BRPI0519197B1 - A PROCESS AND DEVICE FOR THE SAFE OPERATION OF A SWITCHING APPARATUS AND SWITCHING APPARATUS - Google Patents

Description

Report of the Invention Patent for "PROCESS AND DEVICE FOR THE SAFE OPERATION OF A SWITCHING AND SWITCHING APPLIANCE".

[001] The present invention relates to a process for the safe operation of a switching apparatus as well as to a corresponding device and switching apparatus. With switching apparatus, in particular switching apparatus Low-voltage circuits can be connected to the power lines between an electrical supply equipment and consumers, and thus their operating currents. That is, by the fact that current circuits are opened and closed by the switching device, connected consumers can be safely switched on and off- [003] A low-voltage electrical switching device such as a relay, A power switch or a compact starter for connecting the power lines has one or more so-called main contacts, which can be controlled by one or several control magnets. In principle, the main contacts in this case consist of a movable contact bridge and fixed contact parts to which the consumer and the power equipment are connected. For closing and opening of the main contacts a corresponding on or off signal is emitted to the control magnets, whereby these magnets with their armature act on the moving contact bridges such that the contact bridges perform a relative movement relative to the fixed contact parts and close or open the current paths to be connected.

[004] For the best contact between the contact parts and the contact bridges, correspondingly executed contact surfaces are provided at points where they meet. These contact surfaces are made of materials, such as silver alloys, which are applied at these points on both the contact bridge and the contact parts and have a certain thickness.

[005] Contact surface materials are subject to wear in each of the bonding processes. Factors that can influence this wear are: ■ increasing contact burn or contact wear with increasing number of switching on and off processes, ■ increasing deformation, ■ increasing contact corrosion due to electric arc actuation, or ■ environmental influences such as eg vapors or suspended matter, etc.

As a result, operating currents are no longer safely connected, which can lead to power interruptions, contact heating or contact welding.

Thus, in particular, with increasing contact firing the thickness of the materials applied to the contact surfaces will be reduced. As a result, the bonding path between the contact surfaces of the contact bridge and the contact parts becomes longer, which ultimately reduces the contact force during closing. As a result, contacts will no longer close properly with increasing number of call processes. Due to the resulting or also due to current interruptions and reinforced ligament damping, then, contact heating may occur and, as a result, an increasing fusion of the contact material, which then in turn may lead to welding of the contact surfaces of the main contacts.

[008] If a main contact of the switchgear is worn or even soldered, the switchgear can no longer safely disconnect the consumer. So, just in the case of a soldered contact, despite the disconnect signal, at least the current path with the main soldered contact remains conducting current or voltage, and thus the consumer is not completely separated from the supply equipment. Since the consumer thus remains in an unsafe state, the switchgear represents a potential source of failure.

For example, in the case of compact starters according to IEC 60 947-6-2, where an additional protective mechanism acts on the same main contacts as the control magnet during switching on. According to the operation, the protection function can be blocked.

Therefore, for safe operation of switchgear and thus for consumer and electrical installation protection, such sources of failure should be avoided.

The task of the present invention is to recognize such potential sources of failure and to respond accordingly.

The present invention, therefore, with little expense, makes it possible to recognize a contact welding during shutdown and thus an unsafe operation of the switching apparatus and to respond accordingly.

For this purpose, according to the invention in the operation of a switching apparatus, in particular during shutdown it is recognized whether the movable contact bridge of the at least one main contact exceeds an opening point. Continued operation of the switching apparatus is interrupted if, after a predetermined period of time, the opening point has not been exceeded.

In this case, the predetermined opening point corresponds to a previously determined contact bridge opening path, in which this bridge is still still in connection with the contact parts. If, then, after disconnection, that is, after the desired opening of the at least one main contact, an opening path is determined which is smaller than this predetermined opening point, then it can be assumed that, there is a welding and thus unsafe operation of the switchgear. If the occurrence of such an unsafe operation is monitored and acknowledged during the operation, the continued operation of the switchgear may be suppressed in time.

Accordingly, with the process according to the invention and the device according to the invention, safe operation of a switching apparatus such as a relay, a power switch or compact starter and, in particular, the safe operation of a three-pole switching apparatus.

In an embodiment according to the invention, the opening point overrun is recognized by a measurement of a current in a current path to be connected by the main contact, and the opening point has not been exceeded, if the measured current is greater than a predicted current after shutdown.

Overrun of the opening point can also be recognized by measuring a voltage drop through a main contact, and the opening point has not been exceeded if the voltage drop is less than a predicted voltage drop. after shutdown.

In another embodiment, the opening point overrun is recognized by a measurement of a control magnet inductivity, and the opening point has not been exceeded if the inductivity after shutdown has a value other than corresponds to the default value after opening compared to the regular operation.

In addition, the opening point can be recognized by a state of means which are in effective connection with the contact bridge, and the recognized opening point has not been exceeded if, after disconnection, these means remain in this state. which does not correspond to the predetermined state after opening. This is the case, for example, in a weld of at least one main contact.

[0020] In another embodiment according to the invention, during the binding or for the binding of a control magnet, an auxiliary contact is closed, and during the binding of the control magnet, then a contact of the control magnet is closed. opening. A release means, which is connected in series to the contact contacts, then releases a contact break means if during shutdown the auxiliary contact remains or remained in the closed state. In this case too, a weld or bonding of at least one of the main contacts must be allowed.

In particular, the switching contacts are made such that during switching on the auxiliary contact closes before the opening contact, and the fact that during switching off the opening contact closes before of the auxiliary contact.

In another embodiment according to the invention, during a switching actuation, a magnetic flux change of the magnetic circuit of the magnetic magnet is measured, whereby the opening point has been exceeded if during the switching off of the control magnet, the magnetic flux change has exceeded a predetermined comparison value. Preferably, the change in magnetic flux is measured by means of an induction coil.

According to another embodiment according to the invention, the electrical supply to a switching apparatus evaluation and control unit is maintained by means of an electrical storage element, for example by means of a capacitor, an electric coil or an accumulator for a minimum time in order to test or recognize by measuring technique a welded main contact and, in order to control or possibly release a contact and / or a connection closure.

In particular, only if there is a switching order, the control magnet is then excited to drive at least one main contact if the electrical storage element has reached a minimum charge state. . The minimum charge state in this case is measured in such a way that, after switching off the control apparatus and, in particular, after removal of the switching voltage for the electrical excitation of the switching magnet control magnet, the unit The evaluation and control system is supplied with electricity and the release process may still be started.

[0025] In another embodiment of the invention, in the on state of the control magnet a release means is kept active in an excited state in order to prevent the release of a contact breaking medium. During shutdown, then, the excitation of the release medium and the control magnet is removed, and then a reinforcement or a control magnet component that is in an effective mechanical bond with the armature prevents release of the release medium. release.

Thus, for example, a spring of a pre-tensioned spring accumulator may be prevented by the release means from loosening. The release means, in this case, also has a readjustment means, such as a readjustment spring, which upon withdrawal of the power supply to maintain the active excited state, transfers this state to a passive state without excitation. The energy that is released through the readjustment means then releases the larger accumulated energy around a multiple in the contact breakage medium. Upon release, this accumulated energy is transformed into a mechanical impulse, which finally breaks the welded main contact.

