DE102023206442A1 - circuit breaker - Google Patents

Abstract

The circuit breaker (1) according to the invention has a switch housing (2) and a first and a second connection piece (3, 4) which extend outwards through the rear of the switch housing (2) and can each be connected to a busbar there. The circuit breaker (1) also has a switching contact arranged in the switch housing (2) with two contact pieces which lie against one another when the switching contact is closed and are separated from one another when the switching contact is open, the two contact pieces each being electrically connected to one of the two connection pieces (3, 4). The circuit breaker (1) has a switching device (10) with a first contact element (11) that is electrically connected to the first connection piece (3), a second contact element (12) that is electrically connected to the second connection piece (4), a third contact element (13) that is electrically connected to an electronics unit of the circuit breaker (1), and a mechanical switching element (14), the actuation of which enables the third contact element (13) to be connected optionally to the first contact element (11) or the second contact element (12), wherein the switching element (14) can be actuated manually from the outside. In this way, a switchable voltage tap can be integrated into the circuit breaker (1).

Description

Circuit breakers are known, for example, as low-voltage circuit breakers. Such circuit breakers have a switch housing in which a switching contact is arranged for at least one phase line, the contact pieces of which lie against one another when the switching contact is closed and are separated from one another when the switching contact is open, with one of the contact pieces being designed to be movable. The circuit breaker has two connection pieces for each phase line - one on the mains side and one on the load side - which are electrically connected to the contact pieces inside the switch housing and are usually led out through the switch housing on the back of the switch, where they can be electrically connected to one of the main busbars on the mains side or the load side.

Such low-voltage circuit breakers are used to switch a selected current branch of an electrical load circuit on and off. The low-voltage circuit breaker ensures a current interruption in predefinable situations - for example a continuous overcurrent condition or a short circuit - whereby the low-voltage circuit breaker is disconnected from its mains-side power supply, thereby effectively protecting the electrical load circuit from undesirable electrical conditions. The electrical load circuit is interrupted in such low-voltage circuit breakers by separating a pair of electrical contacts which are arranged inside the switch housing of the low-voltage circuit breaker.

It is often desirable for the circuit breaker to be equipped with a voltage measuring system that measures the voltage at the mains-side or consumer-side connection piece and, if necessary, also records the voltage curve over time. Such a voltage tap places relatively high demands on insulation and mechanical strength in order to be able to withstand the electrical and mechanical stresses during operation of the low-voltage circuit breaker.

It is the object of the present invention to propose a simple voltage tap which meets the high requirements in terms of insulation and mechanical strength and is optionally located on one of the two connection pieces.

This object is achieved according to the invention by the circuit breaker according to claim 1. Advantageous embodiments of the circuit breaker according to the invention are the subject of the dependent claims.

1. a) ein erstes Kontaktelement, das mit dem ersten Anschlussstück elektrisch leitend verbunden ist,
2. b) ein zweites Kontaktelement, das mit dem zweiten Anschlussstück elektrisch leitend verbunden ist,
3. c) ein drittes Kontaktelement, welches mit einer Elektronik des Schutzschalters elektrisch leitend verbunden ist, sowie
4. d) ein mechanisches Schaltelement, durch dessen Betätigung das dritte Kontaktelement wahlweise mit dem ersten Kontaktelement oder dem zweiten Kontaktelement verbindbar ist, aufweist, wobei das Schaltelement (14) manuell von außen betätigbar ist.

The circuit breaker according to the invention, in particular a low-voltage circuit breaker, has a switch housing and a first and a second connection piece, which extend outwards through the switch housing at the back and can each be connected to a busbar there. Furthermore, the circuit breaker has a switching contact arranged in the switch housing with two contact pieces, which lie against one another when the switching contact is closed and are safely separated from one another when the switching contact is open, wherein the two contact pieces are each electrically connected to one of the two connection pieces. The circuit breaker has a switching device, which in turn

1. a) a first contact element which is electrically connected to the first connection piece,
2. b) a second contact element which is electrically connected to the second connection piece,
3. c) a third contact element which is electrically connected to an electronic circuit breaker, and
4. d) a mechanical switching element, by the actuation of which the third contact element can be selectively connected to the first contact element or the second contact element, wherein the switching element (14) can be actuated manually from the outside.

With the help of the switching device, the voltage tap can be switched between the first connection piece and the second connection piece, i.e. either the first connection piece or the second connection piece is electrically connected to the third contact element - and thus to the electronics, which is preferably arranged in the switch housing. The voltage tap is therefore already integrated in the circuit breaker, so that no additional installation is required. The installer entrusted with installing the circuit breaker only has to select whether the electrical potential of the mains-side or load-side connection should be measured against the potential of the circuit breaker by positioning the switching element accordingly. This makes commissioning the circuit breaker much easier.

In an advantageous development of the circuit breaker, the switching device is arranged on a cover arranged on the rear of the circuit breaker.

