Extinguishing system and method for operating same

Description

[0001] The present invention relates to a water extinguishing system comprising a fire extinguishing fluid supply configured for providing a fire extinguishing fluid, at least one pump configured for pumping the fire extinguishing fluid from the fire extinguishing fluid supply into a supply line to the pipe system of the water extinguishing system, a control unit configured for controlling the operation of the at least one pump, which is configured to start and operate the pump for a pump test run when a start signal is provided and to end the pump test run and stop the pump when a stop signal is provided.

[0002] Furthermore, the invention relates to a method for operating a water extinguishing system with a fire extinguishing fluid supply configured to provide a fire extinguishing fluid, at least one pump configured to pump the fire extinguishing fluid from the fire extinguishing fluid supply into a supply line to the pipe system of the water extinguishing system, and a control unit configured to control the operation of the at least one pump, which is configured to start and operate the pump for a pump test run when a start signal is provided and to end the pump test run and stop the pump when a stop signal is provided, comprising the following steps: starting and operating the pump for the purpose of the pump test run by means of the control unit when a start signal is provided, ending the pump test run and stopping the operation of the pump in the case of a stop signal being provided.

[0003] Water-based fire suppression systems, also known as sprinkler systems, are used in firefighting. In the event of a fire, a pump is typically started, which delivers an extinguishing fluid to the nozzles or sprinklers. The extinguishing fluid used is water or water with extinguishing agent additives, such as foam or wetting agents. Therefore, in this context, water-based fire suppression systems encompass all extinguishing systems that operate using a fluid-based extinguishing agent. In practice, such systems regularly include pressure switching devices, such as pressure switches. These pressure switches generate a switching signal when the pressure drops below a predefined or predetermined threshold. This switching signal can then be used, for example, to initiate further processes, such as starting one or more pumps.The switching signal can also be used as a warning signal for a pressure drop to be fed to a central control unit for further processing.

[0004] In water-based fire suppression systems, particularly sprinkler systems, a nozzle or sprinkler opens in the event of a fire, allowing a fire-fighting fluid, preferably water or water with fire-retardant additives, to be deployed. In water-based fire suppression systems with open nozzles, an alarm valve opens to trigger the delivery of the fire-fighting fluid to the nozzles or sprinklers. The alarm valve is controlled, for example, by a fire alarm control panel. The opening of a sprinkler or nozzle causes a pressure drop in the pipe system carrying the fire-fighting fluid. Such pressure-switching devices, especially for sprinkler pumps, are subject to, among other things, national standards and guidelines, such as VdS CEA 4001 2000-04 : 2021-01 (07).

[0005] In particular, the guideline stipulates that at least one pressure switch must be provided to start each pump. It is also possible for two such pressure switches to be electrically connected in series. The standards EN 12845:2020-11 and EN 5 12845:2015+A1:2019 are also relevant here. Regular inspections and maintenance are required to maintain the operational readiness of such fire extinguishing systems. For example, the VdS 2212 guideline prescribes weekly inspections of the water-based fire extinguishing system by the system operator.

[0006] Since the reliable starting of the pump for conveying the extinguishing fluid is essential for the functioning of the fire suppression system, the tests also include a check of the pump start-up process. For example, according to FM Global or NFPA guidelines, a monthly test run is required for electrically operated pumps, and a weekly test run for diesel pumps. VdS CEA 4001 and EN 12845 also require a weekly test run for electric pumps. Such pump tests serve to verify the functionality of the entire chain of components and their interaction, from the generation of a pressure drop and the correct functioning of the pressure switch to the start-up of the pump(s).

[0007] In practice, a pressure switching device is provided for this purpose in such water extinguishing systems. This device comprises two pressure switches connected in series as pressure sensing elements. Alternatively, two pressure switching devices are connected in parallel and configured to function as normally open contacts. Both pressure switches must be tested for functionality during a pump test run. The test must verify that the switching signal is generated at the predetermined pressure threshold for both pressure switches and that the pump is started by initiating the switching signal.

