Detcon TP-624D - Manual (Page 7)

Model TP-624D
TP-624D Instruction Manual Rev. 0.4 Page 3 of 40
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 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 master.
Field Replaceable Sensor
The Detcon solid-state H
2
S gas sensor is a field proven, replaceable type sensor. It can be accessed and
replaced in the field by removing the wiring from the connector PCB, and unthreading the sensor from the
junction box. The Detcon solid state H
2
S sensor has an infinite shelf life and is supported by a 10 year,
industry-leading warranty.
Figure 4 Field Replaceable H
2
S Sensor
NOTE: The Field Replaceable H
2
S Gas Sensor 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 H2S Replaceable Sensor.
Terminals for the common and normally open/normally closed relay outputs are also located on the base
connector board.
Figure 5 Base Connector Board
Customer
Wiring
Wiring to
H2S Sensor
Wiring to
Relays