5/12/2017
TECH-538/D.W.O. 23160
Page 113 of 189
Others
The local display remains blank even after power is applied to the positioner
•
Check wiring.
•
The ICoT FF should power up when the voltage is adjusted between 9VDC and 32VDC. The voltage
across the positioner can be checked by removing the electronics’ cover and connecting a
voltmeter across TP10 and TP11 on the display board.
•
In order to check if the positioner is working despite of the LCD mal-function, check the FF
communications and function blocks for proper mode of operation.
The positioner is energized but the position as shown on the local display does not seem to match
the actual position of the actuator / valve
•
The positioner may need to be calibrated. Perform a manual step by step calibration or a full
automatic calibration (see sections 8.9.4 or 8.10.2).
•
The magnet / Beacon may be incorrectly assembled (see Chapter 3).
•
Check if it is properly configured as linear or rotary (see Section 8.9.7, “Cofg” -> “
Type
”, or Section
•
The flow characteristic during calibration was set to equal percentage or quick opening, not linear.
If linear is desired instead, change the flow characteristics to linear. If the problem persists,
re-calibrate the positioner (see calibration instructions in Section 8.9.4 or Section 8.10.2)
See Section 8.9.7 or Section 8.10.4 for configuration of the function
Flow
.
The positioner is properly set-up, and air is applied to the positioner. When powering up the
positioner, the actuator goes into a state of constant oscillation
•
Check for air leaks and other pneumatic and mechanical parts assembly: tubing, actuator, bracket,
cables etc.
•
The gain settings are probably too high for the actuator/valve assembly. If not done yet, perform a
full automatic calibration (see sections 8.9.4 or 8.10.2).
•
It is necessary to run a successful Auto Calibration at least once before start using the positioner.
•
If this problem persists after a successful Auto Calibration, re-run the manual PID calibration
self-tuning function (see sections 8.9.5.2 or 8.12.4, for the function
Auto
PID
).
•
If Auto PID finishes without errors and problem persists, try to manually fine tune the PID.
Enter the calibration mode and decrease the PCAL value until oscillation ceases.
•
If the problem persists, try to increase the ICAL setting until oscillation ceases.
•
And if the problem still persists, try to adjust the DCAL (or set it to zero) until the dynamics
response is satisfactory.
After removing power from the positioner that the output port 1 is at full pressure and zero
pressure in the output port 2
•
On loss of power the positioner should set the full air pressure in the output port 2. Anything
different may indicate a problem with the mechanical assembly or the positioner is damaged.
Contact Westlock for support.
