
109
z
Home return ends in the middle in a vertical application.
Cause: (1) The load exceeds the rating.
(2) The ball screw is receiving torsional stress due to the affixing method of the actuator,
tightening of bolts only on one side, etc.
(3) The slide resistance of the actuator itself is large.
Action: (1) Increase the value set in user parameter No. 13 (Current-limiting value during home
return).
Increasing this value will cause the home return torque to increase, so do not increase the
parameter setting above 75%.
(2) Loosen the fixing bolts and check if the slider moves smoothly.
If the slider moves smoothly, review the affixing method and bolt tightening condition.
(3) If the slide resistance of the actuator itself is large, please contact IAI.
z
Noise occurs during downward movements in a vertical application.
Cause: The load exceeds the rating.
Action: (1) Decrease the speed.
(2) Decrease the value set in the user parameter No. 7 (Servo gain number). Do not decrease
the parameter setting below “3.”
z
Vibration occurs when the actuator is stopped.
Cause: The slider is receiving an external force.
Action: If the external force cannot be removed, increase the value set in user parameter No. 12
(Current-limiting value at standstill during positioning).
Increasing this value will cause the holding torque at standstill to increase, so do not increase
the parameter setting above 70%.
z
The actuator overshoots when decelerated to a stop.
Cause: The load inertia is high due to an inappropriate balance of load and deceleration.
Action: Decrease the acceleration/deceleration setting.
z
The home and target positions sometimes shift.
Cause: (1) The encoder waveform is disturbed by the effect of noise.
(2) In the case of a rod-type actuator, the non-rotation accuracy increased due to application
of rotating moment to the rod.
Action: (1) Check if the grounding is implemented correctly. Also check for any equipment being a
potential noise source.
(2) The actuator may have to be replaced in some cases. Please contact IAI.
z
The speed is slow during push & hold operation.
Cause: The set current-limiting value is low with respect to the load and slide resistance.
Action: Increase the current-limiting value for push & hold operation.