Smoke alarms - hard wired or sealed battery?

[Meady]

Please can anyone give us some advice?

Grade D1/D2 alarms - do they have to be mains powered (with battery back up) or can they be 10-year, sealed, lithium battery powered only?

BS5839-6 seems to suggest that they must be mains powered in some way with options for battery back-up depending on D1/D2.  But can wireless radio-linked devices suffice as a suitable alternative in the guidance?

[Harry]

Hi Meady

here an overview of the BS5839-6 standard and the grades.

D1/D2 can be interconnected with RF but power-supply has to be by mains power. 

Deviation from the mains power supply requirement would have to come from the specifier. BS5839-6 is a standard, not the law, so if it can be justified, deviations are allowed when specifying the grades for a property.

Harry

 

[AnthonyB]

On 13/07/2022 at 17:50, Meady said:

Please can anyone give us some advice?

Grade D1/D2 alarms - do they have to be mains powered (with battery back up) or can they be 10-year, sealed, lithium battery powered only?

BS5839-6 seems to suggest that they must be mains powered in some way with options for battery back-up depending on D1/D2.  But can wireless radio-linked devices suffice as a suitable alternative in the guidance?

By definition a Grade D alarm is powered by a 240V supply, the 1 or 2 defining if the back up supply also required to each alarm is a sealed tamperproof battery/cell or a user replaceable battery.

If you only have the built in power supply and no mains then it is only a grade F alarm (which can only be used in a rapidly decreasing number of situations) being a F1 or F2 again  depending if the (sole) power is from a sealed tamperproof battery/cell or a user replaceable battery.

[Meady]

On 18/07/2022 at 11:17, Harry said:

Hi Meady

here an overview of the BS5839-6 standard and the grades.

D1/D2 can be interconnected with RF but power-supply has to be by mains power. 

Deviation from the mains power supply requirement would have to come from the specifier. BS5839-6 is a standard, not the law, so if it can be justified, deviations are allowed when specifying the grades for a property.

Harry

 

Hi Harry - thank you, that is a great help! ?

[Meady]

On 18/07/2022 at 20:03, AnthonyB said:

By definition a Grade D alarm is powered by a 240V supply, the 1 or 2 defining if the back up supply also required to each alarm is a sealed tamperproof battery/cell or a user replaceable battery.

If you only have the built in power supply and no mains then it is only a grade F alarm (which can only be used in a rapidly decreasing number of situations) being a F1 or F2 again  depending if the (sole) power is from a sealed tamperproof battery/cell or a user replaceable battery.

Hi Anthony - thank you, I think you've made it clear that we need to be going along the 'D' route.  The 'F' style alarms worry me due to the risk of people simply knocking them off the ceilings if they go off! Thanks as always for your advice - genuinely appreciated.