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FIRE SAFETY => Fire Alarm Systems => Topic started by: david911cockburn@btintern on December 06, 2010, 03:57:11 PM
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Hi All,
I think it could be a good idea to start a new thread with this.
I've just been looking at BS 5839-1:2002, Section 2, Figure 1a) - Radial sounder CIRCUITS (please note that the word circuits is a plural).
The author has used ambiguity in order to avoid taking legal responsibility for the use of 'radial SYSTEM' sounders!
'Radial sounder circuits' should be used to describe two or more radial circuits. A 'radial circuit' is a circuit supplied by a 'radial feeder' to a central junction box from where eminate two or more 'stub end feeders' each supplying one socket outlet/light fitting/bell.
But in this example 'Radial sounder circuits' is used to describe two different circuits (one final circuit and one spur final circuit) configured 'radially'.
Therefore our author has not actually suggested that 'radial system' components/sounders should be used on the 'final circuit'.
Cunning little Devils aren't they!
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In fire alarm systems we describe the monitored two wire circuit emanating from control and indicating equipment as a radial circuit. This might be different to the description 'radial' as used in electrical distribution systems.
In current modern fire alarm systems all radial circuits emanate from control and indicating equipment and not from some junction point that is itself fed from the cie.
These radials are monitored for open and short-circuit faults, and to enable this monitoring to work correctly, generally no 'tees' or 'spurs' are allowed on the radial circuit and there is a two-wire circuit from the cie right up to the End-Of-Line monitoring device. (there are some systems that can cope with a specific number of spurs each with it's own speciifc EOL device)
The drawing Figure 1a) shown in BS5839-1 2002+A2:2008 shows two radial sounder circuits so it is clearly described as 'radial sounder circuits' i.e the draweing shows more than one circuit. It can also then be compared to figure 1b) which is described as Ring Sounder Circuits which is the method generally used on addressable fire alarm systems when using loop-powered sounders.
The people who write the fire alarm British Standards are considered experts in the fire alarm system field and I feel they will be taken aback to be described as 'Cunning Little Devils' just for trying to describe two methods of wiring specific to fire alarm systems, in terms that will be understood by fire alarm engineers.
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It is certainly radial wiring in the terms used for fire alarm systems and clearly that is what BS5839 is all about; full stop.
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David as Wiz points out the committee that wrote BS5839 knew exactly what they intended and ducking liability was absolutely the last thing on their mind. All Committee Members give their time and expertise on a voluntary basis. These people give up a great deal of their own time and pore over the midnight oil writing standards for the benefit of the rest of us. They have repeatedly demonstrated their commitment to improving standards in the industry over many years.
I am sure that they would welcome assistance. You clearly think they are getting it all wrong and that you have a great deal to offer.
I suggest you contact the BSI and offer your services. you can read all about how to become a member here:
http://www.bsigroup.com/en/Standards-and-Publications/How-to-get-involved/Become-a-committee-member/
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Sorry I posted this on the other thread where the question was originally raised......
Hi Kurnal/All,
I'm rather glad that I carried on worrying. I've been doing some reading but I didn't have to go to the Library, its' quite literally been right under my nose all day.
I am referring to BS 5839-1:2002, Section 2, Figure 1a) - Radial sounder CIRCUITS (notice this is plural).
Our author has used 'ambiguity' in order to relieve himself of the burden of responsibility.
Radial sounder circuits (plural) should refer to two or more radial circuits, which are circuits supplied by a 'radial feeder' to a central 'junction box' with any number of 'stub end feeders' (or spurs) from the junction box each supplying one socket outlet/light fitting/bell.
But in this case 'Radial sounder circuits' (plural) refers to two different circuits, one spur final circuit and one final circuit (or one zone), supplied in a manner that can be described as radial.
This drawing is not labelled as being a 'radial system', but we actually are using 'radial system' components (sounders).
In effect the author has not accepted the legal responsibility for the use of radial system sounders!
