CN109961986B

CN109961986B - Electrical device for establishing or breaking a current in an electrical circuit

Info

Publication number: CN109961986B
Application number: CN201811502053.8A
Authority: CN
Inventors: C.布尔诺特; B.勒博
Original assignee: Schneider Electric Industries SAS
Current assignee: Schneider Electric Industries SAS
Priority date: 2017-12-14
Filing date: 2018-12-10
Publication date: 2023-03-21
Anticipated expiration: 2038-12-10
Also published as: EP3499540A1; CN109961986A; FR3075458B1; EP3499540B1; FR3075458A1

Abstract

The invention relates to an electrical device for establishing or breaking a current in an electrical circuit, the device comprising: at least two pairs of fixed contacts (19 to 24), each pair comprising two fixed contacts electrically connected to an upstream terminal (11 to 14) and a downstream terminal (15 to 18) of the device associated with the pair, respectively; and a bridge (25 to 27) of two movable contacts, which is movable between a first position, in which it electrically connects the two fixed contacts, and a second position, in which the flow of current between the two fixed contacts is interrupted, wherein one pair of fixed contacts and its associated movable contact bridge is on the line (8, 9, 10) carrying the phase and the other pair of fixed contacts and its associated movable contact bridge is on the line (7) carrying the neutral. The device is characterized in that the electrical connection between the two terminals (11, 15) on the neutral line (7) is a permanent connection.

Description

Electrical device for establishing or breaking a current in an electrical circuit

Technical Field

The invention relates to an electrical device for establishing or breaking a current in an electrical circuit, the device comprising: at least two pairs of fixed contacts, each pair comprising two fixed contacts electrically connected to an upstream terminal and a downstream terminal of the device associated with the pair, respectively; and a bridge of two movable contacts, movable between a first position, in which it electrically connects the two fixed contacts, and a second position, in which the flow of current between the two fixed contacts is interrupted, wherein one pair of fixed contacts and its associated movable contact is bridged on the line conveying the phase and the other pair of fixed contacts and its associated movable contact is bridged on the line conveying the neutral.

Background

Such devices, called "contactors", are known, which are electrical devices for establishing or interrupting the flow of electric current via an electrical or pneumatic control unit.

Depending on its use, the contactor may be a unipolar, bipolar, tripolar or even a tetrapolar contactor. In other words, the contactor has one to four power contacts for withstanding an arc caused by a large current when opened or closed.

In such contactors, all movable contacts are mounted on the same support, so that they can all move simultaneously when a closing or opening command is given to the contactor. Such contactors can be actuated manually or via a coil through which an electric current can pass and which can interact with a fixed armature rigidly connected to the fixed contacts of the contactor and a movable armature rigidly connected to the movable contacts of the contactor. Therefore, when no current passes through the coil, the fixed armature does not exert a magnetic attraction force on the movable armature, and then the magnetic circuit is opened. When sufficient current passes through the coil, the fixed armature attracts and attaches to the movable armature: the magnetic circuit is then closed. Thus, the movement of the movable armature drives the opening and closing of the contacts.

When the device comprises a neutral line, for example a four-pole device comprising three phase lines and one neutral line, the neutral line is formed in the same way as the phase lines, i.e. it comprises two fixed contacts electrically connected with the two terminals respectively, and a movable contact bridge forming two movable contacts capable of interacting with the two fixed contacts respectively.

Each of these fixed and movable contacts includes a contact pad that is susceptible to signs of aging after a certain number of operations of the contactor. This aging phenomenon of the contact pads aging may lead to neutral breakdown, which may lead to overvoltages, which may lead to partial or complete destruction of the receiver.

To overcome this problem and to ensure that the electrical connection between the two upstream and downstream terminals on the neutral line is made correctly, as a precaution, the installer usually adds external wiring that electrically connects the two terminals, which represents a limitation for the installer.

Disclosure of Invention

The present invention overcomes these problems and provides an electrical apparatus for establishing or breaking a current in an electrical circuit (e.g. a contactor), allowing to eliminate the risk of neutral breakdown without additional restrictions of the installer.

To this end, the subject of the invention is an electrical device for establishing or breaking an electrical current in an electrical circuit of the type described above, the device being characterized in that the electrical connection between the two terminals located on the neutral line is a permanent connection.

According to a particular feature, the above-mentioned electrical connection is formed by a single-piece rigid conductor comprising, at its two opposite ends, two end portions respectively forming the respective two connection regions of the two terminals.