By replacing the cover, the switching device on the circuit breaker can be easily retrofitted to an existing installation. To change the voltage tap between the mains-side and load-side connections, the circuit breaker only needs to be pulled out, i.e. separated from the mains and load-side connections, so that the mechanical switching element can be manually switched between its two positions - voltage tap on the first connection piece via the first contact element or voltage tap on the second connection piece via the second contact element. A complex conversion of the circuit breaker, in which the wiring of the voltage tap is moved from the first connection piece to the second connection piece, is therefore no longer necessary, which makes the operation of the circuit breaker much easier.

In a further advantageous development of the circuit breaker, the first contact element and/or the second contact element and/or the mechanical switching element are arranged on a side of the cover facing the circuit breaker.

In a further advantageous development of the circuit breaker, the cover has a first opening for the passage of the first connection piece.

By leading at least the first connection piece, and possibly also the second connection piece, through the first opening of the cover, the switching device is located predominantly or even completely behind the cover, thereby taking into account the requirements for insulation strength and the mechanical strength of the voltage tap.

In a further advantageous development of the circuit breaker, the cover is part of the switch housing.

This significantly simplifies the design of the switch housing - and thus of the circuit breaker. If the customer does not want a switching device, the cover can be omitted or replaced with a simple cover. This modularity enables manufacturing costs to be reduced across a large number of product variants.

In a further advantageous development of the circuit breaker, the mechanical switching element is designed as a slide switch or as a rotary switch. Slide switches and rotary switches represent simple and cost-effective designs for implementing the switching device.

In a further advantageous development of the circuit breaker, several switching poles, each with a switching contact, are accommodated and held in the switch housing. Each switching pole is assigned a first and a second connection piece, which extend outwards through the rear of the switch housing and can each be connected to a busbar, each of the switching poles having its own switching device assigned to it.

In this way, with multi-pole circuit breakers, it can be decided individually for each of the switching poles whether a voltage tap should be implemented there and, if so, at which of the connection pieces the voltage tap should be made. The voltage tap can be easily retrofitted for each of the switching poles, so that the installer can retrofit the voltage tap without great effort if requirements change.

• 1 eine schematische Ausschnitts-Darstellung der Anschlussseite des erfindungsgemäßen Schutzschalters;
• 2 und 3 schematische Darstellungen einer Umschalteinrichtung des erfindungsgemäßen Schutzschalters in einer ersten Schaltstellung in verschiedenen Ansichten;
• 4 und 5 schematische Darstellungen einer Umschalteinrichtung des erfindungsgemäßen Schutzschalters in einer zweiten Schaltstellung in verschiedenen Ansichten;

In the following, embodiments of the circuit breaker are explained in more detail with reference to the attached figures. In the figures:

• 1 a schematic detail view of the connection side of the circuit breaker according to the invention;
• 2 and 3 schematic representations of a switching device of the circuit breaker according to the invention in a first switching position in different views;
• 4 and 5 schematic representations of a switching device of the circuit breaker according to the invention in a second switching position in different views;

In the various figures of the drawing, identical parts are always provided with the same reference symbol. The description applies to all drawing figures in which the corresponding part can also be seen.

In 1 is a schematic representation of a section of the connection side of a circuit breaker 1, more precisely: a low-voltage circuit breaker. The circuit breaker 1 has a switch housing 2 in which at least one switching contact (not shown) is arranged, the contact pieces of which lie against one another when the switching contact is closed and are separated from one another when the switching contact is open. The circuit breaker 1 can, as in 1 shown, be multi-pole, ie it has several switching poles which are arranged next to one another and each have a switching contact, wherein at least one of the two contact pieces of each switching contact is movably mounted in the switch housing 2.

Each switching contact of the circuit breaker 1 is assigned two electrical connection pieces, a first connection piece 3 and a second connection piece 4, which are each electrically connected inside the switch housing 2 to one of the two contact pieces of the respective switching pole, i.e. one of the two contact pieces is electrically connected to the first connection piece 3, the other of the two contact pieces is electrically connected to the second connection piece 4. On the connection side, i.e. on a rear side of the circuit breaker 1, the first connection piece 3 and the second connection piece 4 are led out through the switch housing 2, where they are electrically connected to a connection conductor (not shown) assigned to the respective connection piece, for example a busbar, during the installation of the circuit breaker 1. In the area of the first connection piece 3, the switch housing 2 has a cover 5 which is attached to the switch housing 2 and in turn has an opening 6 through which the first connection piece 3 is led.

The 2 and 3 show schematically a switching device 10 of the circuit breaker 1 according to the invention in a first switching position in different views. The switching device 10 serves to switch, ie to change, the voltage tap between the first connection piece 3 and the second connection piece 4. 2 shows an elevation of the switching device 10, while in 3 a corresponding sectional view along the section line III-III is shown.

The 4 and 5 show the 2 and 3 shown switching device 10 in a second switching position in corresponding views. In 4 the elevation of the switching device 10 in the second switching position is shown again, 3 shows - as before 3 - a corresponding sectional view along the section line VV.

