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FIRE SERVICE AND GENERAL FIRE SAFETY TOPICS => Technical Advice => Topic started by: kernow on March 11, 2011, 09:31:37 AM
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Good Morning
can some of you technical experts answer my question.
i recently veiwed a grade A fire alarm in a new build block of residential flats.
the fire alarm was directly wired into the consumer unit and the unswitched spur was the pop out fuse type.
i was lead to belive that the alarm should be fed directly from the mains via its own consumer unit (red lockable type?) and that the unswithed spur should be a safety isolater type with either a key or secret switch (EL type fish tale)
ive read 5839 chapter 29 and could use other opinions
cheers
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Hi Kernow
Have you access to a copy of BS5839 part 6 2004?
Paragraph 15.4 gives further guidance on power supplies for Grade A systems.
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Ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh!
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Someone trod on your toe Colin?
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I knew I should have stuck to vet medicine. At least animals dont try to read standards.
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kernow which type of system are you talking about a BS 5839 part 6 or BS 5839 part 1. Category A is a part 6 system and what to refer to as chapter 29 is in part 1 you need to be clear which type of system you are referring to.
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Yes Tom, you are correct.
Part 6 does refer back to part 1 to a great extent in respect of power supplies.
The arrangement described by Kernow could be compliant but we also dont know which part of the building is covered by the fire alarm or to whose supply the fire alarm is connected to- the landlords or one of the flats?
What is covered and why?
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The system is Rafiki grade A LD3 covering the communal areas only, with the power fed from the landlords supply DB.
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Kernow
Take another read of the BS and you will see that subject to labelling the installation is probably compliant. Why is the alarm installed? Is it to operate ventilation systems or alert residents? Is it linked to the flats in any way or are they wholly self contained? If it is intended to alert the residents are they likely to hear it?
What instructions will residents be given on hearing the common areas fire alarm?
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Kernow
You should check out BS 5839 part 6:2004 "15.2 Recommendations for power supplies for Grade A systems" which states "(a) Power supplies for Grade A systems should comply with the recommendations of Clause 25 of BS 5839-1:2002, with the exception of 25.4e) plus two other clauses.
Then go to BS 5839 part 1:2008 and check out Clause 25 except 25.4(e).
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Tam, BS 5839-6 does not apply to the common parts, so this whole issue is founded on misconceptions.
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I stand corrected Colin I should have read clause 1 (Scope) and as part 1 only applies then Grade A is irrelevant. I hope that's right, anyway I am blaming you Kernow confusing a wrinkley. ;)
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Ah, Rafiki, a 'Screwfix special' fire alarm system, the sparkie's friend.
I'd put money on it not being required at all!
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Tam, BS 5839-6 does not apply to the common parts, so this whole issue is founded on misconceptions.
So am I right in saying this means that systems advertised as suitable for HMOs - and there are a couple when googled, both hardwired and radio, need to meet part 1 requirements in the common areas when the HMO is more than two storeys or floor area greater than 200m sq ??
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Thanks all for your replies, (even the unhelpful one)
maybe i should have been clearer with my question, so here goes.
the system is a Rafiki grade A L2 Automatic fire detection and alarm system.
it consists of call points and smoke detectors/sounders in the communal stairs and landing area/ escape route.
the fire alarm is wired from the landlords supply consumer unit and the spur is a pop out fuse type, with fire alarm do not switch off on it.
im led to believe that the fire alarm should have its own consumer unit - (that can be locked) and fed directly from the mains, with a safety isolator switch between the lockable consumer unit and the fire alarm control panel.
