EP3537466A1 - Electromechanical protective switching device - Google Patents

Abstract

The electromechanical protective switching device (1) according to the invention, which is designed in particular as a residual current circuit breaker, has an insulating housing (2) and an electromechanical trigger relay (20), which is received and held in the insulating housing (2) and in turn has a plunger (21), which is movably mounted between a release-ready rest position and a triggered position. Furthermore, the protective switching device (1) on a return device (30) for returning the plunger (21) in the tripping ready position. The restoring device (30) in this case has a base body (31) movably mounted in the insulating housing (2), to which a damping element (32) is fastened, which is designed to engage the plunger (21) during a movement of the base body (31). act in order to put this back in the triggering position. The damping element (32) is designed so elastically that thereby the on the plunger (21) acting pulse of the main body (31) is attenuated. In this way, a gentle return of the plunger (21) is made possible, whereby the risk of damaging the sensitive trip relay (20) can be significantly reduced. Thus, a consistently high tripping accuracy can be achieved over the life of the protective switching device (1).

Description

The invention relates to an electromechanical protective switching device - in particular a residual current circuit breaker - with a Isolierstoffgehäuse, an electromechanical trip relay, which is housed and supported in the housing and has a movable between a triggering position and a triggered position plunger, and a restoring device for returning the plunger in the triggering position.

Electromechanical protection devices - such as circuit breakers, circuit breakers or residual current circuit breakers - are used to monitor and safeguard an electrical circuit and are used in particular as switching and safety elements in electrical energy supply and distribution networks. To monitor and safeguard the electrical circuit, the protective switching device is electrically connected via two or more terminals with an electrical line of the circuit to be monitored in order to interrupt the electrical current in the respective monitored line, if necessary. For this purpose, the protective switching device has a switching contact, which can be opened when a predefined state occurs-for example when a short circuit or a fault current is detected-in order to disconnect the monitored circuit from the electrical line network. Such protective switching devices are known in the field of low-voltage technology as DIN rail mounted devices.

In the field of electrical installation technology, suitable circuit breakers are used to detect a so-called differential or fault current for this purpose, for example residual current circuit breakers or residual current circuit breakers, in order to protect persons from the dangers that can occur when live parts of electrical installations are touched. differential currents can arise when, for example, a faulty insulation or - in the case of a touch - through the human body a fault current flows to earth. To detect such an error or differential current, the magnitude of the current in a line leading to an electrical consumer, for example a phase line, is compared with the magnitude of the current in a line from the electrical consumer, for example a neutral conductor, with the aid of a so-called summation current transformer , This has an annular magnetic core, through which the primary conductors (back and returning electrical lines) are passed. The magnetic core itself is wrapped with a secondary conductor or a secondary winding. In the fault-free state, the sum of the electrical currents flowing to the consumer is equal to the sum of the returning electrical currents. If the currents are added vectorially, ie direction-related or signed, then it follows that the signed sum of the electrical currents in the outgoing and return lines in the fault-free state is equal to zero: no induction current is induced in the secondary conductor.

Conversely, in the case of a fault or differential current flowing to earth, the sum of the backward or backward flowing electrical currents detected in the summation current transformer is not equal to zero. The difference in current that occurs causes a voltage proportional to the current difference to be induced at the secondary winding, as a result of which a secondary current flows in the secondary winding. This secondary current serves as a fault current signal and leads after exceeding a predetermined value for triggering the protective switching device and consequently - by opening a switching contact - to shut down the corresponding hedged circuit.

In general parlance instead of the term "residual current circuit breaker" and the terms RCCB (short: RCD), residual current device (short: Di switch) or RCD (for Residual Current Protective Device) alike used.

