EP1413997B1 - Arrangement for detecting a smoke generation and/or a fire in a switch cabinet or the like for activating a fire alarm and method of operation thereof - Google Patents

Abstract

The arrangement has a sensor for detecting a generally slowly changing state parameter, especially for detecting smoke and/or a raised temperature. The sensor or its housing has an arrangement for preferably shape-locking fixing to a bearer or mounting element for low voltage switching devices, preferably a mounting rail, and an output for transferring information. AN Independent claim is also included for the following: (a) a method of operating an inventive arrangement for recognizing smoke generation and/or fire in a switch box or similar for triggering a fire alarm.

Description

The invention is directed to an arrangement, in particular device, or system, for detecting and possibly reporting a smoke and / or fire in a cabinet for switchgear or in any other, enclosed, the installation of technical equipment housing, with a sensor smoke and / or an elevated temperature having an output for transmitting information and a method of operating such an arrangement.

Cabinets, but also other largely or completely locked rooms with technical installations of a building or a mobile device such as ship, train, plane, etc., are subject to an increased risk of developing a fire. Because on the one hand, due to the most diverse causes, for example due to corrosion, the contact resistance at contact points increase over time; This increases the local power loss, it develops heat that can gradually lead to a burning of the insulation or other plastic parts and eventually to the fire. On the other hand, such a smoke or fire development is usually noticed only at a very late stage, since the smoke initially arising does not leave the relevant control cabinet / room and therefore does not reach a building smoke detector or the like.

The utility model DE 200 09 578 U1 concerns a quenching and recovery system for tunnels, whereby the pipe of a specially made sprinkler system is simultaneously used as a guide and rail for the extinguishing and recovery system. Since a tunnel is not a closed enclosure, but rather an elongate, open system on both sides, sensors and temperature sensors are arranged on a trolley and thus movable. However, this means an immense effort, which is generally not economical.

The EP 1 094 186 A1 is directed to a closing device for a preferably double-leaf door, wherein a sliding rail for the door closer is mounted on the stationary door frame. In or on this slide electrical devices are arranged, for example, a smoke detector and / or electrical locking devices, which interact with the sliders of the sliding arm of the door closer. In or on such a slide, the smoke detector is also not in a closed enclosure, but above a two-leaf, automatically closing door, where there is usually a strong Luftverwirbelung, in contrast to a closed enclosure.

The US 6,317,053 B1 relates to a control cabinet which is designed to protect highly sensitive devices as a protective cabinet with an interior sealed off from the atmosphere. This interior is continuously supplied with fresh air by a fan, whereby this fresh air is checked shortly before the fan via early fire detection sensors. These fire early detection sensors activate in case of fire with the inert gas argon filled gas cylinders, so that while suppressing the supply of fresh air argon can be passed to suffocate the fire in the interior. Here, the early fire detection sensors are therefore not within a closed enclosure, but at an air supply or discharge.

The DE 34 33 459 A1 discloses a device or a detection device for the early detection of fire and overheating in electrical, electronic and other equipment, installed in enclosures or cabinets enclosing these facilities. Here, the smoke detection takes place directly at the exhaust air outlet of the unit to be monitored, namely in an external detection device.

Finally, the DE 43 43 887 A1 remove a computer-assisted fire extinguishing system that automatically monitors objects against fire, detects fires and deletes at intervals. There, smoke detectors are installed directly in a control cabinet, but on the ceiling, which is relatively far away from potential sources of fire, so that an early detection of a fire with it is not possible.

There is therefore a need for early detection of a fire in a control cabinet or other, closed space of a technical system.

The solution to this problem is possible in the context of a generic arrangement in that the sensor or a housing receiving the sensor or a socket on which the device or its modules can be plugged, for installation within the monitored cabinet for switchgear or within the other, completed, the installation of technical equipment housing has at least one device for fixing to a mounting rail for low-voltage switchgear in the form of a so-called. DIN rail with a central part of U-shaped cross-section, the side legs have outwardly bent edges.

