EP1916692A1

EP1916692A1 - Residual current operated circuit breaker

Info

Publication number: EP1916692A1
Application number: EP07012656A
Authority: EP
Inventors: Domenico Bosatelli; Sergio Pianezzola; Augusto Contardi
Original assignee: Gewiss SpA
Current assignee: Gewiss SpA
Priority date: 2006-10-23
Filing date: 2007-06-28
Publication date: 2008-04-30
Anticipated expiration: 2027-06-28
Also published as: EP1916692B1; ATE452417T1; CN101170026A; ES2338169T3; DE602007003794D1; ITMI20062032A1; CN101170026B

Abstract

A residual current operated circuit breaker 1 comprising a first terminal strip 40 and a second terminal strip 41, that are associated respectively with moving contacts 10, 11 and fixed contacts 12, a control relay 30 suitable to act on the mechanism for opening the moving contacts, in case of tripping. The moving contacts comprise two separate series of contacts, a series of main contacts 10 and a series of secondary or auxiliary contacts 11, that are supported on a single contact supporting member 8 and can move independently so as to allow the flow of current between the first and second terminal strips when the main contacts 10 are open, by means of the auxiliary contacts 11.

Description

The present invention relates to a residual current operated circuit breaker.
As is known, residual current operated circuit breakers are normally provided in domestic and industrial systems in order to prevent a fault current from causing danger for users and for the loads connected to the electrical line.
Substantially, the residual current operated circuit breaker, when it detects the presence of the fault current, releases the line, thus interrupting the power supply to the load or loads arranged downstream.
After the release of the residual current operated circuit breaker, and once the correct operating conditions for the system have been restored, the residual current operated circuit breaker must be reset.
The operating conditions often restore themselves spontaneously because the fault is of a transient type caused by overvoltages.
This reset normally occurs manually, by acting on an appropriately provided reset lever.
Furthermore, the conventional residual current operated circuit breakers are provided with a test button, by means of which it is possible to release the breaker, simulating a fault, in order to check the correct operation of the release system.
However, as is known, the test is not always performed, both because of forgetfulness and because the interruption of electric power causes inconvenience.
In order to obviate the drawback of the interruption of electric power during the test, some conventional breakers have been provided with secondary contacts that ensure the supply of electric power, while the primary contacts are released in order to test the system.
The aim of the present invention is to provide an improved residual current operated circuit breaker in which it is possible to perform the functional test without interrupting the supply of electric power to user devices.
Within this aim, an object of the invention is to provide a residual current operated circuit breaker which is highly reliable, relatively simple to provide and at competitive costs.
Another object of the invention is to provide a residual current operated circuit breaker which can be coupled to an appropriate device capable of performing the test periodically and in a fully automatic and autonomous manner, without operator interventions.
This aim and these and other objects which will become better apparent hereinafter are achieved by a residual current operated circuit breaker, comprising a first terminal strip and a second terminal strip, associated respectively with moving contacts and fixed contacts, a control relay suitable to act on the mechanism for the opening of said moving contacts, in case of tripping, characterized in that said moving contacts comprise two separate series of contacts, a series of main contacts and a series of secondary or auxiliary contacts, which are supported on a single contact supporting member and can move independently so as to allow the flow of current between the first and second terminal strips when the main contacts are open, by virtue of the auxiliary contacts.
Further characteristics and advantages will become better apparent from the following detailed description of preferred but not exclusive embodiments of the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a perspective view of the residual current operated circuit breaker according to the present invention, associated with a reset device;
Figure 2 is a plan view of the circuit breaker;
Figure 3 is a sectional view, taken along the sectional plane III-III of Figure 2;
Figure 4 is a perspective view of the circuit breaker;
Figure 5 is a perspective view of the internal components of the circuit breaker;
Figure 6 is a partial top view of the circuit breaker with the main and secondary contacts open;
Figure 7 is a side view of the region of the contacts shown in Figure 6, with the main and secondary contacts open;
Figure 8 is a partial sectional view, taken along the plane VIII-VIII of Figure 6;
Figure 9 is a partial top view of the circuit breaker with the main and secondary contacts closed;
Figure 10 is a side view of the region of the contacts shown in Figure 9, with the main and secondary contacts closed;
Figure 11 is a partial sectional view, taken along the plane XI-XI of Figure 9;
Figure 12 is a partial perspective view of the circuit breaker with the main and secondary contacts open;
Figure 13 is a side view of the mechanism shown in the open condition;
Figure 14 is a side view, opposite with respect to Figure 13, of the mechanism in the open condition;
Figure 15 is a side view of the mechanism shown in the closed condition;
Figure 16 is a side view, opposite with respect to Figure 15, of the mechanism in the closed condition;
Figure 17 is a side detail view of the main contacts in the open position;
Figure 18 is a side detail view of the main contacts in the closed position;
Figure 19 is a side detail view of the secondary contacts in the open position;
Figure 20 is a side detail view of the secondary contacts in the closed position;
Figure 21 is a perspective view of the contact support;
Figure 22 is a perspective view, opposite with respect to Figure 21, of the contact support;
Figure 23 is a perspective view of the reset device which can be associated with the residual current operated circuit breaker according to the present invention.

