When does code require that Magnetic door holders be installed and tied to the fire alarm system? Some designers tie the older 120 volt smokes to release doors but according to code the constant power sourse should be supervised and the backup sourse should also be supervised making this method the least prudent design. Can the 120 Volt detectors that are not part of the fire system still be used do release doors?
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When does code require magnetic door holders? 1
- Thread starter LGENE
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I don't see why the power would have to be monitored, or require alternate supply, so long as it was the same power source feeding both the detector and the hold-open. If power dies, then the doors close. You don't get much more fail safe than that.
I don't believe that you are required to monitor the smoke detectors for door holdopens at the FACP. But I could be wrong.
Anyway, regardless of my above statements, if you have an FACP, and you have smoke detectors, I don't see any good reason not to hook them together, you won't be saving THAT much money by keeping them isolated.
How's that for a speedy response, only took 2 months!
I don't believe that you are required to monitor the smoke detectors for door holdopens at the FACP. But I could be wrong.
Anyway, regardless of my above statements, if you have an FACP, and you have smoke detectors, I don't see any good reason not to hook them together, you won't be saving THAT much money by keeping them isolated.
How's that for a speedy response, only took 2 months!
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- Thread starter
- #4
From what we have learned, if you use 120 volt smokes tied to the door closers they need to have a battery backup and they need to be recharged. Yes you are right if you have a fire panel it makes much more sense to tie 24 volt detectors to the panel. Your right about the same power source but offtimes we have electrical contractors that install 120 volt mag holders and sometimes it is not on the same power sourse as the smokes. We are trying to set that issue straight whenever we come upon it. Thanks for your comments.
- Thread starter
- #6
Sorry if I was misunderstood, you are correct that the door holders need not be supervised and they do not need to be on the same power source although if they are tied to the FACP directly then they close on alarm. What I meant, is that electrical contractors will power door holders separately and tie a 120 volt relay to the smokes which is ok but with the new techology on the current fire panels those relays are built into the panel and there is no reason to install a bunch of relays in the field if UL listed ones are built into the panel. This would also allow the door holders to close on other alarms such as pull station alarms or duct detectors, whereas a 120 v relay tied to smokes just at the door would not. Thank you for your answers.
OK.
Your last statement is true.
Except the technology you describe is 12-14 years old in the USA. In fact you can also program the relays in the bases of the 'addressable' smoke detectors and in addressable control moudles to change state upon any signal or event on the system just as the programmable relays in the FACP. The relays in the FACP are more reliable, imho.
Addressble or intelligent control modules hook up same as a smoke detector on initiaiton circuit. Some may require aux. power, most do not.
Your last statement is true.
Except the technology you describe is 12-14 years old in the USA. In fact you can also program the relays in the bases of the 'addressable' smoke detectors and in addressable control moudles to change state upon any signal or event on the system just as the programmable relays in the FACP. The relays in the FACP are more reliable, imho.
Addressble or intelligent control modules hook up same as a smoke detector on initiaiton circuit. Some may require aux. power, most do not.
- Thread starter
- #8
FireRanger
Electrical
Actually its not approprate to tie into the "cheesy" 120VAC smoke detectors with door holders. Commercial buildings with 120VAC detectors do not meet any NFPA or International codes. Why this wants to be done I would seriously question.
- Thread starter
- #10
Your right it is not appropriate and they are "Cheesy" but they are UL listed for door release and under NFPA 72 (2002) 5.14.6 it addresses this and the exception under 6.15.6.2 is an interesting piece of information. I would rather stay away from them completely and use the system detectors. They do this to save money but they complicate things when they do so and we need to move forward with technology instead of backwards. Thank you for your comments.
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