Fluid Components International FLT Series - Manual (Page 30)

FLUID COMPONENTS INTL CHAPTER 3 - OPERATION
FLTÔ Series FlexSwitchÔ 3 - 12 Doc. No. 06EN003246 Rev. B
6. Disconnect the voltmeter from P1.
7. Replace the enclosure cover.
Note: The alarm can be set for a specific flow rate. Follow the Liquid Flow Application Procedure above to
establish the specific flow rate rather than the normal flow. The output signal will be the set point value.
Determine whether the alarm should actuate with decreasing or increasing flow and skip to the appropriate
step, 4 of either Decreasing Flow Rate or Increasing flow rate. Enter the specific flow rate value as the set
point and then follow the Continue With the Liquid Flow Application procedure steps.
The relay logic default configuration is set for the relay coil to be de-energized when the flow signal is
greater than the set point value. (i.e., Assume that the normal process flow condition has been established.
In this state, the relay coil will be energized if the alarm has been set for low-flow detection and de-
energized if the alarm has been set for high flow detection.)
Adjustment by Observation
Note: The control circuit has two mutually exclusive alarms; they are identified as Alarm No. 1 and Alarm No. 2
and each has a set point adjustment potentiometer and LED indicator. Each alarm can be setup for one of
three applications: flow, level/interface, or temperature. The following application specific adjustment
procedures are generic and can be used for setting either or both alarms. The mode switch must be in the
RUN position. Use Figure 3-2 to help locate the adjustment potentiometers and LEDs.
Flow Applications
1. Ensure that the instrument has been properly installed in the pipeline. Fill the pipeline so the sensing element is
surrounded by the process medium.
2. Apply power to the instrument and allow fifteen minutes for the sensing element to become active and stabilize.
3. Flow the pipeline at the normal or expected rate. Remove the enclosure cover to allow access to the control
circuit to make adjustments.
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 varies inversely with flow rate. The output signal level is also relative to the type
of process media, see Figure 3-3.
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.