Fluid Components International FLT Series Rack Mount - Manual (Page 47)

FLUID COMPONENTS INTL CHAPTER 3 - OPERATION
FLT  Series FlexSwitch  Rack Mount 3 - 12 Doc. No. 06EN003250 Rev. N/C
Note: The alarm can be set for a specific flow rate. Follow the procedure above to step 5 except 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
7.d). Enter the specific flow rate value as the set point and follow the remaining steps.
Note: 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.)
Set Point Adjustment by Observation
Note: The control circuit has two mutually exclusive alarms; they are identified as Alarm 1 and Alarm 2.
Each has a set point adjustment potentiometer and LED indicator. Both alarms 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 OP position. Use Figure 3-2 to help locate the important setup components
(potentiometers, LEDs, etc.).
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. Power the instrument and allow 15 minutes for the sensing element to become active and stabilize.
3. Flow the pipeline at the normal or expected rate.
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 backlash plus deadband; 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 backlash plus deadband; therefore if the mark is overshot, the
procedure should be repeated.
Signal Output for Flow Applications
The output signal 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. Power the instrument and allow 15 minutes for the sensing element to become active and stabilize.