L3 or L2?

[AnthonyB]

On another forum the question was posed that if you design a system for life safety and position all the heads as per the minimum cover description for an L3 system with no variations, then add some additional heads to specific areas,again for life safety not property protection, is it then an L2 system?

Most people said yes, as an L2 system has the same goal as an L3 (safe escape) but with additional specific cover where there is a significant risk that could affect this.

However there is a person of prominence saying that it's still L3 because the goal is to protect escape.

Opinions?

[lyledunn]

I wouldn't view the goal as protecting escape as that is probably taken as read no matter whether it is a category M or L1.  I would consider the difference in terms of the assessed need for alert. For example, one might determine that offices with vision panels in the doors opening on to a corridor might require smoke detectors in the corridor only along with detection say in the photocopying room. I would deem that L3. On the otherhand, were it to be sleeping accomodation opening on to a similar corridor, I would think smokes in corridor and all rooms opening on to the corridor but still categorised as L3. If the RA deemed that the latter was still insufficient in terms of an early enough alert and identified the need to locate detectors in other areas then the system would be enhanced to L2. That may be by the placement of one additional detector or many.

[colin todd]

As a person of non-prominence, I think its L2.

[AnthonyB]

Thanks, the FIA tech people seem to think otherwise!

[ahmedh]

The way i read 5.1.3 b) of BS5839-1:2017 it is L2. I don't work for FIA but do have a GCSE in English (an F counts right?)

I would've copy/pasted it here but sneaky people at BSI seem to have disabled that function.

Essentially L2 coverage should satisfy L3 requirements with addition of providing early warning in areas of high hazard/risk. All for protection of life.

[colin todd]

Tony, send me an IM with where you get this from FIA.

[AnthonyB]

Done!