JP6126860B2 - Fire alarm system - Google Patents

Description

  The present invention relates to a fire alarm facility capable of alarming a deterioration in performance of a fire detector.

In a conventional fire alarm facility, a fire receiver is disposed in a central monitoring room, and a sensor line to which a fire detector is connected is extended from the fire receiver. When a fire is detected, the fire detector performs a switching operation to decrease the voltage of the sensor line and increase the current flowing through the sensor line. The fire receiver determines normality, fire occurrence, and disconnection of the wiring of the sensor line by monitoring the current flowing through the sensor line. (For example, see Patent Document 1)
Such a fire receiver is called a P-type fire receiver, which converts the current flowing in the sensor line into a voltage, and compares the converted voltage with each threshold value such as a fire threshold value and a disconnection threshold value. Judgment.

JP-A-6-176289

In the fire alarm facility described in Patent Document 1, abnormality in the wiring of the sensor line can be determined, but when the performance of the fire sensor deteriorates or breaks down, it cannot be notified by the fire receiver.
In order to notify the fire detector's performance degradation or failure, a fire detector equipped with a self-inspection function that outputs a signal such as a pulse to the fire receiver is used. There was a problem that it had to be replaced with a dedicated fire receiver (for example, R type) for communication.

A fire alarm facility according to the present invention includes a detector line connected to a fire receiver and a fire line connected to the sensor line to notify the fire by reducing the line voltage of the sensor line to a fire voltage. In a fire alarm facility comprising a plurality of fire detectors, the fire detector includes an abnormality determination unit that detects a decrease in performance of the fire detector, and the abnormality determination unit detects a decrease in performance of the fire detector. A state output unit for notifying the performance degradation by lowering the line voltage of the sensor line by an abnormal voltage, and the termination line for disconnecting the sensor line is connected to the sensor line. Is characterized in that when the line voltage falls below a fire detector abnormality threshold, it is determined that the line voltage has decreased by an abnormal voltage, and the sensor line is disconnected.

  The fire alarm facility according to the present invention is characterized in that the termination device sets a fire detector abnormality threshold based on the line voltage at the time of activation.

  The fire alarm facility according to the present invention is characterized in that the terminating device sets a fire detector abnormality threshold based on a predetermined number of line voltages.

  ADVANTAGE OF THE INVENTION According to this invention, the performance fall of a fire detector can be alert | reported with the existing P-type fire receiver.

It is a schematic block diagram which shows an example of the fire alarm equipment which concerns on Embodiment 1 of this invention. It is a flowchart which shows an example of operation | movement of the fire detector which concerns on Embodiment 1 of this invention. It is a flowchart figure which shows an example of operation | movement of the termination | terminus apparatus which concerns on Embodiment 1 of this invention. It is a flowchart figure which shows an example of operation | movement of the fire receiver which concerns on Embodiment 1 of this invention. It is a flowchart figure which shows an example of operation | movement of the termination | terminus apparatus which concerns on Embodiment 2 of this invention. It is a flowchart figure which shows an example of operation | movement of the termination | terminus apparatus which concerns on Embodiment 3 of this invention.

(Embodiment 1)
Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a schematic configuration diagram showing an example of a fire alarm facility 1 according to Embodiment 1 of the present invention.

  The fire alarm system 1 includes a fire detector 30 installed in each room or common area of a building (for example, a housing complex such as a hotel or a condominium, an office building, or a commercial facility), and a detection result of the fire detector 30. A P-type fire receiver 10 (hereinafter referred to as fire receiver 10) that performs a warning based on the sensor line 20 is connected. A terminating device 40 is connected to the end of the sensor line 20. In addition, a sound alarm device 50 is connected to the fire receiver 10. The fire detector 30 notifies the fire receiver 10 of a fire by reducing the line voltage of the sensor line 20 to a predetermined voltage by a switching operation.

  Here, in FIG. 1, only a pair of sensor lines 20 extending from the fire receiver is shown, but a plurality of sensor lines 20 may be extended from the fire receiver. Further, although only two disaster detectors 30 are shown, a predetermined number (for example, 30) of fire detectors 30 can be connected to the detector line 20.

