DE102015201009A1 - Display device and fire protection switch - Google Patents

Abstract

The display device according to the invention for a fire protection switch (1) for detecting an arc fault has a triggering device (20), which in turn has a trip coil (21) and a relative thereto movably mounted release plunger (22) by energizing the trip coil (21) of a triggering position in a triggered position can be brought. Furthermore, the display device has a display element (10) which is movable from a first position to a second position when the fire protection switch (1) is triggered. Due to the release plunger (22) in the ready-to-release position, the display element (10) is held in its first position, while it can be released by moving the release plunger (22) to its released position. A reset of the trigger plunger (22) from its tripped position to its triggering position is blocked by the display element (10) in its second position. By the first position of the display element (10) an operator ready state of the fire protection switch (1) is displayed, whereas by the display element (10) in the second position a successful release of the fire protection switch (1) due to a predefined fault current, i. due to an arc fault, is signaled. However, since the reset of the display element (10) in its first position only by a manual intervention of the operator is possible, an automatic restart is effectively prevented.

Description

The invention relates to a display device for a fire protection switch and a fire protection switch for detecting an arc fault.

In electrical installation technology, the term "fire protection switch" is understood to mean a protective device for protection against a fault current caused by an arcing fault. Such arc fault protection devices are used in low-voltage networks to protect the electrical installation technology from damage due to a fault current due to a fault arc and its thermal consequences - such as cable fires.

For example, an arc fault may occur at a defective location of an electrical line, e.g. a loose cable clamp, or due to a cable break occur. If the arc occurs electrically in series with an electrical load, the normal operating current is usually not exceeded because it is limited by the consumer. For this reason, the arc is not detected by a conventional overcurrent protection device, such as a fuse or a circuit breaker. This is particularly problematic at high operating currents as well as existing for a long time arc fault, since in these cases, there is a risk of fire due to the associated with the arc high temperatures.

To determine whether an arc is present, both the voltage curve and the current profile over time are measured by the fire protection switch and evaluated by means of digital signal processing. In particular, the current profile has in a fault arc characteristic, high-frequency components. When evaluating, however, it should be noted that regular fluctuations in the course of the current as well as harmonics or transient current curves that occur during normal operation, such as occur when a load is switched on, do not lead to faulty tripping of the fire protection switch. For this reason, fire circuit breakers have relatively complex algorithms for monitoring the electrical installation as well as for detecting possible arcing faults.

In the (English-language) specialist literature, such devices for detecting arcing faults are referred to as "Arc Fault Detection Device" (AFDD for short). In North America, where the so-called UL standard (Underwriters laboratories, standard with 110 V mains voltage) prevails, the term "Arc Fault Circuit Interrupter" (abbreviated AFCI) is common. In the United States, arc circuit breakers are even compulsory to detect, based on predetermined criteria, whether there may be an electric arc in a circuit. For this purpose, the arc protection switches used there have their own isolating contact, which is opened in the event of the presence of an arc. The principles used in these arc circuit breakers are disclosed, for example, in US patents US 5,729,145 such as US 6,031,699 described.

In most European countries, which prescribe the IEC standard (International Electrotechnical Commission, standard with a mains voltage of 230 V), arc-protective circuit-breakers are not absolutely necessary. Electrical circuits in IEC technology have hitherto mostly been protected by means of fault current circuit breakers and miniature circuit breakers. However, protection against arcing faults is not feasible with the mentioned protective switching devices.

Nevertheless, in order to realize effective protection against arcing faults, additional circuit breakers against arcing faults, so-called fire protection switches, are also being used here in Germany. In contrast to the models available on the US market, however, these fire protection switches generally do not have their own isolating contacts, but are usually used as an independent module, the so-called AFD block, with a further protective device, for example a circuit breaker (so-called LS switch ) or a combined circuit breaker / residual current circuit breaker (so-called RCCB). This combination of the two devices then forms the AFDD circuit breaker. In low-voltage electrical installation technology, such protective switching devices - i. Miniature circuit breakers, residual current circuit breakers or combination devices such as FI / LS or AFDD - also known as "DIN rail mounted devices". This term is due to the fact that in an electrical distribution manifold often a plurality of such modular devices are arranged side by side "in a row".