[0008] Such a pressure switching device, known from the prior art, can be considered a component of a pump test setup, which includes the aforementioned central control unit, in particular a pump control cabinet, a sprinkler pump control cabinet, or a combination of a fire alarm control panel and a pump control cabinet. The pump test setup is configured to start the pump when a predefined pressure drop is generated.

[0009] The pressure switches of the pressure switching device are equipped with a supply line to a main line, which carries the extinguishing fluid from the pump outlet to the pipe system containing the nozzles or sprinklers. The supply line establishes a fluid-conducting connection from the main line to the two pressure switches connected in series. Optionally, this line splits into a first supply line to a first pressure switch and a second supply line to a second pressure switch. In the prior art, the supply line includes, for example, shut-off valves, preferably in the form of a first and a second shut-off valve, as well as valves for releasing extinguishing fluid to generate the necessary pressure drop to start the sprinkler pump, and pressure gauges.

[0010] According to current best practices, the weekly pump test run is performed manually by a trained person. Therefore, according to the state of the art as published in standards and guidelines, it is always necessary for trained personnel to be present on-site during such a test run.

[0011] A pump test run of this type, known from the prior art, is performed, for example, in water extinguishing systems equipped with two pressure switches, as follows: A first shut-off valve in the first supply line is manually operated to interrupt the fluid-conducting connection from the main line to the first pressure switch. This prevents the first pressure switch from registering a pressure drop during the test run and thus from generating a switching signal. In this way, only the function of the second pressure switch and the downstream components is tested. If a pressure switch or pressure sensor is present, the test can be started using a 2 / 3-way solenoid valve activated by the pump controller.

[0012] The valve in the second supply line is then manually opened to generate a pressure drop. At this pressure drop, and at a specific switching pressure reading (as read by maintenance personnel on the pressure gauge), the second pressure switch generates a switching signal. This signal is sent via a signal-conducting connection to the central control unit to start the pump. The pump starts, and in practice, the test run ends when the pump's normal operating parameters are reached.

[0013] The test run then begins with the pump being started via the first pressure switch. For this, a second shut-off valve in the second supply line is manually opened to interrupt the fluid connection between the main line and the second pressure switch. This prevents the second pressure switch from registering a pressure drop during the test run and generating a switching signal. The valve in the first supply line is then manually opened to create a pressure drop. At this pressure drop, the first pressure switch generates a switching signal at a specific switching pressure reading, which is observed by maintenance personnel on the pressure gauge. This signal is then transmitted via a signal connection to the central control unit to start the pump.

[0014] The switching pressure readings of the two pressure switches recorded in this way are then compared by the maintenance personnel with the specified threshold values ​​of the pressure switches to determine whether the recorded switching pressure readings correspond to the predefined threshold values ​​within the permitted or specified tolerance.

[0015] Some common water-based fire suppression systems are also equipped with only one pressure switch. The pump test run is performed as described above, but only using the first pressure switch described there.

[0016] Known water extinguishing systems with test runs are disclosed in JP 2015 130928 A and DE 10 2018 119776 A1.

[0017] A disadvantage of the known water-based fire suppression systems and the aforementioned known procedure is that the pump test run must be performed manually. In particular, a suitably trained person must be present on-site during such a test run to monitor the parameters. Therefore, performing such a pump test run is very labor-intensive. Furthermore, if a fire occurs during a pump test run, there is a risk, especially with automation, that the pump will be stopped at the end of the test run when the stop signal is triggered. Thus, during such a pump test run, the problem arises that despite a fire, the pump will be stopped and the supply of extinguishing agent will be interrupted in an impermissible and dangerous manner.

[0018] It is therefore an object of the present invention to propose a water extinguishing system that ensures a reliable supply of extinguishing agent at all times. Furthermore, it is an object of the present invention to propose a water extinguishing system by means of which a pump test run is automatically ensured in the event of a fire, while continuously guaranteeing the supply of extinguishing agent. Finally, the object is to propose a corresponding method.

[0019] The problem is solved by a water extinguishing system according to claim 1.

