I have a customer who has a Firelite MS-9600 FIRE PANEL that operates normally for 99.99% of the time. Two or three times a day it will go into trouble for 2 seconds and restore itself. Due to the unpredictable nature of the trouble and its short duration this has been a troubleshooting nightmare. I have changed out many of the components to no avail.
I feel like it is some sort of environmental disturbance causing this but have been unable to track it down using traditional troubleshooting techniques.Normally for this kind of unidentifiable trouble I would just disconnect the SLC in the middle and go from there. However due to the unpredictable nature of the problem and its seeming randomness i would have to leave it disconnected for up to a day or so just to decide what direction to go in. Given that this is an occupied 4 story apartment building I feel that the Fire Marshal would take a dim view of this troubleshooting technique.
Anybody had to chase a gremlin like this and if so what helped you find the problem. FireLite technical support is as baffled as I am and can give me no real help. I’m afraid my next step is going to be a medium because I am beginning to think this place was built on an ancient Indian burial ground.
You may already be well beyond this, but have you attempted to use the panel History Log to view the source of the trouble? If everything is working properly, every instance of the fault should be listed in the history buffer as well as a corresponding clear trouble message.
Random troubles seem to most commonly be caused by intermittent ground faults. Please take this this only as a suggestion, as there is obviously many more factors that could play a part in this issue.
Yes. The trouble usually manifests itself as an invalid reply on either a detector or a module. I have roughly 30 modules and about 70 detectors. I’ve got the SLC protocol set to clip so it only polls one device at a time. There will occasionally be an SLC short for the trouble but it is exceedingly rare. I was thinking it might be a ground fault but that has never once been registered as a trouble according to the history.
My theory is that there is some kind of electromagnetic interference such as a bad ballast or other mismatched ballast/lamp combo that starts up and interferes with the signal briefly before normalizing. The SLC circuit is unshielded wire so it could be susceptible to that sort of interference in the right frequency range. The darn thing just won’t stay in trouble long enough to find. It’s starting to make my hair turn grey!
Again, the ONLY thing consistent about it is that it lasts 2 seconds every time. On the last inspection the Fire Marshal made the electrical contractor add a bunch of additional exit signs in the elevator lobbies, some of which he put very close to our recall detectors so I thought those may have had some battery charger issues which caused the interference but I have removed some of the signs and the problem still persists.
break the circuit, run temporary wire to the second half and bring it back to a second SLC. removing lengths of the circuit is probably the easiest way to track it down at this point.
Are there any AHU’s turning on/off? I ask because years ago I worked on a system that would false alarm randomly, but always the same device (a pull station). We replaced the device several times but it kept alarming. We finally had to have a tech sit there and watch the panel one day to try to catch it go into alarm.
Turns out one of the air handlers had a bad motor which would somehow cause alot of noise on the data loop feeding the device. The conduit for the data & power feed was in separate conduit but the distance between the two pipes was only a few inches. The AC tech turned the fan on & off a few times and every time it would alarm.