Fire Alarm strobes

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smallfish

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I am inspecting an installation of a new fire alarm control panel and replacement smoke detectors only in a 8 story hi-rise. The strobes in the hallway were not in synch during test. Since these strobes were not altered by the contractor, does the contractor now have to put them in synch or can they be approved as is? The contractor states that the strobes cannot be modified but must be replaced at a prohibitive cost.
Thanks
 
Is there some sort of synch setting on the new panel?
Was there such a setting on the old panel?
He may be able to fix it at a central point rather than at each strobe.
Are the strobes listed for use with the new panel?
Did he mix two types?
Was it working before?

Non-synched strobes can induce seizures and at a minimum disorientation. That can complicate evacuation.

Sounds like a violation and a hazard.

http://forums.mikeholt.com/showthread.php?t=139915
 
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Don't know how such inspections go in your jurisdiction, but here we would involve the fire chief or fire marshal.

Also this comes under NFPA72 and maybe local fire and building codes. NEC is mostly silent on "performance" of fire alarm systems.
 
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Very old horn strobes, going back to the 80's or so, may very well be un-syncable. They may also have incandescent lamps, not modern strobes. We had to design a system where the owner was made aware of that unfortunate fact. However, unless there are more than two (2) visual devices in the field of view, NFPA 72 does not require they be synced. As long as the corridor is less than 20' wide, you can cover 100' with two units. As for prohibitive cost, you can get a standard System Sensor wall-mount P2R from your local ADI for about $35. Labor and markup is extra, of course, but you shouldn't take more than 5 minutes to replace a unit, not counting picking up the devices, staging them, and clean up.
 
For a longer hallway could you shield the end strobes so that they could not be seen from the other end? Or does their light bounced off the walls count as being in the field of view?

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GoldDigger said:
For a longer hallway could you shield the end strobes so that they could not be seen from the other end? Or does their light bounced off the walls count as being in the field of view?

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Supposing you had a corridor 10' wide and 100' long, with the wall mount horn/strobes facing each other at the ends of the corridor. From either end, how would you make that strobe visible 49' from the end of the corridor and invisible 51' from the same end? I'm speculating, but the smooth transition from one strobe to the other as you move along the corridor is likely part of the consideration for allowing this sort of arrangement. And a third device, now you have to sync them.
 
I was thinking more of having two strobes at the 50 and 150 foot marks facing the nearest end of the corridor and one at the 100 foot mark facing in both directions. That way from any point in the hallway you would have a direct view of at most two strobes.

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Not sure how old the original system was but, as has been mentioned, if the system is ancient the strobes may not be able to be sinc'd. If the contractor was not required (by printed specifications) to change them out I can't see how he would be held accountable to do so. BTW, just for common knowledge and for those who may not know, the induced medical condition is referred to as "photosensitive epilepsy" or PSE. This is an partial excerpt from the Wikipedia definition :
People with PSE experience epileptiform seizures upon exposure to certain visual stimuli..........Flashing lights or rapidly changing or alternating images (as in clubs, around emergency vehicles, in action movies or television programs, etc.) are examples of patterns in time that can trigger seizures, and these are the most common triggers.
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I believe this (and other tweeks to fire alarm installations like lowering the height of manual pull stations) became an issue with the advent of the Federal ADA Act.
 
smallfish said:
I am inspecting an installation of a new fire alarm control panel and replacement smoke detectors only in a 8 story hi-rise. The strobes in the hallway were not in synch during test. Since these strobes were not altered by the contractor, does the contractor now have to put them in synch or can they be approved as is? The contractor states that the strobes cannot be modified but must be replaced at a prohibitive cost.
Thanks
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You say new FACP and replacement smokes. The smokes have finite lifespan; changing them is maintenance. Why was a new FACP installed? That may answer your question.

If this was a change in occupancy classification, I'd say replace the strobes. If not and that FACP was replacement due to old age, that too is maintenance and those strobes can remain, in my opinion, which means nothing.

The safest route is to have the AHJ answer the question, preferably in writing for your file. Maybe you can e-mail the fire marshal.
 
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