In residual current circuit breakers further distinguishes between mains voltage-dependent and mains voltage-independent device types: while mains voltage-dependent residual current circuit breakers have control electronics with a trigger that relies on an auxiliary or mains voltage to fulfill their function, mains voltage-independent residual current circuit breaker to implement the tripping function no auxiliary or mains voltage, but have to realize the mains voltage independent triggering usually a slightly larger summation current transformer, with a larger induction current can be generated in the secondary winding. Since the differential currents determined in this way are generally comparatively small, they also have only a low energy density. Therefore, the fault current can not, as for example in a circuit breaker, directly and directly to trigger a switching mechanism - for example, using a magnetic coil and a shock absorber in the event of a short-circuit release - are used. Instead, an electromechanical trip relay is usually used to realize the mains voltage independent residual current tripping.

The trip relay is electrically connected to the summation current transformer via the secondary winding. However, because of the usually low differential current, the release relay has only a comparatively low release force, which is usually not sufficient for a direct release of the switching mechanism to open the switching contact immediately when a fault current occurs. Instead, the protective switching device has an additional energy storage, which acts on the tripping relay in the event of tripping. Such an electromagnetic tripping device is previously known, for example, from the German patent DE 197 ° 35 ° 413 ° B4.

Due to the low forces, the release relay is designed as a precision mechanical assembly which has a coil in a housing and a relative thereto movably mounted plunger. The plunger is actuated by a movably mounted armature, which is held in the rest position by a permanent magnet against the force of a release spring in its rest position. When triggered, a magnetic field caused by the coil energized by the induction current weakens the magnetic field of the permanent magnet, which reduces its holding force, so that it is no longer sufficient to restrain the armature against the force of the release spring against its pole faces. As a result, the release spring causes movement of the armature and thus of the plunger from its ready-to-release rest position to its released position. Due to the small dimensions and the low energy density, the precision mechanism of the trip relay reacts comparatively susceptible and sensitive to shocks and / or vibrations. Such shocks, which occur in particular in the mechanical reset of the plunger from its triggered position in its trigger-ready rest position, can lead to false triggering and are therefore essential to avoid.

In order to return the plunger back to its release-ready rest position, the protective switching device has a return element, which is mechanically coupled to the switching mechanism and is raised when switching on the protective switching device against a spring element. After triggering the switching mechanism, the restoring element - driven by the spring element - moves against the plunger, whereby this is returned from its tripped position to its rest position. Since the movement of the switching mechanism is highly dynamic, and the reset element meets at high speed on the plunger and pushes it back to its rest position. This highly dynamic return movement, which equates to a blow to the plunger, is undesirable because it can damage the sensitive trip relay. For example, the highly dynamic movement of the return element to a change in the geometric arrangement of the components inside the trip relay - especially the magnetic air gap - lead, whereby the holding force of the trip relay - and thus the tripping of the protective device - are changed in an inadmissible manner. Since this also changes the tripping currents of the protective switching device up to its inoperability over the lifetime, this effect represents a considerable risk for the tripping accuracy of the protective switching device and must therefore be avoided at all costs.

In addition to the pure residual current devices or residual current devices there are also device types in which the functionality of a residual current device (FI or DI) is combined with the functionality of a circuit breaker (LS): such combined circuit breakers are known in German as FILS or LSDI, in English-speaking countries Mostly referred to as RCBO (Residual Current Operated Circuit-Breaker with Overcurrent Protection). These combiners have the advantage, compared to separate residual current circuit breakers and circuit breakers, that each circuit monitored for short circuit and overload (CB) functionality has its own residual current (FI) protection: normally a single fault current circuit breaker will be provided used for multiple circuits. As a result, if a fault current occurs, all the protected circuits are switched off. However, the use of RCBO devices makes it possible to interrupt only the affected circuit. The availability of the electrical supply network is thereby significantly improved.

Further, since in applications in electrical installation technology, the available space - for example, in an electrical distribution distributor - is usually very limited, there is a need to make the protection switching devices as compact as possible. This is especially true for so-called combination devices, in which more and more functionalities are integrated into the devices, so that these the scope of functions cover several single devices. In addition, the protective switching devices for ever higher nominal currents to be used or used. All of these developments mean that less and less space is available inside the devices.

