FT2GAS
Gaseous Extinguishing System
Rev No. 1.3
20
•
Gas release input
monitors the gas manual release mechanism, normally located at the head
of the extinguishing agent contactor. When this input is activated, the “Gas Externally Released”
LED illuminates, the level 2 alarm signs will be activated immediately. This input will not initiate
the automatic sequence of gas releasing.
•
Gas lock-off valve input
, this input monitors the lock-off valve position. If the valve is closed,
the input will be active which causes the “Gas Fault” LED to flash once every 2.5 seconds and
the Extinguishing System Inoperative sign to illuminate.
•
Gas discharged sensor input
, the gas pressure switch or flow sensor is supervised via this
input and confirms that the gas has been released. A pressure switch will normally operate when
the extinguishing agent bottle has low pressure indicating the bottle has emptied or is low. A
flow sensor will operate when the extinguishing agent is discharged through the system pipe-
work past the sensor.
The external inputs are fully supervised for open and short circuit faults.
Figure 6 Supervised Input Circuit
Both the EOL resistor and the active resistor are 47K, 1/2W or 1W, 1%, metal film.
2.5.2.7
Local Control Station (LCS)
The FT2GAS system provides an interface to multiple remote gas control stations. Only the Brooks LCS
can be connected to this interface. It includes the following four signals,
•
LCS +24V,
•
LCS Ground,
•
LCS Gas Release input,
•
LCS Gas Isolate input.
Both LCS gas release input and gas isolate input are fully supervised for open and short circuit faults.
Figure 7 Remote Station Input Circuit
The EOL resistor is 27K, 1/2W or 1W, 1%, metal film. The active resistor is 10K, 1/2W or 1W, 1%, metal
film. The schematics for the LCS can be found in
LCS
10K
27K
EOL
27K
EOL
MCP
ISO
0V (GND)
10K
24V
GAS
CONTROL
BOARD
24V
0V (GND)
MCP
ISO
TB1
CON1
(SUB928)
