Smoke Alarm Wiring Fail
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- Опубликовано: 15 май 2024
- A straightforward replacement of a smoke alarm revealed that it wasn't connected properly, and it only had power when one of the two light switches was in a particular position, independent of the light being on or off.
Property is about 20 years old, this problem may have been there for the whole time.
The old smoke alarm had obviously been removed from the backing plate many times to presumably replace the battery, as it would have often been without mains power. 
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I wonder if all that damage to the clip was from someone just continuously replacing batteries, oblivious to the real problem that the smoke alarm was being left unpowered for so much of the time?
@ bluerizlagirl, that could be a thing.
Most likely, yes.
Switchable smoke alarm, very handy for setting fires uninterrupted.
Actually I would like one. I could switch it odd when make food. there are some but it requires that you press a button in the actual smoke alarm. That makes no sense.
I'm not even a sparky, and even I wouldn't have made that error. Its so obvious to find the live feed. Whoever fitted it didn't have much of a clue I'd say.
Great work John. 👍
Oh boy, not all sparks are equal....
Had a tv amp fitted in loft a few years back. Took the installer 4 return visits and tried three different amps before his boss realised he’d wired off the light switch and no power when light was turned off when leaving the loft. All worked fine of course whilst testing with loft light on. 😀
Stretching the definition of a 'competent person' in this instance.
Lol
"Installer" * not an Electrician, that is pretty poor.......
a fancy power saving feature, i like it
An outlet on the outside of my garage had the same wiring fault. It was a frustrating first few months after we moved in, as sometimes that outlet would be live and other times not. I finally realized the issue one day when the outlet went dead while I was using it, concurrent with the garage light being turned off. A few minutes of flipping switches then the switches near the outlet were removed and the wiring corrected. Not the only wiring problem around this property...
@Sylvan dB, are you from America?
Most other places in the world don't inter-mix socket-outlet circuits and lighting circuits on the same switches.
Not surprised as seen many like this or just a quick wire to just light fitting with a hope and prayer that light would be on enough to charge the battery on rechargeable. Also seen 230v smokes wired into centrally controlled alarms which only supply 48v. Some Housing groups do not employ or train staff enough on smoke detectors fitting or give enough time to bother reading part numbers off the smokes to fit correct types. Like replacing heat heads with optical in kitchens!!!!!!!!
Nice to see this highlighting a problem.
It was either Friday afternoon or the apprentice, while the spark was drinking tea 😂
@jwflame Great video, interesting issue, well explained. I'm curious: The two switches shown have a total of 7 wires connected, and all 7 were red, so it wasn't self-apparent which switch connects to the live, and which switch connects to the light. I know colour standards vary between countries and all, but surely it would make sense to use wires of different colour for always-live and switched-live?
There was the option of using yellow or blue at the time, some places did use that to indicate the switched lines. However that wasn't required, and they could all be red as here.
Modern equivalents would be brown, with the option of black or grey.
Number or letter sleeves are an option and always were, but like most things that adds cost so are rarely used.
Hello, would Mr.Ward consider doing a run through on complying with the newish Scottish Regulations on interinked smoke and heat alarms installation Vs Rest of UK. Thanks and regards, john
I worked with an older tech who told me how he had an apartment building where every smoke alarm was switched with entry light... and he only found it by chance as he happened to go ahead of the manager and try to test one before the light was switched on... this is why smoke alarms should always be wired independently of everything else
This ^^. I'd always thought that mains fed smoke alarms had to be powered by a separate circuit.
@@jackking5567 pretty sure it is code... but why let code get in the way of creating a major deficiency that potentially endangers people?
@@klingoncowboy4 I think people feed the circuit from the lighting circuit so if there is a fault it's obvious and it will get fixed. A fault on the smoke alarm circuit is less obvious, and if it happens you are less likely to repair it quickly because it doesn't affect anything seen as important (while having no light it's something you will call an electrician to fix immediately).
I wonder if someone removed the plates to decorate or replace the switches at some point
That does happen.... decorator pulls plate away from wall and wire pops out.... has a guess at red to red.... bingo.
Exact thought I had too. That switch doesn't look 20~ years old to me.
Probably not, the switches are Tenby and marked Made in England, which dates them early 2000s at the latest. Property built 2001.
