Ampac ZoneSense, Руководство пользователя

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Page 23
ZONESENSE EN54 INSTALLATION COMMISSIONING & OPERATION
11
Calculating Standby Battery Capacity
The minimum capacity of valve regulated lead acid batteries as recommended in BS 5839
– 1 : 2002
should be calculated using the following formula;
 
2 /
2 1 1 min
DI I T C
 
Where;
min
C
= the minimum capacity of the battery required when new at the 20 h discharge
rat
e and at 20˚C in ampere - hours;
1
T
= total battery standby period in hours ( see recommendations of EN54-4 )
1
I
= total battery standby load in amps
2
I
= total battery alarm load in amps
D = the de-rating factor
Criteria
Where
min
C
/ 20 will be equal to or greater than
2
I
, it can be assumed that D = 1. When
min
C
/ 20 is
less than
2
I
the value of D should
either be based on the battery manufacturer’s data or should be
1.75.
In practice,
min
C
/ 20 is unlikely to correspond exactly to an available battery capacity and therefore
the next highest available capacity size should be used.
Batteries other than valve-regulated lead acid batteries
The minimum capacity of batteries, other than valve regulated lead acid batteries, should be
determined by consultation with the battery manufacturer and should take into account the standby
load, the alarm load, any required de-rating to take account of the higher current drawn in the alarm
condition and a de-rating factor to take account of battery ageing during the anticipated life of the
battery.
NOTE: Automotive batteries SHOULD NOT be used.
Note:
Alarm outputs were loaded to 300mA and the open collector outputs were loaded to 50mA for
max current draw measurements
All Quiescent current measurements checked with sounder & buzzer silenced.
All Alarm current measurements checked with sounder & buzzer silenced.
Current Draw (Typical Figures)
Condition 2 Zone 4 Zone 8 Zone
Quiescent current stand alone = 20mA 20mA 21mA
1 zone in Alarm current draw = 40mA 40mA 51mA
All zones in Alarm current draw = 41mA 43mA 56mA
Quiescent current relay board fitted = N/A 24mA 25mA
Quiescent current LAM fitted = N/A 34mA 35mA
Max current draw = 1027mA 1073mA 1580mA