In the event of a spark or a short-duration arc during the operational shift, no smoke or only a negligible amount will be generated, which after swirling with the otherwise clean air will be too thin to be detected by a smoke sensor. On the other hand, consistent stewing develops a much greater amount of smoke, which in turn can be reliably detected, especially if the sensor in question is located in the upper part of the relevant cabinet / room. The same applies to the heat emitted in the event of a spark or an arc. Due to the comparatively short time interval, this is too low to bring about a temperature increase which is clearly perceptible by a temperature sensor. At an increased contact resistance of a contact or even in the subsequent braising a cable insulation od. Like. However, a much larger amount of energy is converted into heat, so that especially in cabinets / rooms with low-voltage installation devices, the heat loss increases significantly and thereby causes a noticeable increase in temperature, the a temperature sensor can be perceived. Therefore, if such a sensor is used for generally slowly changing state variables, no false alarm can be triggered in the case of a brief spark or the like, while an unnatural smoke development or even an increased heat loss can be sensed relatively quickly. This is due to the fact that the sensor is installed inside the control cabinet / enclosed space and thus "on site" and therefore perceives the irregularity much faster than, for example, a smoke or fire sensor installed at another location of the respective building. As a result, valuable minutes can be gained, which are sufficient for a factory fire brigade in an actual fire, for example, to be able to quickly contain the fire still in the making.

The type of assembly brings a great economic advantage by minimizing the assembly time. In particular, the means for securing the sensor housing to a support or mounting element facilitates installation thereof in a control cabinet, where often the entire back wall is covered with such mounting elements, around the most diverse low-voltage switchgear anchor there. At this location, cable ducts are usually laid, which facilitate the wiring. Especially in this area there is an increased risk that a fire is triggered by improperly laid lines or defective devices. By the sensor according to the invention can be mounted here, there is a very short distance to the potential sources of fire and thus a particularly rapid fire detection.

Further advantages result from a device for monitoring the operating temperature within the enclosure. Because often, even in the run-up to a fire, elevated temperatures can be detected, triggered by e.g. in that in a provided with filter fan control cabinet / housing the filter mat is dirty and was not maintained. About the initiation of a pre-alarm, e.g. the fault message "maximum permissible operating temperature exceeded", the maintenance / operating personnel can intervene early. By earliest possible detection of elevated temperatures and / or smoke as well as temperature increases in case of fire, a time window is created which can be used to initiate defensive countermeasures. Damage to the technical equipment inside the enclosures and consequential damage outside of these enclosures are avoided or minimized. Thus, the fire costs incurred by smoke, extinguishing water, etc. are minimized.

It is within the scope of the invention that the sensor can be mounted in the upper region of the respective control cabinet. Since smoke is often accompanied by local heating, air circulation at the point in question takes place, carrying the smoke upwards into the area of the sensor.

The arrangement according to the invention can have a modular design, for example with at least one sensor module, with an evaluation module, possibly an interface module, a power supply module, etc. This structure allows the operation of several sensors on a common evaluation module, which then - for example, for the purpose of common forwarding - summarizes the messages of all sensors.

By having the housings of the modules mutually parallel side walls and preferably an identical and constant vertical section, they can fit together.

The fastening device can be designed for quick assembly, in particular for snapping onto a mounting rail. This technique facilitates assembly, especially in confined spaces.

In continuation of this inventive concept it can be provided that the fastening device has a support rail (partially) engaging behind element which is approximately perpendicular or radial with respect to the support rail and is pressed by a spring element behind the support rail. In this case, for example, the edges of the longitudinal sides can be encompassed in a DIN rail. The mobility of the positive-locking element can, for example, by using a (limited) elastic material, eg. Plastic can be achieved, so that the support rail engaging behind element when snapping first - eg. By mediation of the support rail facing ramp-shaped approach - to the outside is pressed and then springs inward. An example. Hook or pocket-shaped approach to an outside of this element allows the insertion of a screwdriver od. Like. To cancel the positive engagement and to solve the relevant (sensor) assembly of the mounting rail.

The invention further provides that the device or its modules can be plugged onto sockets which are fastened or fixable in a control cabinet, in particular on a DIN rail. In this case, a defective module can be replaced with a few simple steps.

Furthermore, the housing of the device or of the sensor module should have flow openings on at least one side, preferably on two sides, so that the smoke can penetrate into the sensor housing and can also reach the sensor.

The invention is characterized by at least two flow openings, which are located at approximately opposite areas of the housing receiving or surrounding the sensor. This results in an approximately straight flow path through the housing, and about vertical by aligning the natural convection can be conducted within the relevant cabinet with low flow resistance through the sensor housing to pass possibly contained smoke particles directly to the sensor.

According to the invention, throughflow openings can be located on two side walls of the housing receiving or surrounding the sensor, which pass through the ground plane of a mounting surface carrying the mounting element approximately vertically, so that the flow direction within the sensor runs approximately parallel to the mounting surface. Since the vertical walls of a control cabinet usually serve as mounting surfaces, a sensor housing designed in this way can always be aligned on a corresponding mounting surface in such a way that the inner flow direction between the throughflow openings is aligned approximately vertically.

