Table of Contents
Advertisement
PREMIER SX INSTALLATION MANUAL.
10. STANDBY BATTERY CALCULATION
In order to calculate the standby battery size required, the following formula can be used:-
Battery Size (Standby time in Amp Hours) = 1.25 x [(T
Where:
T
= Maximum time in hours required for the alarm [½ hour is most common time]
ALM
I
= Total Alarm Current in amps for all alarm devices connected to the alarm circuits
ALM
T
= Standby time in hours for the system after mains failure [normally 24, 48 or 72 hr]
SBY
I
= Quiescent current in amps of control panel in fault condition [because of mains failure]
QP
I
= Quiescent current in amps of all detection zones. Eg Ion detector 0.00005 Amp
QZ
(50 µA) , Optical Detector = 0.0001 Amp (100 µA)
Typical Example:
A system comprises of 20 ionisation detectors, 14 bells and the required standby is 24 hours. It will
need to operate in alarm for ½ hour.
Calculate the battery size required.
T
= 0.5 Hr
ALM
I
= 14 x 0.025 =0.35A
ALM
T
= 24 Hr
SBY
I
= 0.048A
QP
I
= 20 x 0.00005 =0.001A [the quiescent current for an ionisation detector is 50 µA
QZ
Therefore using the equation:
Battery Size (Standby time in Amp Hours) = 1.25 x [(T
Battery Size (Standby time in Amp Hours) = 1.25 x [(0.5 x 0.35) + (24 x (0.048 + 0.001))]
Battery Size (Standby time in Amp Hours) = 1.25 x [0.175 + (24 x 0.049)]
Battery Size (Standby time in Amp Hours) = 1.25 x [0.175 + 1.176]
Battery Size (Standby time in Amp Hours) = 1.25 x 1.351
Battery Size (Standby time in Amp Hours) = 1.69 Amp Hours
This system would require a minimum of 1.69Ah batteries, so we would recommend using 2Ah
batteries.
Approved Document No: GLT.MAN-101
Issue : 1.95
Authorised: GH
[This assumes the bell current is 25 mA. Most alarm Devices show their operating current]
Date: 09/06/2004
x I
) + (T
x (I
ALM
ALM
SBY
x I
) + (T
x (I
ALM
ALM
SBY
QP
+ I
))]
QP
QZ
+ I
))]
QZ
PAGE 14
Hide quick links:
Advertisement
Table of Contents
