JPH0337142B2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains]

The present invention relates to a terminal device for a watt-hour meter that interconnects the watt-hour meter and external wiring on the power supply side and the load side.

[Prior art and its problems]

A watt-hour meter is a device that is installed between the power supply side wiring drawn from the distribution line and the load-side wiring on the power consumer side to supply the amount of power supplied to the load side. In some cases, electricity meters may be temporarily removed for periodic replacement or inspection and repair at the location. However, conventional watt-hour meters are configured so that external wiring on the power supply side and load side are directly connected to the terminal block built into the watt-hour meter body. Since the interconnection between the power supply side wiring and the load side wiring is disconnected, the load side will be in a power outage state, even if only temporarily, which will disrupt the lives of ordinary household customers, and furthermore, will cause problems for customers such as businesses. This may lead to undesirable situations such as being forced to completely suspend operations. When replacing the watt-hour meter, by making a bypass connection between the power supply side wiring and the load-side wiring in advance using temporary auxiliary wiring, it is possible to replace the watt-hour meter without causing a power outage on the load side. However, in this case, dangerous live wire work would be required, and there would be problems in terms of work safety, such as the risk of electric shock. In addition, for this purpose, an auxiliary external terminal block that is connected removably to the main body of the watt-hour meter is installed after connecting the external wiring all together between the watt-hour meter and the external wiring. When replacing the main unit, a short circuit is connected to the terminal block to bridge the power supply side wiring and the load side wiring, thereby forming a short circuit that bypasses the main unit. A method has been proposed in which the meter can be replaced. However, in this type of conventional system, the external terminal block is left in place even when the watt-hour meter is replaced, so the external terminal block is used for a longer period than the watt-hour meter. become. On the other hand, this type of watt-hour meter is usually used outdoors in places with poor ambient conditions, such as under eaves, and during long-term use, the insulation of the resin molded product that makes up the external terminal block is The terminal block begins to deteriorate. For this reason, even if an external terminal block is installed as in the method described above so that the watt-hour meter can be replaced without a power outage, it would be a failure if the insulated terminal block of the external terminal block cannot be replaced without a power outage. Furthermore, if the power supply to the load side is interrupted when replacing the terminal block of the external terminal block, a contradiction arises in that the effect of installing the external terminal block is halved.

[Purpose of the invention]

This invention has been made in consideration of the above points, and solves the above-mentioned problems, and eliminates the need for a power outage to the load on the consumer side when replacing a watt-hour meter.
Another object of the present invention is to provide a terminal device for a watt-hour meter that allows safe and easy replacement of the insulated terminal block of the watt-hour meter and external terminal block.

[Key points of the invention]

In order to achieve the above object, the present invention provides an external terminal block with an independent structure that is removably connected to an external terminal block built into the main body of a watt-hour meter, and a terminal block that is connected to the external terminal block when the watt-hour meter is replaced. and a short circuit that is used in combination with the block,
The external terminal block has fixed terminal fittings on the power supply side and load side that connect the external wiring on the power supply side and the load side to each terminal fitting installed on the terminal block on the power meter side, respectively, and a row of the fixed terminal fittings. Hold it in place by fitting it in from both sides 2
It consists of an insulated terminal block as a split block structure, and the short circuit is replaceable with one of the split blocks of the external terminal block, and when the short circuit is replaced, the short circuit can be replaced with the power supply side fixed terminal fitting installed on the other split block. It has a built-in shorting piece that contacts and bridges the fixed terminal fittings of corresponding phases between the load side fixed terminal fittings, and when the watt-hour meter is in normal use, the power supply is connected via the external terminal block. A conductive path leading to the current and voltage circuit of the measuring section on the main body side is formed between the external wiring on the side and load side and the watt-hour meter main body, and the power consumption on the load side is measured. When disconnecting the connection between the main unit and the external wiring for replacement, etc., replace the short circuit with one divided block of the external terminal block, connect it to the other divided block, and disconnect the power supply side wiring of the corresponding phase and the load. By short-circuiting the side wiring, the watt-hour meter can be bypassed and the watt-hour meter body replacement work can proceed without a power outage on the load side.Furthermore, the fixed terminal fittings of the external terminal block can be separated into a split block structure. By fitting into the insulated terminal block and holding it in place on the terminal block, the divided blocks of the terminal block can be replaced one by one while maintaining power supply to the load side. be.

