Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Smoke damper power

  1. #1
    Join Date
    Jan 2009
    Location
    Massachusetts, New Hampshire border
    Posts
    1,589

    Smoke damper power

    I was wondering what would be the best idea.

    We were asked to add shutdowns via the FACP to smoke dampers to be installed. I get there and the Tin Knockers are about to slam them in the very tight drop ceiling, plenum space. They are 24 VAC 16 VA each, two of them. Spaced 150 feet apart. No one planned on the power for the dampers.

    Now I have to power them as well, becuase everyone thought they are powered off the FACP. I don't believe there is a UL fire 24 VAC power supply available. This is a Healthcare facilty and HVAC is on the EM gen set. So, we need to keep the dampers powered in the event of a power loss to keep them open, obviously.

    So my thought is find the closest EM circuit and put in a open frame 120>24 transformer close to the dampers and run the power through addressable relays to open on alarm.

    My question:

    Is it permissible to install an open frame xmfr above a drop ceiling in a plenum space in an HCF (what if its in an enclosure)?

    Would adding said xmfr it to a HCF EM light circuit be permissible?(the current draw would be minimal)

    I don't deal a lot with HCF power and lighting so I wanted to ask.

    This is the first idea I came up with, and everyone is open to suggestions.
    Last edited by nhfire77; 08-11-10 at 09:44 AM.

  2. #2
    Join Date
    Sep 2010
    Location
    New Orleans, LA
    Posts
    46
    Unfortunately, I am unable to cite specific codes or regulations for my proposed solution; only the experience gained in a very large installation in a very strict region in Florida.

    In a somewhat similar installation, we ran dedicated circuits from an EM powered panel (with breakers tagged, locked and painted, similar to the power source for the multiple FACP's) to appropriately labeled ceiling mounted transformers within enclosures. We then branched from these transformers to the fire/smoke dampers through a fire alarm relay, addressed to the appropriate ventilation area. Each branch was protected through a fusible terminal within the same enclosure that housed the transformer.

    Such an installation may seem a bit extreme with only two dampers in question, but proved both functionally and cost effective in our installation.

    Again, I can't aver code compliance, but highly doubt that tapping off locally available EM circuits would be acceptable to any knowledgeable fire marshal or other inspector.

  3. #3
    Join Date
    Oct 2007
    Location
    New Jersey
    Posts
    1,544

    FACP Aux Power?

    With only two dampers @ 16VA, your fire alarm control panel probably has enough power to make 'em go, unless you've maxed it out for other purposes. Depending on the make/model, there must be three or four ways to do this.

  4. #4
    Join Date
    Aug 2007
    Posts
    2,754
    I don't see a problem with powering them from EM, but I find the location of the transformers could be a problem, and I would think that the power should be supervised. You might want to consult the FA system designer for their recommendation. (seems like you could add a local nac panel to power them)

  5. #5
    Join Date
    Jul 2006
    Location
    San Francisco bay area
    Posts
    259
    Quote Originally Posted by gadfly56 View Post
    With only two dampers @ 16VA, your fire alarm control panel probably has enough power to make 'em go, unless you've maxed it out for other purposes. Depending on the make/model, there must be three or four ways to do this.
    While the circuit feeding the FACP probably has enough power to do this, said circuit is dedicated. Dampers are auxiliary and need to be powered from a different circuit.

    Quote Originally Posted by nakulak View Post
    I don't see a problem with powering them from EM, but I find the location of the transformers could be a problem, and I would think that the power should be supervised. You might want to consult the FA system designer for their recommendation. (seems like you could add a local nac panel to power them)
    Dampers are 24 Volts AC, I don't think a NAC panel will help here. In my locale, (not sure about yours) supervision of damper power is not required. Transformer manufacturers should be able to tell you if their products are rated for use within plenum space.

    I like Zinskl/E's approach, but some time has passed since the original post. What did you do?
    Last edited by MichaelGP3; 09-03-10 at 11:27 PM.
    In battle, in forest, at the precipice in the mountains,
    On the dark great sea, in the midst of javelins and arrows,
    In sleep, in confusion, in the depths of shame,
    The good deeds a man has done before defend him.
    --Bhagavad-Gita

  6. #6
    Join Date
    Jan 2009
    Location
    Massachusetts, New Hampshire border
    Posts
    1,589
    We tapped off an EM lighting circuit. Nothing prohibits this. Nothing requires the power to be supervised either, as the smoke damper fails safe. However, after explaining to the Fire Marshall and Property manager that the dampers would close if for some reason power was lost and there would be no way to tell. We added a system sensor PR-1 relay SPST. We then tied this into the AC power and wired it to monitor module. So if they lose power the relay would open the monitor module circuit so a supervisory signal is generated.

