Detcon FP-700 - Manual (Page 33)

Model FP-700
FP-700 Instruction Manual Rev. 3.0 Page 29 of 40
5. Service and Maintenance
5.1 Calibration Frequency
In most applications, quarterly to biannual zero and span calibration intervals will assure reliable detection.
However, industrial environments differ. Upon initial installation and commissioning, close frequency tests
should be performed, weekly to monthly. Test results should be recorded and reviewed to determine a suitable
calibration interval.
5.2 Visual Inspection
The Sensor should be inspected annually. Inspect for signs of corrosion, pitting, and water damage. During
visual inspection, the Splash Guard should be inspected to insure that it is not blocked. Examine the porous
316SS flame arrestor within the sensor’s bottom housing for signs of physical blockage or severe corrosion.
Also, inspect inside the Junction Box for signs of water accumulation or Terminal Block corrosion.
5.3 Condensation Prevention Packet
A moisture condensation packet should be installed in every explosion proof Junction Box. The moisture
condensation prevention packet will prevent the internal volume of the J-Box from condensing and
accumulating moisture due to day-night humidity changes. This packet provides a critical function and should
be replaced annually. Detcon’s PN is 960-202200-000.
Housing Bottom
Locking Set-Screw
M
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L
F
P
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Splash Guard
O-Rings
Intelligent ransmitter Module (ITM)
Microprocessor controlled circuit
encapsulated in an explosion
proof housing.
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Bottom Housing
Assembly
Plug-In replaceable
H2S Sensor
Magnetic
Programming
Switches
Lens and LCD
Display
Interconnect Wiring
Figure 15 Sensor Assembly
5.4 Replacement of Plug-in Combustible Gas Sensor
a) Remove power to FP-700 sensor by lifting the + 24VDC wire in J-Box.
NOTE: It is necessary to remove power while changing the plug-in combustible gas sensor in
order to maintain area classification.
b) Use a M1.5 Allen wrench to release the locking setscrew that locks the ITM and bottom housing together
(One turn will suffice - Do not remove setscrew completely).
c) Remove splashguard. Unthread and remove the Bottom Housing from the ITM.
d) Gently pull the plug-in combustible gas sensor out of the ITM. Orient the new plug-in sensor so that it
matches with the female connector pins. It may be necessary to look from below to assure alignment is
correct. When properly aligned, press the sensor in firmly to make the proper connection.