(Fire receiver configuration)
The fire receiver 10 includes a line power supply unit 11, a conversion unit 12, a state determination unit 13, an alarm unit 14, an output unit 15, and a battery 16.
The line power supply unit 11 converts an AC voltage supplied from a commercial power supply (not shown) into a DC voltage of 12 V as a power supply voltage, and energizes the sensor line 20. At the time of a power failure, the line power supply unit 11 switches from the commercial power supply to the battery 16, converts the power supplied from the battery 16 to DC 12 V, and energizes the sensor line 20.

  The converter 12 is supplied to the sensor line 20 from the line power supply unit 11, and causes the current flowing through the common line 21, each fire detector 30 and the termination device 40, and the line line 22 to flow through a receiving resistor (not shown). Then, a voltage (hereinafter referred to as a reception voltage) is generated across the reception resistor.

  Note that the line voltage of the sensor line 20 (voltage between the common line 21 and the line line 22) and the reception voltage are the same as the power supply voltage supplied from the line power supply unit 11 and the impedance (resistance) between the common line 21 and the line line 22. Value) [inter-line impedance of the sensor line 20]: [receiving resistance]. That is, since the power supply voltage is divided into the line voltage and the reception voltage, the reception voltage is a value obtained by subtracting the line voltage from the power supply voltage. Here, the line impedance of the sensor line 20 is a combined impedance of the impedance of the fire sensor 20 connected to the sensor line 20 and the impedance of the termination device 40.

  The state determination unit 13 has a fire threshold and a disconnection threshold for determining whether the sensor line 20 is normal, fire, or disconnection. The state determination unit 13 compares the received voltage converted by the conversion unit 12 with each threshold value to determine the state of the sensor line 20, thereby detecting an abnormality in the fire detector line 20 and detecting fire. Notification of fire detection and abnormality detection from the container 30 is received. Each threshold has a relationship of disconnection threshold <fire threshold.

The alarm unit 14 has an indicator light and a buzzer, and is an alarm unit that warns the occurrence of a fire or abnormality with a display and a buzzer sound.
The output unit 15 outputs the occurrence of a fire or abnormality to a connected external device. The output unit 15 has a fire output contact and an abnormal output contact. In the present embodiment, the contact output is described, but a code signal may be used.

(Fire detector configuration)
The fire sensor includes a smoke sensor, a heat sensor, a flame sensor, and the like. Here, a smoke sensor that detects a fire by detecting smoke generated at the time of a fire will be described as an example.
The fire detector 30 includes a smoke detection unit 31, a fire determination unit 32, an abnormality determination unit 33, an indicator lamp 34, and a state output unit 35.

  The smoke detector 31 detects smoke generated in the event of a fire, and has a dark room, a light emitting element and a light receiving element (not shown). The smoke detector 31 scatters light emitted from the light emitting element by the smoke when the smoke flows into the dark room, converts the received light amount received by the light receiving element into a voltage signal, and determines the fire. And output to the abnormality determination unit 33. The more smoke that has flowed into the darkroom, the more scattered light and the greater the amount of light received.

The fire determination unit 32 determines a fire based on whether or not the voltage signal output from the smoke detection unit 31 has reached the fire level, and detects the fire.
The abnormality determination unit 33 determines an abnormality based on the voltage signal output from the smoke detection unit 31 and detects the abnormality. The abnormality determination unit 32 stores an initial voltage signal that is a voltage signal in a state where the darkroom at the time of shipment from the factory is not dirty and smoke does not flow.

  The indicator lamp 34 is turned on when the fire determination unit 32 or the abnormality determination unit 33 detects a fire or abnormality and notifies the fire or abnormality.

  When the fire determination unit 32 detects a fire, the state output unit 35 reduces the voltage of the sensor line 20 to a fire voltage that is a predetermined voltage, so that more current is supplied to the sensor line 20 than usual. The fire signal is output to the sensor line 20 to notify the fire receiver 10 that a fire has occurred. Further, the state output unit 35 causes a predetermined current to flow through the sensor line 20 when the abnormality determination unit 33 detects an abnormality, and reduces the line voltage of the sensor line 20 by a predetermined voltage. An abnormality signal is output to the line 20 to notify the termination device 40 that an abnormality has occurred in the fire detector 30.