[Embodiments of the invention]

FIGS. 1 to 9 show an embodiment of the present invention intended for a watt-hour meter used in a three-phase three-wire power distribution circuit, and FIGS. 10, 11, 12, and 13 1 shows the configuration of different embodiments. First, in FIG. 1, 1 is the main body of the watt-hour meter that has a built-in power metering section, and 2 is the main body side that is incorporated into the main body 1. A terminal block, 3 is an external terminal block of a terminal device inserted between the terminal block on the main body side and external wiring, 4 is a short circuit of the terminal device, 5a, 5b, 5c are power supply side wirings, 6a,
6b and 6c are load side wiring. As shown in FIG. 8, the main body 1 of the electricity meter described above has a built-in measuring section such as a current detection element 11, a voltage detection element 12, and a power consumption integration and display mechanism (not shown). The fixed terminal fittings 21 connected to and pulled out from each element on the main body side are connected to the terminal block 2 equipped on the main body side, and the fixed terminal fittings on the external terminal block side to be described later are joined to the fixed terminal fittings 21. Fastening screws 22 that are fastened in this state are arranged side by side. On the other hand, the external terminal block 3 is an insulated terminal block 33 which is a two-part structure in which split blocks 31 and 32 made of resin molded products or the like are stacked on top of each other.
and the fixed terminal fitting 2 of the main body side terminal block 2.
1, a power supply side fixed terminal fitting 34 and a load side fixed terminal fitting 3 are arranged side by side on the terminal block 33, facing the terminal block 33.
It is constructed as an assembly with 5. The structure of the fixed terminal fittings 34 and 35 is as shown in FIG. 2, and a pin is inserted into the fixed terminal fitting 21 of the terminal block on the main body side at the tip end thereof.
Furthermore, an insertion hole for external wiring is opened at the rear end. Note that 36 is a fastening screw for external wiring, and 37 is a screw hole for fastening a shorting piece of a short circuit 4, which will be described later, to fixed terminals 34 and 35. Further, the divided blocks 31 and 32 constituting the terminal block 33 are formed with fitting grooves for holding the fixed terminal fittings 34 and 35 in a predetermined position while separating them from each other.
After fitting the fixed terminal fittings 34 and 35 into the fitting grooves and holding them from both sides, the split block 3 is inserted.
1 and 32 are fastened together by a fastening screw 38. In addition, 39 is a terminal fitting 34 that fixes external wiring.
This is a screw operation window opened in the split block 32 in order to operate the fastening screw 36 fixed to the block 35. The short circuit 4 also includes an insulating frame 41 which is overlapped and coupled from the front on the divided block 31 constituting the terminal block 33 of the external terminal block 3;
With the shorting pieces 42, 43, and 44 installed on the inner surface of the insulating frame 41 and the short circuit 4 connected to the external terminal block 3, each of the shorting pieces 42 to 44 is brought into contact with a fixed terminal fitting on the external terminal block side. a short-circuiting screw 45 which is connected to the screw hole 37, and a coupling fitting 46 as a thumbscrew which couples the insulating frame 41 to the split block 31 of the external terminal block 3.
It will be equipped with. Each of the shorting pieces 42 described above
44 are arranged so as to bridge between the power supply side terminal fittings 34 and the load side terminal fittings 35 of the respective phases among the fixed terminal fittings installed in the external terminal block 3. Further, as shown in FIG. 3, the shorting screw 45 of the shorting device 4 is attached to the insulating frame 41 by a washer 47 so as not to fall off. FIG. 4 is a sectional view of the external terminal block 3 in the assembled state, and FIG. 5 is a sectional view of the short circuit 4 in the assembled state.
Further, FIG. 6 shows a cross-sectional view of the terminal block in a state in which the watt-hour meter is in use, in which the external terminal block 3 is coupled to the main body 1 of the watt-hour meter. In Fig. 6, reference numeral 5 denotes a terminal cover that covers the open front surface of the terminal block 2 and the external terminal block 3 when they are combined, and covers the open front surface of both the terminal blocks. Patsukin to prevent 51
