Bad fitting of fp 200 cables.

[Davro]

I have just installed extra detection in a building and found that some of the old detection was not wired in!!! I know it was installed 2 years ago by another company but for some reason not connectd into loop.(firedex 3000).Question is the all cables are in pyro and fitted correctly so i did the same with my fp cable and then connected the detectors that were not on the system all was o.k but am i at fault now because they just slung their cables in and i connected it,making me the last person to deal with it and will it comply with fire regs.

[Graeme]

no your not at fault so long as whatever work you have done complies with BS5839-1 regardless of the state that you find it in.

issue a modification certificate that only holds you responsible for the work that you have done.

in this case fit detectors not the state of the existing wiring.

[Chris Houston]

This should have been spotted before now, as each detector should have been tested at least annually!

[Davro]

Yes your right they should have been spotted by service guys but i think the fault was  did not have the software to introduce them on the loop.Major big company if you know what i mean and if they cant do it who can i thought.

[kurnal]

I have been looking at a new alarm system in a large office building. draka Firetuf soft skin cable has been used, it hangs vertically in 5m high pipe ducts without any support, lies across none fire resisting false ceilings without any support (thats easy specifically covered in BS5839) and where there is no false ceiling metal loop strips have been screwed to the underside of the floor slab above through which the cable loops every 4m or so. A group of 6 cables descend 3m to the panel from the ceiling and have no support except they are tied together with plastic tie wraps and swing freely when pushed. I think the plastic tie wraps are also supporting the cables- and again that is clearly wrong.

I have raised it as unsatisfactory in the risk assessment but the installer is challenging this.

I have referred to the cable manufacturers website but little positive help, looked at BS5939 and BS7671 and "Modern Wiring Practice" hoping to find something specific on spacing for cable supports in concealed and exposed  surfaces.

Modern Wiring Practice refers to standard PVC - clip every 250mm horizontal /400mm vertical for exposed and 4m horizontal / 5m vertical in concealed places for unsupported PVC.

Any comments or guidance please?

[Wiz]

Prof., I presume you are now only asking about the distances between fixings since the other problems are covered by 5839.

The standards won't recommend a general fixing distance because such figures might only be applicable to some versions of cable. It is up to each cable manufacturer to advise specific maximum fixing distances for their product to achieve the fire resistance required in BS.

I've had a quick look on Draka Firetuf website but can find no reference. You might need to phone their technical support to find out more.

It would have be better if 5839 had said something like the cable fire resistance capability must be based on fixings at a maximum of 600mm horizontally and 900mm vertically, for example.

You could always turn the tables on the contractor and ask him to provide written evidence of the cable fixing spacings required for that type of cable before you will amend your risk assessment!

[Galeon]

Kurnal ,
Same old story the holy bible was written and soft skinned cables were not really allocated much attention as when I started on the 14th edition mineral was still the one to use.
I know the 17th is up now and it needs an amendment since soft skin cables have basically taken over.
To my mind there should be a commercial element to this regs , and in particular fire alarms should be separate entity as well.
I would look at the mineral section as this will only give you the possible ammo you need.
You could also see installation spec requirements the cable company has , might be able to achieve not installed as per manufacturer's guide for performance.

[kurnal]

Thanks for your replies. It really goes back to similar arguments to those Thomas Brookes was making in the thread on recognising the technical details of heat and smoke detectors during a fire risk assessment.

I dont particularly  want to go nit picking during a fire risk assessment and ought to have confidence in the certificates presented to me and put a tick in my box. But if the installation and commissioning engineers have  not done their job right and left something as blatantly obvious miles of cable just resting on the top of the false ceiling matrix bearers awaiting the tiles being put in, and every alarm cable just tied together descending several metres to the panel swaying gently in the breeze then something has gone wrong.

Then when you point it out engineers go apopleptic and defensive and make it worse by saying they always do it like that and if fire officers, BCOs  and landlords dont complain who the hell are you to criticise and what qualiications have you got? Tel me whats wrong with this and show me where it says so?

Well its easy to shoot them down in some cases where there is a spefific  breach of BS5839 ( false ceilings and plastic cable ties) but the unsupported cables appears to be a nightmare because each manufacturer has different rules based on their own products fire  tests.  

I would be grateful for any general guidance on this for soft skins-  a bit like we have for mineral and pvc - to use as a rule of thumb to indicate when I should blow the whistle.

