Battery Calculation

[FireFox]

Please find attached battery calculation, for a Secutron 2900 FACP fire alarm system, given by an installer. As far as I know, the standby current and alarm current for all the components need to be considered. But here current consumption of all the components are not considered in alarm condition. Is this calculation correct? Thanks in advance

Regards

[David Rooney]

I don't understand why they only calculate the alarm load by (3.27) by 5 minutes.

The minimum recommendation is 30 mins.

[FireFox]

This was installed as per NFPA standards:

4.4.1.5.3.1 Unless otherwise permitted or required by 4.4.1.5.3.1(A) or 4.4.1.5.3.1(B), the secondary power supply shall have sufficient capacity to operate the fire alarm system under quiescent load (system operating in a nonalarm condition) for a minimum of 24 hours and, at the end of that period, shall be capable of operating all alarm notification appliances used for evacuation or to direct aid to the location of an emergency for 5 minutes.

[Benzerari]

Here you go..., a good difference between NFPA 72 and BS 5839 in terms of batt. calculations...

[David Rooney]

Also.... the alarm currents they are quoting for the sounders etc are huge.......!

Its not clear that the total standby current has been taken into account, or any additional alarm load integral to the control equipment.

[FireFox]

I think this (attached) should be the format which has to be followed. Kindly correct me if I'm wrong.