In particular, during ligament excitation of the release medium is temporarily removed prior to the control magnet. In addition, during shutdown, the control magnet excitation is temporarily removed prior to the release means. Preferably, the release means is a lifting or dipping magnet. The contact rupture means in particular has a spring accumulator such as a cylindrical compression spring.

In addition, the continuation of the switching operation is interrupted by the fact that a connecting element arranged in series with the main contact is opened in the current path.

Finally, the continuation of the switching operation is interrupted by the fact that at least one control conductor for control magnet control is interrupted.

[0030] The process for determining the residual service life of switching contacts, in this case, can consist, on the one hand, of the temporary recording of predetermined discrete positions of the control magnet electromagnet armature, or also components that are in effective connection with the reinforcement and in determining the velocity and average acceleration of the reinforcement or these components at which position measurement is performed. On the other hand, it can be a measurement of the switching moments of the switching contacts during their closing movement.

Thus, for the determination of the residual service life, at least four moments are recorded, one of which represents the moment of contact closure, and of which the others represent the position moments of one or more position generators. In this case at least two of these moments may be time values of two adjacent adjacent positions from which a velocity value of the moved component may then be derived. Since the component controlled during the ligation process generally performs an accelerated motion, alongside this velocity value thus determined, for at least one time interval an average value of a constant acceleration is defined. From the determined values of velocity and acceleration, as well as the relative positions of the position generator relative to each other and their position instants, for the instant of contact closure, the contact position can be defined by closing through a Simple math relationship. From this position it can be defined whether or not the movable contact bridge of the at least one main contact, particularly after disconnection, has exceeded an opening point. If after a predetermined period of time this opening point has not been reached, then further operation of the switchgear is interrupted.

For speed-adjustable switching devices, in particular relays, which consist of an adjustable magnetic drive, then the speed v measured with the position sensor can be used to adjust the iterative drive. -active at a specified speed, or in order to limit the speed to a predetermined range. For this, the control parameters with each drive ligament are placed with a predetermined parameter step in the direction of the highest speed until the speed is less than the theoretical value or below the theoretical range. Alternatively, the drive-switched control parameters are set with a predetermined parameter step in the lower speed direction until the speed is greater than the theoretical value or above the theoretical range. With this it is obtained that, after the speed adjustment reached, the contacts close at the predetermined speed.

Another possibility according to the invention is the registration of the movable contact mass with the aid of a force sensor. This sensor measures the force shock, which is transmitted by the drive to be disconnected to the moving contact. Since the opening velocity of the mobile contact is approximately independent of mass loss, a mass-proportional mobile contact pulse is obtained and, therefore, a mass-proportional force shock at the force sensor. This mass shock is determined by a predetermined time section after the drive shutdown command as a power and time integral, and in the case of a material loss of, for example, 10%, likewise suffers a approximately 10% reduction. The minimum value of the mass remaining in the contact material, in this case, is linked to a corresponding minimum value of the moving contact mass, which according to empirical values include the loss of contact support material.

In a magnetic drive as a switchgear drive the force sensor can be arranged between the electromagnet armature and the mechanical coupling member, which opens the movable contact. Auxiliary electrical power to the force sensor and its measurement signal to the monitoring unit may be conducted through elastic contact members.

By evaluating the signal of the corresponding force value, therefore, according to the invention it can be recognized, if the movable contact bridge of the at least one main contact has exceeded a particular opening point, during shutdown. If the force value signal deviates from a predetermined force comparison value, then further operation of the switchgear is interrupted after a predetermined period of time.

[0036] A respective switching position of the armature or a component that is in an effective bond to the armature may occur, for example, by measuring the capacity of a metering condenser. The measuring capacitor in this case has two capacitor plates which can move relative to each other corresponding to the movement of the reinforcement. The resulting different capacitor plate range leads to a change in capacitance of the measuring capacitor. To define the capacity increase, a constant current pulse can be stored with a constant voltage source in the measuring capacitor. In this case, the current and time integral of the charge current pulse is proportional to the capacity change, and with the other capacitor data thereof the current contact flow pressure can be calculated. If the through-pressure value reaches a minimum value, then the switchgear is taken out of operation by the control unit.

By changing capacity, it can alternatively be recognized if the movable contact bridge of the at least one main contact, which is in an effective mechanical connection to the armature, in particular after disconnection has exceeded one. opening point. The opening point in this case can be calculated from the change in capacity or time value that is required to charge the measuring capacitor. If this time value exceeds a predetermined value, then the measuring capacitor plate range must be very small, and it must be assumed that the armature and the contact bridge attached to it no longer open. In this case, it must be assumed that there is at least one main contact welding. Continued operation of the switchgear is then interrupted.

During shutdown, the velocity of the sensitive v contact depends on the pressure of contact D, since during a magnetic actuation the electromagnet armature and the coupled mechanical components move from the rest position (closing position). ) with approximately constant acceleration b. For the incidence rate of the drive on the moving contact, the ratio V = V (2Db) is obtained and, by approximation v ~ VD.

Speed recording may occur by means of the measuring conduit described above. Since the opening motion of the electromagnet armature causes a reduction in the capacitor plate range, and this leads to a current i from the constant voltage source U to the measuring capacitor, for a contact through pressure D results in relation: t = t6, where t6 is the instant of the opening shock on the moving contact.

With this, the contact flow pressure D can be defined according to the following equation: D = i (t) 2. (2b) '1. (d2 / (eAU)) 2 which, in turn, results by approximation D ~ i (t) 2e, thereby ~ imax2.

In this case, the equation contains the acceleration of armature b, the range of plates d in relation to the moment of opening shock, the surface of plates A, the constant voltage U and the current of capacitor imax in relation to the moment. so If imax2 is less than a predetermined minimum value then the switchgear is taken out of service by the monitoring unit.

In all cases in which the monitoring unit puts the switchgear out of service, the measurement quantity that provides the decision criterion may be obtained first by averaging a predetermined number of measurements.

Due to the dominant moving mass of the switching device drive (electromagnet armature) the closing speed of the moving contact is practically independent of the loss of mass conditioned by the wear of the moving contact. Under normally equal ratios, the closing speed, therefore, is always the same. Undoubtedly, the closing speed will increase with decreasing contact pass pressure, since magnetic forces reach a considerable size with small armature air gap, and accelerate the armature considerably.

Moving contact mass change plays a role in the moving contact mass and spring system and contact force during contact damping, and can be defined by measuring the damping process time by approximation. Any reduction in contact force with contact burn can be considered in the evaluation of contact damping.

With the assumption that in the first damping jump a certain amount of kinetic energy α is available for the contact lift, for the contact lift speed VK, a, the contact closure speed VK, s follows that : Vk, a = Vk, s * (cc) · 0 · 5 and the impulse ratio for the contact mass mK m «* Vk, a = Fk * T / 2 and Διτίκ = ΔΤ * FK / (2 * VK , s * (a) '05) and thus by approximation Διτίκ ~ ΔΤ.

In this case, FK is the contact force and T is the lift duration of the first damping lift.

