"Radial sounder circuits" (plural)

[Wiz]

David

are you telling me that i have been doing it all wrong for 18 years? and why just a 2 zone?

and in you opinion what could be the implications for us all?  Jail or go around all of our sites to rectify the "radial" sounder circuits?

And what would need to be done to achieve this 'rectification'

[Graeme]

David

How can you make a non addressable sounder circuit into a loop? where would the EOL go-in the panel?

A loop in a non addressable panel would just be the same as a spur and not fault monitored.

Self isolating sounders etc are n/a to non addressable systems.

Battery operated or mains devices? what's that alll about?

If what you say is true then it looks like we are all doooooomed...

[Meerkat]

if the British Standards are changed promptly all of the current systems would then fail to comply and this would shift the burden of responsibility on to the owner of the system, it would then be up to the owner of the system to pay you to bring the system up to the British Standard!

All system owners would of course be quite happy to pay to "bring the system up to standard" just because the goalposts all got moved....  Please tell me you aren't serious? 

[Wiz]

I can't see that a loop-wired alarm sounder circuit is inherently any more relaible than two monitored radially-wired alarm sounder circuits.

[Graeme]

Hi Graeme,
Essentially we would have to convert to 'loop' systems for the warning and manual activation devices but automatic devices such as heat and smoke detectors aren't essential components, therefore there is no need to configure them onto the loop if that is inconvenient, remote battery operated automatic devices are perfectly acceptable as would be a sequentially wired, monitored arrangement as long as the manual call points are removed and put on to the loop.

I don't believe that we are all doomed at all, if the British Standards are changed promptly all of the current systems would then fail to comply and this would shift the burden of responsibility on to the owner of the system, it would then be up to the owner of the system to pay you to bring the system up to the British Standard!
The 'British Standards system' hands all of the 'trump cards' to the honest tradesman, so let's play the game. 

So just so i get my head round this....What you are saying is that we need to swap out all of our non addressable systems and replace with analogue addressable. Incorporate all the call points into the loop but leave all the AFD which could then be replaced by Battery operated smoke devices as AFD are not considered important!!

[Galeon]

So just so i get my head round this..

Dave , you wont !

[Wiz]

Any fire capable of distorting a metal mcp enough for the operating glass to break would surely affect a plastic one equally.
I would further suggest that by the time a fire of such intensity did so then it is probably too late to worry about if a the fire alarm had operated anyway because the fire might be too intense to allow safe evacuation.
The idea of self-powered, isolating alarm sounders appears to be an expense that is not considered necessary by the BSI committee. It is assumed that failure of sounders on a monitored circuit outside of a fire condition is an unlikely scenario. During a fire condition the cable and devices should provide enough resistance to fire to allow the sounders to operate long enough to allow evacuation. Self-powered, isolating sounders are therefore not considered necessary.

[Graeme]

David

Have you ever tried to stand in the area when a very loud sounder(KLAXON) is going  off? Hence the 120 dB(A) clause as anything louder will send people into panic.

The louder they are in a block of flats-the more likely they will be ripped off the wall. Also a quick calculation tells you that installing a few very loud sounders as opposed to several low set ones is a waste of time as it will not be nearly loud enough in all areas required but far too loud in the immediate areas they are installed in.

[Tom W]

One in seven people in the UK are deaf or hard of hearing

[Mike Buckley]

"Hence the 120 dB(A) clause as anything louder will send people into panic."

Not to mention getting very close to the maximum limits under the noise at work regulations, and no they may not apply to a fire situation but they will apply to the weekly test.

[Graeme]

One in seven people in the UK are deaf or hard of hearing

pardon

[Wiz]

........A plastic call point has to (where it isn't a 'self isolating' part of a loop) be protected by a smoke detector..................

David, please tell me more about this. I'm intrigued.

[CivvyFSO]

Makes it difficult to install a cat M system doesn't it?

[Graeme]

Hi Wiz,
Where ever I see a break glass, there is a smoke detector above it.

it's not there to protect the break glass....coincidental it just so happens to right above all the ones you have seen.

[Graeme]

Not if you use a loop system Civvy.

Civvy means that Manual systems have no automatic smoke detection