here is an excerpt from Bs5839: p1: 2002
29.2 e) ‘ Means should be provided for double pole isolation of the mains supply to all parts of the system; the isolation facilities should be suitably sited , in the vicinity of the equipment served, for use by maintenance technicians without the need for access to remote parts of the building. It should be possible to lock the facilities in both the normal and isolate positions to prevent unauthorised use
29.2 g) Every isolator, switch and protective device that is capable of disconnecting the mains supply to the fire alarm system should be situated in a position inaccessible to unauthorized persons or be protected against unauthorized operation by persons without a special tool
the answer im looking for is: is this system compiant with Bs5839 p1:2002 A2: 2008 on not: yes or no. as i believe it is not.
hope this makes it clearer to answer
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see section 5839 pt 1 25.2
Basically you need a dedicated standard rated fire proof cable from a local distribution board fed from a dedicated mcb within that board. This board and any other board that may be turned off and disconnect power to the control panel should be labelled as per 25.2 F
- Preferably not rcd protected unless required for electrical safety.
No a dedicated fuse board is not required.
Yes a double pole isolating device is required local to the control panel.
As your system - to my understanding - is essentially a 5839 pt 6 system then you would also normally need 72 hour battery standby capacity.
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As your system - to my understanding - is essentially a 5839 pt 6 system then you would also normally need 72 hour battery standby capacity.
I think it should be a part 1 system because kernow stated “i recently viewed a grade A fire alarm in a new build block of residential flats”.
If you check out clause 1. Scope in Part 6 it defines what is included and what is not included.
This part of BS 5839 applies to forms of dwelling including bungalows, multi-storey houses, individual flats and maisonettes, mobile homes, sheltered houses, housing providing NHS supported living in the community (as defined in Health Technical Memorandum 88 [1]), mansions, and houses divided into several self-contained single-family dwelling units. It does not apply to hostels, caravans or boats (other than permanently moored boats used solely as residential premises), or to the communal parts of purpose-built sheltered housing and blocks of flats or maisonettes.
I accept a dedicated fuse board is not required in most cases but what about the following?
25.2 (a) Where the user requires to isolate the building during closed hours, a separate supply should be provided for the fire alarm system that should not normally be isolated during closed hours.
25.2 (b) It is not acceptable for the electricity supply to be connected via a card or coin operated meter or similar device.
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As your system - to my understanding - is essentially a 5839 pt 6 system then you would also normally need 72 hour battery standby capacity.
I think it should be a part 1 system because kernow stated “i recently viewed a grade A fire alarm in a new build block of residential flats”.
You could be right, but not knowing if these are private residential flats of part of an HMO it may be a part 1 system or a part 6 - Until you know the use and number of storeys it's hard to say.
If it's an HMO according to Table 1 of "part 6" communal areas need a Grade A system. Kernow's last post maintains its a "Rafiki Grade A" - Grade A referring to a part 6 system and following his lead clause 15.2c (part 6) would apply - hence 72 hour standby.
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If you check out clause 1. Scope in Part 6 it defines what is included and what is not included.
This part of BS 5839 applies to forms of dwelling including bungalows, multi-storey houses, individual flats and maisonettes, mobile homes, sheltered houses, housing providing NHS supported living in the community (as defined in Health Technical Memorandum 88 [1]), mansions, and houses divided into several self-contained single-family dwelling units. It does not apply to hostels, caravans or boats (other than permanently moored boats used solely as residential premises), or to the communal parts of purpose-built sheltered housing and blocks of flats or maisonettes.
I accept a dedicated fuse board is not required in most cases but what about the following?
25.2 (a) Where the user requires to isolate the building during closed hours, a separate supply should be provided for the fire alarm system that should not normally be isolated during closed hours.
25.2 (b) It is not acceptable for the electricity supply to be connected via a card or coin operated meter or similar device.
I couldn't be bothered to list every scenario Tom hence my opening line - " see section 5839 pt 1 25.2 and Kernow does mention the feed from the landlord's consumer unit so it is unlikely to be on a coin meter or be turned off as the building is unlikely to ever be closed."
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Tam, BS 5839-6 does not apply to the common parts, so this whole issue is founded on misconceptions.
