Does it matter if the smoke detector's four-wire (power and signal wires) touched?
Posted: Tue Dec 15, 2020 2:25 pm
Question:
The four wires of GND, NO NC 12V touched each other when they were disassembled, and the display light did not turn on after they were connected. What is wrong?
Answer:
1. This should be a security linkage smoke detector with alarm output.
2. The 12V and GND marked by the detector are the power lines of the detector as well as the signal lines, and the working voltage is DC12V (the working power range is usually 9~28V).NO and NC are the output contacts of the detector relay and it actives when the detector alarms. Generally it can be set to normally open or normally closed.
3. If the output contact of relay is used, it can be used as the automatic switch of other circuits with different voltages, generally DC24V. If the contact relay output circuit is not disconnected and the 4 wires touches, it is possible to damage the detector circuit (if the power line is not untied), even if the power line is untied, it is possible to break the electronic component of the detector.
4. If the output contact of the relay is not in use, the detector will not be affected if the power line is only touched and not short-circuited.
5. The indicator light of the detector flashes under normal conditions. After the alarm of the detector, the indicator light is always on; after the alarm is lifted, the indicator light returns to normal.
6. Fault detection: If the output contact of the relay is connected to the DC24V circuit, the power circuit is most likely to fail, and the detector is relatively less likely to be damaged.Therefore, first check whether other detectors in the detector circuit are normal. If other detector indicator lights are not on, the detector power circuit may fail. Check whether the short-circuit isolator or the host's insurance is normal and whether the power cord is broken.If the power circuit is normal, check for damage to other detectors;If the other detector indicator light is normal, change the normal detector to access the disassembly detector position to determine whether the disassembled detector is damaged.
7. To remove the detector, NO and NC loop should be removed firstly, and then the power line should be removed.
The four wires of GND, NO NC 12V touched each other when they were disassembled, and the display light did not turn on after they were connected. What is wrong?
Answer:
1. This should be a security linkage smoke detector with alarm output.
2. The 12V and GND marked by the detector are the power lines of the detector as well as the signal lines, and the working voltage is DC12V (the working power range is usually 9~28V).NO and NC are the output contacts of the detector relay and it actives when the detector alarms. Generally it can be set to normally open or normally closed.
3. If the output contact of relay is used, it can be used as the automatic switch of other circuits with different voltages, generally DC24V. If the contact relay output circuit is not disconnected and the 4 wires touches, it is possible to damage the detector circuit (if the power line is not untied), even if the power line is untied, it is possible to break the electronic component of the detector.
4. If the output contact of the relay is not in use, the detector will not be affected if the power line is only touched and not short-circuited.
5. The indicator light of the detector flashes under normal conditions. After the alarm of the detector, the indicator light is always on; after the alarm is lifted, the indicator light returns to normal.
6. Fault detection: If the output contact of the relay is connected to the DC24V circuit, the power circuit is most likely to fail, and the detector is relatively less likely to be damaged.Therefore, first check whether other detectors in the detector circuit are normal. If other detector indicator lights are not on, the detector power circuit may fail. Check whether the short-circuit isolator or the host's insurance is normal and whether the power cord is broken.If the power circuit is normal, check for damage to other detectors;If the other detector indicator light is normal, change the normal detector to access the disassembly detector position to determine whether the disassembled detector is damaged.
7. To remove the detector, NO and NC loop should be removed firstly, and then the power line should be removed.