LTQ008 – LTQ230 Series 3-Phase
Products
User Instructions –
AIIOM000165
EN
Page
33
of
40
Table 3: Fault symptoms for proportional control models
The act uato r do es no t m o v e w hen co mmande d to do so .
The s upp ly an d cont rols are me as u red to be co rr ect, but the ac tua tor s t ill do es not m ov e.
The mo to r is ex tre me ly h o t to the touch.
The act uato r do es no t s to p at t he co r rect pos itio n at eit he r e nd-of -t rav el.
Target
Action
Power source
Measure incoming power at the actuator terminal blocks.
Reference the correct wiring diagram (
Error! Reference source not
found.
).
Control problem
Generate move commands by the field device. For most analog
control systems, reversing the polarity will render the control system
output as invalid. Check the polarity of the analog control signals
as they are connected to the actuator. The actuator will not
respond to inverted control signals.
Wire sizing
Check for the correct wire size per Table .
Overtorque
Remove the actuator from the driven device. If the actuator now
moves, the torque required by the mechanical device exceeds
that of the actuator. Increase the size of the actuator.
With the actuator removed from the mechanical equipment,
manually rotate the valve or damper through its intended range of
travel to check for mechanical problems.
Insufficient power supply and/or incorrect
wire size during installation.
Measure the voltage between terminals 1 & 2 while commanding
the actuator to move. Also measure the voltage between terminals
L1, L2, and L3. The measured voltage cannot drop more than 10%
from the rated voltage.
Cams improperly set.
Remove power.
Check to see if the cams rotate freely on the cam
shaft using your finger. The cams must be secure and set according
to the procedures in section 5.8.
Control “noise” or excessive duty cycle.
Check for stray voltage fluctuations on the incoming control signals.
Analog control signals are susceptible to “noise” and send unstable
control data to the actuator. This results in a never-ending motor
drive scenario with the usual result being thermal overload of the
drive motor.
Check for parallel wiring of multiple on/off actuators. Review the
site as-built wiring diagrams to verify.
Travel cams and/or mechanical stops not
positioned correctly.
Reset the end-of-travel cams and/or the mechanical stops as
detailed in section 5.8.