7273 and location of detectors

[David Rooney]

I can't remember seeing anywhere that smoke detectors need to be 1.5 metres either side of a magnetically held open door... but we have just had a comment from a fire officer who "expected to see it".

The system is L3 + (i suppose that makes it L2)... are we really expected to install additional detectors in corridors ?

[Wiz]

David, the old 1.5m chestnut was done away with before the new 7273.

Tell the fire officer that you 'expected to see' Father Christmas last December and was also disappointed!

Check out 7273 thoroughly, it can alter detector spacings drastically. Don't ask me to explain it because I find it so difficult to undersatnd I just pretend 7273 doesn't exist.

The very rare L3+ category system is only specified by a select few designers and basically allows you to do whatever you want. Trust me if they don't know what they are doing, they'll have no clue whether what they get is right or not

[Big_Fella]

Check out 7273 thoroughly, it can alter detector spacings drastically. Don't ask me to explain it because I find it so difficult to undersatnd I just pretend 7273 doesn't exist.

Indeed, it is one of those that just baffles me everytime.... and I have to re-read it for every job.  Detector spacings do vary quite drastically given different circumstances.

I do tend to also 'forget' that this standard ever existing 

[David Rooney]

To be honest I don't know anyone that does recognise its existance .... it's an enigma wrapped in a riddle !!

We installed some salamander radio door magnets a while ago and there is a useful commissioning checklist comes with the kit which obviously we filled in ......   

For a Cat A door we made sure that the unit released under the following conditions....

Normal supply fail.......... standby supply fail......... failure of both supplies..(?!).... short or open circuit of manual callpoint cct......      short or open circuit of automatic detector cct..... removal of manual call points or detectors ..... any earth fault on the system......   Blown fuses ....... Software/processor failure .... and any disablement of any callpoint or detector.....

...............honest !!

[Big_Fella]

Sounds like.. in other words, leave it closed 

[Wiz]

You may remember that I have previously highlighted my problems with 7273 on another thread in this forum.

Mr Todd answered that he thought the standard was so straightforward to understand that his proposed plans to write an 'explanation' of it were shelved.

At the time there was no other support on this forum for my complaints regarding the complexity of BS7273 and the difficulty I believed people were having in understanding and implementing it. So the matter fizzled out.

Everyone involved in fire alarm systems needs to implement BS7273 but I've never found anyone who understands it enough to be able to explain it to me.

I am pleading for everyone on this forum involved with fire alarm systems who hasn't seen it to get hold of a copy and read it.

If afterwards you understand it then please use this forum to educate those of us who can't!

However, if you, like myself, have tried and failed to unravel its mysteries and double-talk then please join my protest on this forum against this unfathomable document. Maybe someone will then listen and do something about it.

At the very least I feel that our fellow member Mr Todd could assist in this.

[jokar]

David understands it, he regonised that Salamander is a Cat A device and installed it under the auspices of the the Cat A listing in 7273 part 4.

Do not forget the front bits of 7273 where it states that it overides 5839 for detector spacings.

[Wiz]

Jokar, I refute the suggestion that David understands BS7273 just because he recognises a Salamander as a Cat A device! This demonstrates he may understand a small part of it! Even I understand a small part of it!

I've never spoken to anyone (apart from Mr Todd) who claims to even understand even 75% of it. Where are the experts? Are you one of these? If so, can you provide a summary of the important parts of BS7273 and how to apply them to systems on these forums? We, the unknowing, would all be most grateful!

One of the small parts both David and I are aware of is regarding the modification of BS5839 detector spacings, that you now mention. I had already mentioned it on my first post on this thread and in previous posts on the forum. Unfortunately, this is just a small part of a very confusing document! Furthermore, have you noticed the bit towards the end that basically says some things recommended in it might soon need to be ignored because of impending new related standards? What a waste of paper and busy people's time and money!

[Wiz]

To be honest I don't know anyone that does recognise its existance .... it's an enigma wrapped in a riddle !!

We installed some salamander radio door magnets a while ago and there is a useful commissioning checklist comes with the kit which obviously we filled in ......   

For a Cat A door we made sure that the unit released under the following conditions....

Normal supply fail.......... standby supply fail......... failure of both supplies..(?!).... short or open circuit of manual callpoint cct......      short or open circuit of automatic detector cct..... removal of manual call points or detectors ..... any earth fault on the system......   Blown fuses ....... Software/processor failure .... and any disablement of any callpoint or detector.....

...............honest !!

David, if I hadn't seen the '....honest !!' bit I would have asked where you found this super panel that could cope with all the monitoring and within the specific time criteria specified in the recommendations.

[Allen Higginson]

Im not even sure where my copy of it is!

[Wiz]

Buzz, I presume you've burnt it and that's about the best thing you can do with it!

[kurnal]

Hands up. I havn't bought it. And based on what I have heard of it I dont think I will. I will make do with manufacturers interpretations.

I have just wasted loads a cash this week on the "essential" updated BS8214. What a waste of time and money  that one is. May as well just say "fire doors- follow the manufacturers instructions" 

Thanks thats another £138 in the BSI till. Kerrchinggg. Next customer please.

[Wiz]

Prof., you are right to not waste your money on it. Apart from the difficulty of understanding it, it also asks for some things that are impossible with the equipment available today. Ridiculous! I'm just glad that many specifiers don't know of its existence. As soon as people start  including it as a requirement in their specifications, things will get very interesting.

[David Rooney]

Im not even sure where my copy of it is!

It's probably rolled up and propping open a door on the basis it burns easily and the door will eventually close.....

[David Rooney]

David understands it, he regonised that Salamander is a Cat A device and installed it under the auspices of the the Cat A listing in 7273 part 4.

Do not forget the front bits of 7273 where it states that it overides 5839 for detector spacings.

Errrrrrr I just read the big writing on the box...!!!