'Isolator'/switch for smoke etc. alarms?

[jj4091]

Not much fun, working after dark, with no lighting available, and could be quite dangerous.

Surely it would wait for daylight

 

[Harry Bloomfield]

Surely it would wait for daylight

That, depends upon the urgency of the repair.

 

[JohnW2]

Always on the upstairs lighting circuit and as I always fitted Aico it is simple to remove them from their bases.

Same with me (albeit 'downstairs' lighting circuit) - but the question arose from someone who has alarms which are not quite as easily replaced

Never give people an easy way to isolate life saving alarms

As I wrote, that is obviously undesirable. However, I don't think it would be particularly 'easy' if there were a key-operated switch.

 

[JohnW2]

Increasing the chance of the fire alarm supply, being lost, if the lighting circuit trips due to fault, and it not being able to be restored.

Hmmm. How long are people going to live in a house with the lighting not working, and how likely is it that an alarm will be (legitimately) activated during the period whilst they are waiting for the lighting circuit to be restored/repaired?

 

[JohnW2]

Who regularly checks that the LED is lit? Not me, the mains supply could be missing for months, before I would notice. The bleep, every so often, is quick to be noticed.

Quite. As I've implied, I think that alarms on a dedicated circuit could remain without power for a long time, maybe long enough for the backup battery to go flat, without anyone noticing (or understanding the significance of) the LED or occasional brief bleep.

 

[JohnW2]

I thought you were asking specifally about smoke alarms.

I was (well, smoke/heat/CO/gas etc.). However, I was asked why I would need to 'work on the circuit', and I replied that the reasons would be much the same as with any other circuit.

 

[ebee]

I have been known in the past to put a battery operated mains failure bleeper on things in the past where it might help - notably for power failure of a flood pump i.e. proprty prone to flood risk and a float triggers a pump to run to get local water down sufficiently but if mains not present and it calls for pumping you need to be reminded about that problem if you have a chance to bypasss it.
In this particular case I believe the use of a long extension lead to a property further up the road actually saved the day and they were then considering a genny just for tht pump.
The one time the pump was called but no power caused quite a bit of damage whilst the previous 10 times since the pump was installed was all fine, whatever combination is in place nowadays I have no idea, the couple split up then the lady left the property then I lost contasct with her some 5 or more years later.

As often the case it was a what can we do, how much will it cost, and once you get caught out then how much more will it cost to reduce that risk then on and on add infinitum , meanwhile insurance more expensive and more restrictive if you can get it at all.
Hindsight is wonderull but never applied beforehand regardless of me having opportunities of told yer so moments

 

[JohnW2]

I think as John said in the OP would be the best answer. Whilst I`ve never considered having an isolator for them I can see the merits so a yes from me.

Thanks. It's good to have at least one direct answer to my question

 

[JohnW2]

If a fire alarm system is the only circuit, on an MCB/RCBO, then IMHO - that provides all the isolation needed.

... but that's also the second reason why I don't really like the idea of alarms on a dedicated circuit - since it is then only too easy for someone to disable the alarms by operating the RCBO/RCBO in their CU. If the alarms are powered from a lighting circuit, similar action would disable their lighting as well as the alarms!

Why would a key switch on similar be needed, in addition?

See above. If one has decided to run the alarms off a lighting circuit, one would need some sort of switch to 'isolate' the alarm circuitry without losing lighting - although I do agree that the need for such 'isolation' would be a very rare event.

Mind you, it would be no more silly/unnecessary than having a 'fan isolator' (something which most manufacturers seem to believe we 'MUST' have)

 

[ebee]

Thanks. It's good to have at least one direct answer to my question

Yes I think it would be good or could be good in your situation as I assume your own private use, not in everbodies situation though.

I was working in a dental surgery quite a few years back, helping the plumber/heating bods with their electrical side and a few purely electrical bits too.
I did notice the staff whacking the roostat right down before lunchtime break and a hour later and return and whack it right up. I glibly asked why they had a room state instead of a cheap flick switch lol - a tamperproof state had been tried a few times with no success it seems.

Mind you, I have seen folks place a woolly jumper in a microwave oven to dry it out

 

[JohnW2]

Yes I think it would be good or could be good in your situation as I assume your own private use, not in everbodies situation though.

As I've said, it's not "me" - the question came from a 'third party'. My alarms run off a downstairs lighting circuit but I haven't bothered to include any switch/isolator, key-operated or otherwise.

 

[Harry Bloomfield]

How long are people going to live in a house with the lighting not working,

That could be days, weeks, however long it might take them to find, and engage an electrician to restore the lighting. We are not discussing you, or I, but the average punter, who cannot fix things successfully himself.

 

[sparkymarka]

FFS …Smoke alarms bleep when the back up battery is getting low …..for weeks even months ….i think someone would notice …anyway if you fit the AICO smokes all you need to do is release the faulty one and slide in a new unit …no need to isolate anything

 

[JohnW2]

That could be days, weeks, however long it might take them to find, and engage an electrician to restore the lighting.

You really are scraping the barrel

As has been said, the back-up batteries can keep the alarms going for 'weeks or months' - how many people do you think would wait ('in darkness') for longer than that before getting their lighting restored??

 

[JohnW2]

FFS …Smoke alarms bleep when the back up battery is getting low …..for weeks even months ….

Indeed, and most also flash an LED ....

i think someone would notice …

Someone might 'notice', but would not necessarily understand the significance.

anyway if you fit the AICO smokes all you need to do is release the faulty one and slide in a new unit …no need to isolate anything

That's what I would do, since I have Aico alarms (although I strongly suspect that the manufacturer probably advises isolation when one does that). However, other makes of alarms are not necessarily as 'simply' replaced.