[0020] This ensures that the pump is always prevented from shutting down in the event of a fire. In other words, the control unit according to the invention is designed as a priority circuit that suppresses the provision of the stop signal in the event of a fire. This ensures that a reliable supply of extinguishing agent is always guaranteed if a fire occurs during a pump test run. This offers, for the first time, the possibility of performing a pump test run largely automatically. Preferably, the control unit according to the invention is configured such that the provision of the stop signal is suppressed at least during the pump test run. More preferably, it is configured to suppress the provision of the stop signal for a predetermined blocking period that extends beyond the actual duration of the pump test run.

[0021] Preferably, the control unit is configured as a separate control unit, which is installed in the water extinguishing system according to the invention in addition to a control cabinet already present for controlling the water extinguishing system. It is also possible that the control unit according to the invention is integrated into the aforementioned control cabinet.

[0022] A preferred embodiment of the invention is characterized in that the water extinguishing system further comprises a fire alarm control panel configured to provide a fire alarm signal in the event of a fire, wherein the signal suppression unit is configured to suppress the provision of the stop signal when a fire alarm signal has been provided. The fire alarm control panel is advantageously configured to determine whether a fire has occurred by means of a plurality of fire detectors. If the fire alarm control panel detects the presence of a fire, it provides the fire alarm signal. Advantageously, the fire alarm control panel is further configured to suppress the provision of the stop signal, at least during the pump test run, in order to reliably prevent the pump from being switched off in the event of a fire.

[0023] According to the invention, a flow monitor is arranged between the supply line and the pipe system. This flow monitor is configured to trigger the signal suppression unit to suppress the stop signal when it detects a flow rate of the extinguishing fluid. The flow monitor thus reliably detects whether one or more sprinklers have already been opened due to a fire. If all sprinklers or the alarm valve are closed, the pump builds up a static pre-pressure in the supply line during a test run. In this case, the flow rate through the flow monitor is zero.

[0024] However, if one or more of the sprinklers or the alarm valve in systems with open nozzles are opened due to a fire, extinguishing fluid flows from the supply line through the flow monitor into the pipe system, causing the flow monitor to detect a flow rate that deviates from zero. The flow monitor according to the invention described above is thus designed as a fire detection system, which detects the occurrence of a fire even during a pump test run and then triggers the suppression of the stop signal by means of the signal suppression unit. In this way, it is possible to reliably detect a fire during an ongoing pump test run and to ensure that the pump is stopped and thus a reliable, continuous supply of extinguishing fluid is always guaranteed.

[0025] Another advantageous embodiment of the invention is characterized in that the control unit comprises a pump starting device, wherein the pump starting device is configured to provide the start signal to start the pump upon detection of the volume flow by means of the flow switch. Preferably, the extinguishing fluid in the supply line is pressurized with a static pre-pressure for this purpose.

[0026] When one or more of the sprinklers or the alarm valve in systems with open nozzles are opened in the event of a fire, a minimum quantity of extinguishing fluid flows through the flow monitor. As a result of the detected flow rate, the program start device provides the aforementioned start signal to start the pump. In this way, the flow monitor according to the invention fulfills a dual function. On the one hand, it is designed to detect the opening of one or more sprinklers in the event of a fire during a pump test run and to temporarily prevent the pump from being switched off. On the other hand, the pump is designed to reliably detect the opening of one or more sprinklers or the alarm valve in systems with open nozzles, triggered by a fire, when the pump is switched off and there is static pressure in the supply line.

[0027] A preferred embodiment of the invention is characterized in that the flow monitor is designed to suppress the provision of the stop signal if the detected volume flow exceeds a predetermined minimum volume flow. If the detected volume flow exceeds the predetermined minimum volume flow, this is a clear indicator of a fire. In the event of a fire, this reliably prevents the pump from shutting down at the end of the pump test run and ensures the supply of extinguishing fluid.

[0028] According to a further preferred embodiment of the invention, the flow monitor is designed as a flow switch. The flow monitor is thus advantageously designed to be particularly robust against interference and false triggering.

