Fluid Components International FLT Series Rack Mount - Manual (Page 48)

Doc. No. 06EN003250 Rev. N/C 3 - 13 FLT  Series FlexSwitch  Rack Mount
CHAPTER 3 - OPERATION FLUID COMPONENTS INTL
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 backlash plus deadband;
therefore, it the mark is overshot, the procedure should be repeated.
Detecting Wet Condition (adjustment with sensing element dry)
Caution: Consideration should be given to the fact that air or gas flowing over the sensing element may
decrease the output signal and result in a false alarm. In cases where the sensing element is
exposed to air or gas flow in the dry condition, or where the process media is highly viscous, set
point adjustments should be made 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 one turn past the point at which the LED just goes on.
The potentiometer may have up to one-quarter turn of backlash plus deadband; therefore, if the mark is overshot, the
procedure should be repeated.
Signal Output for Level Applications
The output signal varies relative to the type of process media. (See Figure 3-4).
Temperature Applications
Caution: Do not use the instrument for a dual flow and temperature application in air or gas unless the flow
rate is greater than 5 SFPS. (The instrument may be used for a dual flow and temperature
application in liquids at any flow rate.)
Caution: When using the instrument for dual level and temperature applications, the temperature signal can
be as much as 50°F (28°C) high when the sensing element is dry.
Note: Turn the heater off for temperature only applications. When a temperature alarm is combined with
either a flow or level alarm, best results will be obtained by setting the heater power for 0.75 watt and
ensuring that the sensing element is always in liquid.
1. Ensure that the instrument has been properly installed.
2. Power the instrument and allow 15 minutes for the sensing element to become active and stabilize.
3. Establish the normal or expected temperature.
Detecting Increasing Temperature (high temperature alarm)
If the status LED is off, turn the alarm adjustment potentiometer clockwise until the LED turns on. With the LED
on, slowly turn the potentiometer counterclockwise one half turn past the point at which the LED just turns off. The
potentiometer may have up to one-quarter turn of backlash plus deadband; therefore if the mark is overshot, the
procedure should be repeated.
Detecting Decreasing Temperature (low temperature 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 backlash plus deadband; therefore if the mark is overshot, the
procedure should be repeated.