Fire alarm wiring

[Tom Sutton]

I received the following enquiry, which is outside my comfort zone and your help will be appreciated.

We design and manufacture chemical storage facilities, fire rated cabinets etc. Within one of these fire rated units we have installed a heat detector, and a magnetic door release system (for when the fire is detected).

The company that has purchased this unit is linking these to their own Apollo fire alarm system, but they have said that the cables we use are not to British Standard. I have attached a couple data sheets for your perusal, and I would ask if you could assist me in finding out if this is definitely the case.

Also, when does a heat detector and door closing system become part of a fire alarm?

The data sheets are in image form, cannot attach a pdf file.

http://i419.photobucket.com/albums/pp272/twsutton/J-YStYLg.jpg

http://i419.photobucket.com/albums/pp272/twsutton/JE-YStY.jpg

[Galeon]

Having had a look at the data sheets they seem more in line with the European spec , and not the general cable we would expect which is red fp200 or indeed mineral cable.The crux is the cross sectional area under our BS /Wiring regs which is 1mm . I think thats where your problem arises , along with the fire test and water spray test under cable manufacturer.(UK)
In relation to the heat detector and door closure , where is the power coming from them , and how is the door holder tripped.
If you had your own fire alarm control section for this , ie part of your system machinery thats a different kettle of fish.
However if you are looking for an exterior source for the detection and door holder you will be forced to comply , don't forget although we embrace the E.U (lol) BS still overrides in this country , and there are numerous threads in relation to this.
Here's a thought , a friend of mine did a fire alarm in France , for a British Firm , lovely job but it all had to come out and be changed to meet their country's regulation , appears you might have the same here , best of luck....................

[Tom Sutton]

Thanks Galeon am I right assuming the cable has to comply with BS EN 50200:2006 which is an European standard but this one appears to be a German standard (Din). Also the cross sectional area would not conform so it appears the purchaser has a good point. Dr Wiz please don't forsake me in my hour of need, I know you have been on today.  

[Tom Sutton]

My considered response with many caveats included,

Assuming the heat detector and the operation of the door closing system are controlled by the fire alarm control panel therefore it is part of the fire alarm system. IMO if this is so, this part of the cabinet is subject to BS 5839-:2002+A2:2008 and consequently the wiring is subject to BS EN 50200:2006. The data sheets refer to German standards not a European or British standard therefore not relevant to this situation.

Therefore to the best of my knowledge the purchaser’s concerns are legitimate and it doesn’t conform to the British Standard.

[Galeon]

And there's more ............... door retainers now under a separate BS 7272 Part 4 2007 , enjoy .

[Tom Sutton]

I am aware of it I remember Wiz nearly coming to blows with CT but is it a typo should it be BS 7273-4:2007?

Check out http://www.firecoltd.com/pdf/BS7273.pdf

[Wiz]

I am aware of it I remember Wiz nearly coming to blows with CT but is it a typo should it be BS 7273-4:2007?

Check out http://www.firecoltd.com/pdf/BS7273.pdf

Well Tom, your memory must be playing tricks. I deny coming close to blows with anyone on a forum and ask you to bear that in mind when posting so people don't get the wrong impression!

[Wiz]

Tom, in respect to your original question, does the cabinet with the detector form part of the area(s) to be covered by the premises fire alarm system? I don 't quite understand what these cabinets could be. How big are they? Can a person stand inside them? Are they a room in themselves? Does the door to the cabinet open on to an escape room etc etc ??

[Tom Sutton]

Well Tom, your memory must be playing tricks. I deny coming close to blows with anyone on a forum and ask you to bear that in mind when posting so people don't get the wrong impression!

Sorry Wiz I withdraw that statement unreservedly but as I remember it was an in depth discussion.

In response to your Reply #7 I do not have those answers other than I suspect the purpose of the heat detector is to warn the occupants of a fire in the cabinet and the release device to close the door to prevent the spread of fire. I think the size and location is irrelevant its not a case of is the detector/release device necessary that's what they want

The area of concern was because the heat detector and the release device, is connected to the fire alarm system does the wiring in the cabinet have to conform to the British standard.

[kurnal]

I have kept out of what until now has been a very interesting but technical discussion. But it may be necessary to put some context around this.

If the detector is a heat detector then it is most unlikely to be provided for the life safety of persons in the cabinet. It is much more likely to be for property protection or business continuity.

Compliance with the BS is not mandatory unless it is a contractual or insurance requrement. The BS does of course provide for variations to be made and declared on the system certification. But if it is a requirement of contract or tender then thats that. Unless the enquirer can identify the differences between DIN and EN standards and justify his proposal as equivalent.

BS7273 is fairly specific - five parts have been published each relating to a specific type of interface and may not apply in this case.

If the installation in the cabinet comprises part of the alarm and detection installation category of system- L1,P1,etc  then it should comply unless variations are agreed and approved. If not then its down to tender or contract requirements only.

In

[Wiz]

Tom, Prof. Kurnal's answer was where I was heading in asking the questions I did.

Your answers lead me to understand that the cabinet is within a larger room and that the door to the cabinet is normally held open but controlled by a heat detector within the cabinet. Operation of the heat detector allows the door to close (supposedly to contain the fire).

I am going to make the assumption that the cabinet is itself within a room or space that is protected by smoke detectors that are properly installed to a BS5839 Part 1 system.

If the cabinet is larger than 1m2 and the building fire alarm system is a L1 or P1 system then it might be argued that an automatic detector should be installed within it and wired and connected as a proper part of the building's fire alarm system and would have to comply with the BS.

If the above does not apply, then the heat detector might not be considered as an integral part of the building's fire alarm system and the standard of it's installation might not be such a major issue. It might even be argued that the heat detector/door hold arrangement is superflous and it would be better that the door to the cabinet remained open during a fire so that smoke could reach the nearest 'proper' smoke detector quicker.

Also how the heat detector and hold-open device is connected to the building fire alarm system might have some bearing. If the devices are directly connected to cie zone or other circuits, then it might be important to ensure the cabling used, whilst possibly not complying with BS5839 requirements, would not adversely affect the rest of the system if it failed through not being BS compliant.

If the heat detector and door hold system was only interfaced to the building fire alarm system by use of relays and had it's own power source then, in my opinion, it wouldn't really matter at all that this 'ancillary' system did not fully comply with BS5839. It is a just an 'extra' with no bearing or effect on the building's 'proper' fire alarm system.

[Tom Sutton]

Thanks Kurnal and Wiz, its as I suspected, never straight forward, especially without the complete and full details.

[wee brian]

These cables don't appear to be FR at all (not even the funny German version).

[Galeon]

I am aware of it I remember Wiz nearly coming to blows with CT but is it a typo should it be BS 7273-4:2007?

Check out http://www.firecoltd.com/pdf/BS7273.pdf

Yep , trigger happy on the keyboard !

[Tom Sutton]

True, firing from the hip has always been a problem of mine, acting without ensuring the brain is engaged, I shall write out a thousand times...........

Done it again, I thought you were talking about me.