(Configuration of terminal equipment)
The termination device 40 includes a sensor abnormality receiver 41, a termination resistor 42, and a contact / separation unit 43.
The detector abnormality receiving unit 41 has a fire detector abnormality threshold value, and compares the line voltage of the detector line 20 with the fire detector abnormality threshold value to determine whether or not an abnormality signal is received from the fire detector 30. Determine whether. The termination resistor 42 and the contact / separation part 43 are connected in series between the common line 21 and the line line 22 via the internal wiring of the termination device 40. That is, the termination resistor 42 is connected to the sensor line 20 by connecting the common line 21, the contact / separation part 43, the termination resistor 42, and the line line 22 in series in this order. Note that the order of the termination resistor 42 and the contact / separation portion 43 may be reversed.

The termination resistor 42 allows a minute current to flow through the sensor line 20.
The contact / separation part 43 connects or disconnects the terminating resistor 43 between the common line 21 and the line line 22 in a normal state, and whether or not an abnormality has occurred in any of the fire detectors 30. Is notified to the fire receiver 10.

(Configuration of voice alarm device)
The voice alarm device 50 includes an input unit 51, a voice control unit 52, and a voice unit 53.
The input unit 51 includes a fire input unit and an abnormality input unit, and detects an output from the output unit 15 of the fire receiver 10.
The voice control unit 52 stores a plurality of voice data, and transmits the voice data to the voice unit 53 based on the detection result of the input unit 51.
The sound unit 53 includes an amplifier and a speaker, and outputs sound based on the sound data transmitted from the sound control unit 52.

(Fire detector operation)
The operation of the smoke detector, which is an example of the fire detector 30, will be described with reference to FIG.
The smoke detector 31 causes the light emitting element to emit light in order to detect the amount of smoke, receives the scattered light with the light receiving element, and converts the received light amount into a voltage signal (S301). The fire determination unit 32 determines whether the voltage signal is equal to or higher than the fire level (S302). If the fire level is equal to or higher than the fire level in S302, the fire determination unit 32 detects a fire (S303), turns on the indicator lamp 34, and alerts the fire in the fire detector 30. The fire determination unit 32 notifies the state output unit 35 of fire detection. When receiving the notification of fire detection, the status output unit 35 lowers the sensor line 20 to a fire voltage of 5 V, which is a predetermined voltage, and causes a larger current to flow through the sensor line 20 than usual. Thereby, the fire detector 30 notifies the occurrence of a fire to the fire receiver by increasing the reception voltage generated by the converter 12 of the fire receiver (S304). Thereafter, the process returns to S301.

  If the voltage signal is less than the fire level in S302, the abnormality determination unit 33 determines whether the voltage signal is greater than or equal to a predetermined value than the initial voltage signal (S305). If the determination result in S305 is less than the predetermined value, the abnormality determination unit 33 determines whether the initial voltage signal is greater than or equal to the predetermined value than the voltage signal (S306). If the determination result in S306 is less than the predetermined value, the process returns to S301.

  When the determination results in S305 and S306 are equal to or greater than a predetermined value, the abnormality determination unit 33 continues for a predetermined time (for example, 1 hour) in order to exclude transient noise and actual smoke. It is determined whether or not (S307). If it is not continued for a predetermined time in S307, the process returns to S301. If the abnormality determination unit 33 continues for a predetermined time in S307, the abnormality is detected (S308), the indicator lamp 34 is blinked, the fire detector 30 is informed of the abnormality, and the state output unit 35 is notified of the abnormality detection ( S309).