According to another feature, the above-mentioned conductor is U-shaped, comprising a rectilinear central portion having two consecutive right-angle bends at each of its two opposite ends, the neutral conductor having an overall shape corresponding to the shape of a group of conductors located between the upstream and downstream terminals on each of the phase lines.

According to another feature, all the movable contact bridges of the device are mounted on the same support that can be moved by the control means between the two aforementioned positions, each movable contact bridge passing through an opening in the support so as to be able to be driven thereby respectively towards the closed position and towards the open position, the neutral conductor passing through the support by means of a gap arranged with respect to the conductor so that the conductor does not interfere with the movement of the support, the portion of the neutral conductor passing through the support being in the same plane as the movable contact bridges when they are in the closed position.

According to another feature, the above-mentioned opening allows the insertion of the movable contact bridge parallel to its axis, and the above-mentioned clearance allows the insertion of the conductor into the support perpendicularly to its longitudinal direction.

According to another feature, the above neutral conductor is held and positioned in at least one slide provided in an internal face of a wall belonging to the casing of the device.

According to another feature, the device is a quadrupole device comprising three electrical phase lines and one electrical neutral line.

According to a particular feature, the device is a contactor.

Drawings

However, other advantages and features of the present invention will become more apparent in the following detailed description, given by way of example only, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a contactor according to the present invention;

FIG. 2 is a perspective view showing a portion of a contactor including terminals and electrical connections connecting upstream terminals to downstream terminals;

FIG. 3 is a cross-sectional view of the contactor in a plane parallel to the device attachment plane; and

fig. 4 is a perspective view showing a part of an apparatus including a movable contact support, a fixed contact and a movable contact and a neutral conductor according to the present invention;

fig. 5 is a perspective view of a movable contact support according to the prior art;

figure 6 is a perspective view of a movable contact support adjusted according to the invention;

FIG. 7 is a partial perspective view more particularly illustrating a housing portion of the device including a slide; and

fig. 8 is a detailed view of fig. 7.

Detailed Description

Figure 1 shows an electrical contact C according to the invention. In a manner known per se, the contact C is housed in a substantially parallelepiped case B comprising: a rear face 1 for attachment to a mounting rail; a front face 2 forming a nose; two

lateral faces

3, 4 via which the contactor can be attached to other equipment of the same type on the rail; and two faces, respectively an upper face 5 and a lower face 6, which respectively comprise a set of downstream terminals a and a set of upstream terminals T.

According to this particular exemplary embodiment, the device is a four-pole device and accommodates four

electrical lines

7, 8, 9, 10, namely a neutral line 7 and three

phase lines

8, 9, 10. Associated with each of these electrical lines are an

upstream terminal

11, 12, 13, 14 for electrical connection to the power supply device and a

downstream terminal

15, 16, 17, 18 for electrical connection to the output device, via wires or combs.

Each

electrical phase line

8, 9, 10 comprises: two

fixed contacts

19, 20; 21. 22; 23. 24 electrically connected to the downstream terminal and the upstream terminal, respectively; and two movable-

contact bridges

25, 26, 27 forming, at two opposite ends thereof, two movable contacts a, b intended to interact with the

fixed contacts

19, 20 to 24, respectively. All contacts include contact pads 28 at the contact areas. All the fixed contacts are electrically and mechanically connected by their ends located opposite the movable contacts to the

connection zones

12a, 13a, 14a, 16a, 17a, 18a of the

corresponding terminals

12, 13, 14, 16, 17, 18.

According to the invention, the electrical connection between the upstream terminal 11 and the downstream terminal 15 on the neutral line 7 is permanent and therefore is not equipped with a movable contact and two fixed contacts, as is the case with other phase lines.

According to the shown embodiment of the invention, the electrical connection is formed by a flat rigid conductor 29, which conductor 29 consists of one piece. The conductor includes a straight portion 29a having two right-

angle bent portions

29b, 29c at two opposite ends thereof, and two connection regions or

portions

11a, 15a for insertion into the corresponding two

terminals

11, 15, respectively, are formed at the two opposite ends thereof.

The shape of the neutral conductor 29 generally corresponds to the shape of each group associated with the phase current line and comprising two fixed contacts, a movable bridge and two connection zones. The linear portion 29a of the neutral conductor 29 lies in the same plane as each group associated with the phase line comprising two fixed contacts and a movable contact.