[jokar]

Could we not now use Artcile 38?  The new version of 5839 discusses firefighters getting tangled in cables following the Harrow Court incident.  The current and latest edition of the fire detection and alarm standard is
BS 5839-1: 2002+A2: 2008. The following clauses relate to the changes made as a result of the Harrow Court recommendations:

26.1(A2)Commentary: Unless cables are supported in such a manner that they remain supported for the duration similar to that for which the cable itself can survive a fire, early failure of the circuit might occur because of strain on terminations as a result of collapsing cables.

26.2 Recommendations, (f) Note 9 (A2): Experience has shown that collapse of cables, supported only by plastic cable trunking, can create a serious hazard to firefighters, who could become entangled in cables.

46.2(b)(5): Note 2 (A2): Serious shortcomings in cable support that could result in collapse of a significant length of cable in the event of fire should also be regarded as a major non-compliance.

[Wiz]

.......Then when you point it out engineers go apopleptic and defensive and make it worse by saying they always do it like that and if fire officers, BCOs  and landlords dont complain who the hell are you to criticise and what qualiications have you got? Tel me whats wrong with this and show me where it says so?........

This is a common problem. One way to deal with it is to only deal with your own customer. i.e. don't answer questions from anyone other than the person paying your bill for the report.

If your customer passes your report to, say, the installers, then that is between your customer and the
installers. Don't get involved.

If you start talking with the installer then you are left with only one option i.e. to prove everything you've put in the report. This only gives you more work and him/her free training!!

If you are confident in what you have put in your report then there is no problem. If someone disagrees with something in your report it is up to them prove it wrong.

Playing the good guy and just trying to help some people, doesn't always work.

[kurnal]

Thanks Dr Wiz. Good advice, though often the client puts all of us in the same jar at a pre handover meeting  and shakes the jar up. He is only interested in what comes out at the end.

Jokar- the only problem I have with the new clauses in BS5839 is that my risk assessment is under the RRO, firefighters are not relevant persons under the order

[jokar]

Yes I know, but if they are sent in to save relevant people then that is a subtle change.  In addition the facilities, the FA system, is there for the use of firefighters, zoning etc, therefore you could apply A 38.

[GregC]

I looked into this a while back and found that the cable fixings distances are down to vibrations as measured by the HSE, in a normal enviroment it is recommended that the cables are fixed every 300mm and 450mm, if the property is next to a railway line they may need to be closer etc.

As for ownership due to being the last person to work onthe system, doesnt 5839 say you may not add to the non compliance of an existing system, makes your case a bit more difficult, where the cables part of the system but just linked through, if so you have not introduced a non compliancy, if not then I would say you have.

Also should they have not been found when the site was inspected for the first time and the owners informed?

[Wiz]

Greg,
Surely vibration resistance is not the only criteria. We are talking about fire resistance and surely the spacing of fixings is relevant for this.

I was once told by a cable manufacturer that when a soft skinned fire resistant cable is attacked by flames a chemical reaction causes the skin to 'carbonize' in some way which then provides a fire resistant, but brittle, covering on the cable. However this brittle skin is then very susceptible to cracking open (and losing fire resistance) if it is moved too much.

If the above is correct, then surely the manufacturers have done tests to confirm the maximum fixing distances to ensure the cable does not move and crack open in a fire?

I can understand that vibration could make the 'cracking open' problem worse but surely the cable has to be properly fixed for fire resistance purposes in the first place?

I was also told that the original soft skin fire resistant cables were only tested for fire resistance when affixed to a solid wall because some of the heat generated in a fire would be absorbed by the wall and not the cable. Evidently they didn't tell anyone this. It was subsequently found that cables in fires where flames could 'lick' all around the cable couldn't meet the fire resistance required. Evidently the manufacturer eventually rectified this problem.

Manufacturers are selling fire resistant cable with no clear instructions as to how it should be used. Why do they do this? Have they got something to hide? If a cable fails in a serious fire will they look for ways of getting out of liability and blame the method of installation?

I believe installers should contact their cable suppliers and insist on being given a full set of installation criteria for that cable that will ensure it meets it's fire resistance in a fire.

Is there any other product sold in the fire industry without any installation instructions?

[Goodsparks]

http://www.uk.prysmian.com/en_GB/cables_systems/energy/catalogue_pdf/lv_pdf/fp200_gold.pdf;jsessionid=EE1D3CYLY4LQBFYKJO4SFEY

300mm Horizontal, 400mm vertical for FP200, I doubt the others will be a lot different.

Paul