is attached and fastened to the terminal block side with screws 52. Next, the usage status of the watt-hour meter with the above configuration and the procedure for replacing the watt-hour meter will be explained. In other words, in normal use of the electricity meter, the fourth
As shown in the figure, when the external terminal block 3 is assembled, the power supply side wiring 5a to
5c and the load side wirings 6a to 6c, the external terminal block 3 is connected to the main body side terminal block 2 as shown in FIG. The wiring circuit of the watt-hour meter in this state of use is as shown in FIG. Electric power measuring elements 11 and 12 are inserted, thereby supplying power to the load side and measuring the amount of power consumed by the power meter. Next, when periodically replacing the electricity meter, inspecting and repairing it, etc.
The operating procedure when replacing the watt-hour meter while power is being supplied to the load side will be described with reference to FIGS. 7a to 7e. First, remove the terminal cover 5 of the watt-hour meter and put it in the state shown in figure a. Next, as shown in figure b, there is a divided block 32 on the front side that constitutes the terminal block of the external terminal block 3.
Remove it by pulling it forward. In the state shown in Figure b, the front halves of the fixed terminal fittings 34 and 35 are exposed, but the rear halves are fitted into the fitting grooves of the split block 31 and held, and the tips of the terminal fittings are attached to the terminal block 2 on the main body side. Since it is fastened and fixed to the fixed terminal fitting 21, it will not fall off. Next, as shown in Fig. c, the short circuit 4 is placed on top of the split block 31 of the external terminal block 3, and the thumb screws 46 are used to fasten the two, and the short circuit screw 45 is screwed in as shown in Fig. 5. Short circuit pieces 42, 43,
44 are bridged between respective corresponding phases on the external terminal block 3 side between the power supply side terminal fitting 34 and the load side terminal fitting 35.
As a result, as shown in FIG. 9, the shorting pieces 42, 43, and 44 connect the corresponding phases between the external wiring on the power supply side and the load side, that is, the wirings 5a and 6a, 5b and 6b, and 5c and 6c. A short circuit is formed to form a power supply circuit to the load side that bypasses the main body 1 of the watt-hour meter. Next, terminal block 2 on the main body side
After loosening the screws 22 of the fixed terminal fittings 21, remove the watt-hour meter main body 1 together with the terminal block 2 from the watt-hour meter mounting seat as shown in figure e, pull it diagonally upwards, and remove it from the external terminal block 3. Separate. In this case, the power supply side wiring and the load side wiring are already short-circuited by the short circuit 4 on the external terminal block side as shown in Fig. 9, and therefore the power supply to the load side is interrupted. It becomes possible to disconnect the main body 1 of the watt-hour meter from the external wiring without any trouble. Although it is necessary to operate the screws of the live part when removing the electricity meter, by using a screwdriver with an insulated handle, the work can be carried out safely without fear of electric shock. To replace the watt-hour meter removed by the above operation and install a separately prepared watt-hour meter, connect the terminal block 2 of the watt-hour meter main body 1 and the external terminal block 3 by reversing the procedure described above, and then remove the short circuit. By removing the device 4, connecting the divided block 32 of the terminal block 33 of the external terminal block 3 to 31, and finally attaching the terminal cover 5, the power meter returns to the normal operating state shown in FIG. Next, the procedure for replacing the insulated terminal block 33 of the external terminal block 3 that has deteriorated due to long-term use with a new terminal block without power outage will be explained. In this case, remove the watt-hour meter body 1 from the mounting surface of the watt-hour meter while still connected to the external terminal block 3 from the state shown in FIG. Remove the screw 38 fastening between the divided blocks 31 and 32 of the terminal block 33. Next, remove the divided blocks 31 and 32 one by one and replace them with new divided blocks. In this case, each fixed terminal fitting 34 of the external terminal block 3,
