Interlinked fire alarms

[Scott]

I'll just call Nicola as a defence witness then :-)

[Steve Walker]

It certainly will and is doing here.

[Chris Green]

I was going to say that! :-)

[George Miles]

I put in Aico alarms using 3 core and earth, 1mm I think, with its own RCD in the consumer unit.

Once when the coal burner was smokey and I had guests they all came on which was fun !

george

[ARW]

Actually that is not the case with the new AICOs.

They have a built in ten year timer - so the alarm will bleep 3 times every 48 seconds after 10 years from first power up.

[Andy Burns]

Given that the 1000base-t ethernet spec pre-dates the cat5e cable spec, gigabit networking over copper was designed *for* existing cat5 cabling, provided your cable meets the spec.

[ARW]

I am AICO trained and although I like their stuff their wireless 10 year battery stuff is expensive and hard wired is the best way to go if possible.

The hard wired models have a choice between a 10 year rechargeable lithium battery or a non rechargeable 9V alkaline battery that will need swapping every couple of years (the alarm will start to bleep every minute at about 2am on a Saturday morning to tell you to replace the battery)

[David Wade]

One issue you might face mains alarms and wired links is that they may need to be on the same way in the consumer unit if you have a split unit like mine.

I had mains alarms, one upstairs one downstairs fed from separate lighting circuits. When the consumer unit was converted to a split unit with 2xRCDs I had to switch to wireless linked alarms as the link between the two passed enough current to cause the RCDs to trip.

Possibly not an issue in a flat.

Dave

[Scott]

It shouldn't be. My idea was to connect the first alarm only then to daisy chain to the others, so there would only be one connection.

[John Rumm]

I put in the predecessor of:

That lets you mute them all from one easy to reach position. (and test them, and also identify which of them caused the alarm)

[John Rumm]

Yup that is the way to do it - they must all be on the same circuit - either a dedicated one, or sharing with a light circuit.

(they don't have to be a literal daisy chain - you can branch wherever you like if you need to)

[Mathew Newton]

For ours whilst I provided a dedicated circuit for the smoke alarms I wired the regularly-used understairs cupboard automatic light into it too so we'd know promptly if the supply had ever failed.

[Bob Eager]

I wired in a non-maintained light over the stairs. It lights the stairs in a power cut, and enough leaks into most rooms to be able to find your way around. It's in front of you as you go downstairs (basically on the edge of tyhe landing floor) so it's very obvious if it's on.

[ARW]

That would suggest someone only ran a single core for the interlink between the two devices instead of a 3 core and earth.

[John Armstrong]

In a flat, that is true, and that's what I have in mine. The alarms in my flat are interlinked and hard wired. However....

The guidance in the link above also states: "1 smoke alarm in every circulation space on each storey, such as hallways and landings"

so a two storey house requires at least one smoke detector upstairs.

It also states this:

"If you have a carbon-fuelled appliance, like a boiler, fire, heater or flue you must also have a carbon monoxide detector. This does not need to be linked to the fire alarms. Gas cookers and hobs do not need a carbon monoxide detector."

[Brian Gaff (Sofa]

Could not the fire interfere with the wire? However, I'm a little dubious about some alarms these days, they do not seem to go off easily, compared against the ones say 10 years ago with user replaceable batteries To me that says two things, less time to get out, more chance of wiring or the alarm itself being damaged first.

Brian

[Robin]

Wired alarms have battery back-up so they work even if a fire has caused loss of power.

And I th> Could not the fire interfere with the wire? However, I'm a little dubious

[Scott]

Yes, but bizarrely this excludes the common parts.

I was not including them in the equation as they do not need to be changed.

Apparently so, but I disagree and I have one installed anyway.

[Scott]

Plus, would it not take a long time for the cable to become destroyed? I would want to be offski long before then :-)

[Owain Lastname]

Common stairs in low-rise buildings usually don't need a fire alarm. They should be fire sterile areas with nothing combustible.

A domestic style detector system would be too vulnerable to vandalism and false alarms anyway.

If the size or construction of the building warrants a common fire alarm system it would have to be a commercial style panel system.

Owain