By averaging over a predetermined number of measured damping times, casual swings can be satisfactorily suppressed, and a representative lift duration can be set. For time measurement, the contact voltage signal can be evaluated after the first contact closure.

[0048] For a more accurate evaluation of the mass loss AmK, the current contact closure speed value VK, s is used. · This value can be set with a measuring capacitor. For the contact closure instant t = ts, from constant voltage source U flows the current i (t) = (sAU / d (t) 2) * v (t) in the measuring capacitor. Since d (t) is defined for time ts through the thickness d of the insulating layer between the capacitor plates, VK, s = v (ts) is defined.

[0049] The closing speed of the magnetic drive armature v after the contact touch depends substantially on the contact passage pressure D, since the electromagnet armature acts on ever larger magnetic forces with slit armature becoming smaller. The value of the closing speed of the reinforcement VK, s for the contact ts instant ts can be used as a rough measure for contact wear. If v (ts) exceeds a predetermined value, then this is equalized with the minimum flow pressure range reached. The velocity (value) as described above is defined in an appropriate measurement capacitor, ie by: IVK, s I = I v (ts) I = I i (ts) * (eAU / d (t) 2 I.

The invention as well as advantageous embodiments thereof will be described in more detail with the aid of the following figures. Shown are: Figure 1 a simplified flowchart of the process according to the invention, Figure 2 a first embodiment of the device according to the invention, Figure 3 a second embodiment of the device according to the invention, Figure 4 a third embodiment of the device according to the invention, figure 5 a fourth embodiment of the device according to the invention, figure 6 a basic electrical circuit diagram belonging to the fourth embodiment, figure 7 a fifth embodiment of the device Figure 8 is a time course by way of example of an opening contact and a series connected closing contact according to Figures 6 and 7; Figure 9 is a cross-sectional image by way of example. of the device according to the invention, with a permanent magnet supported with electromagnetic drive and with a measuring coil, figure 10 a sixth form Figure 11 shows the seventh embodiment of the device according to the invention with open main contacts, Figure 12 the seventh embodiment of the device according to the invention with closed main contacts. Figure 13 shows the seventh embodiment of the device according to the invention with a main contact welded with contact means not yet released and Figure 14 shows the seventh embodiment of the device according to the invention with the main contact interrupted by means of the contact breakage medium released.

As shown in Figure 1, in the process according to the invention, following a shutdown signal, the following steps are essentially performed: Step a) Recognition, if the movable contact bridge of the at least one contact main step exceeded an opening point after shutdown, and Step b) interrupting the continuation of operation of the switchgear, if after a predetermined period of time the opening point was not exceeded.

Thus, after shutdown according to the operation, that is, in particular, after a shutdown signal, for opening three main contacts of a three-pole switching apparatus, it is checked that all contacts main switches of the switchgear have been opened. According to the invention this is due to the fact that it is verified whether the movable contact bridges during the opening have traversed a certain opening path which is larger than a predefined and thus predetermined opening point. If the recognized opening path of one of the contact bridges also after a period of time, similarly as previously determined, after opening is always still below this opening point, then a contact welding of such that further operation of the switchgear must be interrupted.

[0053] OFF position consultation can take place at each switching process, for example by means of a forcibly driven contact interlaced in the control current circuit, or by means of current measuring devices, eg by means of of current transformers. Consultation can occur, for example, also optically, magnetically, inductively or capacitively. The evaluation and control preferably takes place via an electronic control unit, such as a microcontroller, after which during or during the shutdown process the current pathways have been opened or the point of contact, after shutdown there is still a current flow.

[0054] If such a case of failure exists, then interruption of the continuation of operation may occur, for example, by opening another internal connection element of the redundant apparatus, which is connected in series to the main contacts. The switching element then separates - regardless of whether the main contacts have been opened or closed - the consumer of the power supply. Because the connecting element can no longer be closed without problems, the continued operation of the switching device is safely interrupted. As an alternative to opening this additional connection element, in the event of failure, the control magnet command can also be interrupted until a reset and thus locked out. Additionally, a correspondingly strong force accumulator may be released from within the apparatus, which acts on or on the main contacts welded such that these contacts are broken again and thereby opened.

Figure 2 schematically shows a first example of embodiment of a switching apparatus 110 with the device according to the invention. Switch-on and switch-off signals for switching on and off of main contacts 10 are made via terminals A1 and A2, and via control equipment 16 for control magnets 12. During shutdown the excitation of the control magnet, which serves as an electromagnetic drive 12 for the main contacts 10, via the control equipment 16. Through connection 18, in this case, a force acts on the contact bridges against the contact load spring 17 The main contacts 10 are then opened, and thereby the consumer M is separated from the supply equipment, characterized here by the three conductors L1 to L3.

Furthermore, after the removal of the control magnet excitation 12, by an evaluation equipment 15 by means of electrodes 11 and 11 ', it is checked whether the contact bridges have exceeded the predetermined opening point. For the measurement of a voltage drop across the main contacts 10, in the execution example in question, two electrodes 11 and 11 'are provided for each current path L1 to L3, and actually one before the contact. 10 and one after the main contact 10. According to the invention, then, after disconnecting the main contacts 10 by the evaluation equipment 15, through the electrodes 11 and 11 'a voltage test is carried out through the main contacts 10. If the voltage drop on one of the main contacts 10 is too small, this indicates that this contact has not been opened sufficiently. That is, the opening path traveled by the contact bridge during shutdown did not exceed the predetermined value, and a welding is very likely.

If after a predetermined period of time of, for example, 100 ms, after a shutdown signal has been released, a too small opening path is acknowledged, it must be ensured that continued operation of the switchgear 110 is interrupted. In this embodiment, for this purpose, the evaluation equipment 15 is connected to the control equipment 16 via a connection not designated in detail. If such a fault is then recognized by the evaluation equipment 15, that fault is transmitted to the control equipment 16 as a result of which such equipment interrupts at least one of the control conductors.

Additionally, in the execution example in question a mechanical release system 14 is activated, with which a spring force accumulator 13 is unlocked. Spring force accumulators 13 of this type may be, for example, known connection locks of power switches or compact starters. Such a fastener then strikes by means of an effective mechanical connection 19 with a strong force on the unopened main contacts 10 of the switching points 110 of the switchgear 110 in order to break the welded main contacts 10. In that case, in order to obtain a rupture, the force of the spring accumulator 13 needs to be correspondingly large. The spring accumulator 13 then remains either in the unlocked position and can no longer pass back, or the spring accumulator 13 has a mechanical system whereby the spring 13 is tensioned again, and the mechanical release system 14. can be locked again. Since restoration of mechanical system 13 and 14 can only take place manually, thus a user's attention is drawn to the incident and needs to counteract accordingly, for example by changing the switchgear 110. .

[0059] In another embodiment not shown in detail, only one current sensor per current may also be provided. Then, by measuring current, each current path is recognized if the opening point after shutdown has been exceeded. If it has been recognized with the aid of current measurement that an overrun of the opening point has not been carried out, further operation of the switching device is interrupted.