I'd concur. Either a decorator pulled the plates off whilst decorating or it was the home owner and neither knew or remembered which terminals they went on to?
Also from the state of that backing plate I'd guess homeowner who had no clue how to pop the smoke alarm off and simply attacked it with a butter knife until it surrendered 😂. Seen it so many times now... the cutlery drawer Tool Set. 😉
@@jwflame I remember Tenby, hated their sockets and switches, just the UK version of Chinese cheapy cheap cheap, however they were alway the manufacturer we went to for earthing stuff, clamps, blocks and so on. Them bit seemed to be good quality
The house I stayed in while at uni had the alarm wired in parallel with the switch. We only found this out when we put an energy saving lamp in and the light strobed when we turned it off. It looked like someone had replaced the drop wires for the pendant and got blue and brown backwards. They then followed the pendant colours without checking which wire did what when they did the alarm.
Only last ten years, in this day and age that is brilliant.
1 am not a electrician but have replaced recently 2 mains powered lnter-connected smoke alarms. A dedicated cb on consumer unit was power source.
Some manufacturers need to step up, Schnieder and others and make RED 6A and possibly 10A B Curve MCB's for fire alarm and smoke detector circuits.
They also need to have different toggles on the front of the MCB, so that they cannot be locked out with standard lock-dogs and left isolated if there is an issue with the circuit.
These are life safety systems, for people in flats, buildings, the means of egress depends on this system working correctly.
Nice little video John.
Very useful video. Thank you
My sister bought a house with a burglar alarm wired this way.
She didn't notice, until a year or so later when the battery in control panel failed and the loss of mains resulted in the external losing power and sounding.
Now because it - like this smoke alarm - wired one branch of her landing light it just so happened that switching her light off when she went to bed set it off.
Now misbehaving alarms aren't welcome at any time, but certainly not returning from e.g. using the bathroom at 2am.
Great video. I can see how that mistake could be made.
Watched this the other week.. makes me scared what other horrors live out there
My bet would be the electrician was used to twin and earth and was working on autopilot and connected the live to L1 probably late on Friday
John, can you do a video on solar pv and how it should be connected to the consumer unit. Should it be connected via a 100mA RCBO on non RCD protected way or can it just be connected to a standard MCB on RCD protected board. Not much guidance on this in 18th edition. Thanks.
P F, you need to do a course on this........
@@mikeZL3XD7029Thanks for reply. I've been on a solar pv course and 18th edition but still not clear guidance as to how an inverter should be connected. I just found an inverter manufacture document stating that a Type A 100mA RCD is required. Most of the installs I've seen are on standard 30mA rcd side of boards.
Seen this many times before when the lights are wired in conduits in high rises and the permanents are at the switches.
Don't know how many times I've wired them up but I usually pull the permanent back to the fitting using it as a draw wire for the new switched permanent then take my line neutral and earth with a ceiling rose adapter and trunking to the smoke 300mm away rather straight forward but to people who don't know the old way of wiring a two way through conduit they get confused, or if the switch has been changed and the electrician or in most cases the tenant or handy man does not know what they are doing and I get called out to a smoke alarm beeping with no power.
Nice LARP there mate
I believe the reason they're supposed to be replaced is not because of the components ageing but that they can get clogged up with dust, hair, and dead bugs impeding airflow to the detector.
it's kind of a big failure since the regulations were changed to require mains powered smoke alarms in all new builds, and now the recommendation is to get the 10 year battery ones so you have to replace the entire detector every 10 years.
My detector is somewhere around 40 years old and still screams like a banshee when I leave a pizza in the oven a little too long. Just seems wasteful having to change them every decade. Ten bucks says they start dropping that interval until it's 'change it every year' or somethin' stupid.
It depends. If you have detector using radioactive element for ionisation it will degrade with time depending on half life of the element.
There are also catalytic gas and carbon monoxide leak detectors that degrade with time as catalytic element wears with use.
One type of detectors that would be more long lasting is optical smoke detector but you still have issue of dirt and grime getting on optical elements.
Not worth to cheap out on safety critical device.
