why do smokes randomly go off??

[jenions]

why would a mains powered smoke alarm just randomly go off??

 

[ezzzekiel]

usually when the house catches fire

is it wired from another circuit or on its own?
dust getting into the unit from above?
battery dying?

 

[davelerave]

cold weather can cause problems too

 

[eskimo39]

If anyone in the house is using deodorants or air fresheners, the particles in these can set them off.

 

[chris gray]

steam can set them off as well.

 

[RexT]

Hi jenions,

Does depend on the type of smoke alarm. Basically they are particle detectors and there is a threshold limit. Typically ionisation smoke alarms react to tiny particles from fast flaming fires and optical larger particles from slow smouldering fires.

They can be affected by steam or anything that produces particles which can enter the sensing chamber. Dust can be an issue as other stuff like that. Positioning is very important.

Electrical interference may be an issue from items that dont comply with the EMCregs etc.

Best advice, keep them clean and bagged if installing on new builds until the works are finished.

Hope this helps a bit,

best wishes

Rex

 

[chris gray]

forgot to say florrys can effect them

 

[alarm man]

If anyone in the house is using air fresheners, the particles in these can set them off.

those plug in ones cause a few problems,

 

[russty]

cold weather can cause problems too

Yeah as it has just turned winter time overnight!

 

[davelerave]

Yeah as it has just turned winter time overnight!

really

 

[leeweimaraner]

i think the reason they are going off is because you have connected them incorrectly,the first detector requires a supply ?but the yellow cable is for interconnection of other smoke alarms (its not an earth)then 3 core between other smoke alarms live neutral and monitoring colour yellow otherwise you get an in balance to earth which trips your rcd

 

[accordfire]

i think the reason they are going off is because you have connected them incorrectly,the first detector requires a supply ?but the yellow cable is for interconnection of other smoke alarms (its not an earth)then 3 core between other smoke alarms live neutral and monitoring colour yellow otherwise you get an in balance to earth which trips your rcd

Can I have some of whatever you've been smoking please?

I have no idea at all, what any of the above has to do with smoke detectors activating spuriously, which is what the OP wanted to know about -

Not only that, if you are wiring anything using yellow sheathed wires in this day and age, you need to go get your qualifications updated FAST.

3 and Earth is Brown, Black, and Grey - and has been for a long while now.

As for earth faults - very unlikely on any BS smoke detector as the earth terminal, if provided is NOT electrically connected to any part of the detector, and earth is used purely for protection on the cable.

 

[accordfire]

While we're on the subject, there are a number of reasons domestic (i.e. interlinked, or non interlinked) mains smoke detectors will activate for no apparent reason.

Number one reason is likely to be the fact you've installed an ionisation type smoke detector in a draught corridor.

Number two reason - back up battery is kerput! Silly little 9V dry batteries should be replaced annually, whatever the manufacturer says - if the detector has been tested at all, that battery has been used, and will lose charge. And the detector *should* have been tested, after all.

Number three reason - build up of dust in OPTICAL type detectors. It's akin to myopia in humans, and means the detector cannot "see" properly - and thinks the dust is a smoke build up.

Number four reason - incorrect choice of detector for environment - e.g. similar to one, but down to things like toast, cooking, burning, heavy smoking.

 

[Tillywolves]

You have to remember that an optical sensor uses an led and receiver, and any dust, particles will set it off... You just need a particle large enough to reflect the light onto the receiver...

 

[millwall ken]

why would a mains powered smoke alarm just randomly go off??

General house dust build up on the sensor?