Ampac ZoneSense Plus - Battery Capacity Calculation

MAN 2326-13
34
13 Battery Capacity Calculation
INTRODUCTION
The standby power source capacity, or baery capacity, determines how long the system will connue
to operate in the event of the loss of the primary power source. It therefore becomes necessary to
calculate the baery and hence power supply / baery charger capacity required for each installaon.
The following calculator has been designed to determine the required capacity to meet the required
standard. Should an exisng panel be expanded the required baery and power supply capacity
should be recalculated to ensure the panel connues to operate within the standard.
DESCRIPTION
Enter the number of units listed in the le hand column which go to make up the panel, complete
the mulplicaon to obtain the quiescent current then mulply by the standby and alarm hours
required by the standard.
POWER SUPPLY RATING
The minimum Power Supply Rang ( 4 ) is obtained by calculang the manufacturers recommended
baery charge current and [ see Note ] ( 1 ) then adding the quiescent current of the enre system
( 2 ) and the alarm current ( 3 ).
1. Baery Capacity (AH) (determined from Calculator) =
Amps
24 x 0.8
2. Add Quiescent Current of the System (Iq) = Amps
3. Add the extra current that is drawn when in alarm (Ia) = Amps
4. Minimum Current Rang of Power Supply is = Amps
Note #1: The capacity of the baery shall be such that in the event of failure of the primary
power source the baeries shall be capable of maintaining the system in normal working (quiescent)
condion for at least 24 h, aer which sucient capacity shall remain to operate two worst case AZF’s
and associated ACF’s for 30 min.
Note #2: Where the re control staon will not receive the system's total power supply failure
signal or, Agent Release is incorporated in the FACP, the baery shall have sucient capacity to
maintain normal system operaon for 96 h. plus 30min. in alarm.
Note #3: When calculang baery capacity, allowance shall be made for the expected loss of
capacity over the useful life of the baery. A new baery shall be at least 125% of the calculated
capacity requirements, based on a loss of 20% of its capacity over the useful life of the baery.