When combining a fire protection switch with the other protection switching device, on the one hand, an electrical connection of the two devices is required to realize a common feed. For this purpose, the fire circuit breaker usually already electrical connection means which are led out of the housing of the fire circuit breaker to be electrically connected to the terminals of the further protection switching device. On the other hand, the fire protection switch also has a mechanical coupling with the further protective switching device to transmit a generated based on a detected fault current trip signal from the fire circuit breaker to the other protection device. When triggering the Fire circuit breaker is the trigger signal consequently to the other protection switching device - for example, a circuit breaker or a combined line protection / residual current circuit breaker - transferred, which then causes by opening its switch contacts an interruption of the monitored circuit. It should be noted, however, that the further protective switching device is only switched on again when the cause for the triggering of the fire circuit breaker is eliminated in order to effectively and permanently avoid a continuing danger to surrounding persons from electric shock or possible property damage due to a cable fire.

It is therefore an object of the present invention to provide a display device for a fire protection switch and a fire protection switch for detecting an arc fault, which are characterized by improved security.

This object is achieved by the display device and the fire protection switch according to the independent claims. Advantageous embodiments are the subject of the dependent claims.

The display device according to the invention for a fire protection switch for detecting an arc fault has a triggering device, which in turn has a trip coil and a relative thereto movably mounted release plunger, which can be brought by energizing the trip coil from a tripping ready position to a triggered position. Furthermore, the display device has a display element which can be moved from a first position to a second position when the fire protection switch is triggered. By located in the triggering position trigger plunger, the display element is held in its first position, while it can be released by a movement of the trigger plunger in its triggered position. A reset of the trigger plunger from its triggered position to its triggering position is blocked by the display element in its second position.

Due to the first position of the display element, a triggering state of the fire protection switch is displayed to an operator, whereas a successful release of the fire protection switch is signaled by the display element in the second position due to a predefined fault condition, for example, a detected fault arc. When the fire protection switch is triggered, the release plunger is moved from its ready-to-release position to its released position. Subsequently, the fire protection switch remains in this tripped state until the release plunger has been returned from its tripped position to its triggering ready position. However, in order to reset the release plunger in its tripping ready position, the display element must first be returned to its first position, since this blocked in its second position, the reset of the release plunger. However, since the return of the display element is possible in its first position only by a manual intervention of the operator, it is ensured that an automatic restart - is effectively prevented - for example, by a coupled with the fire circuit breaker further protection device.

In this way, it is ensured that initially an operator must register the triggering of the fire protection switch and must actively acknowledge before the circuit to be monitored is closed again. Incorrect operations - for example, a restart of the fire circuit breaker and / or the further protection switching device with unresolved, and thus still existing cause of error - can thus be effectively prevented, whereby the safety of the electrical installation, and possibly in the vicinity of persons is significantly improved.

Among the terms used in this application be noted at this point that with respect to the fire circuit breaker and the display device, the term "operating condition" is used, while with respect to the release plunger, the term "position" - tripping ready position and triggered position, with respect to the display element, however, the term "Position" - first position, second position and third position, respectively.

In an advantageous embodiment of the display device, the display element is L-shaped and has a oriented in a direction of movement of the display element shaft with a transversely oriented to the direction of foot. With the aid of the L-shaped display element can be easily blocking both the display element in its first position by the release plunger located in the tripping ready position, as well as blocking the located in the tripped position trigger plunger by in the second position display element can be realized by means of a simple and robust construction.

