Detcon TP-424C - Manual (Page 7)

16 600 2000
14 900 3000
Note 1: This wiring table is based on stranded tinned copper wire and is designed to serve as a reference only.
Note 2: Shielded cable may be required in installations where cable trays or conduit runs include high volt-
age lines or other sources of induced interference.
Note 3: The supply of power must be from an isolating source with over-current protection as follows:
AWG Over-current Protection AWG Over-current Protection
22 3A 16 10A
20 5A 14 20A
18 7A 12 25A
Sensor Location
Selection of physical sensor location is critical to the overall safe performance of the product. Four factors
play an important role in selection of sensor locations:
(1) Density of the gas to be detected
(2) Most probable leak sources within the industrial process
(3) Ventilation or prevailing wind conditions
(4) Personnel exposure
Density - Placement of sensors relative to the density of the target gas is such that sensors for the detection
of heavier than air gases should be located within 2-4 feet of grade as these heavy gases will tend to settle
in low lying areas. For gases lighter than air, sensor placement should be 4-8 feet above grade in open
areas or in pitched areas of enclosed spaces. Give consideration to easy access by maintenance personnel
as well as the consequences of close proximity to contaminants that may foul the sensor prematurely.
Leak Sources - Most probable leak sources within an industrial process include flanges, valves, and tubing
connections of the sealed type where seals may either fail or wear. Other leak sources are best determined
by facility engineers with experience in similar processes.
Ventilation - Normal ventilation or prevailing wind conditions can dictate efficient location of gas sensors
in a manner where the migration of gas clouds is quickly detected.
Personnel Exposure - The migration of gas clouds should not be allowed to approach concentrated person-
nel areas such as control rooms, maintenance or warehouse buildings.
A more general and applicable thought toward selecting sensor location is combining leak source and
perimeter protection in the best possible configuration.
Note: In all installations, the sensor element in stainless steel housing points down relative to grade (see
figure #2). Improper sensor orientation will result in false reading and permanent sensor damage.
Detcon Model TP-424C Hydrogen Sulfide Sensor PG.7
EYS
Seal
Fitting
Drain
“T” Plug any unused ports.
Fig. #2