@@TestECull - I assume you have a smoke alarm in your kitchen? - sounded like you are suffering from nuisance alarming caused by cooking smoke from your oven = it is now regulatory to put a heat alarm in a kitchen to prevent nuisance alarm from occurring as these detect heat rising from a fire under them.
@@samuelfellows6923 Nope! My house was built in the late 60s/early 70s. The smoke alarm is in the hallway.
@@quertize ionisation smoke detectors use americium which has a half life of 432 years, so it should be good for a few years longer than 10.
Nice video JW
You had me at smoke alarm. I collect them.
I would say that it was not the original spark that made the mistake. I would guess the occupant of the property either replaced the switch for some reason, and did not take notice of what wires went where, or the occupant or a decorator removed the switch whilst decorating, and again did not pay attention to where the wires went.
Just what I was thinking 🤔
Bingo
You have no evidence this is the case.
Have you used the New Mk logic plus rapid sockets yet? I would love to hear your thoughts. Thanks.
MK Logic are the best range ever. They look great and are top quality.
I'm a little unsure about the fact they've built Wagos into them though.
@@helijim That is the whole point.
Have got one. Video about it available soon.
Shocking that this passed an Installation Test
You thoughts about Aico 3000 series, comparing to the fireangel?
Never used Fireangel or had any reason to.
A relative's Fire Angel smoke alarm wasn't working. I found the two metal tabs inside weren't being opened by the protruding plastic on the ceiling mounting plate. I assume this enables the battery power and stops the battery going flat in the shop.
I guess the tabs were misaligned, so I bent them apart permanently with a thin screwdriver (bonus - it would work without the plate). It powered up but set off beeping non stop, so in the bin it went.
Reviews also say the 10 year lithium batteries (cheap Chinese brand) fail after 2-3 years and the manufacturer doesn't help. Terrible that the Fire Brigade fit the F.A brand if so.
surely power us taken from the ceiling rose and gets nowhere near the wall switch ?
Why would you power off the back of a light switch on a first fix? I think modern regs state it needs its own power supply from the consumer unit?
'modern regs'. No it absolutely does not say that. Quite the opposite in fact. BS5839 might be worth a read.
Very good
JW what was the cost to the landlord of that little mistake?
The cost was absolutely nothing. The tenants changed the batteries.
@@johncoops6897 I meant the cost of having the faulty wiring diagnosed and corrected by a professional electrician.
@@sepgorut2492 Per hour
Initial hour, or part hour: £75.00
Subsequent hours: £40.00
Ionization alarms are an absolute nuisance and may just account for some deaths because people get so fed up with them going off all the time they end up disconnecting them! I replace ionization with a multi sensor type like the ei2110e that way you get much better protection and more importantly no false alarms!
Another great video JW!
@Dark Dreamz Eh, I'd rather have false positives than false negatives. Mine is bloody ancient and works a treat; predates optical units by a decade or two. If it goes off because I'm cooking steaks and picks up the haze from the spices searing into the outside surfaces it's gonna go off if there's an actual fire.
@Dark Dreamz If it still works, it still works. Ain't no sense replacing something that works just fine, especially if the replacement is from the disposable society we live in today and has a bullshit expiry date attached to it to get you to buy new smoke alarms and throw away perfectly useable ones.
It goes off when cooking because some things I cook get smokey. When I cook a steal and sear the seasoning into it the spices make quite a bit of smoke, haze out the whole damn house. Comes out fucking delicious(Medium rare of course only a heathen goes past that), also usually sets the alarm off. If I leave a pizza in the oven too long or something and overcook it on accident that, too, will set it off; real smoke not the test button.
I can also set it off when I'm soldering if the aircon blows the soldering smoke in just the right direction. Again, real smoke sets it off. Kind of irritating, but again I'd rather have it go off too easily than not go off easily enough.
It's working just fine. It's not getting replaced. When I cook a steak and it doesn't go off is when I'll replace it, as that's when I'll know it's finally done chooching. I'll probably find another radium one somewhere if at all possible; this one's been a good one why change what clearly works fine?
Also it's in the hallway. And it's not a battery unit. It's hardwired into the cieling.
