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FT900003
Rev A1
MAINTENANCE
Step Nine
General:
The Thermo‐Flo™ switch requires no periodic maintenance except to clean off any deposits or
scaling from the sensor tip as necessary. It is the responsibility of the user to determine the appropriate
maintenance schedule, based on the specific characteristics of the application liquids.
Cleaning Procedure:
1.
Power:
Make sure that all power to the sensor, controller and/or power supply is completely
disconnected.
2.
Sensor Removal:
Make sure that the flow is off and the pressure is down prior to removing the Thermo‐
Flo™.
Carefully, remove the sensor from the installation. Replace the sensor with a 3/4” NPT plug to
insure that the liquid does not leak out during this procedure.
Do not re‐install the Thermo‐Flo™ if the
threads are damaged.
3.
Cleaning the sensor:
Use a soft bristle brush and mild detergent, carefully wash the Thermo‐Flo™ flow
switch. Do not use harsh abrasives such as steel wool or sandpaper, which might damage the surface
sensor. Do not use incompatible solvents which may damage the surface sensor. Do not use incompatible
solvents which may damage the sensor’s PP/Ryton or PVDF plastic body.
4.
Sensor Installation:
Follow the appropriate steps of installation as outlined in the installation section of
this manual.
Testing the Sensor (FT10 Series Only):
1.
Immersing the switch:
Place the switch in a cup of water. Make sure the tips are submersed in the water.
2.
Power:
Turn on power to the switch with Red to (+) and Black to (‐)
.
You can reverse the polarity if
desired.
3.
No‐Flow/Flow Test:
With the switch setting still in the cup, wait until the Red LED turns ON (no‐flow
condition).
a.
Swirl the switch in the cup and wait until the Red LED turn OFF (flow condition).
b.
Stop swirling the sensor and let it rest in the cup waiting for the Red LED to turn ON again (no‐flow
condition).
c.
Repeat the above two steps.
4.
Relay Test:
Connect a multimeter (set to read Ohms) to the White and Green Wires. Perform the above
No‐Flow/Flow test with the multimeter connect to observe the actuation of the relay.
a.
With Red to (+) and Black to (‐), the multimeter will read a small resistance during no‐flow (closed
relay) and OL during a flow condition (open relay).
b.
Reverse Polarity [Red to (‐) and Black to (+)] to see the multimeter read OL during a no‐flow state
(open relay) and a small resistance during a flow condition (closed relay).
The No‐Flow/Flow test determines if the switch is capable of sensing the changes between no‐flow and flow.
The Relay test determines the ability of the relay to switch between a no‐flow and flow condition. This is the
basic test to determine functionality of the sensor.