  The state output unit 35 determines whether the terminal device 40 has been notified of the abnormality and whether the previous abnormality notification is within a predetermined time (for example, 24 hours) (S310). If the notification has been made in S310 and the previous notification is within 24 hours, the process returns to S301. If the state output unit 35 determines that the terminal device 40 has not yet been notified of an abnormality in S310, or if 24 hours have elapsed since the previous abnormality notification, the state output unit 35 is in an abnormal impedance state for a predetermined time (for example, 3 seconds), In addition to the current that normally flows through the sensor line 20, a predetermined current is passed through the sensor line 20 as an abnormal current. As a result, the reception voltage generated at the reception resistance of the converter 12 of the fire receiver 10 increases by the amount of abnormal current, and the line voltage of the sensor line 20 decreases by the increased voltage. That is, the state output unit 35 reduces the line voltage of the sensor line 20 by the abnormal voltage 3V, which is a predetermined voltage, and notifies the termination device 40 of the occurrence of the abnormality (S311). Thereafter, the process returns to S301. The fire detector 30 repeatedly detects fires and abnormalities by the above operation.

  Note that in S305, it is determined that dust is attached to the wall surface of the dark room that causes an increase in scattered light, and it is possible to prevent erroneous determination as a fire with a small amount of smoke. Further, in S306, it is determined whether the light emitting element and the light receiving element are deteriorated or failed, and it is possible to prevent the fire from being detected until the amount of smoke becomes large, the alarm being delayed, and the fire from being detected. That is, the fire detector 30 detects its own performance degradation (also referred to as abnormality or malfunction) in S305 and S306.

(Terminal operation)
The operation of the termination device 40 will be described with reference to FIG.
The sensor abnormality receiving unit 41 controls the contact / separation unit 43 to connect the termination resistor 42 to the sensor line 20 (S401) and detect the line voltage (S402). The sensor abnormality receiving unit 41 determines whether the line voltage is equal to or less than the fire detector abnormality threshold value 10V (S403). This is because when the fire detector 20 causes an abnormal current to flow and raises the reception voltage at the converter 12 of the fire receiver 10, the line voltage of the detector line 20 is reduced by 3 V as an abnormal voltage. Since the inter-voltage is 9 V or less, which is the value obtained by subtracting the abnormal voltage 3 V from the power supply voltage 12 V, the abnormality of the fire detector 30 is judged by whether or not the line voltage has become the fire detector abnormality threshold 10 V or less. . When the sensor abnormality receiving unit 41 determines that the threshold value is less than or equal to the threshold value, the sensor abnormality receiving unit 41 controls the contact / separation unit 43 to repeat disconnection and connection of the termination resistor 42 to the sensor line 20 at predetermined time intervals (eg, 3 seconds). Accordingly, the termination resistor 40 notifies the fire receiver 10 that an abnormality has occurred in the fire detector 30 (S404). Thereafter, the process returns to S402 and the monitoring of the line voltage is repeated.

  When the line voltage exceeds the fire detector abnormality threshold value in S403, the detector abnormality receiving unit 41 determines whether or not it continues for a predetermined time (for example, 24 hours) (S405). When continuing, return to S401, connect the terminating resistor 42 to the sensor line 20, notify the fire receiver 10 that no abnormality has occurred in the fire sensor 30, and detect the line voltage again. repeat. When not continuing, it returns to S402 and the monitoring of the line voltage is repeated.

(Fire receiver operation)
The operation of the fire receiver 10 will be described with reference to FIG.
The current flowing through the sensor line 20 is in the case of disconnection <normal time <fire, and the fire receiver 10 determines the occurrence of fire or disconnection by determining the current flowing through the sensor line 20.
In order to monitor the state of the sensor line 20, the converter 12 converts the current flowing through the sensor line 20 into a reception voltage using a reception resistor (S101).

  The state determination unit 13 determines whether the received voltage is equal to or higher than the fire threshold 4V (S102). This is because when the fire detector 20 sets the line voltage of the sensor line 20 to the fire voltage 5V, the reception voltage becomes 7V, which is a value obtained by subtracting the fire voltage 5V from the power supply voltage 12V. The fire is judged by whether or not the threshold value 4V is exceeded. If the determination result in S102 is equal to or greater than the fire threshold, the state determination unit 13 determines that a fire has been notified from the fire detector 30, and determines that a fire has occurred (S103). When determining that a fire has occurred, the state determination unit 13 notifies the alarm unit 14 and the output unit 15 of the occurrence of the fire. Upon receiving the notification, the alarm unit 14 displays a fire alarm, continuously sounds a buzzer to alarm the occurrence of a fire in the fire receiver 10, and the output unit 15 closes the fire output contact and fires an external device. Is generated (S104). Thereafter, the process returns to S101.

