Detcon FP-524HT - Manual (Page 11)

a) FP-524HT “Fault” LED is off.
b) A temporary upscale reading may occur as the sensor heats up. This upscale reading will clear to “0”
% within 1-2 minutes of turn-on, assuming there is no gas in the area of the sensor.
Note 1: If the display contrast needs adjustment, refer to section 3.11.
Note 2: If the sensor has been installed using the remote mounting conf iguration as described in section 3.5.5, the
sensor bridge voltage must be adjusted after initial power up. If this is the case, f irst adjust the bridge voltage as
described in section 3.6.2, then proceed with the initial operation tests below (section 3.6.1).
3.6.1 Initial Operational Tests
After a warm up period of approximately 15 minutes, the sensor should be checked to verify sensitivity to com-
bustible gas.
Material Requirements
* Detcon PN 612-0100000-700 Splashguard with Cal Port
* Detcon PN 600-003427-000 FP-High Temp Splashguard Adapter
* Span Gas 50% LEL methane in air at a controlled f low rate of 200 ml/min.
NOTE: If the sensor has been conf igured for calibration with a gas other than methane you will need to use
that gas. See section 3.7 for further information on calibration gas.
a) Attach the calibration adapter to the threaded sensor housing. Apply the test gas at a controlled f low rate of
200 ml/m. Observe that the LCD display increases to a level of 20% or higher.
b) Remove the test gas and observe that the LCD display decreases to “0 % LEL” .
Initial operational tests are complete. Detcon combustible gas sensors are pre-calibrated prior to shipment and will,
in most cases, not require signif icant adjustment on start up. However, it is recommended that a complete calibra-
tion test and adjustment be performed within 24 hours of installation. Refer to calibration instructions in later text.
3.6.2 Remote Mount Bridge Voltage Setup
If the sensor has been installed using the remote mounting conf iguration as described in section 3.5.6, the sensor
bridge voltage must be adjusted after initial power up. Follow the steps below to set the sensor bridge voltage.
Material Requirements
* Detcon PN 3270 MicroSafe™ Programming Magnet
* Digital volt/ohm meter.
Note: Refer to section 3.6.3 for programming magnet operating instructions.
a) Declassify the area around the sensor.
b) Remove the junction box cover from the remote sensor enclosure (see f igure 4).
c) Using the digital volt/ohm meter, measure the bridge voltage at the remote sensor connector board from the
“White” terminal to the “Blue” terminal as shown in figure 4. Target voltage is 2.7 volts.
d) At the transmitter, enter the programming menu by holding the programming magnet stationary over “PGM 2”
for 30 seconds until the display reads “VIEW PROG STATUS” , then withdraw the magnet.
e) Next, scroll to the “SET BRIDGE VOLTS” listing and then hold the programming magnet over “PGM 1”
for 3 seconds. The menu item appears as “BRIDGE @ #.## VDC”.
f) Use the programming magnet to make an adjustment to “PGM 1” to increase or “PGM 2” to decrease the
bridge voltage. Set the voltage to 2.7 VDC.
g) Exit to the programming menu by holding the programming magnet over “PGM1” for 3 seconds, or automati-
cally return to the programming menu in 30 seconds.
h) Exit back to normal operation by holding the programming magnet over “PGM 2” for 3 seconds, or automati-
cally return to normal operation in 30 seconds.
i) Replace the junction box cover on the remote sensor enclosure.
Bridge voltage adjustment is complete.
3.6.3 Programming Magnet Operating Instructions
Operator interface to MicroSafe™ gas detection products is via magnetic switches located behind the transmitter
Model FP-524HT Combustible Gas Sensor PG.11