In a further advantageous embodiment of the display device, the foot of the display element with the release plunger in the tripping ready position forms an undercut, which prevents movement of the display element from its first position to its second position. In the triggered position of the trigger plunger, however, the foot is released, the foot blocks in the second position of the display element resetting the trigger plunger from its triggered position to its trigger ready position. An undercut of the two movable construction elements of the display device - trigger plunger and display element - is a common structural design feature to realize a mutual blocking or releasing the two construction elements in their respective positions or positions in a simple and robust manner.

In a further advantageous development of the display device, the display element is coupled to a spring element which urges the display element from the first position to the second position. A spring element is a structurally simple way to exert a permanently acting force on the display element, which urges the display element in its second position. In this way, a simple, robust and cost-effective design of the display device is made possible.

In a further advantageous embodiment of the display device, the display element is designed as a light guide for transmitting a light signal. By using a light guide, the state of the fire protection switch can be signaled not only on the position of the display element, but also visually by means of a color signal. In this way, the respective state of the fire protection switch is visually by a corresponding color - and thus faster - detectable. In this way, the tripped state of the fire circuit breaker can be detected faster by the operator, whereby the safety of the electrical installation is further improved.

In a further advantageous development of the display device, the light signal can be generated by means of a multicolor LED or by means of a plurality of individual LEDs in order to optically signal different states of the fire protection switch by a different color scheme. With the help of a multi-color LED - or alternatively: a plurality of individual LEDs of different colors - whose light signal is coupled into the trained as a light guide display element is - depending on the current operating state of the fire protection - state-specific color of the display element in a simple and inexpensive manner feasible ,

In a further advantageous embodiment of the display device, the display element is movable to a third position, whereby a reset of the fire circuit breaker in a ready-triggering state is effected, wherein the first position of the display element between the second position and the third position. By manually moving the display element into its third position, the fire protection switch is set back into its ready-to-trigger initial state. This reset of the fire circuit breaker thus corresponds to a RESET function. This can be realized, for example, by actuating a microswitch arranged in the housing of the fire protection switch by moving the display element into the third position, whereby the RESET function is triggered. This ensures that the RESET can not be performed automatically, but must be done manually.

The fire protection switch according to the invention for detecting a predefined fault current has a housing, a display device of the type described above, which is received and held in the housing, and a coupling element which - formed in a side wall of the housing - provided for coupling the fire circuit breaker with another protective device is on. The coupling element is in this case coupled to the release plunger of the display device such that upon a movement of the release plunger into its triggered position, a triggering signal can be transmitted by means of the coupling element to the further protective switching device coupled to the fire protection switch.

With the help of trained in the side wall of the fire circuit breaker coupling element, the trigger signal of the fire circuit breaker to a coupled to the fire circuit breaker is transferable, which interrupts the monitored circuit due to the received trigger signal. Therefore, the fire circuit breaker does not need its own isolating contacts to interrupt the circuit to be monitored. With the movement of the trigger plunger in its triggered position and the movement of the display element is released to its second position. A reconnection of coupled with the fire circuit breaker further protection device is only possible when the release plunger has been returned to its triggering ready position. However, since this reset is blocked by the display element in its second position, a manual intervention of an operator is first required, which manually resets the Auszeigeelement and thus set the fire circuit breaker back to its initial state ready to trigger. In this way, an automatic restart - both the fire circuit breaker as well as the coupled with the fire circuit breaker further protective switching device - effectively prevented. Thus is ensures that an operator first registers the triggering of the fire protection switch and actively - by manually resetting the display element - must acknowledge before the circuit to be monitored is closed again. Operating errors can thus be effectively prevented, whereby the safety of the electrical installation is significantly improved.

In an advantageous development, the fire protection switch on a micro-button, which can be actuated by moving the display element in its third position, whereby a reset of the fire protection switch is effected in a ready-triggering state. By manually moving the display element in its third position of the micro-switch or switch is actuated, whereby the fire protection switch is set back in its ready-triggering initial state. This reset corresponds to a RESET function of the fire protection switch, which is not automatically initiated, but must be done manually. The safety of the electrical installation is thereby further improved.