  If the determination result in S102 is less than the fire threshold, the state determination unit 13 determines whether the received voltage is equal to or lower than the disconnection threshold (S105). When the determination result in S105 is equal to or less than the disconnection threshold value, the state determination unit 13 drops the termination device 40 (termination resistor) and reduces the current flowing through the sensor line 30, that is, the fire sensor 30 is disconnected. (S106). When the state determination unit 13 determines that a disconnection has occurred, the state determination unit 13 notifies the alarm unit 14 and the output unit 15 of the occurrence of the disconnection. When the notification is received, the alarm unit 14 displays a disconnection alarm, sounds the buzzer intermittently to warn of the occurrence of the disconnection in the fire receiver 10, and the output unit 15 closes the abnormal output contact to cause an error in the external device. The generation is output (S107). Thereafter, the process returns to S101.

  If the determination result in S105 exceeds the disconnection threshold, the state determination unit 13 determines that the state is normal (S108). When determining that the state is normal, the state determination unit 13 notifies the alarm unit 14 and the output unit 15 of the normal state. When the notification is received, the alarm unit 14 and the output unit 15 stop the alarm and stop the output when the alarm is performed (S109). Thereafter, the process returns to S101. The fire receiver 10 repeatedly determines fire, normality, and disconnection by the above-described operation.

(Operation of voice alarm device)
The sound alarm device 50 performs a sound alarm according to the output of the output unit 15 of the fire receiver 10.
The input unit 51 monitors the fire output contact and the abnormal output contact of the output unit 15 of the fire receiver 10 by the fire input unit and the abnormal input unit, and detects the output when the output contact is closed.
The input unit 51 notifies the sound control unit 52 of the detection results of the fire output and the abnormal output.
When the voice control unit 52 receives the notification that there is a fire output from the input unit 51, the voice control unit 52 transmits the voice data of the fire alarm to the voice unit 53, and the voice unit 53 confirms that the fire has occurred. "To announce the occurrence of a fire by voice.

  When receiving the notification that there is an abnormal output from the input unit 51, the voice control unit 52 determines whether the notification of the abnormality continues for a predetermined time or whether the notification of the abnormality is received intermittently at a predetermined time period. When the voice control unit 52 determines that the abnormality notification continues for a predetermined time, the voice control unit 52 transmits the voice data of the disconnection alarm to the voice unit 53, and the voice unit 53 indicates that the disconnection has occurred. Please contact me. " In addition, when it is determined that the abnormality notification is intermittent at a predetermined time period, the voice control unit 52 transmits the voice data of the fire detector abnormality alarm to the voice unit 53, and the voice unit 53 performs “fire detection”. The performance of the detector has deteriorated. Please contact the maintenance company. "

  As described above, in the fire alarm system 1 according to the first embodiment, the fire detector 30 reduces the impedance of the detector line and increases the current corresponding to the abnormal current, thereby causing the voltage of the detector line 20 to be predetermined. By reducing the voltage only, the termination device is notified that the performance has deteriorated, and the termination device that has received the notification repeatedly disconnects and connects the termination resistor to the sensor line, so the existing P-type fire receiver 1 Even if it exists, the malfunction of the fire detector 30 can be notified.

(Embodiment 2)
In the first embodiment, whether or not the fire detector 30 has notified the abnormality depending on whether or not the terminating device 40 has the line voltage of the sensor line 20 equal to or lower than the fire detector abnormality threshold value 10 V, which is a fixed threshold value. An example of making the determination has been described. The termination device 40 of the first embodiment is effective when the voltage value of the power supply voltage converted by the line power supply unit 11 of the fire receiver 10 is the same value. However, the model of the fire receiver 10 having a conversion error and a different power supply voltage value for each individual may not be able to receive an abnormality notification of the fire detector 30.
Here, the fire receiver in which the power supply voltage is converted to any one of 10 to 14 V by an individual will be described. In an individual in which the power supply voltage is converted to 10V, the power supply voltage is divided into the line voltage and the reception voltage. Therefore, the line voltage is always below the fire detector abnormality threshold value 10V, and the terminating device 40 is always in an abnormal state. It is in a receiving state. Further, in the individual whose power supply voltage is converted to 14V, even if the line voltage is lowered by 3V in order for the fire detector 30 to notify the abnormality, the line voltage does not become 10V or less, and the terminating device 40 The abnormality of the sensor 30 cannot be received.