Sorry I'm confused. So where Table 1 refers to Grade A systems for common areas of various dwelling types - basically a part 1 system with the appropriate clauses substituted eg 15.2c for 25.4 (pt 1) referring to standby power supplies.
If part 6 is not applicable does this get certificated to part 1 with variations ??
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The whole thing is a mess David and if we cant express it clearly on here what hope does the jobbing sparkie have of getting it right.
I THINK Colin was coming from here:
1- if it is a purpose built block of residential flats there should be no requirement for a fire alarm and detection system in the common areas so to pick into macro detail of one element of the installation that does not have to be there and serves little purpose is perhaps unnecessary.
2- If the common areas of a purpose built block of flats did require a fire alarm and detection system as a compensatory feature for some other weakness in the design, then it should be a Part 1 system. Part 6 system are designed for dwellings. The common areas are not dwellings.
However in accordance with the latest ADB 2006 there is an increasing requirement for Automatic Opening Vents controlled by smoke detectors in most designs now, and there is a huge variety of hybrid equipment lashed together to achieve this.
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David you know far more than I will every know about fire alarms my knowledge is based purely on reading the Standards.
Based on the standards, if you study clause "1. Scope" of part 6 it lists the premises that part 6 applies to and those it does not. Therefore the way I understand it if the premises does not apply then put it on the shelve and use part 1.
Even when it does apply and you go to clause 15.2 that directs you to clause 25 in part 1?
In Kernow's situation it appears, part 1 should be applied and not part 6, therefore talk about grade A is irrelevant. Because Kernow is the only one with intimate knowledge of the building therefore only he can make that decision after checking the standards.
I agree fully with you you cannot cover all the bases and the only acceptable way, is to apply the relevant standards to the situation.
??? ??? ??? ???
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The whole thing is a mess David and if we cant express it clearly on here what hope does the jobbing sparkie have of getting it right.
I THINK Colin was coming from here:
1- if it is a purpose built block of residential flats there should be no requirement for a fire alarm and detection system in the common areas so to pick into macro detail of one element of the installation that does not have to be there and serves little purpose is perhaps unnecessary.
2- If the common areas of a purpose built block of flats did require a fire alarm and detection system as a compensatory feature for some other weakness in the design, then it should be a Part 1 system. Part 6 system are designed for dwellings. The common areas are not dwellings.
However in accordance with the latest ADB 2006 there is an increasing requirement for Automatic Opening Vents controlled by smoke detectors in most designs now, and there is a huge variety of hybrid equipment lashed together to achieve this.
Thanks K... so where is it acceptable to install "part 6" detection in common areas, I only ask as we see so many of these "AICO" mains powered/radio base things advertised for HMOs etc and they get to be included in the escape routes.
Are we saying this is wrong ?
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David you know far more than I will every know about fire alarms my knowledge is based purely on reading the Standards.
Based on the standards, if you study clause "1. Scope" of part 6 it lists the premises that part 6 applies to and those it does not. Therefore the way I understand it if the premises does not apply then put it on the shelve and use part 1.
Even when it does apply and you go to clause 15.2 that directs you to clause 25 in part 1?
In Kernow's situation it appears, part 1 should be applied and not part 6, therefore talk about grade A is irrelevant. Because Kernow is the only one with intimate knowledge of the building therefore only he can make that decision after checking the standards.
I agree fully with you you cannot cover all the bases and the only acceptable way, is to apply the relevant standards to the situation.
??? ??? ??? ???
Thanks Tom.... it is a little confusing and I think you are right technically it should be a part 1. But if it is a private residential block and doesn't need an FA then anything could have been installed - part 1 or part 6 and it wouldn't be of concern to anyone except who wrote the spec and who paid for it.
If it were installed to part 6 standard then Table 1 refers to Grade A systems for common areas of various dwelling types - you need a part 1 system with the appropriate clauses substituted eg 15.2c (pt 6) for 25.4 (pt 1) referring to standby power supplies - ie. 72 hours.
Clear as muddy coffee on a foggy day in Tokyo!! ;)
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A purpose built bock of flats conforming to the guidance in Approved Document B is not a HMO. It will be designed such that there is no need to sound a general alarm throughout the building in the event of a fire in an individual dwelling. Therefore there will be Part 6 self contained systems in each dwelling and no general fire alarm and detection system in the common areas. The common areas must be maintained sterile and free from fire risk.
A block of flats that does not incorporate the compartmentation standards etc may be a HMO and is likely to require a suitable alarm system such that all occupants will be alarted and will evacuate in the event of a fire anywhere in the building.
The definition of what comprises a HMO and an explanation of the Housing Act can be found in the LACORS guidance - see pages 51-55.
This guide also sets out recommendations for design considerations and grades of systems. see page 24.
http://www.oxford.gov.uk/Direct/HousingFireSafety.pdf
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Sorry to be pain Kurnal but I just want to be clear in my head having read some of these definitions.....
So basically my 4 storey recently built block of self contained privately owned flats with no shared amenities doesn't fit the standard test of an HMO and therefore doesn't need anything in the common areas - just part 6 in the flats - It's a block of flats - I can see that.
But if the same block had been converted from an old warehouse OR one of the 20 residents paid rent to a landlord it would be an HMO and the common areas would be fine with a part 6 Grade A system of protection - Table 1 (pt 6) presumably because no one could guarantee the fire separation or because of the duty of care from the landlord to the tenant?
So are there any circumstances where anything other than a part 6 Grade A system would ever be acceptable within the common areas of an HMO ?
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But if the same block had been converted from an old warehouse OR one of the 20 residents paid rent to a landlord it would be an HMO
David defining it as an HMO is far more complicated than that, just say its an HMO that will make it much easier.
Its only the local housing department that can define it, check out the following http://www.firesafe.org.uk/html/premises/hmos.htm to see how complicated.
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But if the same block had been converted from an old warehouse OR one of the 20 residents paid rent to a landlord it would be an HMO
David defining it as an HMO is far more complicated than that, just say its an HMO that will make it much easier.
Its only the local housing department that can define it, check out the following http://www.firesafe.org.uk/html/premises/hmos.htm to see how complicated.
Ok so in my HMO in this scenario being 4 storeys high, are we still saying the only acceptable means of protecting the common areas is by a part 6 grade A system or are there any circumstances where anything other than a part 6 Grade A system would ever be acceptable within the common areas if the HMO were only 2 storeys for argument sake?
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David I only raised this point to simplify the question and I was waiting for kurnal to respond. I will try to answer the question to the best of my ability and I am sure Kurnal will correct it, if I balls it up.
are we still saying the only acceptable means of protecting the common areas is by a part 6 grade A system or are there any circumstances where anything other than a part 6 Grade A system would ever be acceptable within the common areas if the HMO were only 2 storeys for argument sake?
The answer depends which guidance you use if you use BS 5839 pt 6 2004 then it would only be Grade A category LD2 (Table 1). Using Lacors then it could be Grade A or D or a mixed system depending on the kind of HMO. Also as it is all about risk assessment the FR Assessor could stipulate the standard required, providing he could justify his decision.
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Thanks Tom I appreciate you answer and it does make sense but blimey how on earth is any one to specify a fire alarm system for such dwellings with so many conflicting guides?
And who would win in a fight, BS or Lacors ??!
So if we take over such a dwelling that has anything not resembling a part 1 system we need to qualify all our condemnations as subject to whoever or whatever guidance has been recommended....!
That'll be simple then.
If others feel the need to write guidance for fire systems in particular sectors why can they not at least coordinate the technical detail with the British Standard...?!
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Yes it is surely not intended to be as prescriptive as all that and the benefits of an analogue addressable system under part 1 could be used to good advantage in some HMOs using the opportunity to configure cause and effect for each device and to provide detection in units, protect escape routes with a double knock approach and to operate other systems such as ventialtion all in one system.
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And who would win in a fight, BS or Lacors ??!
David you can add the DCLG Sleeping guide which on page 4 includes "the common areas of houses in multiple occupation (HMO);" the only saving grace is it's recommendations on fire alarms are similar to the Lacors.
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where is the 'don't know' vote button! there's always a 'don't know' vote
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And who would win in a fight, BS or Lacors ??!
David you can add the DCLG Sleeping guide which on page 4 includes "the common areas of houses in multiple occupation (HMO);" the only saving grace is it's recommendations on fire alarms are similar to the Lacors.
So if i were approached by a landlord of an HMO and I installed a grade D system and quoted Lacors, what certificate would I use ?
And then if a local authority questioned the logic and insisted on a grade A 5839 system who would be in the right ?
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1. If I were approached by a landlord of an HMO and I installed a grade D system and quoted Lacors, what certificate would I use ?
2. If a local authority questioned the logic and insisted on a grade A 5839 system who would be in the right ?
1. I guess you would use the certification for a grade D system as recommended in clause 23.3 in BS 5839-6:2004.
2. It would be open to discussion/argument. The landlord has to apply for a Licence (HMO) to the local authority and they would refuse it, consequently the landlord would have to appeal.
The applicant or any relevant person may appeal to a residential property tribunal within 28 days against a decision to refuse to grant a licence or against any terms of the licence. An appeal may also be lodged against any decision to vary or revoke a licence, or a refusal to vary or revoke a licence.
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Hi David
You normally find that Grade A systems are recommended (or required) in HMOs with three or more storeys.
In HMOs with two storeys or less a Grade D is normally accepted.
Would the LHA refuse you a license if you had say a Grade D systems installed in a three storey property instead of a Grade A? It all depends on the size of the property and the number of people residing therein.
Ive known some LHAs accept a Grade D in three storey victorian terrace where there were 6 persons residing, but not allow it in a three storey sprawling converted vicarage where the layout, and size of the property was much bigger and complex, and had 8 residents stayingthere. So it all depends.
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Thanks men...... it's always an interesting learning curve........ :)
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Hi David
You normally find that Grade A systems are recommended (or required) in HMOs with three or more storeys.
In HMOs with two storeys or less a Grade D is normally accepted.
Would the LHA refuse you a license if you had say a Grade D systems installed in a three storey property instead of a Grade A? It all depends on the size of the property and the number of people residing therein.
Ive known some LHAs accept a Grade D in three storey victorian terrace where there were 6 persons residing, but not allow it in a three storey sprawling converted vicarage where the layout, and size of the property was much bigger and complex, and had 8 residents stayingthere. So it all depends.
Why is that Midland?
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Look at BS 5839 Part 6 - it describes in great detail the difference between a Grade A and Grade D system, and why those different grades are required in HMOs, dependent on the size and occupancy of the property.
Whilst all HMOs must be protected by automatic fire detection, human beings often detect fire before automatic detection has been activated. So we need to consider how we manually raise the alarm prior to detector activation in HMOs.
So a small two storey HMO may only need a Grade D system, because the shout of fire could be enough as a means of manually raising the alarm prior to automatic detection being activated. In a three storey property the shout of fire as manual means of raising the alarm is unlikely to be heard - hence the need for a Grade A system incorporating manual call points
But again it comes down to risk assesment, because I could have a very large two storey property where the shout of fire might not be heard in all habitable areas, and therefore I may need to consider the installation of a Grade A system.
The control and indicating equipment aspect of a Grade A system is there for several reasons. The bigger or more complex the premises gets it follows that there is a greater need for system reliability and the ability to monitor faults. Also the CIE provides power to components such as MCPs and Fire Detectors. It also allows the fire and rescue service to locate the point of activation (whether that be a zone, or an actual detector head)
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Ok thanks Midland