The invention can be further developed such that through-flow openings are located on two side walls of the sensor housing or surrounding housing, which run parallel to a mounting rail carrying the housing and enforce the mounting surface carrying this approximately perpendicular. As a result, the flow direction within the sensor is oriented approximately transversely to the - usually horizontally extending - mounting rail. The result is the desired vertical flow.

If the flow openings are covered by grids, the penetration of larger particles into the area of the sensor can be avoided. This measure ensures the proper functioning of the sensor by both falling parts during assembly - eg. Insulating or connecting material, screws, etc. - As well as, for example, insects are kept away.

By the side flow openings are behind or below the plane of a cover surrounding the housing, primarily smoke is sensed behind or under the cover in question. Before such a cover, the risk of a fire is usually much lower.

Preferably, a cross-section parallel to the front side of the sensor housing has a rectangular shape which preferably corresponds to at least one of its dimensions (length and / or width) of a (standardized) recess in a cover which surrounds the low-voltage devices fixed on the respective mounting element , This facilitates the integration of the sensor housing into a recess of a cover.

The invention undergoes further optimization in that a collar or bead is provided on at least one side of the sensor housing. This supports a cover which surrounds the fixed to the respective mounting element low-voltage devices, thus ensuring the position of the flow openings on the desired side of the cover in question, preferably behind the same, so as to direct the smoke monitoring targeted to a particular area of the cabinet.

A further development of the invention provides that the operating and / or display elements are arranged on a part of the front side projecting relative to the region having the input and / or output connections, which preferably protrudes beyond a flat covering of the connections. Such exposed control and / or display elements are easily accessible or visible.

For signaling the state of the device, (for example "mains voltage / power failure", "smoke detection unit active", "interference", etc.), the device or the evaluation module can have at least one display, for example in the form of a light source such as a lamp or LED, have. Such status messages are for installation, adjustment, maintenance and control.

Electrical input and / or output terminals or feedthroughs for lines to input and / or output terminals disposed within the housing may be disposed on the housing receiving or surrounding the sensor. Such connections and / or feedthroughs preferably sit laterally on the housing or on its upper or lower side, so that the relevant lines can be guided as far as possible outwards from the relevant sensor and, for example, to a cable channel laid in the vicinity.

Electrical input and / or output ports can be located near a side of the sensor housing that does not have flow ports, either directly in or near one side. There, a housing flow passing through the air flow is the least disturbed.

According to the invention, at least one electrical output of the device or of the evaluation module is designed as a potential-free contact (for fire alarm, alarm remote release, indicator light, horn, etc.). This can be accomplished in a stand-alone operation of a sensor according to the invention without additional module signal forwarding.

By equipping the sensor with an interface module, the coupling to a preferably digital bus is made possible. Such a bus facilitates the connection of a larger number of sensors according to the invention to a common evaluation unit. In this case, for example, a number of adjacent control cabinets can be monitored, each with its own sensors, for which only a single evaluation unit is required.

The interface module should be designed such that an addressing of the relevant sensor is possible. As a result, the status of a specific sensor can be queried specifically by an evaluation unit.

The invention allows a development to the effect that the bus is designed for serial data transmission, for example. In the form of a single line. In this case, the wiring is much clearer.

As a further, constructive feature, at least one signal input for the signal of a temperature sensor arranged outside the relevant control cabinet / enclosed space is provided on the device or the evaluation module. On the basis of a signal received via this signal input, the sensor can optionally receive further information about the location of the source of the fire, in particular whether it is located inside or outside the relevant control cabinet / enclosed space. This signal can either be linked directly to the sensor signal by the sensor assembly, for example to trigger an alarm only in the event of a fire within the relevant control cabinet / room, or the signal is transmitted as information to a higher-level evaluation unit.

The device or the evaluation module may have at least one signal output for actuating a device for closing ventilation openings of the control cabinet / enclosed space, for example by means of a drop-type slide which, in the de-energized state, falls down in front of the relevant ventilation opening. Thus, depending on the location of the source of the fire, the spread of a fire into / out of the relevant control cabinet / room can be prevented.

Furthermore, the device or the evaluation module according to the invention preferably has one or more signal inputs for decentralized, eg. In adjacent cabinets or rooms, arranged sensor modules, so that their output signals can be processed with. In this case, a parallel connection of several sensors is possible. This structure is practical in a combination of a small number of sensor modules, since such a case, on the one hand limits the cabling and on the other hand, the hardware cost is reduced.

A device in or on the device or the evaluation module is used for the OR connection of a smoke development or a fire positive signal sensor signals sensor modules connected. This can be formed with sensor modules connected in parallel, a collective signal, each smoke message leads to an alarm.

