"Radial sounder circuits" (plural)

[david911cockburn@btintern]

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!

[Wiz]

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.

[Wiz]

It is certainly radial wiring in the terms used for fire alarm systems and clearly that is what BS5839 is all about; full stop.

[kurnal]

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/

[David Rooney]

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?

[Tom Sutton]

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?

[David Rooney]

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 ......

[David Rooney]

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 ?

[John Webb]

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.

[Tom Sutton]

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.

[Graeme]

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? 

[David Rooney]

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......

[kurnal]

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

[Tom Sutton]

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?

[Graeme]

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?