It is therefore an object of the present invention to provide an electromechanical protective switching device - in particular a residual current circuit breaker - which is characterized throughout the lifetime by a consistently high tripping accuracy.

This object is achieved by the electromechanical protective device according to claim 1. Advantageous embodiments of the electromechanical protective switching device according to the invention are the subject of the dependent claims.

The electromechanical protective switching device according to the invention, which is designed in particular as a residual current circuit breaker, has an insulating housing and an electromechanical trip relay, which is accommodated and held in the insulating housing and in turn has a plunger which is movably mounted between a release-ready rest position and a triggered position. Furthermore, the protective switching device has a restoring device for returning the plunger to the release-ready rest position. The restoring device has for this purpose a movably mounted in the housing body, to which a damping element is attached, which is adapted to act upon movement of the body on the plunger to reset this in the release-ready rest position. The damping element is designed so elastic that in this way the force acting on the plunger pulse of the body is attenuated.

The tripping relay is used to trip the protective switching device when a fault current occurs. In this case, the plunger of the trigger-ready rest position is in the triggered position emotional. The restoring device serves to return the plunger to the original rest position. In a corresponding movement of the base body, the damping element acts on the plunger, whereby it is moved back to its rest position. Due to the elastically designed damping element, the momentum of the inert and comparatively massive base body is not transmitted to the plunger. Only the comparatively low mass of the damping element exerts a pulse on the plunger. The risk of damage to the sensitive trip relay can be significantly reduced by the gentle return of the plunger in its rest position, which also over the life of the protective device across a consistently high tripping accuracy can be achieved.

In an advantageous embodiment of the protective switching device, the base body between a recoverable first position and a second position is movable. The damping element is not firmly clamped on the base body, but has a degree of freedom against the movement of the body in the second position.

Upon movement of the body in the second position, the plunger is returned to its rest position. Due to the inventive coupling of the damping element to the base body, the damping element can lift against the movement of the base body in a movement of the main body in the second position against this movement. This applies at least to the part or section of the damping element which comes into contact with the plunger. Due to this structural design, the damping element moves at a lower speed in the direction of the second position than the main body. Since the damping element is also designed to be resilient, the pulse applied to the plunger is further damped thereby, whereby the risk of damaging the sensitive trip relay is further reduced.

In a further advantageous embodiment of the protective switching device of the main body is rotatably mounted in the insulating housing.

In a further advantageous development of the protective switching device, the base body is movable via a spring element supported in the insulating housing.

The spring element is a force accumulator, which provides the required force when triggering the protective switching device and the associated release of the switching mechanism to move the main body from its first position ready for restoring into its second position.

In a further advantageous embodiment of the protective switching device, the insulating material housing at a width of only one division unit (TE) has a first current path region for receiving a first primary conductor and a second current path region for receiving a second primary conductor.

The circuit breaker is compact with a width of only one division unit, which corresponds to approximately 18mm. For reasons of electrical isolation, the two current path regions inside the insulating housing are separated from each other by a housing partition wall or the like, i. arranged separately from each other.

In a further advantageous development, the protective switching device is designed as a RCBO combination device, which has the functionality of a circuit breaker in addition to the functionality of a residual current circuit breaker.

The design of the protective switching device as RCBO combination device follows the fundamental trend to integrate more and more functionality in the switching devices while maintaining the most compact design possible.

Figuren 1 bis 3

schematische Darstellungen eines elektromechanischen Schutzschaltgerätes in verschiedenen Ansichten;

Figuren 4 bis 6

schematische Detaildarstellungen des geöffneten Schutzschaltgerätes in verschiedenen Betriebszuständen.

In the following, an embodiment of the electro-mechanical protection switching device will be explained in more detail with reference to the accompanying figures. In the figures are:

FIGS. 1 to 3

schematic representations of an electro-mechanical protection device in different views;

FIGS. 4 to 6

schematic detailed representations of the open protection device in different operating states.