If only it were that simple, my experience is completely the opposite. I bought my mum 3x fancy ones like DarkDreams talks about, that weren't supposed to have nuisance alarms and 10 year lithium battery life. Well 2 out of the three suffered multiple false alarms going off at all hours not just in the cold of night or when she had windows open, there was no clear pattern or cause. These were expensive around 25 quid each (regular type is 5 quid ea here in NZ) and one of them started the low battery chirp after only 2 years. Absolute rubbish and I'll never spend money like that again. Conversely I have 2x 10yr old ion types that I keep but use in conjunction with photoelectric types. I've had one single false alarm out of them in all those years adn one of them lives in the kitchen near my toaster and frying pan.
@Dark Dreamz This logic caused a consumer group to call for banning ionisation alarms here in NZ but the videos I watched when buying mine made me decide to buy both types - the ionisation alarms appear to be better in some other situations.
@@chocolate_squiggle ionization alarms are better for detecting fast flaming fires whereas optical is better at detecting a slower smouldering type of fire, in my eyes its best to fit a multi sensor type alarm that way you will be alerted quickly regardless of the type of fire ,the only drawback with a multi sensor is they cost more compared to just an ionization or optical type alarm which are only good at detecting one specific type of fire.
John could you dfo a video on reading electrical Drawings involving PLcs. I don't have any experience in industrial elec work and wouls appreciate it . Love your work , God bless
Have put in new fireangel alarm to replace old alarms. Had to disconnect the black interconnect wire because when you connect that up with the fireangel and test the alarm it would constantly go off on testing and would not stop. Removing the black wire from the alarm connections and it works but is this safe? Alarms appear to interconnect via wireless and green lights are on all the alarms. Help?
Are all of the alarms from the same manufacturer? Not possible to mix them, there is no compatibility either by wired or wireless.
@@jwflame yes all are fire angel alarms heat, smoke and co alarms
That new one has a little phone symbol, dose it text you when your house catches fire?
Data can be extracted from it using a smartphone to see when it was activated and various other things.
The control panel for the detector is on your phone. You'll be able to choose your preferred song playlist when the detector triggers. Probably 'London's Burning' or 'Smoke Gets In My Eyes' etc.
luckily the alarm was cabled to that switch and not the one at the other end of the hall
I'd have labelled the smoke alarm wire so no one could mistake it in the future.
Yeah I totally understand wiring from 50 years ago not being labelled, but I know network installers usually label everything (data cables) and it just seems odd electricians wouldn't do the same nowadays. Maybe there's a good reason for it that JW will tell us about.
The switch says "Tandy". Does that suggest it was fitted (or replaced) by a DIYer rather than a pro?
Tenby - it was a popular brand of switches and sockets up to the early 2000s. Was bought up by Legrand and disposed of.
You need to go to a dentist to get your glasses fixed.
0:06 - Ei141RC
10:27 - Ei3016
"Graunch" "Graunched" - what a wonderful word. We should all be mindful to use as much relevant vocabulary as possible just to keep it alive.
Therefore I lay down a challenge - if you work in an office environment, or more likely these days spend your days in endless Teams meetings - use the words above in a meeting or discussion.
1 Internet Point goes to anyone who replies with detail of how they used it with context :D
I take it this isn't setup as an interlinked system?
Up here in Scotland, it's going to be law from next year that you *must* have interlinked alarms in all properties.
It sounds like an invitation for a lot of cheap and exciting botched installs...
No, it's just a single smoke alarm in the middle of a small 2 bedroom flat.
From the few handfull's of rented properties I've been in doing unrelated jobs recently - 605CRF's on the wall above the door in the bedrooms and living room, a 603CRF same position in the kitchen, and the previous mains powered detector in the hall replaced with a 695CRF. Presumably the 9V battery-only was so that anyone with an impact driver could whack them up and check the box off 🤷
Loads more fires in Scotland due to the mass drug taking. Was up in Glasgow for 20 years.
It's already law in Australia that rental properties have interlinked smoke alarms, but in many cases they can be powered by lithium batteries that last the full 10 years, and use RF to interlink. My last place, and I'm assuming my current place will have the same problem, did not have easy access to run wires. My place before that had a hybrid system where they ran wires to the easy places and lithium batteries where they weren't. That was an old Queenslander and it required 9 smoke alarms (7 bedrooms and 2 kitchens)
Sounds like it'll be a continuous alarm then as there'll nearly always be one going off somewhere in Scotland ;)
This has never happened in the history of mains supplied smoke alarm installations!!! 🖖 😁
Why is a cable for a smoke detector even going down to a switch to obtain a live.