What exactly are you arguing ...... the definition of a radial circuit, is that it?
Everyone in the fire detection industry understands a radial circuit generally speaking to be a single cable wired from point to point. It has a beginning and an end and has no spurs coming off of it. Although even if it did this only presents problems from a fault monitoring point of view - pretty much as diagram 1a to which you refer indicates.
What it means to electricians working with LV or Frenchman running "star" cabling I couldn't really care less.
Our circuits will carry Extra Low Voltage at 24 volts dc (give or take) supplied by a safety isolating transformer within the CIE meeting EN54-4.
Are you trying to say that our ELV "radial circuits" are electrically dangerous or are you just trying to get the whole world to agree to a standard definition of the word "radial", if so how would this apply to my car tyres?
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The above definitions come from a British and an International electrical engineering dictionary!
Therefore why isn't Figure 1a) entitled "A Radial System".
It is titled "Figure 1a) — Radial sounder circuits [see 12.2.2j)]" To me a non electrician this says a sounder circuit using a radial system what's wrong with that? Or are you saying sounder circuits should use MICC you haven't been clear what yours concerns are other than clingfilm on a detector head could cause a short circuit which I understand would trigger the cie to FIRE anyway?
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The above definitions come from a British and an International electrical engineering dictionary!
Therefore why isn't Figure 1a) entitled "A Radial System".
It is titled "Figure 1a) — Radial sounder circuits [see 12.2.2j)]" To me a non electrician this says a sounder circuit using a radial system what's wrong with that? Or are you saying sounder circuits should use MICC you haven't been clear what yours concerns are other than clingfilm on a detector head could cause a short circuit which I understand would trigger the cie to FIRE anyway?
No a short circuit would/should cause a fault condition but PLEASE let's not radiate down a different spur ......
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Hi Kurnal/All,
I am absolutely sure that at least 90% of the Gentlemen that you refer to are exactly as you describe, good blokes, mostly ex-Fireman like you, used to working as a team and concerned about looking out for each other. But this is not public service this is the private sector which is full of money grabbing business men who, if they want to be rich money grabbing businessmen, spend their whole lives looking for a 'fall guy', somebody to take all of the risks whilst they get the money!
I still have no better clue as to what point you are trying to make with regard to 24 volt dc SELV radial fire alarm circuits.
Do you think we are still using three wire 230 volt ac systems ?
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We have a matter of semantics here. Virtually every BSI I've had dealings with contains its own list of definitions because every area of work has its own particular terminology (or jargon!). It is widely understood by those who use BSIs (or any other standard) that those definitions apply to the area of work covered by the particular standard. These definitions may or may not agree with those in a dictionary of any sort, but they stand within the context of the standard and it's application.
So the definitions in BS2671 and BS5839 of a 'radial' circuit may not agree with someone else's dictionary or with each other, but that's because they are dealing with particular applications in two particular fields near each other. I am sure there are plenty of examples from other Standards that could be cited! How about 'Header'? For electronic components a device for making connections on a circuit board, to a plumber an elevated water tank.
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I stand corrected Dave and I do agree I should have concentrated on the main point, what's his concerns and not take a chance on another deviation. :-[
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Hi Kurnal/All,
I am absolutely sure that at least 90% of the Gentlemen that you refer to are exactly as you describe, good blokes, mostly ex-Fireman like you, used to working as a team and concerned about looking out for each other. But this is not public service this is the private sector which is full of money grabbing business men who, if they want to be rich money grabbing businessmen, spend their whole lives looking for a 'fall guy', somebody to take all of the risks whilst they get the money!
I still have no better clue as to what point you are trying to make with regard to 24 volt dc SELV radial fire alarm circuits.
