FT2GAS
Gaseous Extinguishing System
Rev No. 1.3
19
Standard Warning Signs on page 48.
2.5.2.4
Fire Alarm / Do Not Enter and Evacuate Signs Output
The gas control board provides a fully supervised bi-directional 22-30V DC / 3A max (current capacity)
to activate a number of gas warning signs (depends on the power supply and battery capacity), refer to
power supply calculation sheet in appendix D on page 39.
The voltage output from the gas module SUB928 has 3 states:
1. Normal, moni24V limited to <1.5mA
2. Level 1 Alarm, active condition is -24V
3. Level 2 Alarm, active condition is +24V
The nominal voltage output of level one alarm is +24V DC when measured across L1-/L2+ and L1+/L2-
of the connector TB3. The level two voltage output is -24V DC when measured across same terminals.
The output is fully supervised for open and short circuit faults. The EOL resistor type is 20K, 1/2W or
1W, 1%, metal film.
The two-wire system of the alarm warning signs output is compatible with Brooks warning signs and
tone / voice sounders.
For more details, refer to the data sheet of the Brooks warning signs in Brooks product datasheets in
appendix I on page 48.
2.5.2.5
Gas Discharge Output
The system gas discharge output is 22-30V DC with up to 5A current capacity. The output is fully
supervised for open and short circuit faults. The EOL resistor type is 20K, 1/2W or 1W, 1%, metal film.
Note: CIE Voltage polarity shown in Figure 5 below is for the output in the active state
Figure 5 Typical Gas Discharge Output Control Circuit
Notes:
1. The series diode is rated @ 3A (1N5404), Brooks part number DI600. If the discharge output
is required to be rated @ 5A continuous, a higher rated diode should be used.
2. The FT2GAS must have suitable power supply to support additional current required by Gas
discharge output if a 5A continuous current is needed.
2.5.2.6
External Supervised Inputs
The system has the following external supervised inputs.
SOLENOID