With reference to the cited figures, a residual current operated circuit breaker according to the invention, generally designated by the reference numeral 1, has a box-like body 2, which has the classic standardized shape for mating with a DIN rail, not shown in the figure, by virtue of a mating means 3.
The body 2 has, on its front face, a protrusion 4 in which the actuation means, of a per se known type, is arranged, the means including a handle 5 suitable to actuate a mechanism for actuating the contacts.
The handle 5 is rigidly coupled to a rotor 55.
The actuation mechanism includes a motor lever 6 connected to the rotor 55 of the handle by means of a cross-member 7 and acting on a contact support 8 by virtue of a bar 9.
The contact support 8 is suitable to support two separate series of contacts: a series of main contacts 10 and a series of secondary or auxiliary contacts 11.
In the specific case, the main contacts 10 are four, with corresponding four secondary contacts 11.
The main contacts 10 and the secondary contacts 11 can move with respect to fixed contacts 12.
The secondary contacts 11 can move on the contact support 8 independently of the main contacts 10.
Each of the main contacts 10 has a presser spring 13 associated with the main contact and with the main shaft 8.
The presser spring 13 of the main contact 10, and a part of the main contact 10, are arranged within a respective first slot 14 formed in the contact support 8.
A second slot 20 is formed externally to a wall 15 in order to accommodate a respective secondary contact 11.
Each secondary contact 11 is actuated by an actuation shaft 16 by means of a bar 17 and is associated with a presser spring 18 by virtue of a lamina 19.
The main contacts 10 are actuated exclusively by the handle 5 of the residual current operated circuit breaker, while the secondary contacts 11 are actuated exclusively by a reset device 100, which is associated with the circuit breaker 1 by means of an actuation means, constituted by a cross-member 111, which engages the actuation shaft 16 of the secondary contacts, as shown schematically in Figure 23.
The reset device 100 has an engagement means 110, which is constituted by a seat in which it is possible to insert a contoured shaft suitable to engage the rotor 55 of the handle 5.
The residual current operated circuit breaker 1 includes, in a per se known manner, an actuation relay 30, which is suitable to act on the mechanism in order to open the contacts 10 and 11 if tripping occurs, and terminal strips 40 and 41 for ordinary electrical connections, which are connected respectively to the moving contacts 10, 11 and to the fixed contacts 12.
The circuit breaker has a test circuit mechanism which includes, in a per se known manner, a test button 50 acting on a test spring 51 to close the circuit and to trip the actuation mechanism that opens the contacts.
The breaker has a marker 60, which indicates the state of both the main and secondary contacts of the circuit breaker, with the usual colored indicator visible through an opening provided in the cover of the box-like body, and an electronic circuit 70 for controlling the operation of the system located downstream.
The remaining control circuit is within the block 100 of Figure 23.
The residual current operated circuit breaker has an emergency release coii, designated by the reference numeral 80, which is actuated by the electronic circuit so that it trips if the relay fails to operate and can also lock the residual current operated circuit breaker in the open condition.
In practice it has been found that the invention achieves the intended aim and objects, providing a residual current operated circuit breaker having a mechanical structure which is simplified and advantageous both in terms of reliability and in terms of low cost during production.
This application claims the priority of Italian Patent Application No. MI2006A002032, filed on 23 October 2006 , the subject matter of which is incorporated herein by reference.

Claims

A residual current operated circuit breaker, comprising a first terminal strip and a second terminal strip, associated respectively with moving contacts and fixed contacts, a control relay suitable to act on the mechanism for the opening of said moving contacts, in case of tripping, characterized in that said moving contacts comprise two separate series of contacts, a series of main contacts and a series of secondary or auxiliary contacts, which are supported on a single contact supporting member and can move independently so as to allow the flow of current between the first and second terminal strips when the main contacts are open, by virtue of the auxiliary contacts.
The residual current operated circuit breaker according to claim 1, characterized in that it comprises a means for actuating the contacts which comprises an external handle, which can be operated manually and is suitable to actuate a mechanism for actuating the contacts, said handle being rigidly coupled to a rotor, said actuation mechanism comprising a motor lever connected to the rotor of the handle by virtue of a cross-member and acting on said contact supporting member by virtue of a bar.
The residual current operated circuit breaker according to claim 1 or 2, characterized in that each of said main contacts has a presser spring being associated with the respective main contact and with a main shaft.
The residual current operated circuit breaker according to one or more of the preceding claims, characterized in that said presser spring of the main contact and part of the main contact itself are arranged within a respective first slot formed in said contact supporting member.
The residual current operated circuit breaker according to one or more of the preceding claims, characterized in that a second slot is formed externally at a wall for accommodating a respective secondary contact.
The residual current operated circuit breaker according to one or more of the preceding claims, characterized in that each secondary contact is actuated by an actuation shaft, by virtue of a bar, and is associated with a presser spring by virtue of a blade.
The residual current operated circuit breaker according to one or more of the preceding claims, characterized in that said main contacts are actuated exclusively by said rotor, while said secondary contacts are actuated exclusively by a reset device associated with said circuit breaker by virtue of a control means, which is constituted by a cross-member, and engaging the actuation shaft of the secondary contacts.
The residual current operated circuit breaker according to one or more of the preceding claims, characterized in that it comprises a test circuit mechanism comprising a test button that acts on a test spring for closing the circuit and tripping the actuation mechanism that opens the contacts.
The residual current operated circuit breaker according to one or more of the preceding claims, characterized in that it comprises a box-like body having the classic standardized shape for mating with a DIN rail by virtue of a mating means; said body having a protrusion on its front face.
The residual current operated circuit breaker according to one or more of the preceding claims, characterized in that it comprises a marker suitable to indicate the state of the main and secondary contact with a colored indicator which can be viewed through an opening provided in the lid of the box-like body and an electronic circuit for controlling the operation of said breaker.
The residual current operated circuit breaker according to one or more of the preceding claims, characterized in that it comprises an emergency release coil actuated by the electronic circuit, so that it trips if the relay fails to operate.
The residual current operated circuit breaker according to one or more of the preceding claims, characterized in that said main contacts are four with corresponding four secondary contacts.