Do you think we are still using three wire 230 volt ac systems ?
what's wrong with a 240v system? ;)
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Hi Kurnal/All,
I am absolutely sure that at least 90% of the Gentlemen that you refer to are exactly as you describe, good blokes, mostly ex-Fireman like you, used to working as a team and concerned about looking out for each other. But this is not public service this is the private sector which is full of money grabbing business men who, if they want to be rich money grabbing businessmen, spend their whole lives looking for a 'fall guy', somebody to take all of the risks whilst they get the money!
I still have no better clue as to what point you are trying to make with regard to 24 volt dc SELV radial fire alarm circuits.
Do you think we are still using three wire 230 volt ac systems ?
what's wrong with a 240v system? ;)
I think we should put you in a straight jacket Graeme and let 911 explain from the beginning...... ;D
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Hi Kurnal/All,
I am absolutely sure that at least 90% of the Gentlemen that you refer to are exactly as you describe, good blokes, mostly ex-Fireman like you, used to working as a team and concerned about looking out for each other. But this is not public service this is the private sector which is full of money grabbing business men who, if they want to be rich money grabbing businessmen, spend their whole lives looking for a 'fall guy', somebody to take all of the risks whilst they get the money!
The BSI fire alarms committee is made up of representatives of the following organisations:
Association of Fire Consultants
B R E - Building Research Establishmen
B R E / L P C Laboratories
Bldg. Svc.s Research & Information
British Cables Association
British Fire Consortium
Building Standards Division of the
C L G - Represented by B R E
Chartered Inst.n of Building Services
Chief Fire Officers Association
Electrical Safety Council
F I A - Fire Industry Association
Fire and Security Association
Fire Brigades Union
Fire Protection Association
I E T - Inst.n of Eng. and Technology
I F E - Institution of Fire Engineers
Institute of Fire Prevention Officers
London Underground Ltd
National Landlords Association
National Security Inspectorate
Nuclear Industry FSCC
Security Systems & Alarms Inspection
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What I can say for certain is that we have mistakenly been using 'radial system' sounders on 'two zone' and 'loop' systems,
What type of sounders should have been used?
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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?
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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'
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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...
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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? :o
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I can't see that a loop-wired alarm sounder circuit is inherently any more relaible than two monitored radially-wired alarm sounder circuits.
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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!!
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So just so i get my head round this..
Dave , you wont !
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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.
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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.
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One in seven people in the UK are deaf or hard of hearing
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"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.
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One in seven people in the UK are deaf or hard of hearing
pardon
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........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.
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Makes it difficult to install a cat M system doesn't it?
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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.
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Not if you use a loop system Civvy.
Civvy means that Manual systems have no automatic smoke detection
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Not if you use a loop system Civvy.
Civvy means that Manual systems have no automatic smoke detection
Civvy means that manual only systems have no automatic smoke detection
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Not if you use a loop system Civvy.
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Not if you use a loop system Civvy.
Are you stuck in a loop?
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Not if you use a loop system Civvy.
Are you loopy?
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loop the loop
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Snooker loopy nuts are we.............. ;D
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Soooooo,as pointed out by others - everything that has been done before is wrong and needs to be changed and that it's all a big conspiracy??
I know what is meant be a radial in the case of a fire alarm system,as do the rst of the guys who work with the things 24/7 on a daily basis (that's 24 minutes out of 7 hours when you take out the tea breaks).
Without knowing the OP's history,you're not a sparkey who has got their hands on a copy of 5839 are you??
I'm away back to my comfort zone as you're all mad in here these days!!
Happy New Year to all btw ;D!
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Im extremely dissapointed that this thread did not continue into the new year :D
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Hi All,
Something has just struck me, why not ask Colin Todd why he has used the term 'radial sounder circuits' (plural).
Inner Monologue :-X
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Hi All,
Something has just struck me
An old ford mondeo being driven as if by the hand of God ?
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No, just me ;D ;D ;D
davo
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Hi All,
Something has just struck me, why not ask Colin Todd why he has used the term 'radial sounder circuits' (plural).
radial-spreading out from a central point.
exactly what a sounder circuit does from the CIE
and there is usually two of them.......