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

In the FIGS. 1 to 3 is an electro-mechanical protection device 1 in the embodiment as a mains voltage-independent residual current circuit breaker shown schematically in different views. While FIG. 1 a view from below of the protection device 1 is shown in FIG. 2 a corresponding thereto side view of the protective switching device 1 is shown; FIG. 3 shows a corresponding plan view in turn. The protective switching device 1 according to the invention comprises an insulating material housing 2 with a front side 4, an attachment side 5 opposite the front side 4, and narrow sides 6 and broad sides 7 connecting the front side 4 and the attachment side 5. In its interior, the insulating housing 2 has a first current path region 8 and a second current path region 9, which are separated from one another by a housing separating wall 10. The housing partition wall 10 extends from one narrow side 6 to the other narrow side 6 and thus extends substantially parallel to the broad sides 7. The two current path areas 8 and 9 are thus arranged side by side in a width direction B.

In the first current path region 8, a physical first current path 11 extends, which extends from one narrow side 6 to the other narrow side 6 and is electrically connected during installation with an electrical first connection conductor - usually the phase conductor P - of the electrical circuit to be monitored. In the second current path region 9 accordingly runs a physical second current path 12, which also extends from one narrow side 6 to the other narrow side 6 and is electrically connected during installation with an electrical second connection conductor - usually the neutral conductor N - of the electrical circuit to be monitored , The protective switching device 1 thus has a phase conductor side (P side), in which the first current path 11 is arranged and which thus corresponds to the first current path region 8, and via a neutral side (N side), the second current path region. 9 corresponds and in which the second current path 12 is arranged.

In the region of the narrow sides 6, each of the two current path regions 8 and 9 has electrical connection terminals 13 - an input terminal assigned to the respective current path region 8 or 9 and an output terminal correspondingly assigned to this current path region 8 or 9. The terminals 13 are received in the insulating housing 2 and supported. By formed in the insulating 2 openings (not shown), the connecting conductors P and N can be inserted into the respective associated terminal 13 and fixed there electrically conductive. Via the two current paths 11 and 12, the respective input terminal 13 of the respective current path region 8 or 9 is electrically conductively connected to the respective output terminal 13 of this current path region 8 or 9.

On its front side 4, the invention, mains voltage-independent residual current protective device 1 further comprises an actuating element 3 for manual operation of the protective device 1 on. The actuating element 3 is coupled in the interior of the insulating housing 2 via a switching mechanism of the protective switching device 1 with one or more switching contacts 15 such that they can be opened and closed manually by means of the actuating element 3. About the front side 4 opposite mounting side 5, the protective switching device 1 can be attached to a locking or DIN rail. Such latching or top hat rails are used in electrical distribution manifolds as standard for attachment of DIN rail mounted devices. Advantageously, the insulating material housing 2 has a width of only one graduation unit (1TE, corresponds to approximately 18 mm).

The FIGS. 4 to 6 show schematically detailed representations of the open protection device 1 in different operating conditions. These representations each show a side view of the neutral conductor broad side 7 of the protective switching device 1, wherein in each case a front housing cover of the insulating housing 2 has been removed in order to allow in this way an insight into the interior of the protective switching device 1.

The protective switching device 1 has on its neutral side an electromechanical trip relay 20 which is received and held in the insulating 2. The trip relay 20 in turn has a plunger 21 which is movably mounted between a tripping ready position and a tripped position and actuated when a fault current at the residual current circuit breaker and its detection via a summation current transformer (not shown) a release lever, thereby releasing a latch and As a result, the opening of the switch contacts 15 is initiated. The plunger 21 is not automatically withdrawn after triggering in the release relay 20 from its triggered position in its release-ready rest position, but must be pressed from the outside back into the release relay 20.