Surely a L & N would be easily available from a nearby ceiling rose, of which the neutral must have gone.
I have always had SDs on their own 3A circuit anyway for past 39 years.
Probably the work of a cowboy builder
The loop in and out is not always at the ceiling roses, sometimes they are at the switches, this property most likely had the loop at the switch.
Looped at the switch, no permanent line at the light fittings.
The advantage of sharing the SD with a lighting circuit is that you are more quickly aware if the circuit has disconnected at the MCB.
As John explained, its in conduit, when in conduit you wire it differently.
You used to be able to gat bayonet fitting detectors that go between the bulb and bulbholder.
Useful to test then with light ‘off’ as alarm will not have the green light
Should not the smoke alarm be connected to a dedicated separate circui not a lighting circuit for reliability.
As lighting circuits or other breakeakers can be triggered by a faulty light or other so if on it's own circuit it should be more reliable, you want the smoke alarm on 24/7.
As you dont want the fire alarm system failing beacuse of a fault in the circuit e.g. tungsten lamps or led driver circuits can fail tripping the breaker.
I don't understand why when mains wiring is fitted that the wire ends are not marked for traceability, fault finding.
I believe this would have greatly reduced the error which could have been fatal if a fire had arrison.
If it's on it's own circuit it's possible that a fault or human action could make that circuit dead without anyone noticing and correcting the problem.
Putting alarms on the lighting circuit is supposed to be a guarantee of supply on the theory that if your lights go out you're likely to do something about it. Of course they have to be wired correctly for this to be effective. 😀
In a rental especially, you don't want to do that as they can be turned off if they are nuisance alarming
Why is it that battery powered smoke alarms always fail at 3am?
Always!
Pretty simple reason - its the coldest part of the night - and cold is when the failing battery gives the least power.
@@Seiskid I was so pleased with myself when I realised this.
I have a weather station with remote external wind/rain/temperature and humidity outside = in the winter with “minus” temperatures, the indoor station would indicate low battery for external transmitter and hours later - data transmission would stop as it was too cold for it’s battery 🥶
Good job it was the switch with the feed and not the one with the Switch wire. I've seen that mistake made before.
Makes u wonder how these things get passed.
Genius idea if you happen to burn your breakfast toast..... To shut the smoke alarm up, just turn the light off... It also magically doesn't inform you if you burn your house down
If this was put in late 90s, shouldn’t it have been using blue/brown instead of red/whatever?
New colours for fixed wiring were introduced in 2004, mandatory from 2006.
@@jwflame so late! We got them here in 1970. Almost a literal electrician’s working lifetime earlier. Before that, red/green/grey for LNE. And yes, the old N thus can easily be confused for a modern E, and old E happens to be the same color as one of the three phases, and that’s not *super* handy.
someone random guy from big clives oh-so-favorite place, NICEIC ?? lol.
rather than smoke alarm live been connected actually to the light sw terminal itself, i would have thought they'd tap into the junction box live line BEFORE it reached the light sw....cant be more time consuming than running wire thru roof and down the cut out via the wall just to attatch to light terminal....the wrong one at that.
Seems to me like an open & shut case of Jim Homowner,who has absolutely NO IDEA what he's doing.
old macdonald detectors are the best.
Only good for his farm....
Guessing they had the light on and fit it in the dark
Just think of all the electric they saved by fitting the smoke alarm to the switched live!
Urm is that switch on upside down or is just me?
Switches don't have a "up" or "down". These are on a two way circuit, so the "on" position alternates depending on the position of the other switch.
2 terminals on the back are at the top relative to the text moulded on the back, single terminal at the bottom.
Strange, most properties 20 years old have their own smoke circuit.
Surely the smoke detector would bleep every 30 seconds or so to warn that it was in battery backup mode?
Some do, others only beep when the battery is low.
This just proves how a little knowledge is dangerous.
