Bosch FCS-320-TM Operation Manual page 54

54 en | Planning
where
I
g
I
A
I
Q
I
PSmax
I
L
K
n
n
n
max
NOTICE!
The power supply units are laid out using the calculated total current I
Please refer to Section 2.8 Technical data, page 28 for the current consumption of the FCS-
320-TM.
Line calculation
The maximum line length is derived from the permissible voltage drop on the supply line. The
permissible voltage drop is the difference between the end-point voltage of the backup
battery (21.5 V) and the lower operating voltage limits of the aspirating smoke detectors.
where
L
max
A
I
g
γ
ΔU
To guarantee the impermeability of the housing, the corresponding cable bushing must be
selected for the existing cable:
–
–
Emergency power calculation
The rated capacity is calculated according to the following formula:
K
n
I
Q
n
t
I
g
The factor 1.25 used in the formula is only applicable with bridging times ≤24 hours.
F.01U.130.928 | 1.0 | 2009.11
= Total current of all connected aspirating smoke detectors in [A]
= Alarm current of an aspirating smoke detector in [A]
= Standby current of an aspirating smoke detector in [A]
= Max. power supply of the network power supply in [A]
= Charging current of the rechargeable batteries (80% of the nominal
capacity within 24 hours) in [A]
= Rated capacity of the rechargeable battery in [Ah]
= Total number of connected aspirating smoke detectors
= The highest number of aspirating smoke detectors in one detection zone
= Maximum line length in [m]
= Strand cross-section in [mm²]
= Total current of all connected aspirating smoke detectors in [A]
= Conductivity: Cu=57 m/Ω mm²
= Charging current of the rechargeable batteries (80% of the nominal
capacity within 24 hours) in [A]
M 25 cable bushing: ∅ 9-14 mm
M 20 cable bushing: ∅ 8-12 mm
= Rated capacity of the backup batteries in [Ah]
= Standby current of an aspirating smoke detector in [A]
= Total number of connected aspirating smoke detectors
= Required bridging time in [hrs]
= Total current of all connected aspirating smoke detectors in [A]
Operation Guide
FCS-320-TM Aspirating Smoke Detector
γ
ΔU A
. .
L
=
max
2
I
.
g
with the highest value.
g
Bosch Sicherheitssysteme GmbH