Hitachi WJ Series

Chapter 9 Inverter Functions
9-5-9
Adjustments when using V/f control with encoder
 If the desired characteristics cannot be obtained, adjust each item referring to the table below.
 When using the automatic torque boost function, first set "Torque boost mode selection [A041]"
to "Manual torque boost (00)" before adjusting V/f control with speed feedback. Note that
[H050]/[H051] adjustments may not be applied properly when the automatic torque boost
function is in use.
 Overcurrent and other issues may occur if motor rotation is obstructed due to motor locking
from braking or interference from foreign objects. If this cannot be resolved with adjustments,
try checking around the motor's periphery.
 If the "Output frequency monitor [d001]" changes significantly under load, a function that makes
automatic changes to the frequency, such as the overload limit function, non-stop operation
during instantaneous power failure, or the overvoltage suppressor, may have been triggered
under certain function settings. For details, refer to "Chapter 15 Tips/FAQ/Troubleshooting".
Event 
Probable cause 
Example of countermeasures
Motor speed follows
commands slowly.
Slow output response, causing
lag in motor speed (feedback
value) changes.
Increase the "Slip compensation P-
gain at V/f with encoder [H050]".
Unstable motor operation.
Response to feedback values is
excessively fast.
Reduce the "Slip compensation P-
gain at V/f with encoder [H050]".
Overshooting and hunting
occur.
Motor speed oscillates gently.
Slow integral action response.
Increase the "Slip compensation I-
gain at V/f with encoder [H051]".
There is a delay before
operations stabilize.
Motor speed oscillates and
struggles to match the
command speed.
Quick integral action response.
Decrease the "Slip compensation I-
gain at V/f with encoder [H051]".
!