With great advantage, the device or a power supply module has an uninterruptible power supply, in particular in the form of a battery or a rechargeable battery, which ensures (emergency) operation in the event of a power failure over a limited period of time. This is particularly important because in a power failure, the risk of fire in a system by no means eliminated, but may still be increased because, for example, fan or other cooling units are stationary.

The operating method according to the invention is characterized in that digital information is preferably transmitted between one or more sensors and an evaluation unit. Although a connection of analog signals is possible; In this case, however, a separate line is required for each signal, so that the wiring effort increases considerably; In addition, the risk of transmission errors increases, for example due to terminal resistance, line breaks, temperature effects, etc.

It has been proven that the transmitted information is provided with an address tag, so that a plurality of sensors and / or evaluation units can communicate with each other via one and the same bus. This allows a targeted query of the information of individual sensor modules. Due to the targeted information obtained thereby, errors or fault messages can be assigned to individual sensor modules, and in a fire the source of the fire can be located fairly accurately.

Finally, it is the teaching of the invention that status information of the various sensors transmitted at approximately regular intervals to an evaluation and evaluated there. This can either be done by the Sensors themselves are triggered, however, preferably by querying from the central evaluation unit, for example. In a recurring sequence of connected sensors (in turn, so-called. "Polling"). As a result, the information about the status of the sensors and their measurement results is updated within short intervals of time within the evaluation unit, and a fire is therefore detected and reported in the shortest possible time.

Fig. 1

eine perspektivische Ansicht einer ersten Ausführungsform der Erfindung;

Fig. 2

eine der Fig. 1 entsprechende Darstellung einer anderen Ausführungsform der Erfindung;

Fig. 3

eine wiederum abgewandelte Ausführungsform der Erfindung in einer der Fig. 1 entsprechenden Ansicht;

Fig. 4

einen für den Einsatz der Vorrichtung aus Fig. 3 geeigneten Schaltschrank;

Fig. 5

ein mit den Komponenten aus Fig. 1 aufgebautes System zur Überwachung mehrerer Schaltschränke;

Fig. 6

eine perspektivische Ansicht auf eine weitere Ausführungsform eines erfindungsgemäßen Rauchmelders;

Fig. 7

eine Draufsicht auf den Rauchmelder aus Fig. 6 in eingebautem und angeschlossenem Zustand, teilweise aufgeschnitten;

Fig. 8

einen Schnitt durch die Fig. 7 entlang der Linie VIII - VIII; sowie

Fig. 9

eine Draufsicht auf den Rauchmelder aus Fig. 6 nach Entfernung der Gehäuseabdeckung.

Further features, properties, advantages and effects on the basis of the invention will become apparent from the following description of preferred embodiments of the invention and from the drawing. Hereby shows:

Fig. 1

a perspective view of a first embodiment of the invention;

Fig. 2

one of the Fig. 1 corresponding representation of another embodiment of the invention;

Fig. 3

a modified embodiment of the invention in one of Fig. 1 corresponding view;

Fig. 4

one for the use of the device Fig. 3 suitable control cabinet;

Fig. 5

one with the components off Fig. 1 built-up system for monitoring several control cabinets;

Fig. 6

a perspective view of another embodiment of a smoke detector according to the invention;

Fig. 7

a plan view of the smoke detector Fig. 6 in built-in and connected state, partially cut open;

Fig. 8

a cut through the Fig. 7 along the line VIII - VIII; such as

Fig. 9

a plan view of the smoke detector Fig. 6 after removal of the housing cover.

In Fig. 1 an arrangement according to the invention is shown in standard version (variant 1).

Fig. 2 shows a device with additional equipment (variant 2).

Finally, in Fig. 3 to see a device for special requirements (variant 3).

The devices according to variants 1 and 2 are suitable for installation in customer-specific and application-specific switchgear, for example in installation distributions of building technology, main building distributions of the power supply, industrial controls, control systems of building technology heating, ventilation, air conditioning.

The device according to variant 3 is designed for installation in fire-retardant and fire-resistant control cabinets and / or partition walls systems with fire load encapsulation and / or functional integrity.

1. a) Raucherkennungsmodul 1,
2. b) Stromversorgungsmodul 2,
3. c) Auswertemodul 3.

Bei der einfachsten Ausführungsform kann auf das Auswertemodul verzichtet werden.All three variants include the following components as standard:

1. a) smoke detection module 1,
2. b) power supply module 2,
3. c) evaluation module 3.

In the simplest embodiment, the evaluation module can be dispensed with.