In the embodiment shown, the switching device 10 is mounted on an inner side of the cover 5 facing the circuit breaker 1 and has a linearly movable mechanical switching element 14, which is designed as a slide switch in the present case. To actuate the switching device, it has an operating element 15, which is mechanically connected to the switching element 14 and is guided through an opening 7 formed in the cover 5, so that it can be manually actuated from an outer side of the cover 5 opposite the inner side. The opening 7 thus serves as a guide for the operating element 15.

Furthermore, the switching device 10 has a first contact element 11, which can be electrically connected to the first connection piece 3 via a first guide rail 17, a second contact element 12, which can be electrically connected to the second connection piece 4 via a second guide rail 17 (see 1 ) can be connected in an electrically conductive manner, and a third contact element 13, which can be connected in an electrically conductive manner to an electronic unit (not shown) of the circuit breaker 1. When the cover 5 is mounted on the switch housing 2, the electrically conductive connections of the first contact element 11 to the first connection piece 3, of the second contact element 12 to the second connection piece 4, and of the third contact element 13 to the electronic unit are then established.

On a side facing away from the operating element 15 - facing the inside of the circuit breaker 1 - the mechanical switching element 14 has an electrically conductive sliding surface 16, which serves to connect the third contact element 13 with the first contact element 11 (first switching position, see 2 and 3 ) or the second contact element 12 (second switching position, see 4 and 5 ) in an electrically conductive manner.

The third contact element 13 establishes an electrical connection between the first or second connection piece 3 or 4 and the electronics of the circuit breaker 1. The electronics are arranged in the switch housing 2 of the circuit breaker 1 and are primarily used to implement the tripping function of the circuit breaker 1. The electronics are therefore referred to as an electronic trip unit (ETU). In addition to initiating the tripping of the circuit breaker 1, a variety of other functions, such as the recording and processing of measurement signals, can be implemented using the ETU. The electronics are therefore responsible for controlling the circuit breaker 1.

When commissioning the circuit breaker 1, the responsible technician can position the mechanical switching element 14 by moving the operating element 15 in one direction or the other so that either the first contact element 11 or the second contact element 12 is electrically connected to the electronics of the switching device 1 via the third contact element 13.

In the illustrated embodiment, the first contact element 11, the second contact element 12 and the third contact element 13 are designed as leaf spring contacts, which in the respective switching position establish an electrically conductive contact with the sliding surface 16. The design as leaf spring contacts is to be understood only as an example: Other contact options may also be considered.

Furthermore, the representations of the 2 to 5 the electrical connections of the first contact element 11 to the first connection piece 3 and of the second contact element 12 to the second connection piece 4 are realized by means of electrical guide rails 17. However, this is not mandatory or even essential to the invention: alternative electrical connections, for example other rigid conductors or stranded wires, would also be possible.

list of reference symbols

1

circuit breaker

2

switch housing

3

first connector

4

second connector

5

cover

6

opening

7

opening

10

switching device

11

first contact element

12

second contact element

13

third contact element

14

switching element

15

control element

16

sliding surface

17

guardrail

Claims (7)

Circuit breaker (1), in particular a low-voltage circuit breaker, with - a switch housing (2), - a first and a second connection piece (3, 4) which extend outwards through the switch housing (2) at the back and can each be connected to a busbar, - a switching contact arranged in the switch housing (2), the contact pieces of which lie against one another when the switching contact is closed and are separated from one another when the switching contact is open, the two contact pieces each being electrically connected to one of the two connection pieces (3, 4), the circuit breaker (1) having a switching device (10) with a) a first contact element (11) which is electrically connected to the first connection piece (3), b) a second contact element (12) which is electrically connected to the second connection piece (4), c) a third contact element (13) which is electrically connected to an electronic system of the circuit breaker (1), and d) a mechanical switching element (14), the actuation of which switches the third contact element (13) can be selectively connected to the first contact element (11) or the second contact element (12), wherein the switching element (14) can be manually actuated from the outside. Circuit breaker (1) after claim 1 , wherein the switching device (10) is arranged on a rear cover (5) of the circuit breaker (1). Circuit breaker (1) after claim 2 , wherein the first contact element (11) and/or the second contact element (12) and/or the third contact element (13) and/or the mechanical switching element (14) is arranged on a side of the cover (5) facing the circuit breaker (1). Circuit breaker (1) according to one of the Claims 2 or 3 , wherein the cover (5) has a first opening (6) for the passage of the first connecting piece (3). Circuit breaker (1) according to one of the Claims 2 until 4 , wherein the cover (5) is part of the switch housing (2). Circuit breaker (1) according to one of the preceding claims, wherein the mechanical switching element (14) is designed as a slide switch or as a rotary switch. Circuit breaker (1) according to one of the preceding claims, - wherein a plurality of switching poles, each with a switching contact, are accommodated and held in the switch housing (2), - wherein each switching pole is assigned a first and a second connection piece (3, 4), which extend outwards through the rear of the switch housing (2) and can each be connected to a busbar, - wherein each of the switching poles has a switching device (10) assigned to it.

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