Alarms in Schools

[David Rooney]

We have recently taken over a school where the fire alarm system has been typically added to and extended without much thought.

The situation now is that the fire evacuation signal in the main part of the school is given as a tone over a public address system - not a pt 8 system, just a basic PA, although the outgoing circuits are fault monitored, and this system also provides the class change pips.

A second part of the school (separate building) has a new fire alarm system and uses loop sounders to provide the evacuation tone, as well as the PA system that has been extended to this area as well...!!

The systems are linked as a single stage evac.

It is all very confusing but the questions are...

a. Is it ok to rely on the PA system to provide the evacuation alarm, as it isn't properly monitored or compliant with pt 8 ?
b. Does it need to comply with pt 8 ?
c. Ideally we would like to turn the fire alarm loop sounders off and rely completely on the PA to give the evacuation, as this is far simpler than wiring new fire alarm sounders to the main building. Depending on the answers given above, would this be acceptable ??!!

Thanks

Dave

[Wiz]

Fire alarm systems using PA speakers to give the fire alarm signal must obviously provide an equal level of fire resistance of equipment and connections and monitoring of circuits to compare with a non PA speaker system. So the recommendations of Part 8 would seem necessary.

Part 1 recommends that fire alarm systems within a building should have similar sound characteristics. Unfortunately, there is no definition of a 'building' (do they mean individual blocks on a site or all blocks on a single site?) or of 'similar' ( do they mean exactly the same, nearly the same or partly the same?) I always consider a 'building' to mean all buildings on the same site especially where it is  part of the same overall system (where people who work in one block could be visiting another block when there is a fire alarm condition) and 'similar' to mean no mixing of bells and electronic sounders and with sounders having exactly the same number of tones, at approx. the same frequency of approx. the same sort of durations.

[wee brian]

You are "allowed" to use the fire alarm for the class change system but I dont think its such a good idea to do the reverse. BB100 points at Pt 8

[David Rooney]

You are "allowed" to use the fire alarm for the class change system but I dont think its such a good idea to do the reverse. BB100 points at Pt 8

Thanks Brian.

I think what this really comes down to is this....

a/ Can you use a PA system that is monitored for open and short circuit faults, and wired in fire proof cabling and with battery back up to provide the fire evac tone?

b/ If the fire evac tone became a pre recorded message, would the system then have to meet pt 8 and require twin amps, overlapping circuits etc etc

If the answer to (a) is yes, why does anyone bother paying for a pt 8 system ??