EST LSS4 - Page 112

System
Calculations
A.8
Battery
Capacity
Formula
The
following
information
is
required
performed:
beforethe
calculationscan be
A
Standby
current
drawnbythe
panel.
B The
numberof
hours
(Typically24 or60)the
panel
must
remain
operational
durin_
primary
power
outage.
C The
total
alarm
current
suppliedbythe
panel.
D
Time
duration
expressedasa
fractionof an
hour
(typically
.083
hours)the
panel
must
deliverthe
total
alarm
current,
afterthe
required
standbyperiodhas
elapsed.
The
formula
below
is
usedto
calculatethe
required
battery
capacity.
[Ax B]+ [Cx D]x 1.2=
Minimum
AMP-HOUR
Battery
Capacity
Where:
• A=
Standby
current
(ampsJ.
• B =
Duration
panel
must
remain
operational
[hours].
• C - Al
arrft
Current
[amps].
— • D = Duration
panel
must
remaininalarm
after
standby
period
ends
[hours].
l4ote:
Brackets[]
indicate
unitsof
measuretobe
used.
Table
A-4:
Minuteto
Decimal
Hours
Conversion
05
minutes=
1/12
houror
.083hrs
10
minutes=1/6
houror
.167hrs
1S
minutes=1/4
houror
.250
hrs.
20
minutes=1/3
houror
.333
hrs.
25
minutes=
5/12
houror
.417
hrs.
30
minutes= 1/2
houror
.500
hrs.
45
minutes=3/4
houror
.750
hrs.
Note:
WhenaLSSPS
power
supply
is
charging
its own
batteries,an
additionalbattery
worksheet
mustbe
filledout to
determinethe
required
battery
capacityfortheLSSPS
battery.
Whena
LSSPS
power
supply
is
sharinga
battery
withthe
LSS4no
additionalcalculationsare
required.
LSS4
Installation,
Operation.and
Maintenance
Manual