false alarm

Alarm System Troubleshooting–Part 3 Detector

Alarm System is a security system consists of 3 parts alarm units. They are detectors, alarm control panel and CMS. We will share our working experience of alarm system troubleshooting categorized into 3 articles according to these 3 parts.
1.Perimeter Beams Detector
a. Alarm Control Panel does not alarm after connection of perimeter beams detector and trigger or alarm control panel can not be armed cause of the perimeter beams detector zone fault.
Possible causes: There is block between transmitter and receiver beams, connection error between beams detector and alarm control panel. The tamp-resistant switch is not closed or there is short-circuit or cut of the wiring, low voltage supplied. The perimeter beams detector zone is not programmed or not correctly programmed.
Solutions: Correctly enroll wireless perimeter beams detector or wire wired perimeter beams detector to the alarm control panel with EOL resistor. Check and confirm there is no short-circuit or cut of wiring and confirm the supplied voltage is more than 9V. Check and confirm the transceiver terminal is calibrated to receiver terminal and check the LED indicator to confirm it is at normal work status. Correctly program the zone attribute of the perimeter beams detector.
b. At installation and adjustment process, the beams detector keeps triggering alarm at alarm control panel disarm status and can not disarm it.
Possible causes: The wired perimeter beams detector circuit is at open status and the defense zone is set as 24 hours zone.
Solution: Check the connection of wired beams detector and alarm control panel and confirm it is close circuit with correct EOL resistor wired. Set beams detector zone attribute as normal zone if it is needed.
c. The LED calibration instruction is flashing or keeps lighting on
Possible causes: Receiver terminal and transmitter terminal is not calibrated correctly, the distance between receiver terminal and transmitter terminal is too long, there is block between receiver terminal and transmitter terminal, low voltage is supplied or tamper-resistant circuit is not closed.
Solution: Correctly wiring the signal and power lines between receiver terminal and alarm control panel, check and confirm the tamper circuit is closed. Adjust the receiver terminal and transmitter terminal angle to make sure it is calibrated. Ensure supplied voltage is more than 9V to the beams detector.
d. False alarm from perimeter beams detector
Possible causes: Voltage fluctuation is too large. Environment interference. There is water input and short-circuit caused of the detector or fault of the detector.
Solutions: Check and confirm the supplied voltage is more than 9V. Check and confirm the wiring is good. Replace the false alarm beams with good beams to confirm whether or not the beams is wrong.

false alarm2. Detector ( wired detector and wireless detector)
a. The detector does not alarm after connection to alarm control panel and triggered or the detector zone has fault and disables arm of the system.

Possible causes: The detector is not correctly connected to alarm control panel, the tamper circuit is not closed, there is short-circuit or cut of the wiring or low voltage is supplied. The detector zone attribute is not programmed correctly or not programmed.
Solution: Correctly wiring detector and alarm control panel (correct value of EOL resistor should be wired according to the alarm control panel). Check and confirm there is no short-circuit or cut of the wiring. Check and confirm the supplied voltage is more than 9V. Check and confirm the alarm indicator on the detector is off then wiring the tamper circuit closed. Correctly program the detector alarm zone.
b. At installation and adjustment process, the detector keeps alarm at alarm control panel disarm status and can not be disarmed.
Possible causes: The detector circuit is open and the alarm zone is set as 24 hours zone.

Solutions: Check and correct the wiring of the detector and alarm control panel. Set the alarm zones attribute as normal zone.
c. False alarm of the detector

Possible causes: There is environment interference such as sun light, flowing air and the detector sensitivity is set as high rate.
Solution: Install the detector correctly at proper place according to detector’s installation instruction. Adjust the sensitivity according to environment interference. Check the detector voltage. Replace another detector to test and if it still makes false alarm, then install a MW+PIR double technology or so for interference resistance.
d. Detector alarm LED keeps flashing and the alarm control panel showed fault of the detector

Possible cause: The detector battery voltage is low
Solution: Replace the battery for the detector

3. Wireless door contact makes false alarm
Possible cause: the the installing distance between the magnetic strip and alarm transmitter is too large.
Solution: Check the distance of magnetic strip and alarm transmitter and adjust it to meet requirement of door contact installation.

About the Author

Chinaalarms

Technical support for alarm systems. Help buyer to buying suitable China alarms system and provide China alarm system information, technology advantage. I work as export sales of Vedard China alarms system for home security and business security. Our company cooperate with security service, alarm installer, security engineer. Provide free security solution for hotel security, restaurant security, fire safety solution conventional fire panel and addressable fire panel system with wireless fire alarm system.

1 thought on “Alarm System Troubleshooting–Part 3 Detector

    • Author gravatar

      The systems are designed to detect and analyse incoming electronic signals received from the sensor cable, and then to generate alarms from signals which exceed preset conditions. The systems have adjustable electronics to permit installers to change the sensitivity of the alarm detectors to the suit specific environmental conditions. The tuning of the system is usually accomplished during commissioning of the detection devices.

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