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FIRE SAFETY => Fire Alarm Systems => Topic started by: lyledunn on May 03, 2012, 01:24:03 PM
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A large local housing authority has dictated that no smoke alarm system should be supplied via a pay-as-you-go type meter. Perhaps a reasonable diktat with respect to effective fire alarm function for Grades A-C but perhaps a little unreasonable for Grade D systems where battery back-up is of the order of years! It is very restrictive for many tenants and indeed landlords who would much prefer the pay-as-you-go type of meter. Does any one know if this requirement is common or do you have any opinion? Really would appreciate your comments.
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Hi Lyle
Detectors should be powered from the landlords supply and I would never advise anything different.
In the case of mains powered detectors fitted with 10 year lithium batteries you could argue the toss I suppose. So long as the battery could not be easily removed (generally they are not when it comes to lithium battery models) then you may be able to justify having them connected to the tenants supply, but it doesn't rest easy with me.
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Thanks for the reply Midland Fire and I accept your points. When served from the landlords supply you then have 230v detectors that are not fed through the isolator in the consumer unit in the flat. This could introduce problems complying with BS7671 2008 and is generally an undesireable situation from an electrical safety perspective. I have pointed this out to the housing authority and they have asked for notices to be placed at the flat consumer units. Unfortunately, folk have become almost blind to warning notices as they seem to an omnipresence in modern life.
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I guess the Housing Authority know their tenants and their behaviour?
There are no stipulations in BS5839-6 with regard to a Grade D system, preventing the smoke alarms being powered from the consumer side of a pre payment meter. I agree it is far less than ideal but must be considered a tolerable risk as the BS is specific in precluding it for a grade A/B system but makes no mention of it in respect of Grade D.
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Oh how naive Big Al. it is not considered a tolerable risk. it is just we never thought of it. it is a well-known issue.
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Interesting response as always Colin.
If it is not considered a tolerable risk what are we doing about it?
Government statistics indicate that 14% of homes in the uk, and up to 28% in NI use pre payment meters. Roughly 4 million dwellings.
Would you agree that if it is a risk, then it is potentially a risk all dwellings with pre payment meters, whether houses or flats? And that only the occupiers of the dwelling are at risk as a result?
The risk will only arise when there is no credit on the meter and the battteries/ capacitor have discharged as a result. In void dwellings no-one is at risk (though the batteries may be badly affected by remaining in a state of discharge for extended periods.)
If someone cannot afford to top up their prepayment meter then they could be at risk and the risk will be elevated because they are more likely to use candles.
On the other hand the likelihood of this will be fairly low because people are likely to make electricity use a priority for all manner of other reasons- phones etc. For those who really cannot afford this they probably will be well known to the Landlord as they will be on housing benefit. As I said the Landlord knows their tenants and their behaviour.
If we cannot use a BS as a benchmark standard then its a poor show.This one has been around a long time and so have pre-payment meters. You probably remember putting a shilling in the slot as I do. There are also risks in rewiring to feed detectors from the Landlords supply. Apart from the issues under BS 7671 and giving it away with a sign there is a possibility that the smoke detector will be unplugged and a feed taken from the Landlords supply for other purposes. I have seen similar diversions of the landlords supply many times over the years usually creating a much more significant fire risk through overloading and improvisiation.
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It is a well known issue.
Lyle are you referring to the fact that BS 7671 states that smoke / heat alarms can no longer be powered from a lighting circuit? Is that specifically what you mean about introducing problems complying with BS7671 2008 and it generally being an undesireable situation from an electrical safety perspective?
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Midland fire,
What I am referring to is the requirement to have double pole isolation at the installation origin in domestic premises. The implication in this requirement is based on the fact that safe systems of work such as safe isolation would obviously be less likely than in a work environment.
Kurnal has neatly summarised many of the concerns. It is my instinct that despite any fire safety concerns relating to security of supply, it is less than a tolerable risk to have 230v detectors fed from the landlords supply, whether or not an isolator is supplied on the circuit.
With respect to smoke detectors on a separate circuit, 560.7.1 requires safety circuits to be independent of other circuits. Simple statement but I bet they were not thinking of domestic smoke alarms!
I would not like to be thought of as churlish but Colins response is to say the least surprising. How come card meters were thought about for Grades A,B and C but not thought about for grade D? As Kurnal points out, like many, I am very reliant on BSs as reference points for good design, construction and verification.
Might I be so bold as to ask Colin; if it wasn't thought about in the formulation of the Standard, have you thought about it since and would you like to proffer even your own perspective on the subject?
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The other problem regarding the use of a Landlord's supply for smoke detectors is that such a supply might be on a different phase to the tenant's supply. BS7671 requires a minimum separation between phases and/or appropriate notices. With light fittings and detectors likely to be in close proximity on a ceiling, the two phases could cause difficulty in complying with BS 7671 requirements.
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There could be simple solutions if we could change the technology. But with 4 million homes already fitted with pre payment meters (it would be interesting to know how many of these have smoke detectors) retrofitting new technology is not going to happen.
Smoke alarms are only mains powered because that was a convenient and reliable source of supply. If it is no longer considered appropriate then alternatives need to be found. The detector only needs 9 volts so an independent SELV feed of this nature could be provided either direct from the mains intake or on a central system in flats.
However, this would require a complete redesign of the current range of alarms for Grade D systems and in my view is unlikely to happen. Certainly not retrospectively and I would suggest that the market is effectively saturated- all existing homes likely to be fitted with pre payment meters will already be so fitted.
Perhaps the current initiative by MP Adrian Sanders - The Fire Safety (Protection of Tenants) Bill - if it takes off- could encompass this?
http://www.thisisderbyshire.co.uk/Smoke-alarms-rented-homes-law-thanks-MP-campaign/story-11604704-detail/story.html
It would be easier and cheaper for the fire service to obtain a list of all premises in their area with pre payment meters from the utility providers and to install long life battery Grade F smoke alarms to supplement the mains powered ones if this is really an intolerable problem.
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Sorry but can you confirm what premises you are talking about please because you seem to have gone off at a tangent. Are you talking about single domestic dwellings or hmos or what. If you are talking hmos then what lyle has said is quite true. Most installs dont comply with 7671. But then again that isnt to say that they have to. Anything pre 2008 is fair game until them come to replace or upgrade. So lets just slow down a bit and make the position clear about the type and age of premises we are talking about.
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Kurnal, because it was not considered tolerable, it does not mean that it was considered intolerable either. You must learn to read things before you hit that reply button and go off on one of your rants. I said it was NOT CONSIDERED -as in CONSIDERED AT ALL.
The concern about Grade A, as Cleveland is trying to tell you, is that it will be used in HMOs, where clearly it is totally unacceptable to run a landlord system off a pre-payment meter. As I keep trying to tell you, this has been a well known issue for EHOs for, to my certain knowledge, more than 10 years ago, when it first began to raise its head.
With regard to dwellings, we DID consider, the issue of pre-payment meters, in defining the minimum standby duration. More specifically, we were concerned to know whether capacitors were ok, given that they cannot last anything like as long as standby batteries. Rather than rush off with opinions based, I acknowledge, with lots of good intent but no research or analysis, as I so often read here, we held discussions with social researchers to find out about patterns of pre-payment meter use by low income vulnerable groups. That is how we came by 72 hours, which is achievable with capacitors. Batteries will last way way longer, but long income families often use pre-payment meters in a manner known to social scientists as cycling, whereby they intentionally let meters run out at certain times, and then use them again when they want the electricity. We were advised that 72 hours would be adequate duration and a benefit of capacitors that trades off against their much much shorter standby time is that they recharge quite quickly.
The commentary in BS 5839-6 kind of explains this. You will also find pages of explanation in my text book on domestic fire detection and BS 5839-6, which I will gladly supply to you at author's discount so that you dont need to lie awake worrying about it. It refers to the research we did and the fact that anyone suffering disconnections for longer periods lie right at the tail of the statistical distribution, but if they are an issue, you make sure that the smoke alarm has a standby battery rather than a bank of capacitors, which will nearly always be the case anyway.
After that, we never considered the issue and did not revisit in when we had to address Grade A. It does not mean that there is a problem, nor that there is a need for people to go buying additional battery operated devices. It is just that the concern realted to HMOs and pre-payment meters-hence the attnetion was focussed on Grade A.
(By the way smoke alarms are not SELV, so you need to revisit your electrical engineering CPD.)
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Thanks Colin. My "rant" as you describe it was actually penned in a good humoured style or thats how I felt.
(Rant- To speak or write in an angry or violent manner).
Anyway thanks for the full picture. (Which I feel you might otherwise not have shared with us?)
I, perhaps wrongly, jumped to the conclusion that Lyle was referring to social housing comprising dwellinghouses of purpose built flats. I assumed this because the question would not have arisen in any premsies in which a Category A-C system is installed because BS 5839-6 is absolutely specific that the supply must not be derived from the consumer side of a pre payment meter. So sorry Cleveland, I should have spelled out more clearly what I was going on about.
OK I did drift into cloud cuckoo land in suggesting that if it was a problem a redesign of detectors operate at 9v rather than 240v and to be fed from a central 9v landlords communal power supply system (which I believe if it were created would have to be a SELV system) But I dont pretend to be an electrical engineer and will always defer to those with greater knowledge.
So Lyle I interpret the word of the oracle to be that provided the Grade D alarms have a battery back up rather than capacitor there is no need to be concerned. No doubt if I have misread that I will be corrected ;)
(thinks I wonder if the gradual deterioration of battery capacity with age was taken into account?)
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They deteriorate slower than retired firemen, who have much less capacity of value than standby batteries.
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As always, Big Al, you are close. You do not need to worry about batteries or capacitors or anything else, other than, for this evening at any rate, what Mrs Kurnatowski is going to give you for supper tonight. In exceptionally rare cases, you might want to ensure that there is plenty of capacity in the standby supply, but almost without exception there will be, so I would be more worried about the effect of BS 9991 on domestic fire safety. BS 5839-6 is fine and will be getting even better before too long. It has always been in safe hands, so sleep well tonight and dream of the days when there were beds in Matlock Bath fire station.
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How things can get out of hand when standards are not crystal clear; I have just learned that the hmo licensing authority is prosecuting the landlord for not removing the pre-payment meter as required in their notice to him. The case is this Tuesday so I will keep you posted on the outcome.
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I hope the landlord appoints someone competent to represent them so that all sides of the argument are adequately explored. Legal precedent is needed- but it should be based on a fully rounded argument. Sounds like a job for Toddy.
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I, myself will be in Northern Ireland next week, so look forward to hearing about the case.
Thanks for the plug Big Al......... I can see the strapline in the Belfast Telegraph already.....
"From the producers of heat detectors in hotel bedrooms and no need to retrofit intumescent strips and smoke seals all over the place, fresh from their latest successful determination, CSTA proudly present....... smoke alarms connected to pre-payment meters.......Now showing at a Courtroom near you."
It has a certain ring to it, I will admit, Big Al.
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Is there something here which would be relevant to emergency lighting fed from prepay meters as well?
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Is there something here which would be relevant to emergency lighting fed from prepay meters as well?
Sorry nearlythere am I missing something. Why would escape lighting be on the residents pre pay meter?
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Although not normal practice I am told that some lighting in smaller blocks is fed from one of the tenant supplies and they are compensated by the housing management for the use and inconvenience so there is a possibility of EL being affected.
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Is there something here which would be relevant to emergency lighting fed from prepay meters as well?
Sorry nearlythere am I missing something. Why would escape lighting be on the residents pre pay meter?
I'm thinking about student accommodation, digs not halls, where landlords might be concerned about occupants doing a bunk with unpaid bills or prepaid meters installed as a preference for occupiers especially for students who hate large quarterly bills.
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Is there something here which would be relevant to emergency lighting fed from prepay meters as well?
Sorry nearlythere am I missing something. Why would escape lighting be on the residents pre pay meter?
I'm thinking about student accommodation, digs not halls, where landlords might be concerned about occupants doing a bunk with unpaid bills or prepaid meters installed as a preference for occupiers especially for students who hate large quarterly bills.
Point taken, not come across that situation myself - It is Friday
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Nearlythere
I've come acrossa few HMOs where the supply for the EL has been taken from the tenants supply which is a bit naughty.
Back to the court case mentioned above - I think I am right in stating that a notice from the Housing Authority is similar to those issued by a Fire Authority in so far as failing to comply with a notice is a straight forward black / white offence. The landlord should have appealed the notice before the whole matter got to court. In other words the offence is failing to comply with a notice, and not about the technical aspects / improvements detailed in the notice.
I think the housing authority are probably justified in their actions, but equally I hope they allowed the landlord reasonable time to comply!
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Resurrecting an old thread here but.....
The above discussion relating to Grade D devices in flats being off pre payment meters is useful, but what do you all think of the below situation:
2 flats above a shop, each flat had an Grade D:LD3 system off it's consumer unit's lighting circuit, in turn off a pre payment meter. This is dealt with in BS5839-6 and the above.
However there is no landlords supply to the common areas and the stairway lighting and door entry system is fed off the 1st floor flats pre payment meter and main switches.
A BS5839-1 conventional system to L3 has been installed for full evac as per LACORS covering the stair and with HD to each flat lobby - this is also off the first floor tenant's pre payment meter and every time it runs out (more common after the alarm was installed as consumption has risen and no compensation is paid) the panel goes into fault (and runs off batteries).
This can't be good for the batteries and also raises the concern of if the first floor go on holiday for a week or two and let the meter run out - the panel will die and the communal system be out of action (you could argue no electricity does mean the risk of fire whilst empty is minimised...).
Worse still the stair relies on artificial light so EL is being considered which will be subject to the same issue.....
Whilst the providers master incoming supply and fuse is easily accessed I dread to think what the cost would be of laying in a new circuit, fuse and consumer unit to cover the common stair flight, EL & fire alarm would be.
What would you suggest?
The 1st floor flat is looking at being allowed to go onto a standard meter and payment plan anyway and as long as they get an allowance for the common usage whilst not perfect this would at least ensure a continual supply to the common life safety systems unless they really got into difficulty - or would you want a totally new common supply?
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However there is no landlords supply to the common areas and the stairway lighting and door entry system is fed off the 1st floor flats pre payment meter and main switches.
Whilst the providers master incoming supply and fuse is easily accessed I dread to think what the cost would be of laying in a new circuit, fuse and consumer unit to cover the common stair flight, EL & fire alarm would be.
Probably not that much, if the supplier can add to the existing service intake without a new main in from the street.
A new supply in from the street might be a couple of thousand.
An alternative if it's a rented property is to take the supply meter back into the landlord's area, the landlord to take the account over and have a credit meter, and then resell electricity to the tenant(s) through credit or prepayment sub-meters.