FT2GAS
Gaseous Extinguishing System
Rev No. 1.3
39
Connection
Requirement
Cable Specifications
Maximum Cable
Length
Alarm Warning
Signs Output
Use Equation 2
Two cores, Red, 1.5mm
2
conductive
area
Specified Cable Resistance 0. 0128
Ohm / m,
Real Cable Resistance 0. 0256 Ohm /
m
52 metres with up to 3A
current and the lowest
voltage of 18V
Gas release
output
Use Equation 2
Two cores, Red, 1.5mm
2
conductive
area
Specified Cable Resistance 0. 0128
Ohm / m,
Real Cable Resistance 0. 0256 Ohm /
m
31 metres with up to 5A
current and the lowest
voltage of 18V
4.4
Appendix D – Power & Battery Calculation Spreadsheet
In order to configure the Brooks dual zone gaseous extinguishing system, a power calculation of shall
be performed.
The following Table 22 shows the quiescent and alarm current of FT2GAS, different warning signs,
ancillary and optional equipment.
Table 22 Table of current consumption
System
Components
Description
Quiescent
Current (mA)
Alarm
Current (mA)
FT2GAS
Standard FT2GAS system
75
250
BWS-XXXX
Warning or System Inoperative Sign
0
95
BLCS1
Local Control Station
0
60
Gas Discharge Output
Instant discharge device
0
3A for <1 Min.
B24V-SPEAK
Brooks 24V Alert / Evac / Voice Module
0
135
SUB938 (Rev 2)
Optional Dual Strobe Driver Board
0
30
Strobes
Red or yellow strobes
N/A
Depends on
selected strobe
type
The current consumption shown in Table 22 is calculated at the nominal voltage (24V DC) in normal
state (quiescent) state and in the alarm state (active) with ambient temperature at 25 degree Celsius.
In normal conditions, the power supply shall be capable of delivering the total current consumption of
the system including the battery charging current. In alarm, the power supply shall deliver the total
current in alarm condition excluding the battery charging current. FT2GAS is fitted with 150 Watt switch
mode power supply which can deliver up to 5.5A @ 28V.
As per AS1670.1 Section 3.16.4, the battery capacity requirement shall be determined as follow:
C
20
= 1.25
[(
I
Q
x
T
Q
)
+
F
C
(
I
A
x
T
A
)]
Where
C
20
= Battery Capacity in AH at 20h discharge rate at 15
°
C - 30
°
C
1.25 = Compensation factor for expected battery deterioration
