'Isolator'/switch for smoke etc. alarms?

[Harry Bloomfield]

I think that the majority of people are probably familiar with the fact that they can (e.g. 'in an emergency') switch off any circuit by simply opening the CU door.

'In an emergency' I think, says it all. A segregated 'switch', rather than one which might be accidentally operated.

The idea of multiple circuits, minimises the chance of a fault, affecting multiple items - it also makes fault-finding so much easier.

 

[JohnW2]

'In an emergency' I think, says it all. A segregated 'switch', rather than one which might be accidentally operated.

So, as I asked, what about a switch, fed from a lighting circuit, inside an easily-opened enclosure?

 

[Harry Bloomfield]

So, as I asked, what about a switch, fed from a lighting circuit, inside an easily-opened enclosure?

It's still very much a compromise, on a separate circuit for the alarm.

 

[JohnW2]

It's still very much a compromise, on a separate circuit for the alarm.

a 'compromise' between what and what?

... and what do you mean by "on a separate circuit for the alarm" if, as I wrote, the switch is fed from an existing lighting circuit?

 

[JohnW2]

The idea of multiple circuits, minimises the chance of a fault, affecting multiple items - it also makes fault-finding so much easier.

I can't argue with that but I could mention 'practicalies'. I suppose the 'ideal' in your eyes (if one had a large enough CU and could afford all the cable) would be to have one circuit for each socket, one circuit for each light and one circuit for each hard-wired piece of equipment?

 

[Harry Bloomfield]

I can't argue with that but I could mention 'practicalies'. I suppose the 'ideal' in your eyes (if one had a large enough CU and could afford all the cable) would be to have one circuit for each socket, one circuit for each light and one circuit for each hard-wired piece of equipment?

That would be the ideal, but unachievable for most.

 

[JohnW2]

That would be the ideal, but unachievable for most.

'Easily' enough achievable, but at substantial cost, monetary and otherwise.

As with so many things, the question is whether the cost (in the broadest sense) of an 'ideal' is actually justified by the potential 'benefits' - and I feel sure that, in this case, the answer would be 'no', wouldn't it?

 

[ebee]

'Easily' enough achievable, but at substantial cost, monetary and otherwise.

As with so many things, the question is whether the cost (in the broadest sense) of an 'ideal' is actually justified by the potential 'benefits' - and I feel sure that, in this case, the answer would be 'no', wouldn't it?

Indeed and in my opinion the word "minimise" in a particular reg is incorrect (strictly speaking) because to do that we need to take it right down to its lowest common denominator, which we do not. What word or phrase is best to replace it I do not know but we might strive to achieve its probable intention I think.

 

[Harry Bloomfield]

As with so many things, the question is whether the cost (in the broadest sense) of an 'ideal' is actually justified by the potential 'benefits' - and I feel sure that, in this case, the answer would be 'no', wouldn't it?

My system, was installed by A N Other, some years ago. One of the alarms, was located, in the hall, close to the consumer unit, in the understair cupboard. They used a small, extra consumer unit to power the system. Last year, I replaced my old cu, and the small one, with a larger one, supporting many more ways, so I could split several circuits, to improve the redundancy. I could have added the fire alarm circuit, to one of the lighting circuits, but made a decision not too, and for the reasons I have already stated.

 

[JohnW2]

Indeed and in my opinion the word "minimise" in a particular reg is incorrect (strictly speaking) because to do that we need to take it right down to its lowest common denominator, which we do not.

Agreed. "Minimise" seems to be imply "get as small as is theoretically possible" - which would often be impractical and/or silly.

What word or phrase is best to replace it I do not know but we might strive to achieve its probable intention I think.

If one wants a single word, rather than a more explicit lengthy phrase (e.g. "to get as small as is reasonably practical (and/or sensible)", how about something like "moderate"?

 

[JohnW2]

My system, was installed by A N Other, some years ago. One of the alarms, was located, in the hall, close to the consumer unit, in the understair cupboard. They used a small, extra consumer unit to power the system. Last year, I replaced my old cu, and the small one, with a larger one, supporting many more ways, so I could split several circuits, to improve the redundancy. I could have added the fire alarm circuit, to one of the lighting circuits, but made a decision not too, and for the reasons I have already stated.

That's all fair enough.

However, what I said had a 'cost' (in the broadest sense) that could not really be justified by the potential 'benefits' was your 'ideal' - of having every socket, every light and every hard-wire appliance on it's own separate circuit.

 

[Harry Bloomfield]

However, what I said had a 'cost' (in the broadest sense) that could not really be justified by the potential 'benefits' was your 'ideal' - of having every socket, every light and every hard-wire appliance on it's own separate circuit.

It's called 'a compromise'.

 

[Murdochcat]

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

Better still just fit the ones with the lithium b batteries so you don’t have to touch them for over 10 years

 

[JohnW2]

It's called 'a compromise'.

Indeed so- but that's merely a word to describe what I was talking about - the 'balance' between cost (in the broadest sense) and potential benefit.

A very high proportion of decisions are 'compromises', since most things in life come with 'pros' and 'cons'. The ones we most commonly discuss here tend to be compromises between providing protection against extremely small risks and the cost (in the broadest sense) of providing that protection - and, as we know, opinions/attitudes to risk (hence the justification of costs to avoid them) vary widely between individuals.

 

[JohnW2]

Better still just fit the ones with the lithium b batteries so you don’t have to touch them for over 10 years

Do you mean non-rechargeable lithium batteries? If so, that's an approach to alarms which seems to be frowned upon thee days.