RU213933U1 - DEVICE FOR MEASURING, ACCOUNTING AND CONTROL OF ELECTRIC ENERGY CONNECTED TO ELECTRIC WIRES WITHOUT THEIR BREAK - Google Patents

Abstract

The solution belongs to the field of measuring technology, and is designed to connect metering, control and measurement of electricity in the domestic and industrial sectors. The device contains a detachable housing, including a base and a cover; an electrical wire holder disposed between the base and the cover and having guide grooves; a measurement board installed between the housing base and the electrical wire holder; current transformers having a split core, each of which is installed in one of the grooves of the electric wire holder so that the electric wire passes into the hole of the core; V-shaped knife contacts, the cutting edges of which are installed across the groove and fixed on its sides with the possibility of cutting the insulation of the electrical wire and creating electrical contact with it; clamps of electrical wires, each of which is mounted on a holder with the possibility of pressing and holding the electrical wire in the groove. The technical result is to simplify the design of the device, increase the convenience of connecting an electrical measuring instrument, reduce the complexity of the connection operation, reduce insulation damage, increase the reliability and security of the connection. 5 z.p. f-ly, 4 ill.

Description

Technical field

The solution belongs to the field of measuring technology, and is designed to connect metering, control and measurement of electricity in the domestic and industrial sectors.

Previous level

Connection to electrical wires of all devices for accounting, control, measurement of electrical energy, currently produced in the Russian Federation and abroad, is based on breaking the wires going from the substation to the client, in which there are input electrical wires from the supply phases and neutral, and output electrical phase and neutral wires that go to the load, that is, to the consumer of electrical energy. Thus, the electrical energy metering device is included in the break of each electrical wire, and this leads to a significant complication of the device and an increase in labor intensity during its installation and replacement. The complication of the device lies in the fact that in order to connect it, it is necessary to provide a number of details in it:

power block made of high fire resistance plastic (T>900°C),

power sockets (4 pcs. for single-phase devices and 8 pcs. for three-phase ones),

screws for connecting wires to power buses (8 pcs. for single-phase devices and 16 screws for three-phase ones),

power busbars made of pure copper for 100A current with a cross section of ~ 20 mm ² with a length of at least 10 cm (2 pcs. for single-phase devices and 4 pcs. for three-phase ones).

The complexity of installing an electrical energy metering device consists in the following operations:

cutting each electrical wire and stripping the ends (4 pcs for a single-phase device and 8 pcs for a 3-phase device),

inserting each wire into the sockets of the device and tightening 8 screws for a single-phase device, and 16 screws for a three-phase device.

It should be borne in mind that the points of entry and exit of wires are quite difficult to seal, and the sealing sleeves can only be located outside and therefore accessible to unauthorized intervention (a sealed access cover and terminal screws do not work). In addition, repeated rupture of wires, through which a current of 100 A can flow and subsequent connection by welding or screws, leads to heating of all power parts and creates the possibility of fire and the presence of additional losses in the device, so the power block must be made of non-combustible material.

In this work, the task is to eliminate all the above details from the device, to create a small-sized device with absolute protection from external weather factors according to IP65, IP66, with the ability to install this device on the site in a few seconds.

Known electric energy meter with all of the above disadvantages (RU 182808, G01R 11/00, published 09/04/2018).

The technical result is to simplify the design of the device, increase the convenience of connecting an electrical measuring instrument, reduce the complexity of the connection operation, reduce insulation damage, increase the reliability and security of the connection.

Technical solution

It should be noted the popularity of the solution disclosed in the Power Electronics magazine, No. 4, 2015 (https://power-e.ru/wp-content/uploads/5518.pdf, found on 09/25/2021), where the advantages of current transformers, with a toroidal core, including a split core.

Connectors are also known for connecting flat cables using knife contacts, by cutting through the cable insulation (https://web.archive.org/web/20140630082236/http://www.jaycar.com/images_uploaded/IDCconnJ.pdf, found 25.09. 2021).

The claimed solution is based on the use of split current transformers operating on the principle of current clamps, i.e. having a core with a moving part.

A device for connecting an electrical measuring instrument to electrical wires contains a detachable housing, including a base and a cover; an electrical wire holder disposed between the base and the cover and having guide slots each for receiving an electrical wire; a measurement board installed between the housing base and the electrical wire holder; current transformers having an annular core, each transformer being installed in one of the slots of the electrical wire holder so that the electrical wire passes into a hole in the core; V-shaped knife contacts, the cutting edges of which are the inner edges of the knife contact, installed across the groove and fixed on its sides with the possibility of cutting the insulation of the electrical wire and creating electrical contact with it; clamps of electrical wires, each of which is mounted on a holder with the possibility of pressing the electrical wire to the blade of the V-shaped knife and fixing the electrical wire in the groove.

An option is to use a toroidal transformer whose core has a detachable moving part. In this case, for reliable fixation of the movable upper part of the transformer, there are silicone stops on the inner surface of the housing cover, which are made with the possibility of pressing the movable part of the transformer core to its part fixed in the groove when the cover is closed.

In FIG. 1 shows a three-dimensional image of the device with the lid open, in Fig. 2 is an enlarged view of a fragment of a longitudinal section of the device for connecting to electrical wires shown in FIG. 1. In FIG. 3 shows an enlarged three-dimensional image of the groove in the dielectric housing of the device for connection to electrical wires. In FIG. 4 shows a three-dimensional image of the device assembled, installed on the wires of a 3-phase network.