Figure 3 schematically shows a second embodiment example of the device according to the invention, in which the opening path to be recognized of the contact bridges of the connection point 20 is consulted directly by the evaluation equipment 25. This may occur, for example, by means 21 corresponding but not shown in detail in figure 3. Thus, for example, connection monitoring means may be provided, which in a first state are carried if the main contacts 20 are closed during switching on and also after switching off remain in this first state if at least one of the main contacts 20 is welded.

In this case, it was assumed that the recognized opening path did not reach the predetermined value if these means 21 remain in this first state after shutdown, which does not correspond to the predetermined state after opening.

As another embodiment and not shown in detail for recognizing the opening path of the main contacts, an inductivity measurement would also be possible directly on the control magnet coil. The control magnet in the regular on state has another inductivity than in the off state. If this inductivity of the switched off state is not reached after switching off, it is assumed that the opening point has not been exceeded and the switchgear is switched off.

[0063] Figure 4 shows a third embodiment example of the device according to the invention. In this case, in the event of a failure, for further interruption of operation, a further connecting element 39 'is provided, which is arranged in series for the individual main contacts 30 to be actually connected to the main contacts 30 in the case of L1 to L3. In the case of welding of one of the main contacts 30, the evaluation equipment 35 recognizes, through electrodes 31 and 31 ', a voltage drop too small on this main contact 30. As a result, the evaluation equipment 35 causes that, a mechanical release system 34 is activated and thereby a spring force accumulator 33 is unlocked. This spring force accumulator 33 acts on the coupling element 39 'through the effective coupling 39, and opens that element. As a result, the current paths L1 to L3 are interrupted safely and regardless of whether the main contacts 30 are open or are still closed and the continued operation of the switchgear 310 is interrupted.

Figure 5 shows a fourth embodiment of the device according to the invention. The device has an auxiliary contact as a lead monitoring means 45, which is connected in series to an opening contact 41 of a control magnet 42 or electromagnetic drive 42. The opening contact 41, as shown, during the ligament, that is, in the case of control magnet excitation 42, is opened. Furthermore, an actuator 44 is connected in series for the opening contact 41 and the auxiliary contact 45, which in the excited or current state can release a rupture means 46, such as a power accumulator or, as shown. Figure 5 shows a connection lock. Control magnet 42 drives a contact slide 43 via a drive lever 49 which can open and close the main contacts 1, and in the excited state of control magnet 42 the main contacts 1 are closed in the operation, whereby a contact load spring 40 closes the main contacts 1. The auxiliary contact 45 is mechanically connected by means of an auxiliary contact slide 48 and the contact slide 43 with the main contacts 1, such that Through these slides, the bonding state of the main contacts 1 is "reflected" over auxiliary contact 45, that is, it is transmitted. In this case, the mechanical connection occurs such that, in the case of welding at least one main contact 1 also the auxiliary contact is closed or remains closed.

According to the invention the connection monitoring means 45 is transported to a first state if during switching on the device the main contacts 1 are closed. The opening contact 41 is opened. During shutdown, the opening contact 41 is closed and the connection monitoring means 45 is opened. In this case, call monitoring means 45 remains in this first state after shutdown, if at least one of the main contacts 1 is soldered.

If, then, after disconnection, one of the main contacts 1 is soldered, then the opening contact 41 is closed and at the same time also the auxiliary contact 45 is closed, since despite the disconnection order , one of the main contacts 1 is closed. Through these two contacts 41,45, then, actuator 44 can be admitted with current. Actuator 44 may be, for example, a lifting magnet which then, in the case of excited current, releases breakaway means 46, such as a spring accumulator, or releases connecting lock 46. Through the lever of the A locking clamp 47 and the contact slide 43 can thereby be applied with a breaking force on the main contact 1 welded, such that the welding can be interrupted, and thereby said consumer can be disconnected.

Since, during shutdown, the mains voltage is normally "removed", this means that the mains voltage is interrupted for the mains supply, in particular the control magnet, is of great advantage. if the connecting voltage is damped by means of an electrical storage element such as a capacitor. The capacitor voltage in this case can be separated by a diode from the connection voltage.

The switching contacts 41, 45 are made such that the auxiliary contact 45 closes during switching after the opening contact 41 has been opened, and the opening contact 41 during the shutdown closes, after auxiliary contact 45 has been opened.

Without this special execution of the time delay of the contact contacts 41, 45 it may occur that in normal connection operation the two contact contacts 41, 45 are closed simultaneously, although only for a short time. The effect of this short-term bonding state, which could ultimately lead to an involuntary release of the contact breakdown means 46, can be prevented by the fact that the electrical release signal connected through the two bonding contacts 41, 45 closed is temporarily filtered or flattened. This is possible, for example, by means of a reaction coil, which is connected in series to the connecting contacts 41,46, or by means of a capacitor.

Alternatively also, during the binding or for the binding of a control magnet 42, a corresponding auxiliary contact may be opened and during the switching of the control magnet 42 a closing contact not shown in detail may be closed. . A release means then releases a contact breakage means 46 if during shutdown the auxiliary contact remains or remained in the open state, whereby the respectively open bonding state of said bonding contacts is evaluated.

Said switching contacts are preferably made such that during switching on the auxiliary contact is opened after the closing contact has been closed and the closing contact has been opened during shutdown. , after the auxiliary contact has been closed.

Said contact contacts may be connected, for example, in parallel, and in the event of failure, ie if both contact contacts are open, a release signal may be produced for the release medium. . The release signal can be produced, for example, through the existing control unit.

[0073] Figure 6 shows a basic electrical circuit diagram belonging to the fourth embodiment according to figure 5. In the central part of figure 6 are represented, by way of example, the three main contacts 1, which are actuated by contact slide 43 by the control magnet 42 as well as by the lock 46. Parallel to the two connecting terminals A3 and A4, through which a control magnet excitation coil 42 can be supplied with current, The serial connection consisting of opening contact 41, connection monitoring means 45 and actuator 44 for releasing connection lock 46 is shown. If terminal voltage A3 and A4 are then applied to the connection the control magnet drive excitation coil 42 is crossed with a current in order to close the main contact 1. In the event of failure, ie in the case of a main contact 1 soldered undoubtedly the auxiliary contact 45 or the link monitoring means also remains closed, so that the actuator 44 can be supplied with current to release the link 46. In this case, the applied link voltage to terminals A3, A4 are used to power the actuator 44. Such a device, as it were, is inherently safe until the end of its life, and achieves a safe connection state.

The switching device can be particularly advantageously employed in a compact starter, in which both the contact opening during closing according to the operation, as well as an overcurrent shutdown can only occur through a primary contact disposition.