[0029] A further advantageous embodiment of the invention is characterized in that the signal suppression unit comprises a first controllable electromagnetic switch with a controllable first normally open contact, wherein the stop signal is electrically routed via the first normally open contact such that the provision of the stop signal is suppressed when a fire alarm signal is present, by opening the first normally open contact. This offers the advantage that the suppression of the stop signal is performed in hardware. The suppression of the stop signal is thus predetermined by the circuit design and is free of further control components, particularly those that are computer program-based. Preferably, the suppression of the stop signal is also configured redundantly with respect to the other control components.This ensures that the suppression of the stop signal in the event of a fire is always guaranteed, regardless of whether other control components, especially those based on microprocessors, are functioning correctly or not. This guarantees reliable suppression of the stop signal in the event of a fire at all times.

[0030] A further advantageous embodiment of the invention is characterized in that the first controllable electromagnetic switch is configured such that the provision of the stop signal is automatically suppressed in the event of a power supply failure, by the first normally open contact automatically opening when the power supply is interrupted. Advantageously, this ensures that the provision of the stop signal is reliably suppressed in every case, even in the event of a power supply failure. A power supply failure or shutdown thus leaves the suppression of the stop signal according to the invention unaffected.

[0031] A preferred embodiment of the invention is characterized in that the signal suppression unit comprises a second controllable electromagnetic switch with a controllable second working contact, wherein the stop signal is electrically transmitted via the second working contact such that the provision of the stop signal is suppressed by the flow monitor when the volumetric flow rate of the extinguishing fluid is detected, by opening the second working contact. This embodiment of the invention has the advantage that, in addition to the aforementioned measures for suppressing the stop signal, the second working contact also opens when a volumetric flow rate is detected.

[0032] According to another preferred embodiment, the first and second working contacts are connected in series. In this way, the first and second working contacts form an interruption chain designed to suppress the provision of the stop signal as soon as either of the two working contacts opens. In other words, the working contacts are configured as a safety signaling chain through which the stop signal is routed. Opening one or both working contacts always suppresses the provision of the stop signal and, in the aforementioned cases, ensures the continued operation of the pump.

[0033] According to a further preferred embodiment of the invention, the water extinguishing system comprises a control unit configured to accept manual input and / or to automatically initiate a pump test run, and configured to provide the start signal for initiating the pump test run and starting the pump, as well as the stop signal for ending the pump test run and stopping the pump. The control unit is preferably designed as a logic unit, for example as a programmable logic controller or the like, and forms a subunit of the control unit.

[0034] A preferred embodiment of the invention is characterized in that the control center and the control unit are configured to suppress the provision of the stop signal in the event of a fire. For example, the suppression of the stop signal in the control center and / or the control unit is implemented via software. In conjunction with the aforementioned embodiments of the signal suppression unit, the suppression of the stop signal is designed redundantly. In particular, this ensures that in the event of a failure or malfunction of the control center and / or the control unit in the event of a fire, the provision of the stop signal is always prevented by means of the signal suppression unit in order to ensure the continuous supply of extinguishing fluid.

[0035] According to a further preferred embodiment of the invention, the signal suppression unit is designed without a computer program. This ensures high reliability and continuous functionality of the signal suppression unit. For this purpose, the signal suppression is preferably implemented using analog or digital circuits. Suppression is also preferably implemented using hard-wired relay or contactor combinations.

[0036] The task is further accomplished by a corresponding method according to claim 13.

[0037] The advantages achieved with the method according to the invention correspond to the advantages already mentioned previously with regard to the water extinguishing system according to the invention. Therefore, to avoid repetition, only selected aspects of the method according to the invention will be discussed in more detail here and in the following; otherwise, the advantages and explanations previously mentioned in connection with the water extinguishing system according to the invention also apply analogously to the method according to the invention.

[0038] A preferred embodiment of the invention is characterized by providing a fire alarm signal by means of a fire alarm control panel in the event of a fire and suppressing the provision of the stop signal by means of the signal suppression unit when a fire alarm signal has been provided.