    As stated its 24 VAC, not 24 VDC, so that was the challenge.

  7. #7
    Join Date
    Feb 2003
    Location
    Massachusetts
    Posts
    48,197
    Quote Originally Posted by nhfire77 View Post
    We added a system sensor PR-1 relay SPST. We then tied this into the AC power and wired it to monitor module. So if they lose power the relay would open the monitor module circuit so a supervisory signal is generated.
    Is it even allowable to add miscellaneous supervisory circuits to a fire alarm system?

    What if a restaurant own asked to add a temp monitor to all his coolers that would cause a FACP supervisory signal?


    My point is there is no safety issue in the smoke dampers being closed, if they want them monitored for postion they should do it independently of the FA system.

  8. #8
    Join Date
    Jan 2009
    Location
    Massachusetts, New Hampshire border
    Posts
    1,589
    Quote Originally Posted by iwire View Post
    Is it even allowable to add miscellaneous supervisory circuits to a fire alarm system?

    What if a restaurant own asked to add a temp monitor to all his coolers that would cause a FACP supervisory signal?


    My point is there is no safety issue in the smoke dampers being closed, if they want them monitored for postion they should do it independently of the FA system.
    Well, you might say, you got a code reference for that? ( I would quote one if I was at work, but it's hide from the hurricane labor day week end)

    The reason being it's a nursing home/ assisted living facility. If the dampers close it will take hours if not days for the facilities guys to figure out why there is no heat/cooling ( if not saying they are dumb... I'm just implying it)

    Because the smoke dampers are directly controlled by the fire alarm, there is no conflict of interests between the two systems. In fact, most smoke control panels in high rise buildings supervise power. Now, I realize the smoke control system is technically an independent system in that case. In my situation there is not seperate smoke control system.

    In the case of the temp sensor, I don't think its a great idea, but it's permissible as long as all the fire alarms troubles and supervisories take priority of the non fire conditions.

    It's done a lot. Again, since this is directly related to fire/life safety, I see no reason not to.

    In fact I've seen temp sensors for sprinkler and pump rooms. Would you argue that they should be monitored by a non FACP? I'm ok with that. The better you can document the series of events, for the pending investigation from frozen pipes, or a fire the better.

    A position sensor, showing the state of the dampers would be optimal, such as in the case of a smoke control system. However, it was not required in this building. Additionally, these dampers were added after a engineer noticed there were no dampers in this spot. So it's an add after the facility renovation 18 months ago.

  9. #9
    Join Date
    Jul 2006
    Location
    San Francisco bay area
    Posts
    259
    Here is a loaded question... How many relays did you use?
    In battle, in forest, at the precipice in the mountains,
    On the dark great sea, in the midst of javelins and arrows,
    In sleep, in confusion, in the depths of shame,
    The good deeds a man has done before defend him.
    --Bhagavad-Gita

  10. #10
    Join Date
    Feb 2003
    Location
    Massachusetts
    Posts
    48,197
    Quote Originally Posted by nhfire77 View Post
    The reason being it's a nursing home/ assisted living facility. If the dampers close it will take hours if not days for the facilities guys to figure out why there is no heat/cooling ( if not saying they are dumb... I'm just implying it)

    Because the smoke dampers are directly controlled by the fire alarm, there is no conflict of interests between the two systems.
    There is no fire safety reason to add montitring into the FA system.

    Again it could be montitored by other means if they feel it is needed.




    In fact, most smoke control panels in high rise buildings supervise power.
    That is a different situation entirely, in that case the power to open and close the dampers is a direct requirement of the system.

    In the case of the temp sensor, I don't think its a great idea, but it's permissible as long as all the fire alarms troubles and supervisories take priority of the non fire conditions.
    I find that highly unlikely.

    It's done a lot. Again, since this is directly related to fire/life safety, I see no reason not to.
    No it is not, the dampers being closed when not required to be is no concern of the fire depts.

    Do you also monitor unpowered fire dampers for position to ensure they are not effecting HVAC needs?

    Should we supervise power for optional mag door holders?


    In fact I've seen temp sensors for sprinkler and pump rooms. Would you argue that they should be monitored by a non FACP?
    In that case preventing the sprinkler pipes from freezing is a direct need for life and property safety.

    A position sensor, showing the state of the dampers would be optimal,
    Yes, one that reports to the HVAC controls.


    Hey, whatever the FD wants, just asking some questions.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •