Bad fitting of fp 200 cables.

[kurnal]

Thanks goodsparks that is really useful practical advice. And to everyone else who has assisted with my query. If I can find out how to attach pics I will post a couple of real eye openers I have come across this week.

[Wiz]

Good work, Good Sparks!

It does disappoint me that in the example you have found, that the note for fixing distances really only relates to using the LSOH clip because the 'note' relates to this. It doesn't confirm if there are any differences in using any other method of fixing. The manufacturers should be aware of all the typical methods of installing their cables and provide advice according to each method.

I agree with your thoughts that it is likely that other cable types would recommend similar fixing distances and it is likely that a similar fixing distance would apply to alternative fixings for this type of cable. But how can anyone be sure? I feel It should be made clear in black and white for such a critical application

[AnthonyB]

Thanks goodsparks that is really useful practical advice. And to everyone else who has assisted with my query. If I can find out how to attach pics I will post a couple of real eye openers I have come across this week.

Open a free account at Photobucket and upload your pictures to there. It will then give the you correct [img] tag to insert the photo on a post on here - just copy & paste it, thats how I do it

[Allen Higginson]

Im lucky in that the contractor that we use for installation runs horizontals' in 20mm metal conduit with metal saddles because it saves labour hours.

[Owen66]

The installation of the cables will fall under BS 7671 - several parts.

Reg 560.8.1  requires that cables installed for "safety services" to be mounted to maintain circuit integrity in fire conditions for as long as possible - that suggests firmly clipped to me so the when BS 5839 takes over and mandates metal cored clips then you still need to meet the requirements of BS 7671.

Examination of the whole of regulation group 522.8 - other mechanical stresses suggests in several regs that cables should be adequately supported both horizontally and vertically and that minimum bending radii are abserved. It does not stipulate minimum's as these would depend on the cable size.

Reference to Guidance Note 1 (Selection and Erection) shows in Table G2 that for cables exceeding 9mm and not exceeding 15mm diameter (typical soft skinned) then horizontal clipping distance is 300mm and vertical distance is 400mm.

So there appear to be lots of reasons why loose laid soft skinned fire alarm circuits don't comply with either BS 7671 or BS 5839
Regards

Owen

[Wiz]

Initially, It doesn't matter what any general purpose regulations might say, or what instructions for similar products might say, I would not be happy until the manufacturer of the cable I was using, provided clear, concise, written instructions as to how to use their product properly, and specifically what the maximum fixings distances are for my method of fixings to achieve the stated fire resistance.   I would only then consider any general purpose recommendations and, if necessary, modify the manufacturer's instructions if the general purpose recommendations required closer/more effective fixings. It is incumbent on a product manufacturer to provide the instructions for use required.

[GregC]

Owen, loose laid I would take it means laid on joists or inaccessable areas, such as closed in ceilings, it would be safe to assume that the joists/inaccessable areas would support the cable at least as well as a cable clipped to the underside of the joist or closed ceilings, even following all the guidence.

But Wiz, how are the cable manufacturers expected to know of every possible installation, they can only give guidence based on their controlled lab tests, all an installer can then do is prove he followed the guidence and requirements of BS5839, even then if he hasnt taken into account all the potential risks he may still be at fault and up in front of the judge.

I think the term "as far as reasonably practical" comes into use here, in old languange "common sense"

[kurnal]

The BS recommends fire resisting cables should be used, with enhanced protection required in some circumstances. Where enhanced fire resistance is required it is usually due to phased evacuation or in a building with different alarm zones. In these cases all alarm cabling is critical and installation standards must be upheld to the highest standard.

But how important is it in a simpler building with conventional evacuation strategy? What do we achieve by enforcing the highest standards of installation? I would like to explore why and what this achieves. What is the liklihood of a poorly installed soft skin cable with inadequate support  burning through or failing as a result of exposure to a fire before the alarm has been raised and evacuation complete? If the cable serves sounders as well as detectors then it appears to me to be particularly critical- and most do nowadays. In the old days I remember higher standards were applied to sounder circuits than detector circuits. Now everything is on the same loop but the loop and the isolators make this arrangement  more resilient.  Could a burn though affect more than the immediate vicinity of the fire?

Owen, loose laid I would take it means laid on joists or inaccessable areas, such as closed in ceilings, it would be safe to assume that the joists/inaccessable areas would support the cable at least as well as a cable clipped to the underside of the joist or closed ceilings, even following all the guidence.

Yes you could argue that  in the situation you describe we have a detector protecting the area beneath a ceiling with the cables laid on top of the ceiling. If the ceiling offers fire resistance, it will protect the cable. But presumably there will also be a risk of fire and other devices in the ceiling void as well, and ifwe could take account of the fire ressitance of the ceiling the BS would state this

But Wiz, how are the cable manufacturers expected to know of every possible installation, they can only give guidence based on their controlled lab tests, all an installer can then do is prove he followed the guidence and requirements of BS5839, even then if he hasnt taken into account all the potential risks he may still be at fault and up in front of the judge.

I think the term "as far as reasonably practical" comes into use here, in old languange "common sense"

Every day I see alarm systems installed by engineers I respect that do not come anywhere near the 300mm/450mm guidance for FP200 cables. Usually I turn a blind eye because poor standards are indeed the norm and I only rock the boat if something is strikingly bad.  But I am starting to wonder if the industry needs to get its act together a bit more and the Trade associations, Building Inspectors and Fire Authorities ought to look a little bit closer too.
Thanks to the responses to this thread we already have an understanding of the underlying reasons for the poor standards.