[0039] The invention is characterized by detecting a volume flow of the extinguishing fluid by means of a flow monitor arranged between the supply line and the pipe system and by causing the signal suppression unit to suppress the provision of the stop signal if a volume flow of the extinguishing fluid is detected by means of the flow monitor.

[0040] Another advantageous embodiment of the invention is characterized by providing the start signal for starting the pump if the volume flow is detected by means of the flow monitor.

[0041] Another advantageous embodiment of the invention is characterized in that the provision of the stop signal is suppressed by means of the flow monitor if the detected volume flow exceeds a predetermined minimum volume flow.

[0042] A preferred further development of the invention is characterized by

[0043] Initiating a pump test run via a control center by manual input and / or automatically, comprising the steps: initiating the pump test run and starting the pump by providing the start signal and optionally ending the pump test run to stop the pump by providing the stop signal.

[0044] Another advantageous embodiment of the invention is characterized by suppressing the provision of the stop signal in case of fire by means of the control center and / or the control unit.

[0045] Further preferred and / or advantageous features and embodiments of the invention will become apparent from the dependent claims and the description. Particularly preferred embodiments are explained in more detail with reference to the accompanying drawing. The drawings illustrate both the water extinguishing system and the method according to the invention. The drawing shows: Fig. 1 a schematic representation of the water extinguishing system according to the invention according to a first embodiment, Fig. 2 a schematic representation of the water extinguishing system according to the invention according to a second embodiment, Fig. 3 a schematic representation of the water extinguishing system according to the invention according to a third embodiment, Fig. 4 a schematic representation of the water extinguishing system according to the invention according to a further embodiment, Fig. 5 circuit diagram of an embodiment of the signal suppression unit with the flow monitor not activated, and Fig. 6 circuit diagram of the signal suppression unit with the flow monitor activated.

[0046] Based on the Fig. 1 The water extinguishing system and the method according to the invention will be explained in more detail below.

[0047] The water extinguishing system according to the invention and the method comprise a fire extinguishing fluid supply 10, which is designed and configured to provide a fire extinguishing fluid (not shown in the drawing). The fire extinguishing fluid supply 10 is, for example, configured as a fire extinguishing fluid tank or a fire extinguishing agent supply line.

[0048] The water extinguishing system according to the invention further comprises at least one pump 14 designed to pump the extinguishing fluid from the extinguishing fluid supply 10 into a supply line 12 leading to a pipe system 13 of the water extinguishing system. The pump 14 comprises a motor 15, which is preferably designed as a diesel engine or an electric motor. Preferably, a motor control unit 16 is connected upstream of the motor 15, which is configured to operate the motor 15 of the pump 14 in a control-variable manner.

[0049] A control unit 17 is provided for the controllable operation of the pump 14 or the motor 15. Upon receiving a start signal, the control unit 17 starts and operates the pump 14 for a pump test run, and upon receiving a stop signal, it terminates the pump test run and stops the pump 14. Preferably, the control unit 17 provides the start and stop signals, which are processed by the motor control unit 16 to operate the motor 15 of the pump 14 in a controllable manner as described above.

[0050] Depending on the type of engine used, the motor control unit 16 is configured to start and operate the motor 15. For example, if the motor 15 is an internal combustion engine, such as a diesel engine, the motor control unit 16 includes the necessary electric starter and all control components required for operating the motor 15. If an electric motor, or a three-phase synchronous or asynchronous motor, is used, the motor control unit 16 includes, for example, a suitably programmed and configured frequency converter to perform the aforementioned functions in a variable control manner.

[0051] According to the invention, the control unit 17 comprises a signal suppression unit 18, which is configured to suppress the provision of the stop signal, at least temporarily, in the event of a fire. In other words, the signal suppression unit 18 is designed to prevent the stop signal from being transmitted to the control unit 17 during a fire, in order to prevent the pump 15 from stopping under any circumstances. Temporary suppression means that the suppression of the stop signal occurs for a predetermined minimum or blocking time, or even permanently. Preferably, the stop and start signals are transmitted from the control unit 17 to the motor control unit 16 via a signal-conducting connection 19. The signal-conducting connection 19 is preferably configured as a wired or wireless interface, for example, as a signal bus system.