[0075] Figure 7 shows a fifth embodiment of the device according to the invention in detail. In the upper part of Fig. 7 a connection lock 46 with an integrated spring accumulator as a force element is shown for breaking a welded main contact 1. The combined connection lock 46 acts directly on the movable contact bridges in the event of a release through, for example, two pins 47, 51 which are in an effective mechanical connection with each other. A primary contact 1 soldier can be broken in this way. An actuator 44 as a release unit is connected to the connection lock 46 by means of, for example, a lever 52, which can be rotated. Actuator 44 is preferably an immersion armature or a lifting magnet. For release, actuator 44 is supplied with current. This is the same as in the device according to figure 5 and figure 6. That is, if the release means 45 or the auxiliary contact and the opening contact 41 of the control magnet 42 are closed for the connection of according to the operation of the switchgear. In this case, the actuator 44 is supplied with current through the voltage applied to the excitation coil 56 of the control magnet 42. In the left part of the figure 7 can be seen the control magnet 42. During switching on the armature 55 of the control magnet 42 is attracted, whereby armature 55 then actuates a supported drive lever 54 and can rotate 53. In normal operation, this contact slide drive 43 is moved "up" so that the contacts 1 may be closed by the spring force of the contact load spring 40. The spring force of the contact load spring 40, in this case, is designed such that the force released during release of the contact closure The connection 46 with the integrated force element is significantly larger to overcome the breaking force required for the welded main contact as well as the spring force of the contact load spring 40.

[0076] In a special embodiment, for safe release of the force element 46, it is provided that the opening contact 41 and the release means 45, executed as a bonding contact, are correctly actuated with respect to each other. respect for time. Thus, it is advantageous if during opening the opening contact 41 opens immediately before closing the release means 45, and during shutdown the opening contact 41 closes immediately after opening the release means 45.

This is shown in Figure 8 below, where ZO designates the time course of opening contact 41 and ZS, the time course of release means 45 executed as closing contact. With reference signal CL the open state of said connection contact 41, 45 is designated. With ΔΤ the time displacement between the connecting flanges of time courses ZO and ZS is exemplary. Through this targeted time delay of the bonding relationships, the filtering and flattening elements necessary in the description of the figures with respect to figure 5 become superfluous.

Alternatively, the opening contact may also be performed as closing and the release means as opening. Preferably, in the regular operation of the device, the two switches 41 and 45 should have both transient on and transient off states opposite contact positions, ie switch 41, 45 "open / closed" or "closed / open" "

This can occur, for example, mechanically by damping, or electrically by electrical retarding members, which have different time constants for on and off.

In addition, the switching voltage for switching on and off of the switching apparatus, which is applied to the electrical connections A3 and A4 for the excitation of the control magnet 56 of the control magnet 42, may be damped by a diode for voltage decoupling and through a subsequently connected capacitor. In this way, sufficient electrical energy for releasing the power element 46 or jumper 46 is available during removal of the jumper voltage for device shutdown in the event of a failure.

Fig. 9 shows a cross-sectional image through an exemplary embodiment of the device according to the invention with electromagnetic drive 60 supported with a permanent magnet 68.

In the upper half, in this case, the magnetic flux in the electromagnetic drive 60 in the ON state is shown (see back plate 58 shown in dashed form). In the lower part of figure 9, by contrast, the magnetic flux in the electromagnetic drive 60 is shown in the OFF state (see back plate 58 shown in full).

In the center of the figure is shown an excitation coil 66, which is wound on a winding body 67. The excitation coil 66 has, for example, two connections for supplying a coil current i. With reference signal u, the coil voltage applied to the excitation coil 66 is designated as the connecting voltage. The winding body 67 and the excitation coil 66 form a cylindrical OF opening in which an armature 61 of the electromagnetic drive 60 can move around. The armature 61 has a cylindrical pin adjusted to the dimensions of the cylindrical OF aperture as well as a thrust plate 58 disposed therein. The entire armature 61 in this case is made of a ferromagnetic material and in particular soft magnetic such as iron. The winding body 67 and the excitation coil 66 are surrounded by an inner breech 65 of a soft magnetic material for conducting magnetic flux of the magnetic field produced by the excitation coil 67, with a portion of the inner breech 65 extending. to the cylindrical OF aperture, and therein forms an inner pole 63. The magnetic field thus produced finally acts in the area shown of the cylindrical OF aperture.

The electromagnetic drive 60 is supported by at least one permanent magnet 68 such that in the OFF position of the electromagnetic drive 60 additional holding force is produced for the armature 61. The permanent magnets 68 in this case are placed on the outer side of the inner breech 65 of the electromagnetic drive 60. The magnetic poles of the two permanent magnets 68 are respectively designated N and S. The permanent magnets 68 are preferably disposed along the circumference of the inner breech 65. Instead of a multitude of permanent magnets 68 a magnetic ring or necklace can also be employed which is polarized such that on its inner side forms a north pole N or south pole S, and on its outer side a south pole S or north pole N. In the example of figure 9, the side of the outwardly directed permanent magnets 68 is connected with a soft magnetic pot-shaped external breech 64. The outer breeder 64 likewise has a cylindrical OF aperture in which a contact slide 59 is conducted. The contact slide 59 can be driven by the backing plate 58 of the armature 61 such that a contact bridge connected The contact slide 59 not shown in detail can be actuated.

In addition, within the cylindrical OF aperture, between the inner pole 63 and the cylindrical pin of the armature 61 is a readjustment spring 69, which in the no-current state of the drive coil 66 drives the armature 61 from the cylindrical OF opening. The geometrical dimensions of the cylindrical pin of the armature 61, the outer side of the inner breech 65 as well as the inner side of the outer breech 64 are geometrically adjusted such that the thrust plate 58 of the armature 61 hits a ON position excited against the outer side of the inner breech 65, and in the non-excited state abuts against the inner side of the outer breech 64. The dashed representation of the back plate 58 shows in this case the ON position of the electromagnetic drive 60.

In the lower half of figure 9 is marked, for the OFF position of the electromagnetic drive 60, the course of the magnetic field MF1 resulting from the permanent magnets 68 as dash line and dot. In the upper half of Figure 9, for comparison is marked the course of the magnetic field MF2 resulting from the permanent magnets 68 to the ON position of the electromagnetic drive 60. In the latter case, there is no path with a magnetic resistance on the external breech 64. for the magnetic field MF2 such that a magnetic distribution field necessarily forms around its permanent magnet 68.

Through the permanent magnet chain force on the armature 61 occurs the instantaneous switching process, such that at the moment of interruption the movement of the armature 61 compared to the pure electromagnetic drive immediately and at full force.

According to the invention, then, a change in magnetic flux can be recognized, in particular outside the drive coil 66 and in particular outside the inner breech 65 of the electromagnetic drive 60 surrounding the coil. 66 by means of a suitable measuring means. In the example of Fig. 9, for this, a particularly advantageous measuring coil 62 is wrapped around an outer breech flap 64. Instead of the measuring coil 62 a magnetic field sensor may also be employed, such as a Hall sensor. Starting from the OFF position, the magnetic flux MF1 passes through the measuring coil 62 stationary. If then the armature 60 moves instantly left to the ON position, then the magnetic flux also instantaneously changes such that a distribution field MF2 is formed according to the representation of figure 9, also in the inner area, whereas at the same time the magnetic flux almost disappears in the external breech 65. This dynamic change of the magnetic flux in the external breech flap 65 manifests itself in an induction voltage u, existing in the measuring coil connections 62, whose peak value The larger the faster the magnetic flux changes.

The induction voltage u can then be compared to a predetermined comparison value, and from the result of the comparison a digital signal is generated for complete processing in the signal technique.