How many times do DIYers take down ceiling roses for a bit of decorating without first marking wires? The absence of a tester (or a brain) can end up mixing switch returns with loop-in wiring etc. They must wonder why they turn on the landing light, which no longer works but lights in the bedroom come on. :)
If you fit Lithium PP3s in the battery powered ones, the battery lasts about 10 years. At which point I don't see the value of mains powered smoke alarms, simpler to change a Lithium PP3 once a decade.
Good point, I guess mains ones are normally linked together so when 1 triggers, they all sound. Think there's a new law in Scotland that state that all houses have to have interlinked smoke detection now.
@@neilcaldwell870 You could interlink battery powered smoke alarms with low voltage telephone style cabling, no need for mains.
Smoko connected to one leg of a 2-way switch (veksellüliti). Classic stichup._
Smoko?
It's not even 10am where you are.
Why is this even a thing ?
Over here we use only battery powered alarms.
Usually comes with built in lithium batteries that last up to 10 years or 9v batteries(lithium 9v avaliable for 1,5,10 year span)
Relying on mains seems really stupid as if the power goes out then you're SOL
Obviously there's space for a battery in it aswell but i doubt most people would put one in if it's already powered.
Battery only devices are considered the lowest grade of system (F1 or F2) in BS5839-6. Better than nothing but far from desirable as they only have a single source of power, and those with removeable batteries are likely to have those batteries removed for various reasons.
For most installs, mains powered with battery backup are recommended, either a replaceable 9V battery (grade D2) as in the old one in the video, or those with rechargeable non-removeable lithium batteries as in the new one shown at the end (grade D1). Where multiple alarms are installed, they should all be linked together either by fixed wiring or a radio link.
The type with the 9V battery backup can't be fixed to the ceiling plate without a battery installed.
@@jwflame great reply thanks I didn’t know any of that, not being able to instal it without a battery sure makes it superior as you have redundancy
@@BMWe-ed2tn you must be murican yeeh?
@@yourrightimsooosorry884 not one bit, I’m not an educated electrician(if my comment seemed stupid) either just like to watch jw’s stuff :)
@@BMWe-ed2tn so you're from over where??? 🖖 😁
"over here we use only battery powered alarms"
A load of old Junk the way that smoke alarm was wired in. They should be on a separate circuit I.E on a separate circuit Breaker. correct me if im wrong.
Sorry you are wrong. (You did ask) If smoke alarms are on their own MCB how will anyone know it has tripped? (They wont) But if it is on a lighting circuit and a fault occurs the lights will not work, so they get investigated.
@@tonipeters4543 to me Smoke alarms should Beep every few seconds if the mains power is cut or even failed... And also should beep if the battery fails as well.
They can be on their own circuit, or on a regularly used local lighting circuit.
There are advantages and disadvantages for both options.
Lighting circuit - more likely for people to notice a failure of that circuit, but a fault with the lighting could result in no power to the smoke alarm.
Own circuit - unlikely for faults to occur, but if one did or it was switched off, people may not notice for a very long time.
@@jwflame True. Smoke alarms dont use very much power So yes you can put them on a lighting circut. But wired on the Main cable and Not the light switch.
Wrong
Looks like the alarm went off as the battery died, prompting the householder to change the battery, oblivious to the fact the alarm was running on battery only most of the time. The householder must have destroyed the alarm casing with frustrating stabs at the alarm trying to get the cover off for yet another battery change. Must've drove him / her nuts.
They must have kept taking it down as it wasn't working on many occasions.
Absolutely, probably constantly replacing the battery.
Yeah Afaict the battery life without mains is far shorter than the battery only type... Cos its only supposed to be a backup for power cuts.
With the switches being close together maybe one of them was only being used very infrequently.
Once a year change battery
Decorator done it. Paint on the wires. Open and shut case...
Oops! 😲
yay but not a two ways would show this exact fault
Strapper detector
With a battery in the smoke alarm you can't even use the excuse of wanting to be able to turn the alarm off :)
poor client, driven mad by smoke alarm that beeps after you turn the light off, then to make matters worse the problem couldn't be found because sometimes they turned the light off with the other switch and the alarm worked ok then. i think i know why the alarm was on and off the backing plate so often.
You can only have a fire if the light is on!
Support sir
All of my smoke alarms are wired back to the distribution board and on there own fuse marked up. That's lazy workmanship.