35 is fitted and held in either one of the split blocks 31 and 32, and is further coupled to the fixed terminal fitting 21 of the terminal block 2 on the main body side and supported in a predetermined position, so that there is no possibility of the terminal fitting falling off or improper contact between the terminal fittings. can be avoided. Also, during the process of replacing the watt-hour meter described in FIGS. 7a to 7e, the external terminal block 3
When replacing the insulated terminal block 33, first replace the divided block 32 removed in state b with a new divided block. For the other divided block 31, loosen the thumbscrew 46 of the short circuit 4 in the state shown in Figures d or e to release the connection with the divided block 31. In this state, pull out the divided block 31 backwards and install the new divided block. Replaced with. In this case, each fixed terminal fitting of the external terminal block 3 is fastened to the shorting pieces 42 to 44 provided on the insulating frame 41 by the shorting screw 45 of the short circuit 4 and held in a predetermined position, so that the fixed terminal fittings may fall off. Of course,
There is no need to cause a power outage on the load side. Next, another embodiment of the short circuit 4 is shown in FIGS. 10 and 11.
As shown in the figure. That is, in the short circuit 4 of the embodiment shown in FIG. 1, the short circuit pieces 42 to 44 and the external terminal block 3
Although a structure is shown in which the short-circuiting screws 45 are used to fasten and make contact with the fixed terminal fittings on the side, in the embodiment shown in FIG. Each short circuit piece 42 is fitted and locked and supported by the insulating frame 41.
A biasing spring 49 that presses the shorting piece from behind is interposed between both ends of the shorting pieces 44 and the insulating frame 41, and when connected to the external terminal block shown in FIG. Spring 4 described above with ~44
9 is pressed into contact with the fixed terminal fitting on the terminal block side, thereby bridging the power supply side terminal fitting 34 and the load side terminal fitting 35. Note that instead of providing the biasing spring 49, the shorting pieces 42 to 44 themselves are made of an elastic conductive material such as phosphor bronze, and the elasticity of the shorting pieces themselves is used to bring them into contact with the fixed terminal fitting on the external terminal block side. It is also possible to do so.
Furthermore, a butterfly fitting 46 for connecting and fastening the insulating frame 41 of the short circuit to the split block 31 of the terminal block on the external terminal block side has an L-shaped tip at its shaft end, and connects the insulating frame 41 to the external terminal block side terminal block 31. After inserting the butterfly fitting 46 into the engagement hole formed on the dividing block 31 side while superimposing it on the dividing block 31 of the side terminal, rotate the butterfly fitting 46 90 degrees to attach it to the dividing block side in a bayonet manner. Locked and fixed. With this structure, the short circuit 4 can be easily installed, and the replacement workability can be further improved. FIG. 12 shows a still different embodiment, and the difference between this embodiment and the embodiment shown in FIG. Rearrange the power supply side wirings 5a to 5c and load side wirings 6a to 6
The fixed terminal fittings are arranged so that the corresponding phase wirings of c are adjacent to each other, and in particular, the fixed terminal fittings corresponding to the external wirings 5b and 6b are integrally structured terminal fittings as shown by reference numeral 6. As a result, the shorting pieces incorporated in the shorting device 4 only need to be equipped with two pieces of shorting pieces 42 and 43 that bridge between the fixed terminal fittings 34 and 35 adjacent to each other, and the structure of the shorting device 4 can be significantly simplified. Furthermore, the embodiment shown in FIG. 13 is different from the embodiment shown in FIG.
4 and 35 are of the bidirectional insertion type, and the fixed terminal fitting 21 of the terminal block 2 on the main body side is configured as a pin terminal so as to be connected to the fixed terminal fitting on the external terminal block 3 side by insertion. . These twelfth
The embodiments shown in FIGS. 1 and 13 allow uninterrupted replacement of the watt-hour meter and replacement of the insulated terminal block of the external terminal block, as in the embodiment shown in FIG.

