with the terminal;
An electric wire holding member provided between the tip of the screw and the electric wire, and formed using a conductive material;
A terminal box provided with a plurality of recesses into which the electric wires can be inserted; and
A ring-shaped member formed using a conductive material having a hole that allows the screw to pass therethrough inside the recess,
With
The ring-shaped member and the wire holding member are electrically connected to the measuring unit,
The screw is screwed into the terminal box from a direction intersecting the insertion direction of the wire so that the tip is positioned in the recess, and the tip of the screw is in contact with the wire holding member at a plurality of locations and tightened. The electric wire is fixed by urging the electric wire holding member in a direction in which the electric wire holding member comes into contact with the electric wire.   2. The electric energy according to claim 1, wherein the electric wire pressing member includes a curved surface that is curved along an outer peripheral shape of the electric wire, and is provided in a state where the curved surface is opposed to the electric wire. Total. The screws, the power meter of claim 1 or 2, characterized in that it is formed by using a ceramic material.

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