BS5839 is far too vague

Manufacturers do not give clear instructions on how their cable should be installed  

BS7671 is not specific as to whether its guidance applies to fire alarm cables and does not reflect the development of soft skin cables

There is a lack of understanding in the Industry

Commisssioning engineers do not have to look at cable workmanship as part of the commissioning process.

How much does it matter though?

[Wiz]

But Wiz, how are the cable manufacturers expected to know of every possible installation, they can only give guidence based on their controlled lab tests, all an installer can then do is prove he followed the guidence and requirements of BS5839, even then if he hasnt taken into account all the potential risks he may still be at fault and up in front of the judge.

I think the term "as far as reasonably practical" comes into use here, in old languange "common sense"

Greg, I don't mean every variation possible.

I would suggest it would be something like:

a) When the cable is affixed to any fire resistant surface that is anything other than horizontal, fixings should be every (say) 500mm.

b) When the cable is laid on or under a horizontal surface that partly exhibits less fire resistance than the cable itself, it must be affixed to a structure of at least equal fire resistance as the cable every (say) 400mm.

See, that wasn't difficult! Why don't the cabl;e manufacturers say something similar? I think they are hiding something!

[Wiz]

The BS recommends fire resisting cables should be used, with enhanced protection required in some circumstances. Where enhanced fire resistance is required it is usually due to phased evacuation or in a building with different alarm zones. In these cases all alarm cabling is critical and installation standards must be upheld to the highest standard.

But how important is it in a simpler building with conventional evacuation strategy? What do we achieve by enforcing the highest standards of installation? I would like to explore why and what this achieves. What is the liklihood of a poorly installed soft skin cable with inadequate support  burning through or failing as a result of exposure to a fire before the alarm has been raised and evacuation complete? If the cable serves sounders as well as detectors then it appears to me to be particularly critical- and most do nowadays. In the old days I remember higher standards were applied to sounder circuits than detector circuits. Now everything is on the same loop but the loop and the isolators make this arrangement  more resilient.  Could a burn though affect more than the immediate vicinity of the fire?

Owen, loose laid I would take it means laid on joists or inaccessable areas, such as closed in ceilings, it would be safe to assume that the joists/inaccessable areas would support the cable at least as well as a cable clipped to the underside of the joist or closed ceilings, even following all the guidence.

Yes you could argue that  in the situation you describe we have a detector protecting the area beneath a ceiling with the cables laid on top of the ceiling. If the ceiling offers fire resistance, it will protect the cable. But presumably there will also be a risk of fire and other devices in the ceiling void as well, and ifwe could take account of the fire ressitance of the ceiling the BS would state this

But Wiz, how are the cable manufacturers expected to know of every possible installation, they can only give guidence based on their controlled lab tests, all an installer can then do is prove he followed the guidence and requirements of BS5839, even then if he hasnt taken into account all the potential risks he may still be at fault and up in front of the judge.

I think the term "as far as reasonably practical" comes into use here, in old languange "common sense"

Every day I see alarm systems installed by engineers I respect that do not come anywhere near the 300mm/450mm guidance for FP200 cables. Usually I turn a blind eye because poor standards are indeed the norm and I only rock the boat if something is strikingly bad.  But I am starting to wonder if the industry needs to get its act together a bit more and the Trade associations, Building Inspectors and Fire Authorities ought to look a little bit closer too.
Thanks to the responses to this thread we already have an understanding of the underlying reasons for the poor standards.

BS5839 is far too vague

Manufacturers do not give clear instructions on how their cable should be installed  

BS7671 is not specific as to whether its guidance applies to fire alarm cables and does not reflect the development of soft skin cables

There is a lack of understanding in the Industry

Commisssioning engineers do not have to look at cable workmanship as part of the commissioning process.

How much does it matter though?

Hear, hear, Prof. I'm with you on all of the above,

[kurnal]

I saw a  new variation yesterday in a posh shopping centre. One of my clients has just completed their fit out to a stringent spec from the landlord. The landlords common areas fire alarm cables are clipped to the UNDERSIDE??? of a galvanised 300mm wide metal cable tray that is used for security and data traffic. Hundreds  of metres of enhanced protection cables fastened onto the bottom of the tray with plastic tie wraps.

[Galeon]

Sounds like a case of :
' Physician heal thyself'

[Graeme]

quick blast through the ammended standards today and noticed that any cable unsupported over a significant length should be regarded as a major non compliance.

[kurnal]

Any idaea of what a significant length may be?

If carrying out a 6 monthly  service on an old installation pre 1988 with PVC T&E for the detector circuits and soft skin for the sounder circuits  how many of you guys would see this as a problem and bring it to the attention of the client?  Would you ever upgrade it without the panel falling over first? If the panel did fall over and you replaced it would you replace the detector circuits at the same time or leave the PVC in situ??

No trick questions just trying to identify a consensus. Seen a new panel installed recently on horribly substandard wiring and no comment on commissioning cert.

[Galeon]

Personally , I would advise them of the actual facts of what they have got , based upon a reasonable system .
I would advise them to make budget allocations for the future to bring it in line within the requirements at present which we hope are the best at this present time .
However there seems to be a trend outside the fire companies to bash the owner of the installation with 'It don't comply to 2002 standards'.
If you are realistic and honest with people they seem to take it on-board .
If you have advised on matters and they only want to change the panel , fine then the panel is changed and correct paperwork is issued , I have been to some jobs after a so called upgrade and the original installation and kit was better than the cr*p that has replaced it.