[0052] Preferably, pressure gauges 19 and 20 are arranged on both the suction and pressure sides of the pump 14, by means of which the pressure of the extinguishing fluid is measured and displayed on both the suction and pressure sides of the pump 14. Alternatively, the pressure gauges 19 and 20 are designed as pressure sensors. More preferably, the suction side of the pump 14 is equipped with a first shut-off valve 21 to isolate it from the extinguishing fluid supply 10. A second shut-off valve 22 is arranged on the pressure side of the pump 14, by means of which the pressure side of the pump 14, including the supply line 12, is isolated from the pipe system 13.

[0053] As in Fig. 3As shown, according to a practical embodiment of the invention, the water extinguishing system further comprises a fire alarm control panel 23. The fire alarm control panel 23 is configured to provide a fire alarm signal in the event of a fire. In particular, the fire alarm control panel 23 is configured to determine whether a fire has occurred by means of a plurality of fire detectors (not shown in the drawing). If the fire alarm control panel 23 detects such a fire, it provides the fire alarm signal as described above. The signal suppression unit 18 is configured to suppress the provision of the stop signal when a fire alarm signal has been provided, in order to reliably prevent the pump 14 or the motor 15 from being switched off in the event of a fire.

[0054] The signal suppression device 18 is preferably designed as an integral component of the control unit 17. The control unit 17 thus provides all functionalities for controlling the motor 15 or the pump 14, including the signal suppression described above. Alternatively, the signal suppression device 18 can be configured as described in Fig. 2 schematically represented - executed as a separate unit.

[0055] According to the invention, a flow monitor 24 is arranged between the supply line 12 and the pipe system 13. This flow monitor 24 is configured to cause the signal suppression unit 18 to suppress the delivery of the stop signal when it detects a flow rate of the extinguishing fluid. The flow monitor 24 is thus configured to detect whether one or more of the sprinklers have already been opened due to a fire. If all sprinklers are in the closed position, the pump 14 builds up a static pre-pressure in the supply line 12 during a test run in the extinguishing fluid supply 10. In this case, the flow rate through the flow monitor 24 is zero.

[0056] In the event of a fire with open sprinklers or alarm valves, extinguishing agent flows from the supply line 12 through the flow monitor 24 into the pipe system 13, which detects a flow rate that deviates from zero. This makes it possible to reliably detect a fire during a pump test run and prevent the pump 14 from stopping, thus ensuring a reliable and continuous supply of extinguishing agent fluid at all times.

[0057] Another advantageous embodiment of the invention is characterized in that the control unit 17 includes a pump starting device (not shown in the drawing). The pump starting device is configured, for example, to provide the start signal to start the pump when the flow rate is detected by the flow monitor 24. A pressure sensor 25 or pressure switch 25 is preferably also connected to the pump starting device. This sensor or switch is configured to provide the start signal when a pressure drop is detected by the pressure sensor 25. Preferably, a non-return valve 26 is arranged between the supply line 12 and the pipe system 13.

[0058] A preferred embodiment of the invention is characterized in that the flow monitor 24 is configured to suppress the provision of the stop signal if the detected volume flow exceeds a predetermined minimum volume flow. If the detected volume flow exceeds the predetermined minimum volume flow, this is a clear indicator of a fire. Switching off the pump 14 or the motor 15 at the end of the pump test run is thus reliably prevented in the event of a detected fire, and the supply of extinguishing fluid is ensured. According to a further preferred embodiment of the invention, the flow monitor 24 is configured as a flow switch. The flow monitor is thus advantageously particularly robust against malfunctions and false triggering.

[0059] Figure 4 shows another variant of the design already in the Figure 1 and 2 as shown. In Fig. 4Alarm valves 27 and 28 are also shown. The nozzles / sprinklers 29 shown, for example, are hydraulically connected to alarm valve 27. Alarm valve 27 is linked to the fire alarm control panel 23.