In the second embodiment, the operation of the termination device 40 that sets the fire detector abnormality threshold based on the line voltage of the detector line 20 at the time of start-up (initial time) will be described with reference to FIG.
In addition, about the structure of the fire alarm equipment 1, it is the same as that of Embodiment 1. FIG.
The operations other than the termination device 40 are the same as those in the first embodiment.

  When the sensor line 20 is energized and activated, the sensor abnormality receiving unit 41 controls the contact / separation unit 43 to connect the termination resistor 42 to the sensor line 20 (S421) and detect the line voltage. This is performed (S422). The sensor abnormality receiver 41 determines whether the fire detector abnormality threshold has been set (S423), and if not, determines whether the number of detections of the line voltage has reached a predetermined number (S424). . If it is determined that the predetermined number of times has not been reached in S424, the sensor abnormality receiving unit 41 returns to S422, and repeats S422 to S424 until the number of detections of the line voltage reaches the predetermined number. When the number of detections of the line voltage reaches a predetermined number, the detector abnormality receiving unit 41 sets a voltage value obtained by subtracting 2V, which is a predetermined voltage, from the average value of the line voltages detected a predetermined number of times as a fire detector abnormality threshold value. Set (S425). If the detector abnormality receiving unit 41 sets the fire detector abnormality threshold value in S425, it skips S424 and S425 in the determination of S423, and thereafter does not set the fire detector abnormality threshold value.

The sensor abnormality receiver 41 determines whether the line voltage is equal to or less than the fire detector abnormality threshold (S426). When the sensor abnormality receiving unit 41 determines that the threshold value is less than or equal to the threshold value, the sensor abnormality receiving unit 41 controls the contact / separation unit 43 to repeat disconnection and connection of the termination resistor 42 to the sensor line 20 at predetermined time intervals (for example, 3 seconds). Thereby, the termination resistor 40 notifies the fire receiver 10 that an abnormality has occurred in the fire detector 30 (S427). Thereafter, the process returns to S442 and the monitoring of the line voltage is repeated.
If the line voltage exceeds the fire detector abnormality threshold value in S426, the sensor abnormality receiving unit 41 determines whether or not it continues for a predetermined time (for example, 24 hours) (S428). When continuing, return to S421, connect the terminating resistor 42 to the sensor line 20, notify the fire receiver 10 that no abnormality has occurred in the fire sensor 30, and detect the line voltage again. repeat. When not continuing, it returns to S422 and the monitoring of the line voltage is repeated.

  As described above, the fire alarm system 1 according to the second embodiment sets the fire detector abnormality threshold based on the line voltage measured by the termination device 40 at the initial stage of operation when the power is turned on, for example. Even if the power supply voltage converted by the line power supply unit 11 is a different voltage value due to the individual difference of the receiver 10, the termination device 40 notifies the abnormality that the fire detector 20 reduces the detector line 20 by a predetermined voltage. Can be received. Therefore, even with the existing P-type fire receiver 10, the malfunction of the fire detector 30 can be notified.

(Embodiment 3)
In the first and second embodiments, the example in which the power supply voltage supplied to the sensor line 20 does not vary has been described. However, for example, when the battery is operated due to a power failure, the fire receiver is directly energized from the battery to the sensor line 20, so that the voltage gradually decreases and the sensor line 20 is energized. In some cases, the line voltage varies with time.
As described above, when the line voltage of the sensor line 20 varies with time, if the termination resistor 40 determines the line voltage of the fire sensor 20 with a fixed value of the fire detector abnormality threshold, the fire sensor 30. You may not be able to receive notification of abnormalities.