The similarities of the three embodiments are the following:

It is a modular device with quick mounting for DIN rail mounting.

The housings 31, 32, 33 of the various modules 1-3 are completely encapsulated in the front area (in front of the contact protection cover) and in the visible operating area.

The housing size can be standardized; a preferred value for the width corresponds to a multiple of 1 TE (1 TE = 17.5 mm). A preferred range for the width of a housing 31-33 is between 50 mm to 90 mm.

In particular, the housing 31 of the smoke detection module 1 is provided at the bottom, top and possibly on the back with flow openings 34 to the smoke inlet.

In the context of one of the modules 1 to 3, a battery 21 may be arranged to ensure an uninterruptible power supply in case of mains voltage failure.

The power supply unit / power supply module 2 is supplied via the input terminals 6 from an external separate circuit breaker with mains voltage 230 V AC.

Via a transformer and the rectifier unit, the voltage 24 V DC is made available on the output side 7 of the power supply module 2 and transmitted to the input terminals 8 of the evaluation unit 3.

The output terminals 10 serve the supply voltage for the smoke detection unit 1, input terminals 4. The terminals 9 on the evaluation and 5 on the smoke detection unit are used for monitoring. A built-in battery 21 is used in case of power failure to maintain the smoke detection.

When the mains voltage is applied and during normal operation, the LEDs 12 - "Operation" and 13 - "Smoke detection active" light up.

If the mains voltage fails, the message "Fault" occurs via a potential-free contact 16, and the light-emitting diode 14 "mains fault" lights up. Both light emitting diodes 14 - "power failure" and 13 - "smoke detection active" and the smoke alarm unit are powered by the built-in battery. If the smoke detection unit 1 disturbed or failed, the message "smoke detection disturbed" is output via potential-free contact 17. This could also be used with aging of the battery.

Detects the smoke detector unit 1 smoke, 18 "alarm remote" is triggered via potential-free contact.

Thus, the properties and functionalities of the arrangement 1 to 3 according to variant 1 are exhaustively described. The devices according to variants 2 and 3 have additional functionalities, which are described below:

The device according to variant 2 is based on the basic device of variant 1. The details described under Variant 1 are valid in their entirety.

In addition, the supply voltage 24 V DC for the local alarm with indicator lights and horn is provided to the evaluation unit 3 at the terminals 11. The indicator "local alarm" is controlled via a potential-free contact 19 with flashing light. The horn for the local alarm is controlled via the potential-free contact 20. Indicator and horn may be installed in the cabinet door or in a building control panel. By pressing the acknowledgment button 15, the horn is turned off and the flashing light goes into steady light. After rectifying the fault, the continuous light goes out.

The arrangement 1 - 3 according to variant 3 represents a further development of variant 2. The details described are valid in their entirety. The other additional devices are described below.

The arrangement 1 - 3 of variant 3 is intended to be used in fire-retardant / fire-resistant control cabinets and door / partition wall systems. Here are basically two use cases:

On the one hand, the so-called "fire load encapsulation". In other words, if a fire occurs inside the control cabinet or in the enclosed room or door / partition wall system, the fire-resistant / fire-resistant enclosure should prevent the fire from spreading further into a building.

On the other hand, the so-called "function preservation". Here it is assumed that it burns in the building, and then important equipment and systems in the control cabinet or enclosed space must remain in function for the duration of the evacuation (function maintenance time).

These requirements apply to all public buildings. The details are laid down in the Model Building Regulations (MBO), the State Building Codes (LBO), the Model Line Systems Directive (MLAR 03/2000) and the regulations of DIN 4102.

In the enclosures and enclosures described above, the electrical equipment such as protection, switching, measuring, control and control devices are installed. In normal operation, waste heat is generated here due to the electrical power loss of the devices. If this waste heat is too high, the electrical devices may already fail during normal operation. Although the electrical equipment is installed according to the valid VDE regulations, a fire due to the failure of a device can not be completely ruled out. In order to remove the waste heat from a cabinet 35, 36 openings 37 must be provided in the door to allow fresh air to enter the cabinet 35 or the enclosures.

If a smoldering fire develops inside, smoke first becomes noticeable. Smoke can also be cold. It must now be prevented that the smoke over the designated for normal operation vents 37 into the building spreads and z. B. makes escape and rescue routes unusable. For this, the operational vents 37 must be closed when smoke message. This is done via drop gate 38, which are held during normal operation of locking magnets 39, fall down, see. Fig. 4 ,

Have the drop gate 38 triggered, a limit switch 40 per drop gate 38 is operated by falling. In the door 36, a temperature sensor 41 is installed, which detects the outside temperature. If a fire then arises in the building, then the temperature increase outside the cabinet 35 via the temperature sensor 41 likewise triggers the drop slides 38. The indoor temperature sensor detects an increase in the internal temperature to an unacceptably high level during normal operation.