[0060] Figure 5 Figure 1 shows a circuit diagram of the signal suppression unit 18, which is schematically represented as a simplified signal or circuit diagram. Preferably, the signal suppression unit 18 is designed as a first controllable electromagnetic switch 30 with a controllable first normally open contact 31. The stop signal, for example, is electrically routed via this first normally open contact 31 such that the provision of the stop signal is suppressed when a fire alarm signal is present, by opening the first normally open contact 31.

[0061] In Fig. 5The flow monitor 24 is shown in its inactive state, i.e., closed in its resting state. The stop signal provided by a control unit 32 is routed via the flow monitor 24, for example, to the first controllable electromagnetic switch 30. As long as the flow monitor 24 is electrically closed, the holding coil 33 is energized, and the switch 30 transmits any stop signal provided via the first normally open contact 31 to the motor control unit 16. The control unit 32 is specifically designed to initiate a pump test run upon manual input and / or automatically. Furthermore, the control unit 32 is designed and configured to initiate the pump test run and start the pump 14 by providing the start signal, as well as to terminate the pump test run and stop the pump 14 by providing the stop signal.

[0062] Preferably, the control center 32 and the control unit 17 are configured to suppress the provision of the stop signal in the event of a fire. Preferably, the signal suppression unit 18 is designed without a computer program sequence.

[0063] The control unit 32 is preferably designed as a logic unit, for example as a programmable logic controller or the like, and forms a subunit of the control unit 17.

[0064] Preferably, the first controllable electromagnetic switch 30 is configured such that the provision of the stop signal is automatically suppressed in the event of a power supply failure by automatically opening the first working contact 31 when the power supply is lacking. As in Fig. 6 As shown, the holding coil 33 drops out in the event of a power supply failure, thus suppressing the provision of the stop signal to the motor control unit 16.

[0065] Optionally, this only includes the Figures 1 to 3 The signal suppression unit 18 shown comprises a second controllable electromagnetic switch (not shown in the drawing) with a controllable second working contact. The stop signal is electrically routed via the second working contact such that the provision of the stop signal is suppressed by the flow monitor 24 when the volume flow of the extinguishing fluid is detected, by opening the second working contact. Alternatively, the second working contact is formed by the flow monitor 24 itself. Preferably, the first working contact 31 and the second working contact are connected in series.

[0066] Figure 6 shows a circuit diagram of the signal suppression unit 18, however, unlike the Figure 5with flow monitor 24 activated. If the flow monitor 24 opens, the supply voltage is withdrawn from the holding coil 33, so that the first electromagnetic switch 30 drops out and opens the first working contact 31, so that in case of fire the provision of the stop signal is interrupted in any case.

Claims

1. Water extinguishing system, comprising an extinguishing fluid supply (10) adapted to provide an extinguishing fluid, at least one pump (14) adapted to convey the extinguishing fluid from the extinguishing fluid supply (10) into a supply line (12) to the pipe system (13) of the water extinguishing system, a control unit (17) adapted to operate the at least one pump (14) in a controllable manner, which control unit is configured to start and to operate the pump (14) for a pump test run on provision of a start signal and to end the pump test run and to stop the pump (14) on provision of a stop signal, characterised in that the control unit (17) has a signal suppression unit (18) which is adapted to at least temporarily suppress the provision of the stop signal in the event of a fire, and a flow detector (24) is arranged between the supply line (12) and the pipe system (13), which is designed to cause the signal suppression unit (18) to suppress the provision of the stop signal when a volume flow of the extinguishing fluid is detected by the flow detector (24).

2. Water extinguishing system according to claim 1, further comprising a fire alarm centre (23) which is adapted to provide a fire alarm signal in the event of a fire, wherein the signal suppression unit (18) is adapted to suppress the provision of the stop signal when a fire alarm signal has been provided.

3. Water extinguishing system according to claim 1 or 2, characterised in that the control unit (17) comprises a pump start device, wherein the pump start device is configured to provide the start signal for starting the pump (14) on detection of the volume flow by means of the flow detector (24).