According to the invention, by the existence of a minimum value of the induction voltage u, it is recognized that the movable contact bridge of the at least one main contact after disconnection must have exceeded an opening point. . If, on the contrary, after a predetermined period of time, or within the predetermined period of time, the minimum value of the induction voltage Ui is not recognized, then further operation of the switching apparatus is interrupted. In this case, it can be assumed from the fact that there must be contact welding, which leads to the fact that the reinforcement plate 58 then does not completely touch the inner or outer breech 65, 64. Correspondingly lower is the stress. of induction u, produced.

[0090] In this case, it is a special advantage that also signs of stealthy wear of the mechanical drive system of the electromagnetic drive 60 can be seen, which then lead to linkage drives that become slower with an induction voltage. u smaller.

Figure 10 shows a sixth embodiment of the device according to the invention.

The essential aspect of the device according to figure 10 is that a power dampening occurs during operation, such that during shutdown and thus after disconnection of the power supply, An evaluation and control unit may still be provided for a minimum of time, so that in the event of the existence of a welded main contact, it may control or release a means of contact breakage and / or a connection closure.

In the case of the device in question according to Figure 10, by way of example, there is an electric energy accumulator 94 in the form of a capacitor. This is, firstly, when applying a supply voltage, is charged through the control terminals A5, A6 to the evaluation and control unit 91. Only when the energy accumulator 94 has reached a minimum charge state is an electromagnetic drive 92, such as a control magnet, is commanded for switching on the main contacts 1. In the case of a capacitor 94, the minimum charge state of the electric accumulator 94 corresponds to a minimum charge voltage Umin for the capacitor voltage Uc. This voltage can be, for example, 80% of the bonding voltage applied at terminals A5, A6. The minimum charge state of the energy accumulator 94, in this case, is measured such that this voltage is sufficient for the release of contact rupture means 80 through the evaluation and control unit 91 by means of a signal from control for a release medium.

The control magnet 92 shown, during a command for switching on the switchgear, drives an armature 97, which is in an effective mechanical connection with a contact slide 73, which in turn acts on a jumper. contact 74. The contact bridge 74 then covers, as a movable guide piece, the fixed guide pieces of the current paths L1 to L3. During switching on the control magnet 92, a pre-tensioned contact load spring 75 is relieved in the off state of the switchgear, which then presses the contact bridge 74 against the fixed conducting parts of the current paths L1 to L3 and contact them. Alternatively or additionally, for the breakage of a welded main contact 1, a connection lock can also be controlled, which is constructively carried out so as to generally interrupt a welded main contact 1.

Reference numeral 93 designates means for recognizing at least one primary contact 1 soldier. The means according to the invention serve for recognition if the movable contact bridge 74 of the at least one main contact 1 has passed an opening point after disconnection. In the example of Fig. 10, means 93 is a current sensor, in particular a 3-way current sensor, for recording the current flow in the main current paths L1 to L3 of a three-pole switching apparatus. The current sensor 93 in this case is connected to the evaluation and control unit 91 via a connection conductor for the emission of a current measurement value.

According to the invention, further operation of the switching apparatus is interrupted if, after a predetermined period of time, the opening point has not been exceeded. In the example of Fig. 10 in question, the evaluation and control unit 91 for that purpose evaluates the current flow in the current paths L1 to L3 within the predetermined period of time, such as 100 ms, after the power off. control apparatus. If a current flow is detected, then the evaluation and control unit 91 outputs a current pulse to the release means 95. The release means 95 is, for example, an actuator in the form of a lifting magnet or whose actuator armature 96 releases release means 80 in the form of a spring accumulator. For this, the actuator armature 96 formed as a locking tooth disengages a retaining core 82 from a break contact slide 81 pre-tensioned by a spring 83. This break contact slide 81 then strikes the contact slide. 73 for the break of the main contact 1 welded.

Alternatively, by means of a technical regenerative measuring coupling the inductivity of the electromagnetic drive could be measured and therefore the OFF position of the main contacts 1. Or it could be determined by means of an auxiliary switch such as a reflection contact according to IEC 60947-4-1, which is electrically connected to the evaluation and control unit 91, if the main contacts 1 have opened. If it is found that the main contacts 1 have not been opened, then the energy accumulator 94 is discharged through the release means 95.

Particularly high technical requirements must be placed on the reliability of the energy store after a long operating time of many years, possibly under high ambient temperatures. One could imagine the employment of convicts, who are designed for military employment. These capacitors have a significantly longer service life than traditional capacitors. The electric capacitor 94 could be charged by means of an appropriate charge connection of the induced voltage during the switching off process of the control magnet excitation coil 92. This accumulated electrical energy is then available for following short time for feeding the evaluation and control unit 91 as well as for releasing the release medium 95.

Instead of electric capacitors a small flywheel would also be conceivable, whose kinetic energy is available as electrical energy through a dynamo after shutdown.

Alternatively, the current transformer (s) 93 could be sized larger so that the current transformer power L1 to L3 which is required for unit operation could be derived from the current transformers 93. 91 and for the release of the release medium 95.

A solution would also be conceivable in which the evaluation and control unit 91, next to terminals A5, A6 still has additional power supply terminals. If voltage is captured by the additional power supply terminals, then the evaluation and control unit 91 is also supplied with power from this independent power supply after shutdown.

For the disruption of a welded main contact 1, a special bonding closure construction, which in the area of contact contact has either a high opening force and / or a high opening impulse, is advantageous. Through a corresponding reduction gear it can be obtained that the energy accumulated in a shut-off spring is not reduced through the opening path, but preferably through the path from the "ON" position to the "touch contact" position. After the "touch contact" position to the "OFF" position, the remaining power is still supplied to pre-tension the contact load springs to the on position.

[00103] Figure 11 shows a seventh embodiment of the device according to the invention with open main contacts 1. It is assumed that the main contacts 1 are not yet closed and have been opened regularly.

[00104] In the right part, Figure 11 shows a control magnet 72 in the non-excited off state. In this case, the reset magnet 79 of the control magnet 72 compresses a contact bridge 74 through armature 77 and through a contact slide 73, which is in an effective mechanical connection, in the OFF position. In this case, a weaker contact load spring 75 is pre-tensioned compared to reset spring 79. In the state shown, the main contacts 1 then have a contact opening interval a. With this, current flow through current paths L1 to L3 is not possible.

During shutdown, armature 77 of control magnet 72 goes to a connector 76 which is securely connected with contact slide 73. Contact slide 73 and connector 76 can also be manufactured as a component only. In the DES state shown, at the end of the armature 77, which is opposite the control magnet 72, laterally engages an actuator armature 86 of an un-excited actuator 85. Actuator 85 serves as the release means for contact rupture means 80. In the state shown, the armature 77 acts as a backrest such that the locking tooth formed at the opposite end of the actuator armature 86 cannot disengage from a retaining core or retaining edge 82 of the contact rupture means 80. In this case, an actuator reset spring 85 remains pre-tensioned due to retention of the bump. In this case, the mounting arrangement of the contact breaking means 80 corresponds to that of figure 10.