In the third embodiment, the operation of the termination device 40 that sets the fire detector abnormality threshold based on the line voltage of the detector line 20 every predetermined time will be described with reference to FIG.
In addition, about the structure of the fire alarm equipment 1, it is the same as that of Embodiment 1. FIG.
The operations other than the termination device 40 are the same as those in the first embodiment.

  The sensor abnormality receiving unit 41 controls the contact / separation unit 43 to connect the termination resistor 42 to the sensor line 20 (S441) and detect the line voltage (S442). The sensor abnormality receiver 41 calculates the average value of the line voltage for a predetermined number of times (S423). The sensor abnormality receiving unit 41 determines whether the difference between the calculated average value and the fire detector abnormality threshold is within a predetermined range (S444), and if it is within the predetermined range, subtracts 2V, which is a predetermined voltage, from the average value. The detected voltage value is reset as a fire detector abnormality (S445). If the difference exceeds the predetermined range in S444, the sensor abnormality receiving unit 41 has a high voltage on the sensor line 20 because the sensor line 20 is disconnected or the fire sensor 30 notifies a fire. It is determined that it has fluctuated, and the process proceeds to S446 without resetting the fire detector abnormality threshold.

The sensor abnormality receiver 41 determines whether the line voltage is equal to or less than the fire detector abnormality threshold (S446). When the sensor abnormality receiving unit 41 determines that the threshold value is less than or equal to the threshold value, the sensor abnormality receiving unit 41 controls the contact / separation unit 43 to repeat disconnection and connection of the termination resistor 42 to the sensor line 20 at predetermined time intervals (for example, 3 seconds). Thereby, the termination resistance 40 notifies the fire receiver 10 that an abnormality has occurred in the fire detector 30 (S447). Thereafter, the process returns to S442 and the monitoring of the line voltage is repeated.
When the line voltage exceeds the fire detector abnormality threshold value in S446, the sensor abnormality receiving unit 41 determines whether or not it continues for a predetermined time (for example, 24 hours) (S448). When continuing, return to S441, connect the terminating resistor 42 to the sensor line 20, notify the fire receiver 10 that no abnormality has occurred in the fire sensor 30, and detect the line voltage again. repeat. When not continuing, it returns to S442 and repeats monitoring of a line voltage.

  As described above, the fire alarm facility 1 according to the third embodiment is supplied to the detector line 20 in order to reset the fire detector abnormality threshold based on the line voltage at the predetermined time measured by the termination device 40. Even when the power supply voltage changes with time, the termination device 40 can receive notification of an abnormality that causes the fire detector 20 to lower the detector line 20 by a predetermined voltage. Therefore, even with the existing P-type fire receiver 10, the malfunction of the fire detector 30 can be notified.

DESCRIPTION OF SYMBOLS 10 Fire receiver, 11 Line power supply part, 12 Conversion part, 13 State determination part, 14 Alarm part, 15 Output part, 16 Battery, 20 Sensor line, 21 Common line, 22 Line line, 30 Fire detector, 31 Smoke Detection unit, 32 Fire determination unit, 33 Abnormality determination unit, 34 Indicator lamp, 35 Status output unit, 40 Termination device, 41 Sensor abnormality reception unit, 42 Termination resistance, 43 Contact / separation unit

Claims (3)

A sensor line connected to the fire receiver, and one or more fire detectors connected to the sensor line and reporting a fire by reducing the line voltage of the sensor line to a fire voltage. Fire alarm equipment,
The fire detector includes an abnormality determination unit that detects a decrease in the performance of the fire detector, and when the abnormality determination unit detects a decrease in the performance of the fire detector, the line voltage of the sensor line is decreased by an abnormal voltage. With a status output unit that notifies performance degradation,
The sensor line is connected to a terminating device for disconnecting the sensor line,
The termination device determines that the line voltage has decreased by an abnormal voltage when the line voltage is equal to or lower than a fire detector abnormality threshold, and disconnects the sensor line. .   2. The fire alarm system according to claim 1, wherein the termination device sets a fire detector abnormality threshold based on the line voltage at the time of startup. The fire alarm system according to claim 1, wherein the termination device sets a fire detector abnormality threshold based on a predetermined number of line voltages.

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