In order to properly control such drop gate 38, the device 1 - 3 according to variant 3 has the following additional functions:

About the smoke detection unit 1, smoke and / or via the built-in door 36 outside temperature sensor 41, a temperature increase is reported to a preferably definable threshold. About the potential-free contact 18 "alarm remote" is triggered. If "alarm remote" is triggered, the holding magnets 39 are de-energized as a result of the alarm triggering. The drop gate 38 fall down and close the vents 37. The limit switch 40 of the two drop gate 38 are closed. No fault message is triggered.

Trigger the drop gate 38 in case of power failure, aging or mechanical failure, a fault message is triggered via the potential-free contact 16.

The LED 29 - "Door ventilation closed" lights up.

Before the first time the mains voltage is applied, the drop slides 38 are closed and must be manually switched on when the mains voltage is first applied be pushed up and then hold themselves to the locking magnet 39.The limit switch 40 of the case slide 38 open, the LED 29 goes out.

Via the internal temperature sensor 26, an increase in the internal temperature to 63 ° C + -2 ° C via the floating contact 16 also triggers a fault message. The LED 20 - "Internal temperature too high" lights up.

The device variants described above are to be used in electrical switchgear 42. Electrical switchgear 42 often consist of individual cabinets 43, which may be partitioned off by internal partitions 44 against each other. In the interest of earliest possible fire / smoke detection, it is advisable to install a smoke detection module 1 in the individual cabinet panels 43 and to use a single smoke detection and reporting unit 1 - 3 with an evaluation module 3 for the entire switchgear 42, as described in US Pat Fig. 5 is shown.

An OR link can be realized between the individual smoke detection modules 1 in such a way that the respective, potential-free switch contacts are connected in parallel, so that when a switch contact of any smoke detection module 1 is closed, a (common) supply or input voltage is switched through to a common output. If normally closed contacts are used instead of make contacts, these should be connected in series and supplied with a constant current, as in Fig. 5 is shown. If a contact is opened, the current is interrupted, which can be registered on the evaluation module 3.

Furthermore, an interface for connecting a programming device and an interface to bus systems of building technology z. B. EIB, ION, etc., may be provided.

The Fig. 6-9 show a modified smoke sensor 45, which is designed specifically for mounting on a mounting rail 46. In the mounting rail 46 is a so-called. DIN rail with a central portion 47 of U-shaped Cross-section whose side legs 48 have outwardly bevelled edges 49, as shown in FIG Fig. 8 is reproduced.

Such mounting rails 46 are usually bolted to rectangular profiles 50, which in turn are fixed to the rear wall 51 of a cabinet 35, 43.

For attachment of the smoke sensor 45 to the mounting rail 46 are used (in the present example, two) clamp-shaped fastening elements 52 which engage around the opposite edges 49 of the mounting rail 46 in a form-fitting manner. These mounting brackets 52 have an approximately U-shaped structure with a central portion 53 of I-shaped cross-section. Of one of the two edge or stiffening webs of this I-profile 53 rise in the manner of a U two mutually approximately parallel, end legs 54, 55. Both legs 54, 55 have on their sides facing each other transverse to the central part 53, grooved recess 56 for receiving a rail edge 49. These mounting brackets 52 are made of limited elastic plastic, so that their legs 54, 55 can temporarily spring outward when the clamp 52 is to be snapped onto the mounting rail 46. This is facilitated by the fact that at least one leg 55 has a ramp-like projection 57 on its inner side facing the other leg 54, which experiences a continuous thickening from the free end of the leg to the central web 53 as far as the recess in question. To release the mounting bracket 52 from a mounting rail 46 is on the outside of a leg 55, for example. Pocket-shaped extension 58 is present in the example. A screwdriver can be introduced from the cabinet front side to bend the respective leg 55 to the outside and thereby the Releasing positive engagement with the edge 49 of the mounting rail 46.

Two such mounting brackets 52 are each used in one of two, mutually parallel, groove-shaped recesses 59 a base plate 60. The base plate 60 is, for example, made of a rigid plastic. It has an approximately the base of the smoke sensor 45 corresponding base area, but can in the area each one mounting bracket 52 in the longitudinal direction of the respective central web 53 be extended along its length, as can be seen in particular from Fig. 9 results. The brackets 52 are fixed in the groove-shaped recesses 56 by screws 61, which pass through the plate 60 and the bottom 62 of the sensor housing 63 fixed thereto. To accommodate these screws 61 extend between the two stiffening webs of the I-profile 53 sleeve-shaped hollow cylinder.