Wrong, smoke alarms should never ever be wired on their own circuit /fuse, lazy arsed people will simply turn the mcb/rcbo off instead of replacing the battery!
I house burned down and it was found that the mcb was in the off position, if the smoke alarms were working the two infants and mother would have survived as it was an unextinguished cigarette that smouldered for an hour before igniting an actual flame, the smoke alarms would have activated long before the property was a blaze!!! 🖖 😁
@@yourrightimsooosorry884 I agree... It's not an absolute though. It is recommended that it be installed off a local lighting circuit to minimise the chance of it being inadvertently shut off or left off in the event of a fault - definitely makes sense to me and its how I do it.
It wasn’t a mistake and it’s obvious.
Those smoke alarms can be a nuisance. You leave your toast in for a split second too long and it goes off and is annoying.
Some muppet fitted the wrong type in my house and it’s infuriating. It’s on my list to swap for a different type.
What someone did here was take the thing out, probably because they smoked and I bet it is a rental.
In the end they just decided to be clever and change the wiring so they could switch it off instead of removing it every two minutes. Which is why you see the holding clip damaging.
With the 9V backup you can’t actually turn it off just by removing the live.
Who the hell uses 220v powered smoke detectors ? I dont even wanna know how mutch a 220v unit costs...or how one gets his hands on it in der first place.
all the industrial and state owned buildings in EU run on centralized low cost voltage 24v/12v systems, u can install the low cost systems based on security panels für your home.
My smoke alarm nearly killed us!!!
I had the same smoke alarm, mains powered & battery backup first night around 4am we are awoken to a Hugh electrical bang scared the life out of us.
Everything tripped, in my bare feet half asleep half dazed I'm trying to work out where the explosive bang came from, checked the fuse box all went back on fine nothing tripping.
I couldn't sleep, eventually got around to the single smoke alarm, took it off the backing plate, I was shocked (pun intended) the mains power was fine, but the culprit was all too visible, the Duracell 9v battery had exploded in the smoke alarm!
For years I've been trying to work out how a smoke alarm nearly caused a fired & killed us.
The nearest explanation i can come up with is the Flat was empty for a good while and power was off so relying on the 9v battery to run independently the first night we moved in switched on the mains, maybe there is a diode that went bad in the smoke alarm and current flowed into the non-chargeable battery which exploded from somehow receiving a reverse charge
Some dumb CLINT put the battery in the wrong way!!! Simples! Sweet dreams!!! 🖖 😁 😜
@@yourrightimsooosorry884 I wish it was that, but the remains of the batt terminals were attached correctly to their respective posts. Would be ironic to have a house burn down due to a smoke alarm.
Wonder if some smoke alarms have a rechargeable PP3 option as the backup and someone has replaced it with a non-rechargeable type. After some time she will take no more and...there she blows?
Yeah don't know how or what thay wear thinking you should know the common in your switch is your live permanent feed if thay only seen the terminal marked com it would have been job done so for that reason I'm saying close but no cigar 🤔🤣👍
It depends on which two way switching configuration is being used…
Not all Permanent L enters at COM.
Never assume this or that. Get a probe to prove it.
Have a look at that power usage, 7kWh per year.... These things need banning - EEVblog #1284 - How Bad Product Design Kills The Environment
The new one is far better at 0.25W, 2.2kWh per year.
Having the same wire colors for live and ignition was the root cause. Great video.
that's the kind of dumb mistake I'd make hahaha
in all seriousness though at least attention has been paid to it's operation state (it seems), perhaps being constantly being un-mounted to replace the battery of a normally mains operated unit.
hello i'm jw
No, you aren't. Stop being a dickhead.
Pl,
I have always found you need to replace the 9v backup battery once a year, else the alarm will start beeping.
In the USA this is called a 3-way switch. You called it a 2- way which is not expected.
Cos, bleeding obviously, the power can go one of only TWO ways. There's 1 IN and 2 OUTs.
There may be a layman's interpretation too - the light can be turned on in one of two ways - either switch A or switch B
If it were a relay, it'd be referred to as a double throw. But a double throw switch is a different thing altogether ;)
@@millomweb a little Google search finds this: The name for these types of switches is different depending on where you are in the world.
The US calls these three way switches and the EU calls these two way switches.
@@neilbrookins8428 Yes, I know that - and I've explained the reasoning.
