Firedoor - auto closer - circuit breaker?

Discussion in 'The Projects Forum' started by Matty1973, Dec 1, 2011.

  1. Matty1973

    Thread Starter New Member

    Dec 1, 2011
    10
    0
    I have a firedoor on my property that is always being jammed open and hence no use as a firedoor.

    I wish to design something that allows people to leave the door open for a while but then automatically close it after say 15mins.

    I was thinking of using an always on electro magnetic door holder - then cut of the power briefly to allow the door to close naturally under the spring mechanism it already had installed.

    So I have ordered these two items:

    http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=120791910232#ht_500wt_1287

    http://www.ebay.co.uk/itm/220759492048?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

    But as it is I think the door will remain open all the time except when someone presses the red button.

    How can I make it close after say 15mins (or just every 15mins - doesn't have start the time when the door is opened - just close it regularly as a safety precaution)
     
  2. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    What is the purpose of the firedoor? I 'm not sure I understand its usefulness as opposed to a normal door?
     
  3. Matty1973

    Thread Starter New Member

    Dec 1, 2011
    10
    0
    It is in a rental property between the kitchen and the hallway. The local authority insisted I install a heavy firedoor that closes automatically with a heavy spring.

    This is very inconvenient for the tenants (although indeed beneficial in case of a fire). The fire safety officer says it is not acceptable that the door is left open by a wedge but that is inevitably what happens when people want to carry hot food/drink from the kitchen. Then they don't bother unwedging it and the door gets left open over night.

    So I want a system that is easy for them to open the door for a while when needed (electro magnet?) but will close on its own after not too long.
     
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    A fire door like that SHOULD be used with a electro-magnetic catch that releases when the fire alarm sounds. It should be installed that way and if it were..problem solved.
    A tenant can always just give a good pull and close it if they want then push it back open and it will stay open..because the magnetic catch remains energized until the fire alarm goes off.

    Why close it every 15 minutes.. That's just annoying.
     
  5. Matty1973

    Thread Starter New Member

    Dec 1, 2011
    10
    0
    The problem is when the tenants are carrying hot food and drinks they don't have a spare hand to close the door after them - so it doesn't get closed and then the door is of no benefit.

    The fire safety officer wants it closed all the time except when people are going through it. It's catch 22.

    I don't think it would be annoying because it would only get closed automatically if it is open. If it is already closed then cutting the power to the electro magnet won't make any difference since it is closed already.

    So what I think I need is a way to momentarily interrupt a 24v power supply roughly every 15 minutes, just to makes sure the door is closed most of the time and keep the fire safety officer happy.
     
  6. Georacer

    Moderator

    Nov 25, 2009
    5,142
    1,266
    I like mcgyvr's option better. Keep it open constantly, until either the fire alarm is off, or someone pulls it. The question is, is it possible for the magnet to be strong enough to oppose the spring but feeble enough for someone to separate it from the door?
     
  7. strantor

    AAC Fanatic!

    Oct 3, 2010
    4,302
    1,988
    In my experience, inspectors are like god; what they say has to be followed, whether they are right or wrong. There's no system to keep them in check. if the inspector says it has to be closed unless someone is walking through it, then thats how it has to be, regardless of whether regulation agrees with him or not. I think installing anything, whether it's your 15 min auto-closer or mcgyver's always-opener, it's going against what the inspector said so it doesn't cut it. You could always ask the inspector if this or that would be ok, but if he says no, thats it. maybe hire a doorman?
     
  8. Matty1973

    Thread Starter New Member

    Dec 1, 2011
    10
    0
    Many thanks for all the advice and opinions so far. I appreciate the input.

    Does anyone have an idea how I can put a momentary break in a continuous 24v circuit once every approx 15mins?
     
  9. Matty1973

    Thread Starter New Member

    Dec 1, 2011
    10
    0
  10. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    I think you are really misunderstanding what the fire official is asking. What I said above is how fire doors in a home should be installed to meet fire codes. Here are the products too.
    http://www.simplexfire.com.au/ancillaries/magnetic_door_holder

    Requiring a fire door to be closed at all times in a residence is ridiculous. If he really wants it closed then you simply put a note on the door that "this door must remain closed at all times" as there is NOTHING you can do to prevent the occupants from putting a door stop under it again as soon as you walk away.
     
  11. DumboFixer

    Active Member

    Feb 10, 2009
    219
    34
    A lot of fire doors in the UK do have signs on them say "Fire Door - Keep Closed".