The sensor housing 63 consists of a trough-shaped bottom part 64 and a likewise trough-shaped cover part 65. Both can be - with their open sides against each other - plug together, the cover part 65, the bottom part 64 engages and with locking lugs 66 on its inner side into corresponding recesses of the bottom part 64th locks.

The bottom part 64 has a rectangular plan, which corresponds approximately to the minimum dimensions of the base plate 60. The ratio of length to width of the bottom part 64 is about 3: 1. Accordingly, the bottom part is divided in its longitudinal direction into three sections of approximately equal size. The middle section houses the actual sensor body 67, an approximately cube-shaped body with air inlet and outlet openings on opposite sides with the outer light retaining aperture. Within this hollow body 67 are a light source and a photosensitive member, the optical axes are not facing each other, so that the photosensitive member receives a light radiation only when the emitted light from the light source, for example, is scattered on smoke particles. To control the light source and for a (first) evaluation of the signal of the photosensitive member is an electronic circuit, which is housed on one or both sides of the sensor body 67.

Near the air inlet and outlet openings of the sensor body 67, the bottom part 64 each have an air flow opening 68.

The dome-shaped cover or upper part 65 of the housing 63 is provided in the region of these flow openings with corresponding air slots 69, to allow the optionally laden with smoke air as unobstructed access to the actual sensor body 67. On the outer side of the lid or upper part 65 extends along the longitudinal slots each interspersed by the air slots 69 a spring-like collar 70. This extends above or in front of the relevant air slot 69 and serves to support a laid in channels supply lines 71 covering plastic plate 72, so that the louvers 69 are always below or behind this cover plate 72.

In order to guide the supply lines 71 out of the housing 63 from terminals arranged inside the housing 63, in particular terminals 73, the bottom part 64 has perforations 75 or corresponding predetermined breaking points 76 in the region of its end faces 74, at which areas of the housing 63 can be cut out. Under such a bottom opening 75 or predetermined breaking point 76, the bottom plate 60 is correspondingly cut 77th

In the region of the terminals 73, a current or voltage supply can be provided, also a potential-free switching contact for controlling a horn or other actuator, at least one input for an external sensor, for example. A temperature sensor 41, and / or at least one terminal for connection to a digital bus via which an exchange of information with an intelligent module of the sensor electronics, for example. A microprocessor od. Like., Is possible. For this purpose, an interface module can be provided which decodes received (serial) signals and forwards the contained command and / or encodes information generated or buffered in the sensor for the purpose of output, for example in the form of a telegram.

On the front or top side 78 of the cover or upper part 65, a light-emitting means, for example. A light-emitting diode 79 may be provided, at which the operational readiness, disturbances od. Like. Can be displayed.

Claims (23)