In a further advantageous development of the fire protection switch, the coupling element has a spring element which counteracts the movement of the coupling element initiated by the triggering element. A spring element, which pushes the coupling element back into its starting position, represents a simple and inexpensive possibility for realizing a reset function of the coupling element.

In a further advantageous embodiment of the fire protection switch, the coupling element is mounted as a rotatable driver in the side wall of the fire circuit breaker. The design of the coupling element as a rotatably mounted driver provides - especially in a bidirectional signal transmission between the fire circuit breaker and the other protection device - a structurally simple and cost-effective way to realize the signal transmission between the two protection devices.

In the following, an embodiment of the display device and the fire circuit breaker will be explained in more detail with reference to the accompanying figures. In the figures are:

1A and 1B schematic representations of the display device and the fire protection switch in a first operating state;

2A and 2 B schematic representations of the display device and the fire circuit breaker in a second operating state;

3 a schematic representation of the display device in a third operating state.

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 1A and 1B are the display device according to the invention and the fire protection switch according to the invention 1 in a first, tripping ready operating state shown schematically. In 1A Here is an external perspective view of the fire protection switch according to the invention 1 with the housing closed 2 shown while in 1B a detailed view of the open fire circuit breaker housing 2 is shown with the display device arranged therein.

The fire protection switch 1 has a housing 2 which in turn is a front page 3 , one of the front 3 opposite mounting side 4 , as well as the front 3 and the attachment side 4 connecting narrow sides 5 and broadsides 6 having. The attachment side 4 serves to fasten the fire circuit breaker 1 on a support or DIN rail (not shown), as used for example in an electrical distribution box for mounting a plurality of DIN rail mounted devices. Furthermore, the fire circuit breaker 1 a display element 10 on what's inside the case 2 arranged but through one in the front 3 of the housing 2 trained opening is visible to trigger the fire circuit breaker in case of tripping 1 to signal. This signaling can be achieved both by a mechanical movement of the trigger element 10 , as well as by an additional optical marking done.

1B shows the opened fire circuit breaker housing 2 with the display device arranged therein, wherein the fire protection switch 1 is in a first, ready to trigger operating state. The fire protection switch 1 has a triggering device 20 on which in turn a trip coil 21 and a - in a first direction x - relative to movably mounted trigger plunger 22 having. In the in 1B shown representation is the release plunger 22 in a tripping ready position and is by energizing the trip coil 21 in a triggered position (see 2 B ).

The display element 10 is in principle in a second direction y, which is transverse - in particular orthogonal - oriented to the first direction x, relative to the housing 2 between a first, in 1B position shown, and one in 2 B shown second position, slidably mounted. The display element 10 consists essentially of an elongated shaft 11 which extends in the second direction y and one at a lower end of the shaft 11 trained foot 12 , which in the first direction x over the shaft 11 protrudes. The foot 12 can attach to the shaft 11 be formed, so that the display element 10 is integrally formed.

Furthermore, the fire circuit breaker 1 one inside the case 2 attached microswitch 40 on, which is designed as a micro-switch and by moving the display element 10 in a third position (s. 3 ) is operable. For this purpose, the display element 10 by hand or with the aid of a tool against the second direction y a little way into the housing 2 the fire protection switch 1 pushed in until the foot 12 or the shaft 11 of the display element 10 the microswitch 40 touched and pressed. By pressing the microswitch 40 is a RESET function of the fire circuit breaker 1 can be initiated by this is set back to its ready-initial state.

Furthermore, the fire circuit breaker 1 an LED 30 on which inside the case 2 below the shaft 11 of the display element 10 is arranged. If the display element 10 is designed as a light guide for transmitting a light signal, with the help of this LED 30 in addition to the mechanical change in position of the display element 10 an optical signal is generated which signals an operator that the fire protection switch 1 has been triggered due to a fault current detected by him. Is the LED 30 In addition, designed as a multi-color LED, as well as a plurality of different operating states of the fire circuit breaker can by a correspondingly differentiated color 1 are displayed.

To transmit the trigger signal to a with the fire circuit breaker 1 coupled, another circuit breaker, such as a circuit breaker (circuit breaker) or a combined circuit breaker / residual current circuit breaker (LS / FI switch), the fire alarm switch 1 a coupling element 50 which is in one of the broadsides 6 of the housing 2 is rotatably mounted. The coupling element 50 has an operative connection to the trigger plunger 22 on, such that the coupling element 50 in the event of triggering of the fire protection switch by the release plunger 22 is caused to rotate. This rotational movement is to the with the fire circuit breaker 1 coupled transmitted further protective switching device and causes this is also triggered, whereby the monitored electrical line is interrupted. To reset the coupling element 50 in its original position is a return spring 51 provided, which is designed as a torsion spring, on the coupling element 50 attacks and on the case 2 is supported.

In the presentation of the 1B takes the display element 10 a first position in which the foot 12 of the display element 10 with the release plunger 22 the triggering device 20 forms an undercut. In this way - in the in 1B illustrated, tripping ready operating state of the fire circuit breaker 1 - A movement of the display element 10 from the in 1B shown first position in his in 2 B shown second position inhibited. As long as the trigger tappet 22 is in its triggering position, a moving of the display element 10 in its second position, which is an operator a tripping of the fire protection switch 1 due to the undercut of the right end of the trigger plunger 22 with the foot 12 of the display element 10 , effectively prevented.

The 2A and 2 B show schematically the display device according to the invention and the fire protection switch according to the invention 1 in a second operating state, in which the fire protection switch 1 has already triggered due to a detected fault current. The display element 10 is in its second position and protrudes with its upper end over the outer contour of the front 3 of the fire circuit breaker housing 2 out. 2A again shows a perspective external view of the triggered fire protection switch 1 with the housing closed 2 while in 2 B the corresponding detail of the open fire circuit breaker housing 2 is shown with the display device arranged therein, wherein the fire protection switch 1 is in a second, triggered operating state. A trip signal due to a detected fault current turned the trip coil 21 energized, causing the trip rod 22 was moved by means of a movement in the first direction x in its second, triggered position.

By the movement of the trigger tappet 22 in its triggered position is the undercut of the right end of the trigger plunger 22 with the foot 12 of the display element 10 canceled. This is the display element 10 no longer blocked in his movement. Due to the spring element 15 on the display element 10 applied spring force is the indicator 10 in his (in 2 B shown) second position moves and held there. In this second position is the foot 12 of the display element 10 at the level of the trigger tappet 22 , causing a reset of the release plunger 22 is blocked from its triggered position in its triggering position. This is as long as the case until the indicator 10 manually or with the help of a tool back into his, in 1B shown, first position is returned. Only when the display element is in its first position again is the trigger plunger 22 no longer blocked and can - for example, by means of its own return spring - are returned to its triggering ready position.

Is the display element located? 10 in its second position, this is not just the reset of the trigger plunger 22 in its triggered position, but also the reset of the coupling element 50 blocked, causing a reconnection of the fire alarm 1 coupled, further protective switching device is prevented. In order to switch the further protective switching device back on, therefore, first the fire protection switch must be activated by a manual actuation of the display element 10 be set back to its ready-to-operate state before the circuit to be monitored is closed again by switching on the further protection switching device. In this way, it is ensured that initially an operator tripping the fire circuit breaker 1 register and actively acknowledge. An automatic restart by closing the circuit to be monitored is thus effectively prevented.

In 3 is the display device in a third operating state, in which the display element 10 assumes its third position, shown schematically. To the display element 10 to spend in its third position, it is by hand or with the help of a tool against the second direction y a little way into the housing 2 the fire protection switch 1 pushed in until the foot 12 or the shaft 11 of the display element 10 the microswitch 40 touched and pressed. This can be from both the second position and the first position of the display element 10 out. By operating the microswitch 40 Then a RESET function is initiated, which the fire protection switch 1 returned to its trigger ready initial state.