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Thought the police were a decent group back in their day
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In electrical engineering terms 'a radial system' is a number of 'spurs' eminating from a central point; and you are using radial system sounders on 'sounder circuit two' of a 'two zone system'!
Just because a 'final circuit' and a 'spur final circuit' can loosely be descibed as being 'radial' to one another, does not mean that they constitute 'a radial system', therefore you are making a mistake by using 'radial system' components in this way.
The problem is, when it hits the fan who is going to be held responsible? (please see Royal Marsden Hospital).
So how many how many people have been injured / died as a result of using the "wrong" radial components - presumably you mean sounders
If I install a Roshni on my definition of a radial circuit as indicated in the manufacturer's literature are you saying that is wrong ?
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David you have mentioned the Royal Marsden Hospital before but the official report into the fire makes no mention whatsoever of any problems with the fire alarm system.
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Have to be honest and say that i won't loose any sleep over it David if the sh1t hits the fan because 95% of us have been doing it wrong for years with using radial sounder circuits.
It will be a big case and probably take a while to get to my turn in the dock. All the boff's from the BS committee will be before me.
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Graeme, You should listen to David. The writing is on the wall. Best hire me now as an expert witness for you, as come the Armageddon, I will have lots of others wanting my services. Please send forthwith a cheque for £100,000 for the first year's retainer. Annually recurring fees thereafter will be subject to negotiation.
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Blimey
There must be a recession on when you discount your rates. Does that include the services of that Reknowned fire expert ex H&S bank guy you employ :P
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Graeme, You should listen to David. The writing is on the wall. Best hire me now as an expert witness for you, as come the Armageddon, I will have lots of others wanting my services. Please send forthwith a cheque for £100,000 for the first year's retainer. Annually recurring fees thereafter will be subject to negotiation.
a bargain..Thanks Colin
I will put in a good word for you if you want when you get the call too.
;)
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Always happy to discount the rates for a fellow Scot.
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even better... thanks
i feel you may be busy then as according to David we are all doomed. :'(
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i presume the tramp was sleeping outside in a cardboard box? when someone set fire to it
i can see how a sounder circuit wired as a radial can be held accountable on that one.
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Hi All,
People were hurt at the Royal Marsden because some people only took it seriously when they smelt smoke, the qoute from Doctor Jones made it clear that the system failed.
There was a tramp killed a while back who was asleep in a pile of cardboard up north somewhere.
Last year I saw that there were four (or maybe six) dead fireman within half a dozen headlines at BT Yahoo.
Mr. Todd had to go to Preston the other week to explain away the death of a 91 year old man.
I don't even watch the news!
Bottom of the barrel well scraped there for justification of the original post.
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Hi Graeme,
The tramp was in a loading bay, at the back of a shop.
Does anybody know the details surrounding the dead fireman, or more precisely the fireman who were killed that has resulted in two senior fire officers being thrown to the lions?
How on earth is the link made between the homeless person dying in a loading bay of a warehouse and sounders?
How do you attribute firefighter deaths to a problem with sounders?
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Lateral thinking civvy, beyond your wildest dreams.
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Hi All,
People were hurt at the Royal Marsden because some people only took it seriously when they smelt smoke, the qoute from Doctor Jones made it clear that the system failed.
There was a tramp killed a while back who was asleep in a pile of cardboard up north somewhere.
Last year I saw that there were four (or maybe six) dead fireman within half a dozen headlines at BT Yahoo.
Mr. Todd had to go to Preston the other week to explain away the death of a 91 year old man.
I don't even watch the news!
Bottom of the barrel well scraped there for justification of the original post.
EH OOP DUCKS, aH aint never been t' preston, to sort out no trobble at mills, so moast av been case of mistaken identity
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CT
Please try to remember we are in the presence of a very fertile mind here, eh ???
davo
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My mind is fertile enough to remember that my mumm went to Preston once. I seem to remember her talking about the market.