Detcon FP-624D - Manual (Page 8)

Model FP-624D
FP-624D Instruction Manual Rev. 1.2 Page 4 of 42
Figure 6 Transmitter Module
The transmitter module includes four LED status indicators (see Figure 3). These indicators are labeled FLT,
ALM1, ALM2 and CAL. The ALM1 and ALM2 LEDs are illuminated when the sensor is above the
corresponding alarm threshold. The FLT LED is illuminated when the sensor is in fault. The CAL LED is
illuminated solid when the sensor is completing an AutoZero or AutoSpan calibration. If the sensor is not
being calibrated, the CAL LED will flash each time the sensor answers a poll request from a Modbus
TM
master.
Field Replaceable Sensor
The Detcon combustible gas sensor is a field proven, replaceable type sensor. It can be accessed and replaced
in the field by removing the threaded insert from the lower housing and unplugging the replaceable sensor.
The Detcon combustible gas sensor has an infinite shelf life and is supported by a 2 year warranty.
Figure 7 Field Replaceable Combustible Gas Sensor
NOTE: The Field Replaceable Combustible Gas Sensor housing is constructed from 316 Stainless Steel in
order to maximize corrosion resistance in harsh environments.
Base Connector PCB
The base connector board is mounted in the junction box. The connector board includes lug-less terminal
connections for incoming power, Modbus, and mA output, and connections for the Combustible Gas
Replaceable Sensor. Terminals for the 3 common and normally open/normally closed relay outputs are also
located on the base connector board.
PGM 1
PGM 2
MODEL FP-624D
HOUSTON, TEXAS
FLT 1 2 CAL
MicroSafe LEL Gas Sensor
ALM ALM
TM
Replaceable Sensor
Main Housing
Threaded Insert
O-ring