4. Water extinguishing system according to either claim 1 to 3, characterised in that the flow detector (24) is configured to suppress the provision of the stop signal when the detected volume flow exceeds a given minimum volume flow.

5. Water extinguishing system according to any one of claims 1 to 4, characterised in that the flow detector (24) is configured as a flow switch.

6. Water extinguishing system according to any one of claims 2 to 5, characterised in that the signal suppression unit (18) comprises a first controllable electromagnetic switch (30) having a controllable first working contact (31), wherein the stop signal is guided electrically via the first working contact in such a manner that, when a fire alarm signal has been provided, the provision of the stop signal is suppressed, in that the first working contact opens.

7. Water extinguishing system according to claim 6, characterised in that the first controllable electromagnetic switch is adapted in such a manner that, in the event of failure of the power supply, the provision of the stop signal is suppressed in a self-acting manner, in that the first working contact opens automatically in the absence of a power supply.

8. Water extinguishing system according to any one of claims 1 to 7, characterised in that the signal suppression unit (18) comprises a second controllable electromagnetic switch having a controllable second working contact, wherein the stop signal is guided electrically via the second working contact in such a manner that the provision of the stop signal is suppressed, on detection of a volume flow of the extinguishing fluid through the flow detector (24), in that the second working contact opens.

9. Water extinguishing system according to claim 8, characterised in that the first working contact and the second working contact are connected in series.

10. Water extinguishing system according to any one of claims 1 to 9, further comprising a central control unit (32) which is adapted to initiate a pump test run in response to a manual input and / or automatically and which is configured to provide the start signal for initiating the pump test run and for starting the pump (14) and to provide the stop signal for ending the pump test run and for stopping the pump (14).

11. Water extinguishing system according to claim 10, characterised in that the central control unit (32) and the control unit (17) are configured to suppress the provision of the stop signal in the event of a fire.

12. Water extinguishing system according to any one of claims 1 to 11, characterized in that the signal suppression unit (18) is configured to be free of executing a computer program.

13. Method for operating a water extinguishing system having an extinguishing fluid supply (10) adapted to provide an extinguishing fluid, at least one pump (14) adapted to convey the extinguishing fluid from the extinguishing fluid supply (10) into a supply line (12) to the pipe system (13) of the water extinguishing system, and a control unit (17) adapted to operate the at least one pump (14) in a controllable manner, which control unit is configured to start and to operate the pump (14) for a pump test run on provision of a start signal and to end the pump test run and to stop the pump (14) on provision of a stop signal, comprising the following steps: starting and operating the pump (14) for the purposes of the pump test run by means of the control unit (17) when a start signal has been provided, ending the pump test run and stopping operation of the pump (14) in the case where a stop signal has been provided, characterised by at least temporarily suppressing the provision of the stop signal in the event of a fire by means of a signal suppression unit (18) of the control unit (17), detecting a volume flow of the extinguishing fluid through a flow detector (24) arranged between the supply line (12) and the pipe system (13), and causing the signal suppression unit (18) to suppress the provision of the stop signal if a volume flow of the extinguishing fluid through the flow detector (24) is detected by means of the flow detector (24).

14. Method according to claim 13, further comprising providing a fire alarm signal by means of a fire alarm centre (23) in the event of a fire, and suppressing the provision of the stop signal by means of the signal suppression unit (18) when a fire alarm signal has been provided.

15. Method according to claim 13 or 14, characterised by providing the start signal for starting the pump (14) if the volume flow is detected by means of the flow detector (24).

16. Method according to either claim 13 to 15, characterised in that the provision of the stop signal is suppressed by means of the flow detector (24) if the detected volume flow exceeds a given minimum volume flow.

17. Method according to any one of claims 13 to 16, characterised by initiating a pump test run by means of a central control unit (32) by manual input and / or automatically, comprising the steps: initiating the pump test run and starting the pump (14) by provision of the start signal, and optionally ending the pump test run to stop the pump (14) by provision of the stop signal.

18. Method according to any one of claims 13 to 17, characterised by suppressing the provision of the stop signal in the event of a fire by means of the central control unit (32) and the control unit (17).

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