Seems a bit wasteful to replace these things like that. Mine is probably 40 years old, maybe older still, and it works a treat. Set it off with the oven on occasion leaving something in a little too long.
Definitely time for replacement. It will fail. A cap in it will give up or something else will happen. And it will sit there for eight months before you discover it.
@@Seiskid I cook steaks weekly. If it fails I'll know plenty quick.
@@Seiskid - good quality electrolytic capacitors operating at room temperature can last for a lot longer than twenty years. Other types can last for over fifty years.
@@Mark1024MAK 100% your cheap smoke alarm has the cheapest caps they could get on the day. This is the same smoke alarm your rely on for critical safety and no one ever tests. If they are that old change them.
@@Seiskid - so open up a smoke alarm and show me a picture of the capacitors you say will fail…
Only red wiring? Shouldn't that at least be 2 colours? Brown for live Input and black for switched?
It would be nice if there were a distinction between permanent and switched lives but there never has been in the UK regulations. When this place was built red was the standard for all lives.
Also we changed colour schemes some years ago, brown is live in the new scheme and black is neutral in the old scheme so your particular suggestion there would confuse / upset people (as well as fail local code). 😀
There are different categories of 'switched' live. Would the live from a fused switch spur count as as permanent or switched? The live from an MCB could be classed as switched because BS7671 permits CPDs to be used for functional and other types of switching. You could technically use an MCB to turn your hallway lighting on and off.
Really you should not rely on the colour of the insulation. Push on labels are available. Here’s a link www.hilltop-products.co.uk/app-htp-z4.html. How difficult would it be to label the switched line “SL”?
@@Mark1024MAK It doesn't have a switched live, it is 2 way switching, they are called strappers.
@@tonipeters4543 - Yep, well aware of that. My post was in reference to the post above where it was discussed about having a different insulation colour for the “switched line (live)”. I don’t agree with this. Obviously in a two way (or where there are more than two switches) circuit that control lights, the strap wires are not as simple as a “switched line”. But they also could be labelled, say “S1” and “S2”.
I wonder if those things suddenly expire after 10 years just because you are mandated to have one and it's just free money for the sellers and manufacturers.
Surely the testing feature on them should also account for aging and using them as long as they work is most ecological, rather than hauling thousands of tons of unnecessary chinese plastic and electronics around the globe every year...
They don't suddenly stop working after 10 years, but 10 years is the lifespan that the manufacturer has determined they will still work reliably for, 10 years being around 88000 hours of continuous operation.
After that they may work, or perhaps not.
Aico alarms are made in Ireland, not China.
I think it's because these alarms have inside a small quantity of radioactive americium that is used to detect the smoke, and that radioactivity decays over time.
This type of smoke detector is based on the use of a small amount of a radio-isotope, which has a known mass and half-life. The manufacturer can calculate with quite a high degree of accuracy when the amount of radioactivity available will drop to a level that means the unit should be replaced to avoid a failure to operate, almost certainly incorporating a factor of safety.
@@alerighi The radioactive element does decay over time, however the half-life of Americium is over 400 years, irrelevant in the lifespan of any smoke alarm.
@@jwflame WARNING: This alarm expires in 2421.
Just had to replace a CO detector, the sensor in that is chemical and really does expire.
Am I only the one who sees the irony with hard-wired mains-connected lithium batteries in a smoke alarm? I sure hope they weren't made by Samsung...
Why Samsung? Lithium batteries from all manufacturers can fail. Some Apple devices have their batteries manufactured by the same suppliers who make them for Samsung, which is why they didn't make a big deal out of that Samsung tablet with bad batteries some years ago. In this case, the smoke alarm batteries will be relatively small, contain relatively little energy, and fairly unlikely to have any catastrophic failure.
The batteries in a smoke alarm are NOT rechargeable Lithium cells.
This is why mine have mains and traditional 9volt batteries. I do not trust lithium in my home.
@@johncoops6897 It's easy enough to google and find plenty of mains smoke alarms that *do* have rechargeable lithium cells as backups so I don't understand what point you're trying to make here.
@Dark Dreamz - Wasn't replying to you.
You could get sued for saying batteries last years you better learn the Ul listing for product every year change batteries