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Magnetic Fire Door Retainers

Discussion in 'Electrics UK' started by Speakercon, 6 Dec 2017.

  1. Speakercon

    Speakercon

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    Hi guys, for anyone familiar fitting these, are there any additional requirements or things to be aware of other than ensuring the wiring is done correctly and the power is automatically removed when the fire alarm is activated?


    Thanks
     
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  3. mwatsonxx

    mwatsonxx

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    That's about it if you mean normally held open.
     
  4. john4703

    john4703

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    From experience it is a good idea to make sure tat the doors are correctly labelled as otherwise some people will insist on closing them. It is fairly common to see a label "fire door keep closed" on a door held open by a magnetic catch. Better to have a label that states "this door will close in the event of a fire alarm" or some similar wording. (signs are available to purchase)
     
  5. Speakercon

    Speakercon

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    Sounds good! Our current ones are 24V and wired with twin & earth which seemed unusual to me?


    We're looking to install some more and were wondering if this is something we could do ourselves (apart from getting a spark to connect the PSU to a mains supply and the fire alarm).


    The current ones also all have their own key switch located next to the mag, do you know if this is a requirement of just good practice?
     
  6. 333rocky333

    333rocky333

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    Most now have a button on them to release the door, I think they are meant to be Manually closed each night

    BS 5839 covers fire alarms may be worth reading as any work will need to conform to that
     
    Last edited: 7 Dec 2017
  7. ban-all-sheds

    ban-all-sheds

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    OK - I'll bite.

    Where are you planning to do this work, what sort of environment, and are you sufficiently qualified to discharge your legal obligations and comply with any insurances or commercial legal agreements which apply to wherever it is?
     
  8. oldbutnotdead

    oldbutnotdead

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    Using T & E for 24v could be because that's all the installer had with him at the time. Seen them done with twin flex before now, the current draw isn't massive. If your doors have doorclosers on them as well it is a good idea to put the mag hold-opens at the top of the door (otherwise over time the doors can twist).
     
  9. Lectrician

    Lectrician

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    You don’t wire them in firetuff. If the cable fails in a fire, the doors will close. A key switch or switch is common to isolate them to allow the door to not be retained open at certain times. The final connection to the fire alarm should be done by your fire alarm engineers.
     
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  11. john4703

    john4703

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    In one place I fitted a time switch in the 24v lead so the doors closed at night. There were about ten of the magnetic catches and they were all fed from one connection on the fire alarm system.
     
  12. Lectrician

    Lectrician

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    It's quite common to have a time clock included, and a momentary push near reception or similar. It is usual to use the panels 24v aux output, via a NC output on the panel, this supplying a 24v relay. The relay is on at all times, and will drop out during a fire alarm, closing the doors. This is fail safe, and as it should be. Some people wire the relay in the panel via the NO contacts, so the relay only energised during a fire alarm, and the energising relay opens the contacts holding the doors open. This is not fail safe, as you're relying on the cable and relay working when needed.
     
  13. JohnW2

    JohnW2

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    Isn't there a concern about liabilities which might arise if a heavy door closing 'unexpectedly' due to remote control, in a non-emergency situation, hit someone in, say, the face (or squashed a child'd head)?

    Kind Regards, John
     
  14. sparkymarka

    sparkymarka

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    IMG_1716.PNG Fitted a few of these on systems requiring door closers as a afterthought
    Bit more flexibility on these if your panel does not have a relay only a switched output , can power 5 retainers and has a manual release button on the front
    Made by C-Tec
     
  15. Speakercon

    Speakercon

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    The timer sounds a good idea tbh. Thanks guys.
     
  16. JohnW2

    JohnW2

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    What about my point about the potential hazards of closing the doors by remote action? I've seen people in hotels going around at night manually closing the fire doors, and I've always assumed this was being done by humans so they could ensure that no-one was at risk of being injured.

    My understanding is that there are a lot of regulations relating to gate closers, garage doors etc. because of a similar hazard, so I would be a little surprised if the same were not true of automated/remote closing internal doors.

    Kind Regards, John
     
  17. sparkymarka

    sparkymarka

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