LIST OF REFERENCE NUMBERS

1

Fire protection switch

2

casing

3

front

4

mounting side

5

narrow side

6

broadside

10

display element

11

shaft

12

foot

15

spring element

20

triggering device

21

trip coil

22

Actuation tappet

30

LED

40

Micro button / microswitch

50

coupling element

51

Return spring

x

first direction

y

second direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 5729145 [0005]
• US 6031699 [0005]

Claims (11)

Display device for a fire protection switch 1 for detecting an arc fault, - with a tripping device ( 20 ), which a trigger coil ( 21 ) as well as a relative to this movably mounted release plunger ( 22 ), which by energizing the trip coil ( 21 ) can be brought from a release-ready position into a triggered position, - with a display element ( 10 ), which at a triggering of the fire circuit breaker ( 1 ) is movable from a first position to a second position, - wherein the display element ( 10 ) by the release tappet located in the ready-to-release position ( 22 ) is held in its first position and by a movement of the release plunger ( 22 ) is releasable in its tripped position, - wherein a reset of the trigger tappet ( 22 ) from its released position to its triggering position by the display element ( 10 ) is blocked in its second position. Display device according to claim 1, - wherein the display element ( 10 ) Is L-shaped and one in a direction of movement of the display element ( 10 ) oriented shaft ( 11 ) with a foot oriented transversely to the direction of movement ( 12 ) having. Display device according to claim 2, - wherein in the triggering position the foot ( 12 ) with the release plunger ( 22 ) forms an undercut, which movement of the display element ( 10 ) from its first position to its second position, - the foot ( 12 ) in the tripped position of the trigger plunger ( 22 ), and - wherein the foot ( 12 ) in the second position of the display element ( 10 ) resetting the triggering plunger ( 22 ) blocked from its tripped position to its triggering position. Display device according to one of the preceding claims, wherein the display element ( 10 ) with a spring element ( 15 ) is coupled, which the display element ( 10 ) from the first position to the second position. Display device according to one of the preceding claims, wherein the display element ( 10 ) is designed as a light guide for transmitting a light signal. Display device according to claim 5, wherein the light signal is transmitted by means of a multi-color LED ( 30 ) or a plurality of individual LEDs can be generated to different states of the fire circuit breaker ( 1 ) visually signal. Display device according to one of the preceding claims, wherein the display element ( 10 ) is movable to a third position, whereby a reset of the fire circuit breaker ( 1 ) can be brought into a trigger ready state, wherein the first position between the second position and the third position is located. Fire safety switch ( 1 ) for detecting a predefined fault current, - with a housing ( 2 ), - with a display device according to one of the preceding claims, which in the housing ( 2 ) is received and held, - with a coupling element ( 50 ), which in a side wall ( 6 ) of the housing ( 2 ) designed for coupling the fire protection switch ( 1 ) is provided with a further protective switching device, - wherein the coupling element ( 50 ) so with the release plunger ( 22 ) is coupled to the display device, that during a movement of the release plunger ( 22 ) in its triggered position, a trigger signal by means of the coupling element ( 50 ) to the with the fire circuit breaker ( 1 ) Coupled further protective switching device is transferable. Fire safety switch ( 1 ) according to claim 8, wherein the fire protection switch ( 1 ) a microprobe ( 40 ), which by moving the display element ( 10 ) is operable in its third position, whereby a reset of the fire circuit breaker ( 1 ) is brought into a ready to trigger state. Fire safety switch ( 1 ) according to one of claims 8 or 9, wherein the coupling element ( 50 ) a spring element ( 51 ), which by the triggering device ( 20 ) initiated movement of the coupling element ( 50 ) counteracts. Fire safety switch ( 1 ) according to one of claims 8 to 10, wherein the coupling element ( 50 ) as a rotatably mounted driver in the side wall ( 6 ) of the fire protection switch ( 1 ) is stored.

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