Detcon FP-524HT - Manual (Page 4)

3.0.2 Microprocessor Control Circuit
The control circuit is microprocessor based and is packaged as a plug-in f ield replaceable module, facilitating easy
replacement and minimum down time. Circuit functions include a basic sensor pre-amplif ier, sensor temperature
control, on-board power supplies, microprocessor, back lit alpha numeric display, magnetic programming switches,
and a linear 4-20 mA DC output.
3.0.3 Base Connector Board
The base connector board is mounted in the explosion proof enclosure and includes: the mating connector for the
control circuit, reverse input and secondary transient suppression, input f ilter, and lugless terminals for f ield wiring.
3.0.4 Explosion Proof Enclosure
The sensors are packaged in a cast metal explosion proof enclosure. The enclosure is f itted with a threaded cover
that has a glass lens window. Magnetic program switches located behind the transmitter module face plate are acti-
vated through the lens window via a hand-held magnetic programming tool allowing non-intrusive operator inter-
face with the sensor. Calibration can be accomplished without removing the cover or declassifying the area.
Electrical classif ication is Class I; Groups B, C, D; Division 1.
Model FP-524HT Combustible Gas Sensor PG.4
WHT
BLK
YEL
BLU
mA
VDC Power In
4-20 mA Output
To
Sensor
Base Connector Board
Blue wire
Empty
Green wire
Red wire
detcon inc.
Program Switch #2
FLT CAL
MicroSafe™ LEL Gas Sensor
HOUSTON, TEXAS
PGM 2
PGM 1
MODEL FP-524C
CONTRAST
Fault & Cal LEDs
Program Switch #1
Menu Driven Display
Plug-in Microprocessor Control Circuit
Display Contrast Adjust