【Effect of the invention】

As described above, according to the present invention, the external terminal block has an independent structure that is removably connected to the terminal block built into the main body of the watt-hour meter, and the external terminal block is connected to the terminal block when the watt-hour meter is replaced. and a short circuit used in combination with the power meter, and the external terminal block connects the external wiring on the power supply side and the load side to each terminal fitting installed on the terminal block on the power meter side, respectively. It consists of a fixed terminal fitting on the load side and an insulated terminal block which is a two-part block structure that holds the row of fixed terminal fittings in a predetermined position by fitting them from both sides. It is possible to replace one divided block of the blocks, and at the time of the exchange, a contact type is used to connect the fixed terminal fittings of the corresponding phases between the power supply side fixed terminal fittings and the load side fixed terminal fittings installed on the other divided block. By configuring the terminal device of the electricity meter with a built-in shorting piece that bridges the
In addition to being able to safely and easily replace the watt-hour meter without causing a power outage on the load side when disconnecting the watt-hour meter from external wiring for periodic replacement, inspection and repair, etc., It is possible to provide a terminal device for a watt-hour meter with high practical value, in which an insulated terminal block of an external terminal block that has deteriorated during use can be replaced without interruption.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view of a terminal device of a watt-hour meter according to an embodiment of the present invention, and FIGS. 2 and 3 are perspective views of a fixed terminal fitting of an external terminal block and a portion of a short circuit in FIG. 1, respectively. 4 and 5 are structural sectional views showing the assembled state of the external terminal block and the coupled state of the external terminal block and the short circuit in the embodiment of FIG. 1, respectively.
The figures are a partial cross-sectional side view showing the state of use of the watt-hour meter according to the embodiment shown in FIG. 1, FIGS.
The figures are wiring circuit diagrams of the watt-hour meter showing the usage state of the watt-hour meter and the state of disconnection between the watt-hour meter main body and the external terminal block, and FIG. 10 is a perspective view of the configuration of a short circuit according to an embodiment different from that in FIG. 1. , FIG. 11 is a sectional view of the short circuit shown in FIG. 10 coupled to an external terminal block, and FIGS. 12 and 13 are exploded perspective views of a terminal device according to an embodiment different from the above embodiment. In the figure, 1: Main body of the watt-hour meter, 2: Terminal block on main body side, 21: Fixed terminal fitting, 3: External terminal block, 31, 32: Divided blocks of terminal block, 33: Insulated terminal block, 34: Power supply side terminal fittings,
35: Load side terminal fitting, 4: Short circuit, 41: Insulating frame, 42: 43: 44: Shorting piece, 45: Shorting screw, 49: Biasing spring for shorting piece, 5a, 5b,
5c: power supply side wiring, 6a, 6b, 6c: load side wiring.

Claims (1)

[Scope of Claims] 1. A terminal device for connecting external wiring on the power supply side and load side to a watt-hour meter, which has an independent structure that is detachably connected to a block built into the main body of the watt-hour meter. and a short-circuit path used in combination with the external terminal block when replacing the watt-hour meter, and the external terminal block connects the external wiring on the power supply side and the load side to the power supply side, respectively. Fixed terminal fittings on the power supply side and load side connect to each terminal fitting equipped on the terminal block on the meter side, and a two-part block structure in which the rows of fixed terminal fittings are held in place by fitting from both sides. Furthermore, the short circuit can be replaced with one of the divided blocks of the external terminal block, and when the short circuit is replaced, the power supply side fixed terminal fitting and the load side fixed terminal fitting installed on the other divided block are replaced. A terminal device for a watt-hour meter, characterized by incorporating a short-circuiting piece that contacts and bridges fixed terminal fittings of corresponding phases between the terminal fittings. 2. The terminal device according to claim 1, wherein each divided block constituting the terminal block of the external terminal block has a structure in which each fixed terminal fitting is individually fitted and held in a predetermined position. Terminal device for meter. 3. In the terminal device according to claim 1, the short circuit includes an insulating frame that holds a shorting piece therein and is coupled to the terminal block on the external terminal block side, and the insulating frame is connected to the terminal block of the external terminal block. 1. A terminal device for a watt-hour meter, characterized in that it is equipped with a shorting screw that brings the shorting piece into contact with a fixed terminal fitting on an external terminal block side in a connected state. 4. In the terminal device according to claim 1, the short circuit includes an insulating frame that holds a shorting piece therein and is coupled to the terminal block on the external terminal block side, and the insulating frame is connected to the terminal block of the external terminal block. A terminal device for a watt-hour meter, characterized in that it is equipped with a spring member that presses and biases the shorting piece from behind so that it comes into contact with the fixed terminal fitting on the external terminal block side in the connected state.