September 2021
Installation, Operation and Maintenance Manual
VCIOM-01249-EN Rev. 0
100
Troubleshooting
Section 12: Troubleshooting
12.4
The Motor Is Very Hot and Does Not Start
•
Check that no alarm other than motor overheating is present.
•
Wait until the motor cools down and the normally closed contact of the thermal
switch automatically resets before trying to operate the actuator again.
•
Check that the number of operations per hour and their duration is suitable for the
actuator service (see the nameplate menu).
•
Check that the valve operating torque is within the range of the unit’s designed
operating torque.
•
Always check the causes of abnormal operation.
12.5
The Motor Runs but the Actuator Does Not
Move the Valve
In case the local display does not change, the valve position indicators:
•
Rotate the handwheel a few degrees to remove all possible sticking between the
handwheel and the drive sleeve.
In case the local display changes, the valve position indicators:
•
Verify the stem nut correctly fits in the actuator base.
•
Verify the stem nut has sufficient engagement with the valve stem.
•
Verify the key correctly fits in bore/keyways applications.
•
Check that the valve works in manual operation.
12.6
The Valve Does Not Seat Correctly
•
If the valve is stopped by the torque limit in closing, increase the actuator output
torque limit.
•
If the valve is stopped by the position limit in closing, check that the valve reaches
its seat position, then readjust the setting of the position limit.
•
The internal trim of the valve may be damaged.
12.7
Excessive Torque for Valve Operation
•
Clean, lubricate and check the valve stem.
•
Valve packing too tight: loosen the gland bolt nuts.
•
Coupling: ensure there are no axial forces on the valve stem by leaving an
adequate axial clearance between the stem and the drive bush. Also check that
all transmission shafts, universal joints or bulkhead passages have sufficient
lubrication and check that the transmission shafts are not bent.
•
Check that the internal valve trim or the reducer gears are well lubricated and
not damaged.
•
Check the alphanumeric display for diagnostic messages and proceed with the
suitable corrective actions as described in Section 12.10, Diagnostic messages.