As shown in fig. 4 to 6, all the

movable contact bridges

25, 26, 27 of the device are mounted in the same support 30, which support 30 can be moved between the two aforementioned positions by means of a manual or electromagnetic control. Each movable contact bridge passes through an opening 30a in the support so as to be able to be driven thereby towards the closed position and the open position, respectively, while the neutral conductor 29 passes through the support 30 through a gap 30b, which gap 30b is arranged relative to the conductors so that it does not interfere with the movement of the support 30, the neutral conductor being in the same plane as the movable contact bridges when they are in the closed position. The opening 30a allows the bridge to be inserted parallel to the axis of the bridge, while the above-mentioned gap 30b allows the neutral conductor to be inserted into the support 30 perpendicularly to the longitudinal direction of the conductor.

Thus, the support used in the prior art contactor may be used by removing the end portion 30c from the support such as is commonly used in prior art contactors to allow the neutral conductor to be inserted into the support perpendicular to its longitudinal direction.

The neutral conductor is mounted in the following manner.

First, the neutral conductor 29 is placed into the two

slide ways

31, 32 of the housing B of the apparatus shown in fig. 7 and 8, and then the two

neutral terminals

11, 15 are respectively mounted at both ends of the conductor.

Next, the support 30 fitted with the

movable contact bridges

25, 26, 27 is placed into the housing of the device until it is located directly above the neutral conductor 29, optionally after the support 30 has been modified as described above in the case of the use of prior art supports. Next, the fixed contacts 19 to 24 are inserted into the housing B together with the corresponding terminals 11 to 18.

By means of the invention, an electrical device for establishing or breaking a current in an electrical circuit (for example a contactor) is made which makes it possible to overcome the problem of neutral breakdown occurring as soon as the contact pads age, without external wiring, using a shunt incorporated in the device on the neutral line. This solution can be easily incorporated into existing contactors with minimal modifications.

Of course, the invention is not limited to the embodiments described and shown, which are given as examples only.

On the contrary, the invention includes all technical equivalents of the means described and combinations thereof, provided that they are implemented according to the spirit of the invention.

Claims

1. An electrical device for establishing or breaking a current in an electrical circuit, the device comprising: at least two pairs of fixed contacts, each pair comprising two fixed contacts electrically connected to an upstream terminal and a downstream terminal of the device respectively associated with at least one of said at least two pairs of fixed contacts; and a bridge of two movable contacts, which is movable between a first position, in which it electrically connects the two fixed contacts, and a second position, in which the current flow between the two fixed contacts is interrupted, wherein one pair of fixed contacts and its associated movable contact is bridged on the line carrying the phase and the other pair of fixed contacts and its associated electrical connection is on the line carrying the neutral,

characterized in that the electrical connection between the two terminals (11, 15) on the neutral line (7) is a permanent connection, said electrical connection being formed by a one-piece rigid conductor (29) comprising, at its two opposite ends, two end portions respectively forming two connection regions (11 a, 15 a) respectively belonging to the two terminals (11, 15), and in that

The conductor (29) is U-shaped and comprises a rectilinear central portion (29 a) having two consecutive right-angle bends (29 b, 29 c) at each of its two opposite ends, said conductor, called neutral conductor (29), having an overall shape corresponding to the shape of a group of conductors located between the upstream (12, 13, 14) and downstream (16, 17, 18) terminals on each of the lines (8, 9, 10) of the transport phase.

2. An electric device according to claim 1, characterized in that all movable contact bridges (25, 26, 27) of the device are mounted on the same support (30) which can be moved between the two aforementioned positions by control means, each movable contact bridge (25, 26, 27) passing through an opening (30 a) in the support (30) so as to be drivable thereby towards the closed position and the open position, respectively, said conductor (29) passing through the support (30) through a gap (30 b) which is arranged relative to the conductor (29) such that the conductor (29) does not interfere with the movement of the support (30), the portion of the conductor (29) passing through the support being in the same plane as the movable contact bridges when the movable contact bridges (25, 26, 27) are in the closed position.

3. An electric device according to claim 2, characterized in that the opening (30 a) allows the movable contact bridge to be inserted parallel to the bridge axis and the void (30 b) is capable of allowing the conductor (29) to be inserted into the support (30) perpendicular to the longitudinal direction of the conductor (29).

4. The electrical apparatus according to claim 1, characterised in that the neutral conductor (29) is held and positioned in at least one slideway (31, 32) provided in an internal face of a wall of a housing B belonging to the apparatus.

5. An electric device according to claim 1, characterized in that the electric device is a four-pole device comprising three electric phase lines (8, 9, 10) and one electric neutral line (7).

6. The electrical device of claim 1, wherein the electrical device is a contactor C.