1. Arrangement (1-3; 45), in particular device or system for detection and if applicable identification of smoke generation and/ or fire in an electric cabinet (35-43) for switch gears or in another closed enclosure serving the installation of technical systems with a sensor (67) for smoke and/or increased temperature which features an exit for transmission of information, characterised in that a sensor (67) or an enclosure (63) carrying the sensor (67) or a socket on which the device or its modules can be clipped on for the purpose of installation within the electric control cabinet (35,43) for switch gears to be monitored or within all other closed enclosures serving the installation of technical systems providing at least one facility (52) for the fixing on a mounting rail (46) for low voltage switching devices in form of a so-called top-hat rail with a centrepiece (47) of U-shaped cross-section whose sides (48) feature edges offset to the outside (49).
2. Arrangement according to claim 1, characterised in that the device is built modular, e.g. with a sensor module (1; 45), an evaluation module (3), if applicable an interface module, a power supply module (2), etc.
3. Arrangement according one of the precedent claims, characterised in that the mounting facility (52) is designed for positive-fit fixing on the mounting rail (46).
4. Arrangement according one of the precedent claims, characterised by a mounting facility (52) designed for quick installation, in particular for snapping up a supporting rail (46).
5. Arrangement according to claim 3 or 4, characterised in that the mounting facility (52) provides an element (54, 55) (partly) engaging behind the mounting rail (46) which is approximately perpendicularly movable to the supporting rail (46) and is pressed by means of at least one spring element behind the supporting rail (46).
6. Arrangement according to one of the precedent claims characterised in that the enclosure (31-33;63) of the device (1-3) or the sensor module (1;45) provides stream-through apertures (34;68,69), on the upper, bottom, front and / or back side, in particular for the entering of smoke.
7. Arrangement according to one of the precedent claims, characterised by at least two stream-through apertures (34; 68, 69) which are each located approximately within opposite areas of the enclosure (31;63) carrying or surrounding the sensor (67).
8. Arrangement according to claim 6 or 7, characterised by stream-through apertures (34;68,69) located on two side walls of the enclosure (31;63) carrying or surrounding the sensor (67) which pierce approximately perpendicularly the basic plane of a mounting area (51) carrying the mounting element (46) so that the streaming direction within the sensor (67) respectively of the sensor module(1;45) runs approximately parallel to the mounting area (51).
9. Arrangement according to one of the claims 6 to 8, characterised by stream-through apertures (34;68,69) located on two side walls of the enclosure (31;63) carrying or surrounding the sensor (67) which run parallel to a mounting rail (46) carrying the enclosure (31;63) and which pierce this carrying mounting area (51) approximately perpendicularly so that the streaming direction within the sensor (67) respectively the sensor module (1;45) is approximately aligned diagonally to the mounting rail (46).
10. Arrangement according to one of the claims 6 to 9, characterised in that the lateral stream-through apertures (34;68,69) are located behind respectively underneath the level of a cover (72) surrounding the enclosure (31;63) so that primarily a smoke generation behind respectively under the cover (72) concerned is sensed.
11. Arrangement according to one of the precedent claims, characterised in that a cross-section parallel towards the front side of the enclosure of the sensor (31;63) shows a rectangular shape which preferably with regards to at least one of its measurements corresponds to a (standardised) cut-out in a cover (72) which surrounds the devices fixed on the mounting element (46) concerned.
12. Arrangement according to one of the precedent claims, characterised in that the operation and/or display elements are arranged on the overhanging part of the front side opposite the section featuring the input and/or output contacts which sticks out due to a flat cover of the contacts.
13. Arrangement according to one of the precedent claims, characterised in that electric input and/or output terminals (73) are arranged laterally on the enclosure (63) carrying or surrounding the sensor (67).
14. Arrangement according to one of the precedent claims, characterised in that the sensor module (1;45) features an interface component which allows a coupling to a preferably digital bus.
15. Arrangement according to claim 14, characterised in that the interface component is designed in such a manner that the addressing of the sensor module concerned (1;45) is possible.
16. Arrangement according to claim 14 or 15, characterised in that the bus is designed for serial data transfer, e. g. in form of a single cable.
17. Arrangement according to one of the precedent claims, characterised in that the device (1-3) or the evaluation module (3) features at least one signal output for triggering a facility (38) for the closing of louvers (37) of the switch gear cabinet (35,43) / the encased space, e. g. by means of a drop indicator (38) which drops in front of the concerned louver when in power-off condition.
18. Arrangement according to one of the precedent claims, characterised in that the device (1-3) or a power supply module (2) provides an uninterruptible power supply, in particular in form of a battery (21) or an accumulator, which guarantee (emergency) operation for a limited period of time in case of a power failure.
19. Method of operation of an arrangement according to one of the precedent claims for detection and if applicable identification of smoke generation and/or fire in an electric cabinet (35-43) for switch gears or in another closed enclosure serving the installation of technical systems with a sensor (67) for smoke and/ or increased temperature which features an exit for transmission of information whereas the sensor (67) or an enclosure (63) carrying the sensor (67) or a socket on which the device or its modules can be clipped on for the purpose of installation within the electric control cabinet (35,43) for switch gears to be monitored or within all other closed enclosures serving the installation of technical systems providing at least one facility (52) for the fixing on a mounting rail (46) for low voltage switching devices in form of a so-called top-hat rail with a centrepiece (47) of U-shaped cross-section whose sides (48) feature edges offset to the outside, characterised in that between one or several sensor modules (1;45) and an evaluation unit (3) digital information are transferred.
20. Method as per claim 19, characterised in that the information transmitted are provided with an address identification so that several sensor modules (1;45) and/or evaluation units (3) can communicate over the same bus.
21. Method as per claim 19 or 20, characterised in that status information of the several sensors are transmitted in approximately regular time intervals to an evaluation unit where to be evaluated.
22. Method as per claim 19 to 21, characterised in that the information transferred between a sensor module (1;45) and an evaluation unit (3) contain measured values of temperature.
23. Method as per claim 22, characterised in that the measured values of temperature are compared to a critical value, in order to create a pre-alarm or a further fault signal when the critical value is exceeded.

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