[00106] Figure 12 shows the seventh embodiment of the device according to the invention with closed main contacts 1. In this case, the control magnet drive coil 72 is energized through the electrical connections A5 and A6. In the example of Fig. 12, the armature 77 moves to the right, and relieves the contact slide 73. Due to this relief, and due to the relief of the pre-tensioned contact load spring 75, the contact bridge 74 then closes. , the main contacts 1.

According to the invention, during ligation, the release medium 85 is excited to the contact rupture means 80 and, simultaneously or shortly thereafter, the control magnet 72. With this, the release spring readjustment of the release means 85 remains pre-tensioned and then active. Compared to Fig. 11 it can be recognized that the actuator reset spring 85 is even pre-tensioned a little further. The delay of the actuation of the control magnet 72 in relation to the release means 85 may occur, for example, by mechanical damping means, which only act for the bonding process. Alternatively, electric damping means may also be employed in the control magnet excitation circuit 72, such as a coil connected in series to the control magnet excitation coil 72. Now the actuator armature 86 does not releases contact rupture means 80, although due to the drive now introduced, the control magnet 72 armature 77 releases the stop and hold function.

As shown in Fig. 12, now, with an externally forced excitation withdrawal, due to the previously tensioned reset spring, the actuator armature 86 would move downward in accordance with Fig. 12 and thereby releasing contact disruption means 80. In this case, the particular advantage is that releasing contact disruption means 80 occurs safely, since no energy for the release needs to be compensated or continuously available. The energy required for release is in the pre-tensioned reset spring of actuator 85. With this, the release and break contact mechanism shown in figure 12 runs as "fail safe".

As still shown in Figure 12, due to the actuation of the armature 77 for the connector 76, a gap of a few millimeters appears, which adjusts due to the new state of the connection contacts 1. This gap reduces with the wear of contact material. In the ON state, then, the connector 76 is in front of the actuator armature end 86, which is in front of the locking tooth. The connector 76 has, for example, in the area of the actuator armature 86 a recess 78, regardless of whether the main contacts 1 are new or already worn. The recess 78 is sized such that during the fall of the release means 86, i.e. the actuator executed as a lifting or dipping magnet, the contact breakage means 80 is reliably released. Alternatively, the connector 76 could also have along its entire length a constant cross section corresponding to the dimensions of the connector 76 in the final area.

[00110] Figure 13 shows the seventh embodiment of the device according to the invention with a welded main contact 1, with a contact breakage means 80 not yet released. Switching off of the control apparatus is normally due to the fact that the connection voltage is interrupted or withdrawn at terminals A5 and A6 of control magnet 72. Preferably, the connection voltage also feeds release medium 85 through terminals A7. and A8, such that upon removal of the binding voltage this medium also falls. The excitation circuits of control magnet 72 and release means 85 may also be serially connected.

According to the invention, the switching apparatus now recognizes or examines, if upon disconnection, the movable contact bridge 74 of the at least one main contact 1 has passed an opening point. As shown in Figure 13, the main contacts 1 then no longer open due to welding, such that even after a predetermined period of time an opening point is not exceeded. The predetermined time period may be, for example, 100 ms. Preferably, during shutdown, release means 85 is delayed relative to control magnet 72, such that during shutdown, armature 77 may again assume the stop and hold function for actuator armature 86. Continued operation of the switchgear is then interrupted after the predetermined period of time has elapsed if, due to a welded main contact 1, the armature 77 can no longer be actuated such that it could still "receive" the already falling actuator 86 armor. Now the release means 85 falls completely and thereby releases the contact breakage means 80.

Fall delay during shutdown of actuator 85 may occur, for example, by means of mechanical damping systems, or by a no-load electrical circuit with a no-drive diode in the circuit. excitation of actuator 85. In this case, the idle circuit still maintains the magnetization of the magnetic circuit of actuator 85 for a predetermined period of time. In contrast, during shutdown, the control magnet 72 excitation circuit may be electrically damped by a relatively high ohmic resistance such that the magnetic energy in the control magnet 72 magnetic circuit can be reduced so as to very quick.

[00113] Figure 14 shows the seventh embodiment of the device according to the invention with the main contact 1 broken through the released contact breaking means. As described above, the spring force of the contact rupture spring 80 is dimensioned such that, in addition to the required breakout force, this force can also exceed the spring force directed in the opposite direction of the contact load spring. 75. For this reason, re-closing of main contacts 1 is no longer possible. With this, the operation of the switchgear remains interrupted. The contact rupture means 80 may also have an unrepresented mechanical system allowing the tensioning of the released spring 83 as well as the release means 85. This restoration of the mechanical system may occur, for example, manually.

Claims (39)

