Fire alarm feed

[supasparxs]

Hi Guys,
Is there a reg stating that a Fire alarm must be supplied with a fire proof cable?

I did a EICR today and the building has a sub main in 2.5 T&E in a metal trunking to a fuse isolator then MICC from the isoator to the local spur (10 meters away) which was local to the panel

I have looked in Ch 35 and 560.10 but can't find an actual reg

Richard

 

[telectrix]

nothing in 7671. it has been common practice for a few years to mains feed fire alarm panels in MICC or FP200. but any reg. on this will be in the fire alarm BS5839, might have forgot the number . DOH.

 

[Darkwood]

Reading 351 note 1 explains you need to follow statutory authorities requirements, as well as this check 560.5.2 this suggests the safety source (battery back-up for example) needs to maintain supply for adequate duration in fire conditions, most times they are in the fire panel but if external then cable needs to be fire rated, now the normal source (public supply) dosn't have this requirement, as your safety source can take over in case of fault or fire damage to supply cable, if you are using a 230v system then common sense would denote it requires all to be wired in fire rated cables but this system by its nature may not comply to local fire regulations.
Also as Teletrix says its the BS 5839 that you need to have at hand as that will give deeper insight to requirements.

 

[supasparxs]

Thanks guys,
I don't have a copy of BS 5839, but the refferences for the 351 note 1 and 560.5.2 should be enough

Richard

 

[Guest123]

BS 5839-1 states as a minimum "standard fire resisting cables are to be used for all final circuits to the fire system".

 

[telectrix]

but what is a final circuit re. a fire alarm.? is it the alarm detector and sounder circuits, or the supply circuit to the panel?

 

[Guest123]

but what is a final circuit re. a fire alarm.? is it the alarm detector and sounder circuits, or the supply circuit to the panel?

The alarm & sounder circuits are classed as "critical signal paths".

I take "final circuits" to mean just that, a final circuit supplying the alarm system from the LV mains.

 

[telectrix]

can't disagree, lenny. just was not sure of the definition.

 

[Darkwood]

Now here's the issue i have; as Lenny states it is a requirement in the Bs 5839-1 but the OP is doing an inspection under the scope of the 17th BS 7671 which dosn't give a written requirement for the query he has brought up but agree in the green book it has been ammended to express that the BS 5839-1 should be complied to in 560.8.1 / note1-(i), im on the thinking here that the OP should make the Fire Alarm circuit an exclusion from his inspection and should come under the scope of a Fire Alarm inspection cert.

A large majority of the sparkies i know dont carry or have ever used a copy of the BS5839 so only have the 17th and are unlikely to get a copy so this will mean they can't or shouldn't be doing a inspection on the supply to such a system and either make it an exclusion from the cert' or buy the BS 5839-1 and thus have the knowledge to properly inspect it.

Opinions please as this is the way i see it, im up for debate as thats the learning curve of life.

 

[sedgy34]

we wired fire alarm and from the lanlords DB to the panel its all fp (good practise) if its not a reg