Fluid Components International FLT93 Nuclear - Manual (Page 29)

FLT ® Series FlexSwitch TM OPERATION
Fluid Components International LLC 29
Detecting Wet Condition (adjustment with sensing element dry)
Caution: Give consideration to the fact that air or gas fl owing over the sensing element may decrease the output signal resulting in
a false alarm. If the sensing element is exposed to air or gas fl ow 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 fl ow 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 at which the LED just goes 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 Level Applications
The output signal at P1 is lowest in water and highest in air. See Figure 3-4.
Temperature Applications
For temperature versus voltage values, see Table 3-7 located at the rear of this chapter. These values have an accuracy of ±5°F (2.78°C).
There is also a conversion formula later in this chapter to convert the temperature output voltage to degrees fahrenheit. If a factory calibra-
tion chart was ordered look for it in the plastic page protector at the back of this manual. Make sure the serial number of the chart matches
the instrument to be adjusted.
Note: It is reccommended not to use the instrument for a dual fl ow and temperature application in air or gas unless the fl ow rate is
greater than 1.0 SFPS. (The instrument may be used for a dual fl ow and temperature application in liquids at any fl ow rate.)
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 in still air.
Turn the heater off for temperature only applications. To turn off the heater remove the heater control jumper from the
heater, control header. The jumper may be stored on the control circuit by plugging it across J12 and J14. Placing the jumper
here will not turn on the heater.
1. Remove the instrument’s enclosure cover.
2. Ensure the confi guration jumpers on the control circuit are correct for this application. See Tables 3-3 through 3-6.
3. Check to make sure the input power jumpers match the power to be applied to the instrument. See Table 3-2.
4. Apply power to the instrument. Verify the yellow LED is on. Allow the instrument fi fteen minutes to warm-up.
5. Verify the mode switch is in the RUN position.
6. Attach a DC voltmeter to P1 with the positive (+) lead to position 3 and the negative (-) lead to position 4.
Note: The terminal block can be unplugged from the control circuit to facilitate easy connections.
7. Establish the normal process temperature condition and allow the signal to stabilize.
8. Record the normal temperature signal value.
Normal Temperature Signal = ________ volts DC
Note: The output signal at connector P1 will vary proportionally with the process temperature.
9. Follow either the Detecting Increasing Temperature or the Detecting Decreasing Temperature procedure for each temperature application
alarm.