What are some things you heard people believe about fire alarms that aren’t actually true?
When the fire alarm system activates, the sprinklers go off.
When one sprinkler is tripped, they all are.
Actually, in a dry deluge system, every sprinkler will activate if an ID in a zone is activated. These are typically used in places dealing with hazardous materials or situations, such as chemical facilities, aircraft hangars and other industrial hazards.
My godmother when I had my alarms at her old house was convinced they’d go off on their own if they “detected” smoke of any kind. I had to prove to her they wouldn’t by blowing cigar smoke directly at my P241575 than explained to her just how they worked (and that it wasn’t a smoke detector).
I always though only one went off cause there’s a meltable cap that when it melts opens the thing for the water at that one sprinkler.
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That’s true for “regular” sprinklers, like the ones in hotel rooms.
I loaded some basic sprinkler system information. It defines four typical scenarios of sprinkler operation.
Link: Basic Types of Sprinkler Systems
Yeah, I know there are some sprinkler systems that activate if the fire alarm sounds, but it’s a common belief that all sprinkler systems including those in offices, hotels, schools and stores will activate when the fire alarm does. Movies often show the fire alarm system activating the sprinklers which encourages people to believe this.
Fire alarm NAs detect smoke.
Sprinklers detect smoke.
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This is an interesting myth I’ve heard, I remember that I shared my input on this on this particular subject before that topic was lost, so I’ll share it again.
I used to believe this particular myth when I was much younger, mostly with ceiling mount devices. Interestingly enough, I mistook the candela indicator on a Gentex Commander 4 mounted on a ceiling as some kind of photocell for detecting smoke. Since then, I have learned more and more about notification appliances, and that they cannot detect smoke…and that the candela selection indicator is not a photocell.
If a Stopper has been lifted and it starts squealing, the fire alarm has been set off.
YouTube has examples of how ignorant people can get. Luckily, most of the time it prevents the malicious activations.
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My 7-8th grade history teacher told us the ceiling mount simplex strobes had security cameras in them
When I was in grade school, I heard people say that shining a light at a N/A will set off the system.
Well I have shined a 1000MW laser into a TrueAlarm detector before and it actually activated.
(Please don’t go trying this on a public system, this was on a friends test bench system that was set off in a closed enviroment. Theres a 99.9 Percent Chance your gonna look like an crazy obsessed idiot, theres also probably a chance of homeland security being called on you for pointing lasers at things. Oh and i’m pretty sure its a felony to falsely activate a fire alarm system. So 100% illegal. Be Smart. :P)
I mean its an 1000MW laser so it might have gotten to the photoelectric chamber. Granted my friends detectors were also REALLY dusty so that also could have been a random false alarm.
I wouldn’t be surprised if you cooked the freakin thing. :lol:
Shining bright lights into certain alarm panels can cause them to activate. This is a particular concern when taking pictures of the interiors of operating panels. One of my panels, my Ansul AutoPulse 2000, has a documented history of this happening. Check out this article from 1997: Information Notice No. 97-82: Inadvertent Control Room Halon Actuation due to a Camera Flash | NRC.gov
Fire alarm NAs are touch sensitive, and you can set off the system by touching them.
I remember when an elementary school teach told us that the fire alarm NA in the classroom was also a camera trying to scare us into thinking we were being recorded.
i believe it. in telecom CO’s we often don’t put in strobes because the equipment can be photosensitive, especially in some of the older CO’s.
Touching an NA will set off the system.
An NA getting hit by something such as a ball will cause it to go off.
Stoppers are NAs.