7273-4 General Question

[David Rooney]

Out of interest .... Acoustically controlled hold open devices should not be installed on doors judged to meet the "Critical" category of the standard.

So would this be likely to influence an insurance claim in the event of injury or general building damage if it were determined such devices were used in the wrong circumstances?

Also I have a three storey Academy with a dozen door magnets on two ground floor corridors. The FDS system is Manual (!!) and the magnets were added this year apparently .... oh and they don't actually release under any circumstances!!

Shouldn't someone get sued ??

[Golden]

Hi David, I have a similar situation with the hold open devices linked to a manual alarm and these operate on the buildings security system that apparently has an interface with the fire alarm system to release the doors in case of the fire alarm sounding - I was quite surprised when looking at 7273 that this is acceptable as far as I can determine for cat 'C' systems however I'm still digging into the details of the installation with the school. The BS indicates that the system should be commensurate with the risk to people in case of fire and if its not a single staircase or sleeping risk (generalisation!) then any category (usually 'C' is chosen for cost purposes)  is normally acceptable.

I'm not sure about the insurance situation and this may depend on the individual policies.

[David Rooney]

I thought schools came under the general Critical category in Table B

And if your system doesn't have an "L" category system compliant with 5839 installed how can it be permissible to install magnets ? 

[kurnal]

I agree with Dave. I have not referenced bs 7273-4 before responding on this occasion but if a door is required to be self closing as an element of the means of escape then to have it held open on magnets linked to a manual alarm system only is a nonsense and no better than wedging it open.

[Daffodil]

Again I have not read the BS before responding but I think this would depend on the type of premises.  If the building would not normally warrant automatic detection and the manual alarm (can be demonstrated to activate the devices, without manual repetition throughout the building) preferably BS complaint and there are plenty of people moving around the building that have been trained to sound the alarm on suspecting a fire and that the system is maintained, it may be acceptable.

A lot of this would depend on specific circumstances.  It certainly shouldn't be regular practice or as I found at one property a battery operated listening, "hold open device" where the method of raising the alarm was to shout fire which could not be heard throughout the building and on demonstration was not at the correct frequency/loud enough to operate the listening devices.

Preparing myself to be shot down in flames by those that know better.

[Golden]

I've just checked table B again and schools are only in the critical category for release of electronically locked doors on means of escape (B2) - there is no mention of schools in B1 that relates to release of self-closing fire doors and apart from the few mentioned earlier the rest are in 'any' category. I am as surprised as you about this and had to eat a bit of humble pie after explaining to the responsible person in my school that they would need AFD to control the door closing and had to back track when I read the BS.

[colin todd]

Silver I may have to demote you to bronze as a result of your complete misinterpretation of BS 7273-4(one of the finest standards known to man).  Now you will need to eat humble dog s***, cos you were right the first time.

[kurnal]

Silver I may have to demote you to bronze as a result of your complete misinterpretation of BS 7273-4(one of the finest standards known to man).  Now you will need to eat humble dog s***, cos you were right the first time.

Colin I for one haven't a clue what you are saying here. Please clarify.

[Golden]

Non-precious metal will suffice. I've had a look at the BS this morning and I have misinterpreted clause 7 relating to actuation of release mechanisms whereby this is intended to occur in response to any of the following conditions of which a) appeared to apply "operation of the fire detection and alarm system, whether by operation of a manual call point or activation of an automatic fire detector" which I read to mean either/or would be applicable - and then on reading Table B finding that the criteria for category A only applied in specific circumstances considered the matter closed. However Clause 12 'Special considerations for the design of any associated fire detection and fire alarm system' does clearly indicate (12.1 & 2) that any system should not rely on manual operation and smoke detection should be fitted; therefore I will have to eat some more pie and return to the RP. Thankfully I laid it on quite thick in the report that I considered SD necessary and  this is on a long term priority so all is not lost.

(Even the finest standards however do contain some errors and there is reference to a sub-clause that hasn't been numbered.)

[David Rooney]

Clause 12.2 Commentary

"Where a Category L1, L2, L3, L4 system is not present, detectors will need to be installed specifically to initiate release of the doors; such a system is, by definition, a Category L5 system."

12.2.2 In buildings with a Category L1, L2 or L3 system, the selection, provision and siting of automatic fire detectors are deemed to be satisfactory for compliance with this part of BS 7273. In all other cases, a Category M/L5 system conforming with 12.2.3 to 12.2.7 should be provided or in the case of a Category L4 system the provision and siting of automatic fire detectors should conform to 12.2.3 to 12.2.7 in those parts of the escape routes in which electrically held-open doors are provided.

I'm still a little confused ........  surely it still needs L5 minimum ?

[kurnal]

Yes an L5 system is required as a minimum.
In practical terms detectors are required on both sides of the doors involved, the actual siting of the detectors may vary depending on the fire detection system provided. Where detectors are installed  as part of an L1- L3 system the BS5839-1 recommendations on siting will satisfy the requiements of BS7273-4, but where an L4 or L5 system is provided BS7273-4 makes specific recommendations on the siting of those detectors to ensure they are close enough to be effective in controlling the doors involved.

[colin todd]

Kurnal, My reading of Silver's posts is that he told the punter they needed afd to operate mdh held doors, then mis-read BS 7273-4 (the finest cop known to mankind) and thought they didnt and then scarily went back and tell them he was wrong and a manual system was ok. Thats why I demoted him-for not reading the standard correctly.

[Tom Sutton]

Sorry to jump on your parade Dave, but I have just received a question and would appreciate any help, I will be researching it aswell, it goes like this,

As far as I can gather BS7273-4 stipulates certain maximum times for failing safe with door closers which are different for Category A, B or C. Can someone with access to the spec please tell me if there is an maximum activation time from normal fire alarm specified? The maximum time to activation for faults such as short or open circuits is 2 minutes and 6 minutes for loss in radio comms for Cat A and 120 minutes for Cats B & C. There are other documents I've seen that state that the system should behave in fault conditions exactly as it would in fire alarm conditions, so does that imply a maximum of 2 minutes from fire alarm activation?

Also if BS7273-4 are guidlines, and a piece of equipment fails certain time criteria (but otherwise still fails safe in conformance), can that equipment be given a Category A certification if those conditions are noted on the conformance certificate?

[kurnal]

We have discussed this before Tom though without coming to any particular conclusion, here's a link to one such discussion with a couple of very useful posts within, hope it helps a bit.

http://www.crisis-response.com/forum/index.php?topic=4143.0

The crux is in page 2 with comments by Dr Wiz and responses by Colin Todd

[kurnal]

To summarise the above , (as  I understand it) although BS7273-4 provides for fail safe operation of the devices under a wide range of fault conditions and within time constraints, when we previously discussed this there were  many challenges in delivering these with the current standard hardware and software configurations, and indeed members felt it was not possible to achieve with some with some existing CIE hardware. It was felt that  few if any installations were ever compliant with the requirements of  BS7273-4.

I would be interested to hear if things have moved on since our previous threads,  whether the recent updates of BS 7273-4 and bs 5839-1 have made a difference, whether I have interpreted the situation correctly and above all whether anybody, including enforcers, manufacturers or engineers cares?