I am using a 4100ES FACP in a large building in Korea. The problem is that both the 4098-9714 smoke detector and the isolated detector are continuously generating fire alarm signals.
At first, I thought that the fire alarm signals were being triggered by dust on the sensors, so I cleaned them, but after some time, the fire alarm signals reoccurred.
After that, I replaced the hardware for both the smoke detector and the isolated detector with new ones, yet the fire alarm signals reappeared again after a while.
When I check the TRUESITE WORKSTATION program, both the PEAK and CURRENT VALUE show 255. (*In past records, the fire alarm signals usually showed values below 120.)
Therefore, I thought it might be a wiring issue, but I have a question. Both the isolated detector and the smoke detector are connected to the M3 IDNET CARD, and a heat detector is installed in between them.
If it were a wiring problem, why wouldn’t the heat detector be affected? What actions can I take?
Additional Information:
The IN/OUT of the IDNet card on the 4100ES panel was tested with a tester, and the voltage was the same as that of the other cards. Interestingly, most of the fire alarm signals occur during the early morning or morning hours.
The maximum alarm value for those particular TrueAlarm sensors is 255 (and the maximum the detector can automatically raise its alarm level to when it’s dirty).
I wonder if you have a batch of bad detectors or bases. I would cross-check your point status at the FACP as well - pull up the point info and press More Info until you see detector values for CURRENT, PEAK, etc., just to ensure data is properly reported to the TSW.
To answer your question regarding the difference between heat & smoke detectors, the data is reported back to the FACP in a different way for each type of sensor - the heat detector is fundamentally different in the way it operates, and is not susceptible to dirt/dust causing false alarms (since there is no photoelectric eye/sensor, only a heat sensing element).
Thank you for your answer.
I also suspected a faulty unit, so I had already replaced the device with a new one. Both the base and the head were replaced, yet the symptoms remained the same.
I believe that the location where the isolate is installed may be prone to false fire signals due to high winds, but that is not the case for where detector #15 is installed.
There are two reasons why I think this:
There is a smoke detector (#16) installed near the location of detector #15. If dust were triggering the fire signal, detector #16 should also be activating.
The isolate and detector #15 are triggering fire signals simultaneously (intermittently). The two detectors are approximately 10–15 meters apart in a straight line. Given that they are in different areas of the building, it is unlikely that dust is causing simultaneous false alarms.
Both the peak and current readings show 255.
For now, I have deactivated the isolate detector to test whether detector #15 will still trigger a fire signal.
I suspect that the isolate might be the main trigger for all these issues, but I am not entirely sure. As you mentioned, I will also test with the isolate properly shielded to minimize dust.
I have identified the cause.
The issue was caused by an abnormal signal due to terminal contamination of the 42:M3-16 detector.
After replacing the detector, the fire alarm no longer sounds.