For this purpose, the protective switching device 1 has a restoring device 30, which serves to reset the plunger 21 from the triggered position back to its release-ready rest position. The restoring device 30 in turn has a main body 31 which is mounted rotatably in the insulating housing 2 between a first position ready for restoring and a second position. In order to apply the force required for the return movement of the main body 31 to the second position, the restoring device 30 further comprises a spring element 33, the first end 33-1 eccentrically engages the base body 31, and the second end 33-2 formed on a housing 2 on the insulating Retaining element 14 is attached. When switching the protective switching device 1, the restoring device 30 is first wound up by the switching mechanism against the spring force of the spring element 33 and remains in this mounted, restoring first position until the switching mechanism is triggered in the case of tripping the protective switching device 1. As a result of this release, on the one hand, the switching contacts 15 are opened, on the other hand, the restoring device 30 is no longer held in the first position. Instead, the main body 31 moves at high speed within a few milliseconds on the trigger relay 20 and pushes the plunger 21 back to its original position, i. in his resting position.

The highly dynamic movement of the main body 31 in the direction of the plunger 21 is not without problems, since it equals a shock or impact on the plunger 21, which causes the coupled to the plunger 21 anchor (not shown) of the trip relay 20 at the end of the application movement the plunger 21 with its pole faces on the pole faces of the magnetic leg (not shown) of the trigger relay 20 would strike. Because of the high speed and the relatively large, inertial mass of the body 31, there is a risk that this could damage the pole faces and change the magnetic air gap, thereby increasing the holding force and thus the triggering properties of the trigger relay 20 - would change. In order to avoid these consequences, the restoring device 30 has an elastic damping element 32, which is provided to act on a movement of the main body 31 in the second position on the plunger 21 such that it is reset to its trigger-ready rest position.

In FIG. 4 For this purpose, a first state is shown, in which the base body 31 is rotated counter to the force of the spring element 33 in the counterclockwise direction and is in the reset-ready first position. The spring element 33 serves as a tension spring, against the pulling force of the restoring device 30 is wound up when switching on the protective switching device 1 via the switching mechanism and in this state - which is also referred to as "tripping ready state" or "retracted state" of the restoring device 30 - is fixed. In this state, which represents the restoring ready first position of the main body 31, the damping element 32 is clearly spaced from the plunger 21 of the trigger relay 20 and allows after triggering the protective switching device 1 and releasing the fixation of the return device 30 by means of the spring force 33 applied spring force reset of the plunger 21st

FIG. 5 shows a second state of the protective switching device 1, immediately after the plunger 21 has been reset by the damping element 32 in its rest position. In this case, the base body 31 of the return device 30 has not yet reached its end position of the return movement, ie its second position. The plunger 21, however, has already been fully restored by the damping element 32 in its release-ready rest position, wherein the damping element 32 is still in contact with the plunger 21. This state, in which the plunger 21 is already in its rest position and the damping element 32 is still applied to the end of the plunger 21, is also referred to as "applied state".

FIG. 6 shows a third state of the trigger relay 20 and the restoring device 30 immediately after the in FIG. 5 illustrated state: the damping element 32 is still in contact with the returned to its rest position plunger 21, the main body 31 has now reached its second position, in which he after the release of the protection device 1 and the associated release of the fixing Restoring device 30 has been accelerated by the force applied via the spring element 33 spring force. However, the pulse required to return the plunger 21 to its trigger-ready rest position is not transmitted directly from the main body 31, but indirectly via the damping element 32 to the plunger 21. Since the damping element 32 is designed to be elastic, the momentum of the main body 31 acting on the plunger 21 during the movement of the main body 31 into the second position is thereby damped.

Furthermore, the damping element 32 is not only elastically formed, but also has a degree of freedom against its movement in the second position relative to the main body 31, ie the damping element 32 is not firmly clamped on the main body 31, but mechanically coupled to the main body 31 that the free end of the damping element 32, which serves to reset the plunger 21, can lift against the movement of the base body 31 in its second position relative to this. This moment of lifting the free end of the damping element 32 from the base body 31 opposite to its direction of movement in the second position is in FIG. 6 illustrated: the position of the free end of the damping element 32 corresponds to the in FIG. 5 However, the main body 31 has now reached its second position.