    The other thing you need to consider in the insurance - it could be invalidated by having the Fire Door held open.

    There is no guarantee that the property (I get the impression it is a domestic retal property) has a fire/smoke alarm or if it does it may be a small stand alone unit and not connected to the outside world so the system holding the door open would not know the alarm has been activated.
     
  12. strantor

    AAC Fanatic!

    Oct 3, 2010
    4,302
    1,988
    if you want to go that route, I recommend this relay (data sheet). it does thae same thing, but it is a better brand, has a better range(2-60min), and come with a relay base (so you can connect wires to it; with the other relay, you need to buy this seperately).
    Either relay starts timing as soon as you apply power to it, and once the set time has elapsed (and power is still applied to it) it just sits there indefinitely until you remove power and reapply power, at which point it starts timing again. It will not do what you want (15 min on, 1 sec of, 15min on, so forth). what I would do, is run the power through a limit switch behind the door, then to the timer. this way, someone opens the door, limit switch trips, timer starts, door stays open until 15min elapses, then door shuts and power is cut to the whole circuit (saving power by not running continuously) until someone opens the door again.
    here's a limit switch.
    I still say that you should consult the inspector first; unless your stance is that "it's better to ask for forgiveness than permission" - in which case I might agree. But, I feel obligated to tell you the right way.
     
  13. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    You should simply hang a sign on the door stating "This door must remain closed at all times". Then you should send a letter to your tenants stating that the Fire Inspector has required that the door remain closed at all times. Then keep taking/throwing out the wedge they keep putting back in the door again and again. Even with a timer they will still wedge it open.
     
  14. Matty1973

    Thread Starter New Member

    Dec 1, 2011
    10
    0
    Yep we have one of those but it doesn't do any good! I understand where the tenants are coming from - if you are carrying hot food and drinks you don't want to have to put it down on the ground and close the heavy door after you.
     
  15. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    Just let them burn then :) that will teach them.

    You timer idea is actually a safety risk too and opens you up for liability. What happens when a fire actually breaks out and there are 14 minutes left on the timer because they all fled the building.. Now you can be sued because your "device" prevented proper operation of a fire door.
     
  16. Matty1973

    Thread Starter New Member

    Dec 1, 2011
    10
    0
    Thank you. I think this solution is exactly what I am looking for.
    I did think every 15mins would be simpler but it then raises the possibility of the timer stopping at the wrong moment and then hot food all over the new carpet! Much better if it starts when the door is opened - can then reduce the time down to 5 mins or less may be. And may be in the summer set it to an hour so that people can have a breeze for a while but still have a guarantee of eventual closing - something using a wedge will never offer. Probably wiser to run it by the safety inspector first.

    A couple of questions:

    1) I don't understand if this timer is always on until the time expires or always off and then comes on once the time had past. Or may be you can chose which depending how you wire it?

    2) Does the trigger come in a 24v version? I had a search on ebay and could not find one. Since the power coming through the wall to the magnet will be 24v then that would be more convenient (and safer?). But would this get in the way of the power saving advantage of being off until triggered?

    Thanks again for the proposed solution to my problem, it looks very good to me.
     
  17. Matty1973

    Thread Starter New Member

    Dec 1, 2011
    10
    0
    This is true - although if they have all left I guess the worse thing that can happen is that my house gets burnt down - and the insurance refuse to pay! Probably best to run it all by the safety officer.
     
  18. BreadCrum6

    New Member

    Aug 17, 2011
    18
    3
    Apart from adding a relay to the button I would go with what McGyvr said and just get a door holder with an automatic release.
    Another option is to just use an alarm circuit like the one below that sounds whenever there is contact with the magnet. Just place the alarm above the door and a reed switch to the metal that makes contact with the electromagnetic.

    http://forum.allaboutcircuits.com/showthread.php?t=20276
     
  19. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    You should just ask him what he suggests. No way in hell I would do anything but #1 add additional signage or #2 install a magnetic catch triggered by loss of power/fire alarm signal. A DIY timer gizmo is NOT appropriate in this situation.

    I'm still not 100% clear on where this door really is but it really doesn't matter. Either the door should stay closed whenever possible or close automatically in a fire situation.
     
  20. Matty1973

    Thread Starter New Member

    Dec 1, 2011
    10
    0
    Thinking about it maybe you are right about linking it to the fire alarm. Having it automatically close when the alarm is triggered does make sense from a safety point of view. How that gets worked into the design does create more problems though.

    But the current situation of always being wedged open is clearly not working.
     
Loading...