FLUID COMPONENTS INTERNATIONAL LLC
FLT93 Flow Switch Series
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6
Doc. No. 06EN003312 Rev. D
Detecting Decreasing Flow (low flow alarm)
If the status LED is off, turn the set point adjustment potentiometer clockwise until the LED turns on. With the LED
on, slowly turn the potentiometer counterclockwise one turn past the point at which the LED just turns off. The
potentiometer may have up to one-quarter turn of hysteresis, therefore, if the mark is overshot, the procedure should
be repeated.
Detecting Increasing Flow (high flow alarm)
If the status LED is on, turn the set point adjustment potentiometer counterclockwise until the LED turns off. With
the LED off, slowly turn the potentiometer clockwise one-half turn past the point at which the LED just turns on.
The potentiometer may have up to one-quarter turn of hysteresis, therefore, if the mark is overshot, the procedure
should be repeated.
Signal Output for Flow Applications
The output signal at connector P1 is a non-linear voltage representation of the flow rate. The output signal level is
also relative to the type of process media, see flow application signal output figure on the previous page.
Level Applications
1. Ensure that the instrument has been properly installed in the vessel.
2. Apply power to the instrument and allow fifteen minutes for the sensing element to become active and stabilize.
3. Remove the enclosure cover to allow access to the control circuit to make adjustments.
Detecting Dry Condition (adjustment with sensing element wet)
Verify that the sensing element is wet. If the status LED is off, turn the set point adjustment potentiometer clockwise
until the LED turns on. With the LED on, slowly turn the potentiometer counterclockwise one turn past the point at
which the LED just turns off. The potentiometer may have up to one-quarter turn of hystereses, therefore, if the mark
is overshot, the procedure should be repeated.
Detecting Wet Condition (adjustment with sensing element dry)
Alert:
Give consideration to the fact that air or gas flowing over the sensing element may decrease the
output signal resulting in a false alarm. If the sensing element is exposed to air or gas flow in the
dry condition, or where the process media is highly viscous, make set point adjustments in the wet
condition only.
Field adjustments made in the dry condition should be performed in the actual service environment or within a
condition that approximates that environment. Provision should be made for the worst case condition of air or gas
flow on the sensing element. If the status LED is on, turn the set point adjustment potentiometer counterclockwise
until the LED turns off. (If the LED cannot be turned off, the instrument must be set in the wet condition.)
With the LED off, slowly turn the potentiometer clockwise 1 turn past the point where the LED just lights. The
potentiometer may have up to one-quarter turn of hysteresis, therefore, if the mark is overshot, the procedure should
be repeated.
Signal Output for Level Applications
The output signal at P1 is low in liquid and high in gas. See the level application signal output figure on the
previous page.
Temperature Applications
Note:
It is recommended not to use the instrument for a dual flow and temperature application in air or gas
unless the flow rate is greater than 5.0 SFPS. (The instrument may be used for a dual flow and
temperature application in liquids at any flow rate.)