In the illustrated case, the movement of the main body 31 is stopped in its second position by the housing of the trigger relay 20. The inertial mass of the main body 31 therefore does not strike the plunger 21 at the end of the movement into the second position, but rather the housing of the triggering relay 20, whereby the risk of damage to the sensitive components of the trigger relay 20 is significantly reduced. In principle, however, it is also possible to stop the movement of the main body 31 in its second position by a formed on the insulating housing 2 stop or projection to prevent any acting on the trigger relay 20 vibration.

According to the invention acts to reset the plunger 21, no rigid body 31 on this one. Instead, a damping element 32 is provided for this purpose, which is coupled to the base body 31 in such a way that the free end of the damping element 32 can leave the base body 31 in its movement into the second position. Thus, the inertial mass of the body 31 does not strike the plunger 21. Instead, the body 31 continues to move to its second position until it finally encounters a suitable stop - for example, the housing of the trip relay 20 or a housing-fixed contour - which impulse of the main body 31 receives. In this way, the pole faces of the magnet legs are not additionally loaded by the inertial mass of the main body 31, since only the small inertial mass of the damping element 32 strikes the pole faces via the plunger 21. The dynamic load on the pole faces of the magnet legs is thereby minimized without reducing the static force component required for a reliable reset operation.

For reasons of space, the damped restoring function has been divided into two separate springs: the relatively strong tension spring 33 provides the force required to reset the plunger 21, the damping element 32 designed as a leg spring reduces the dynamic load - ie the impact or impact, via the plunger 21 hits the pole faces of the magnet legs. This division allows a damped reset the plunger 21 in its release-ready rest position, especially in compact switching devices with a housing width of only one division unit.

LIST OF REFERENCE NUMBERS

1

Protection device

2

Insulated

3

actuator

4

front

5

mounting side

6

narrow side

7

broadside

8th

first current path area

9

second current path area

10

housing partition

11

first rung

12

second current path

13

terminal

14

retaining element

15

switching contact

16

fixed contact

17

moving contact

20

tripping relay

21

tappet

30

Reset device

31

body

32

damping element

33

spring element

B

width direction

P

first connection conductor / phase conductor

N

second connection conductor / neutral conductor

Claims (6)

Electromechanical circuit breaker (1), in particular residual current circuit breaker, with an insulating material housing (2), - An electromechanical trip relay (20) which is received and held in the insulating housing (2) and a plunger (21) which is movably mounted between a release-ready rest position and a triggered position, - A return device (30) for returning the plunger (21) in the tripping ready position, characterized,
in that the restoring device (30) has a base body (31) movably mounted in the insulating housing (2), to which a damping element (32) is fastened, which is designed to act on the plunger (21) during a movement of the base body (31) in order to return this to the triggering ready position, wherein the damping element (32) is designed so elastically that thereby the on the plunger (21) acting pulse of the base body (31) is damped. Protective switching device (1) according to claim 1,
characterized, - That the base body (31) between a recoverable first position and a second position is movable, - That the damping element (32) is not firmly clamped on the base body (31), but has a degree of freedom against movement into the second position. Protective switching device (1) according to one of the preceding claims,
characterized,
that the base body (31) is rotatably mounted in the insulating housing (2). Protective switching device (1) according to one of the preceding claims,
characterized,
in that the base body (31) is movable via a spring element (33) supported in the insulating housing (2). Protective switching device (1) according to one of the preceding claims,
characterized,
that the insulating housing (2) with a width of only one pitch unit (TE) a first current path region (8) for receiving a first primary conductor (P) and a second current path region (9) for receiving a second primary conductor (N). Protective switching device (1) according to one of the preceding claims,
characterized,
in that the protective switching device (1) is designed as a combination RCBO device which, in addition to the functionality of a residual current circuit breaker, has the functionality of a circuit breaker.

Images