In the drawings, the elements of the device are indicated by the following positions:

1 - base of the instrument case,

2 - cover of the instrument case,

3 - dielectric housing of the device for connecting to wires,

4 - guide grooves for laying wires,

5 - current transformer with toroidal core,

6 - fixed part of the toroidal core,

7 - moving part of the toroidal core,

8 - hole of the toroidal core of the transformer,

9 - V-shaped knife contacts,

10 - wires,

11 - wire clamps in the guide groove for fixing the blade contact on the wire,

12 - silicone stops,

13 - hooks on the side walls of the groove for fixing the clamp 8,

14 - wedge-shaped protrusions on the side walls of the groove to prevent longitudinal displacement of the wire in the groove,

15 - connection of knife contacts with the measuring board.

To illustrate the solution, the drawings show the design of a device for connecting to electric wires of a three-phase network, the body of which has a non-conductive base 1 and a cover 2, a measuring board (not shown) and a device for connecting to wires 10, including a dielectric housing 3 having guide grooves 4 for laying wires 10 in them, current transformers 5 with a toroidal core installed in each of the grooves 4 of the dielectric housing 3 so that the wire 10 laid in the groove 4 passes into the hole 8 of the core of the current transformer 5, and the clamps 11 of the wires 10 fixing the wire in the groove 4. On the side walls of each groove 4, V-shaped knife contacts 9 are fixed, which serve to cut through the wire insulation and provide an electrical connection between the wire conductor 10 and the measuring board.

Device for connection to the current-carrying part of the wire works as follows. An electrical wire 10 is placed in each of their grooves 4 (the wire is shown only in the nearest groove). This is possible when the clamps 11 are open, fixing the electric wire 10 passing through the hole 8 of the toroidal transformer 5 placed in the groove 4. After laying the wires, the clamps 11 are closed and fixed. When the clip 11 closes, the wire 10 moves down and the blade contacts 9 cut through the insulation of the electric wire and come into contact with the conductors of the wire 10. Thus, each clip means is configured to move the wire 10 along the V-shaped blade contact 9 and is provided with a locking means in the guide groove 4.

Voltage through the knife contacts 9 is supplied to the measuring board (not shown). Knife contacts 9, made of beryllium bronze, cut the wire insulation 10. To avoid loss of contact when the device is moved or the wire is twitched to one side or the other, wedge-shaped protrusions 14 are arranged in the walls of the groove 4, the pointed edge of which is adapted to prevent longitudinal displacement of the wire in the groove, located to the left and right of each clamp 11. These protrusions also cut into the insulation of the wire 10, preventing it from moving in the longitudinal direction. Knife contacts 9 and fixing protrusions have a V-shape, converging to the bottom so that wires of different diameters (within certain limits) can be used for connection. A wire with a smaller diameter will be immersed by clamp 11 more deeply. In order for the hooks 13 and the locking protrusions 14 not to disengage, the clamp 11 is fixed by the stops 12 when the cover 2 of the device is closed.

Current transformers 5 are held in their position due to friction with the plastic of the body 3 of the holder 1, and after closing the cover 2 they are pressed with the help of additional silicone stops 12 installed on the cover 2, or by other methods (there are many of them).

It should be noted that this design is preferable when using split current transformers, since in this case the technical result is achieved in a larger area of application of the device. The claimed device is especially convenient for Split-meters. In this case, both versions (with a split transformer and a one-piece in the form of a torus) will be almost the same in terms of installation labor, since the distance from the electrical measuring device to the electrical wires is usually small.

Connecting a device with a split core transformer is as follows.

The cover 2 of the instrument housing opens, the clamps 11 open, the upper movable parts 7 of the current transformers 5, installed in the grooves 4 of the dielectric housing of the device, each wire 10 is inserted into one of the guide slots 4 of the specified dielectric housing 3, the upper movable parts of the current transformers 5 are closed, with finger pressure, the clamping means 11 moves the wire along the V-shaped knife contact deep into the guide groove and is fixed by the clamp 11 on the walls of the groove (4 and 8 pieces, respectively, for single- and three-phase devices), the cover 2 of the device case is closed, and the upper movable part 7 of the transformers 5 is pressed against its lower part 6 with the help of silicone stops 12 attached to the cover 2. If necessary, a test switch is made and the LEDs present in the measuring circuit show that there are contacts in all phases.

Claims (12)

1. A device for measuring, accounting and controlling electrical energy, connected to electrical wires without breaking them, containing the body of the device, including the base and cover; measuring board; a device for connecting to electrical wires, having a dielectric housing and means for clamping wires, characterized in that the dielectric body of the connection device has guide grooves for laying electrical wires, a current transformer with a toroidal core is installed in each guide slot so that the wire passes into the core hole; on the side walls of the guide grooves, V-shaped knife contacts are fixed, the cutting edges of which are installed across the guide groove to cut the wire insulation and create electrical contact with its current-carrying part, while the groove walls have wedge-shaped protrusions, the pointed edge of which is adapted to prevent longitudinal displacement of the wire in groove, and each wire clamping means is configured to move the wire along the V-shaped knife contact and is provided with a locking means in the guide groove. 2. A device for measuring, recording and controlling electrical energy according to claim 1, characterized in that the toroidal core of the current transformer has a movable part, while the fixed part of the toroidal core is fixed in the guide groove of the dielectric housing of the device for connecting an electric wire. 3. A device for measuring, accounting and controlling electrical energy according to claim 2, characterized in that the inner surface of the cover has silicone stops for pressing the moving part of the toroidal current transformer. 4. A device for measuring, accounting and controlling electrical energy according to claim 1, characterized in that the dielectric housing of the connection device has two guide grooves for laying electrical wires of a single-phase network. 5. A device for measuring, accounting and controlling electrical energy according to claim 1, characterized in that the dielectric housing of the device for laying the connection has four grooves for accommodating electrical wires of a three-phase network. 6. A device for measuring, accounting and controlling electrical energy according to claim 1, characterized in that it has a display mounted under a transparent cover of the device housing.

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