Connecting multiple smoke alarms

Discussion in 'Getting Started FAQ' started by highlander7, Jul 11, 2018.

  1. highlander7

    highlander7 New Member

    Wondered if anyone could help please ?

    I'm looking to connect five smoke alarms. I know that the first is twin core and earth then the rest are connected via three core and earth (1.5mm). However, most show that one is connected to the next which is then connected to the next and so on.

    My query is whether the first can be powered with twin+earth. Then first connected to second with three core+earth. After that, can the second be connected to the third and the second connected to the fourth and the second connected to the fifth each via three core and earth and all go off if one goes off

    OR

    does first need to be connected to second, second to third, third to fourth then fourth to fifth ?

    We're building an extension and the new smoke alarms need to be connected to the existing house. I'm looking to see whether there are options to save long cable runs out and back before the builder's electrician comes in.

    Thanks
     
  2. CGN

    CGN Well-Known Member

    Yes

    Power to first, then 3 core to all others. The 3rd core allows them to talk to each other.
     
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  3. KIAB

    KIAB Well-Known Member

  4. highlander7

    highlander7 New Member

    Great - many thanks
     
  5. CGN

    CGN Well-Known Member

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  6. highlander7

    highlander7 New Member

  7. CGN

    CGN Well-Known Member

    Every Aico 'detector' comes with a hard wireable base. You can buy a radio base, for approx £50 which is useful if retro fitting as there are times when its more cost effective to use them. You can also use a combination of the 2.
     
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  8. Sparkielev

    Sparkielev Well-Known Member

    You better using 1.0mm t&e 3core easier to terminate by the way England lost and am f@#$ing bereft
     
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  9. Pollowick

    Pollowick Well-Known Member


    Building regs are way behind the time. I had agreement to install an integrated intruder and smoke/fire alarm - all wired but BC demands that they are mains powered. Even though the system uses mains to provide the distributed 12v and has a lead acid back up because each detector is not mains powered it may well not be acceptable. So, the job almost disappears. Also, if I used wireless, not acceptable, even though the system monitors every few minutes for loss of detector or low battery and will alert if there is an issue - not acceptable.
     
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  10. rogerk101

    rogerk101 Active Member

    Building and fire regulations (especially for multi-party dwellings like HMOs) do indeed specify hard wiring, but that's hard wiring for power, not for alarm signalling. It is perfectly within all the regs that I'm aware of the signalling can be done wirelessly provided each device is powered with a permanent live and neutral.
    I save myself some really messy new wiring that I thought I was going to have to do to interconnect a heat alarm in my kitchen, when my building control officer actually suggested I just take local power to it with wires, but interconnect it with the other alarms wirelessly. I fitted a pair of wireless bases - one to the new heat alarm, and the other to any of the other smoke alarms and they now all talk to eachother.
     
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  11. Pollowick

    Pollowick Well-Known Member


    And why do they require Live and Neutral - 230v? A battery backed 12v supply, with 24 hours of reserve is surely better. Would BC accept it?
     
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  12. highlander7

    highlander7 New Member

    Many thanks for all the replies - this has been very useful. Cheers :)
     
  13. rogerk101

    rogerk101 Active Member

    You'd have to ask your building control officer that. However, I expect that he, like me, would want to know why you want this so badly.

    The approved alarms already need to be battery backed, usually with a 9V brick battery, which only kicks in when the mains supply to the alarm fails. What kind of battery backed 12v supply are you thinking of?
     
  14. Pollowick

    Pollowick Well-Known Member

    These are high quality, highly resilient, intruder alarms designed for continual operation wit a float charged lead acid battery. Different styles of smoke and heat detectors can be fitted, continual monitoring of the sensors - in case of activation they will sound internal and external alarms; if required auto dial the fire service; alert the user by phone/text/data if set up; will sound an internal (and possibly external) alarm if a sensor is tampered with; mains power and battery are continually monitored and will alert the user after a few minutes of mains failure with several hours of battery backed standby power.
     
  15. rogerk101

    rogerk101 Active Member

    It sounds like a system designed for the job, so will most likely be just fine. The manufacturers would ave done their research into what is / is not approved, and they wouldn't be bringing something to market that wasn't going to pass a simple building inspection.
     
  16. Pollowick

    Pollowick Well-Known Member

    It certainly would, just that BC here are insisting on a linked mains system; that is 230v with an extra communication core.
     
  17. rogerk101

    rogerk101 Active Member

    Are you using council BC or private?
     
  18. Ronan Lang

    Ronan Lang New Member

    hardwiring will be a cheap and an easy option for you.
     
  19. Pollowick

    Pollowick Well-Known Member

    Not me, but the customer ... council BC, I believe.

    Too late now, he is probably paying an extra £200 for the wiring to be run in - 1/2 day or more of work, whereas the alarm solution would have taken 5 minutes per detector.
     

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