1. Process for the safe operation of a switchgear (110; 210; 310) with at least one main contact (1; 10) which can be switched on and off, which has contact parts and a contact bridge ( 74) movable, and with at least one control magnet (12; 42; 72), which has a movable armature (77), and during switching on and off the armature (77) acts on the bridge of contact (74) such that the corresponding main contact (1; 10) is closed and opened with the steps: recognition if the movable contact bridge (74) of at least one main contact (1; 10 ) has exceeded an opening point after shutdown, interruption of the operation of the switching apparatus (110; 210; 310) if after a predetermined period of time the opening point has not been exceeded, characterized in that in the state connected to the control magnet (12; 42; 72) a release means (95) is kept active in an excited state , in order to prevent the release of a contact rupture means (80), and where, during shutdown, the excitation of the release means (85) and the control magnet (12; 42; 72), whereby an armature (77) or a control magnet component (12; 42; 72) that is in an effective mechanical bond with the armature (77) prevents release of the release means (85). . Process according to claim 1, characterized in that the overrun of the opening point is recognized by a measurement of a current in a current path to be switched by the main contact (1; 10), wherein the opening point has not been exceeded if the measured current is greater than a predicted current after shutdown. Method according to claim 1, characterized in that the overrun of the opening point is recognized by a measurement of a voltage drop across the main contact (1; 10), wherein the opening point has not been exceeded if the voltage drop is less than a predicted voltage drop after shutdown. Method according to claim 1, characterized in that the opening point overrun is recognized by a measurement of a control magnet inductivity (72), whereby the opening point has not been exceeded if the inductivity after shutdown has a value which does not correspond to the predetermined value after opening. A method according to claim 1, characterized in that the opening point is recognized by a state of means which are in effective connection with the contact bridge (74), wherein the recognized opening point has not been exceeded if after shutdown these means remain in this state which corresponds to the predetermined state after opening. Process according to Claim 5, characterized in that, - during the binding or for the binding of a control magnet (42), an auxiliary contact (45) is closed, - that during the binding from the control magnet (42) an opening contact (41) is opened, and - by the fact that a release means (44), which is connected in series to the connecting contacts (41, 45), releases a medium break contact (46), if during shutdown the auxiliary contact (45) remains or remained in the closed state. Method according to Claim 6, characterized in that the connecting contacts (41, 45) are made such that during disconnection the auxiliary contact (45) closes after the opening contact. (41) has been opened, and by the fact that during shutdown the opening contact (41) closes after the auxiliary contact (45) has been opened. Process according to Claim 5, characterized in that - during the binding or for the binding of a control magnet (42) an auxiliary contact (45) is opened, - that during the binding of the control magnet (42) a closing contact is closed, and - by the fact that a release means releases a contact breaking means (46), if during shutdown the auxiliary contact (45) remains or has remained in the open state, whereby the respective open connection state of said connection contacts is evaluated. A method according to claim 8, characterized in that said connecting contacts are made such that during switching on the auxiliary contact (45) opens after the closing contact has been closed, and the fact that during shutdown the closing contact opens after the auxiliary contact (45) has been closed. Process according to Claim 1, characterized in that during a switching actuation a magnetic flux change of the magnetic circuit of the control magnet (60) is measured, whereby the opening point has been exceeded if during shutdown of the control magnet (60) the magnetic flux change exceeded a predetermined comparison value. Process according to Claim 10, characterized in that the change in magnetic flux is measured by means of an induction coil (62). Process according to Claim 1, characterized in that the electrical supply to an evaluation and control unit (91) of the switching apparatus (110; 210; 310) is maintained by means of a storage element. (94) electrical for a minimum time in order to recognize, by measuring technique, the existence of a welded main contact (1) and, in order to control or possibly release a contact breaker (80) and / or a connection lock. The method according to claim 12, characterized in that, only in the case of a switching order, the control magnet (92) is then excited to drive at least one main contact. (1) if the electrical storage element (94) has reached a minimum charge state. Process according to Claim 1, characterized in that during release the release means (85) is excited prior to the control magnet (72), and that during shutdown the excitation is removed. of the control magnet (72) before the release means (85). Process according to Claim 14, characterized in that the release means (85) is a lifting or dipping magnet. Method according to Claim 14 or 15, characterized in that the contact rupture means (80) has a spring accumulator. Method according to any one of Claims 1 to 16, characterized in that the continuation of the operation is interrupted by the fact that a switching element arranged in series with the main contact (1) is opened in the pathway. current (L1-L3). Process according to any one of Claims 1 to 17, characterized in that the continuation of the operation is interrupted by the fact that at least one control conductor is interrupted for control magnet control. . 19. Device for the safe operation of a switching apparatus (110; 210; 310), wherein the switching apparatus (110; 210; 310) has at least one main contact (1; 10) which may be on and off, which has contact parts and a movable contact bridge (74), and comprises at least one control magnet (12; 42; 72), which has a movable armature, and during ligation and disconnecting the armature acts on the contact bridge (74) such that the corresponding main contact (1; 10) can be closed and can be opened, whereby first means are provided for recognition if a point opening of the contact bridge (74) of the at least one main contact (1; 10) has been bypassed, and other means are provided which interrupt the further operation of the switching apparatus (110; 210; 310) if after shutdown means recognizing that the opening point after a period of time predetermines was not exceeded characterized by the fact that a release means (85) is provided, which in the on state of the active control magnet (72) is kept in an excited state in order to prevent the activation of a disruption means (80), and the excitation of the release means (85) as well as the control magnet (72) is removed during shutdown, and then an armature (77) or a component of the control magnet (72) which is in an effective mechanical connection with an armature (77) prevents the release means from being actuated (85). Device according to Claim 19, characterized in that the first means comprise a current sensor which measures current in a current path to be connected by the main contact (1; 10). Device according to claim 19, characterized in that the first means comprise two electrodes, the first and second electrodes being arranged such that a voltage drop can be deflected through the main contact ( 1, 10). Device according to claim 19, characterized in that the first means comprise a means for detecting an inductivity, which measures the inductivity of the control magnet (12; 42; 72). Device according to claim 19, characterized in that the first means comprise an opening mechanism which is in effective connection with the contact bridge (74) and can assume a first and a second state. Device according to Claim 23, characterized in that, - an auxiliary contact (45) is provided which closes during control magnet switching (42) or that for control magnet switching ( 42) is closed, - an opening contact (41) is provided, and is executed such that this contact is opened during control magnet switching on (42), and - a release means (44) is provided, which is connected in series to the connecting contacts (41, 45), and which triggers a contact breaker (46) if during shutdown the auxiliary contact (45) remains or has remained in the closed state. Device according to claim 24, characterized in that the connecting contacts (41, 45) are made such that the auxiliary contact (45) closes during connection after the contact has been made. opening (41) has opened, and by the fact that the opening contact (41) closes during shutdown after the auxiliary contact (45) has been closed. Device according to Claim 23, characterized in that an auxiliary contact (45) is provided which opens during control magnet switching (42) or that for control magnet switching ( 42) is opened, - a close contact is provided and is executed such that during the switching of the control magnet (42) this contact is closed, and - by the fact that a release means is provided which it activates a contact breaker (46) if the auxiliary contact (45) remains or remained in the open state during shutdown, by means of which evaluation means assess the respectively open switching state of said connecting contacts. Device according to Claim 26, characterized in that the contact contacts are made such that the auxiliary contact (45) opens during the connection after the closing contact has been closed, and at least fact that the closing contact opens during shutdown after the auxiliary contact (45) has been closed. Device according to claim 19, characterized in that a means is provided for recording a magnetic flux change of the magnetic circuit of the control magnet (60) during a switching actuation, wherein the point of The opening was exceeded if, during the control magnet (60) switch-off, the magnetic flux change exceeded a predetermined comparison value. Device according to Claim 28, characterized in that the change in magnetic flux can be measured by means of an induction coil (62). Apparatus according to claim 19, characterized in that an electrical accumulator element (94) is provided for maintaining the power supply for an evaluation and control unit (91) of the switching apparatus (110; 210; 310) for a minimum time in order to recognize the existence of a main contact (1) welded with metering technique and, if necessary, to control or release a contact breaker (80) and / or a connection closure. . Device according to claim 30, characterized in that means (91) are provided which, in the event of a switching order, only then drive the control magnet (92) to actuate at least least one main contact (1) if the electric accumulator element (94) has reached a minimum charge state. A device according to claim 31, characterized in that means are provided that during the ligation remove the excitation of the release means (85) temporarily before the control magnet (72), and during the disconnection temporarily the excitation of the control magnet (72) before the release means (85). Device according to Claim 31 or 32, characterized in that the release means (85) is a lifting or dipping magnet. Device according to any one of claims 31 to 33, characterized in that the contact breaker (80) has a spring accumulator. Device according to any one of Claims 19 to 34, characterized in that the other means comprise an evaluation device which for interrupting the continuation of the operation opens a connecting element arranged in series with the main contact. (1; 10) in the current path. A device according to any one of claims 19 to 35, characterized in that the other means comprise control equipment for controlling the control magnet (72) which interrupts the continuation of the operation by interrupting Control conduction for control magnet (72). Switching apparatus (110; 210; 310) which for safe consumer switching performs the process as defined in any one of claims 1 to 18, characterized in that the switching apparatus (110; 210; 310) is a relay or a power switch or a starter. Switching apparatus (110; 210; 310) which for the safe switching of consumers with a device as defined in any one of claims 19 to 37, characterized in that the switching apparatus (110; 210; 310) is a relay or a power switch or a starter. Switching apparatus (110; 210; 310) according to claim 37 or 38, characterized in that the switching apparatus (110; 210; 310) is a switching apparatus (110; 210; 310). three-pole, with three main contacts for switching on and off three-way current with a control magnet (12; 42; 72).