Model FT2
101364
In the non-isolated configuration, the 24 VDC power supplied to board power input connector
(TS1) can be connected to the 4-20 mA (+) input supply voltage. The 24 VDC return wire and the
(-) connection of the 4-20mA output must be connected back to the customer’s measuring device.
4.
Improper sensor wiring
The FT2 monitors the sensor signals and will issue an Error Code 22 when a sensor is out of
range. If the temperature of the probe is excessive it will shut down the current to the sensor in
order to protect it. The display indicating flow may fluctuate on and off from 0 to some value
every ten seconds.
5.
Flow measurement seems inaccurate.
Ensure that the flowmeter is installed so that the Flow Direction Arrow engraved on the flat
surface of the fitting below the electronics housing is properly pointing in the direction of flow.
Refer to Figure 2-6.
If you have a Fox Insertion Flowmeter, verify that the insertion depth of the sensor/probe is
correct. The end of the probe should be adjusted as per section 2.2.2. Refer to Figure 2-1.
Ensure there is a minimum of ten diameters of straight pipe upstream of the sensor and five
diameters downstream. If complex flow disturbances are upstream of the sensor, extension of the
straight pipe may be required. Contact Fox for assistance.
The internal cross sectional area of the pipe is programmed into the flowmeter through the front
panel (see section 4.1.10 Flow Parameters). This area is programmed in square feet or square
meters. The Calibration Certificate delivered with the flowmeter contains the area that was
programmed into the flowmeter at the Fox factory. Verify that this area was entered correctly.
6.
Erratic flow reading especially a flow reading spiking high.
This is a symptom of moisture in the flow stream. Fox flowmeters are designed to work in
relatively dry gas applications only. Contact Fox to discuss resolutions to this problem.
7.
The FT2 flowmeter is not responding to flow.
This problem could be caused by a number of items. First check to ensure adequate power is
supplied to the flowmeter as described above. If things appear to be correct, an easy functional test
can be performed. Carefully remove the probe and sensor from the pipe or flow body. Caution:
the sensor is
HOT
. For flowmeters with a display is reading zero, blow on the sensor to see if a
response occurs. If nothing happens, take a damp rag or sponge and place it in contact with the
sensor. A reading should occur. Contact Fox Customer Service with this information.
8.
Display and/or 4-20mA signal reading above zero flow when no flow is occurring in the pipe.
If the reading is less than 5% of full scale, it is likely this is a normal condition caused by
convection flow created by the heated sensor. It does not mean that the zero of the instrument is
improperly set. The Fox sensor is extremely sensitive to gas flow and can even read the small
flow caused by convection. If this is an unacceptable condition, please contact Fox Customer
Service for alternatives.
6.1.
Replacements Parts
F1 – Fuse. FOX Part Number 100045. Digi-Key Part Number F1142CT-ND.
Front Panel Display Module.
Page 48
Fox Thermal Instruments, Inc., 399 Reservation Road, Marina, CA 93933
