Inverter Instruction Manual
E6581090
M-8
13
13.4 How to determine the causes of other problems
The following table provides a listing of other problems, their possible causes and remedies.
Problems Causes and remedies
The motor runs in
the wron
g
direction.
• Invert the phases of the output terminals U, V and W.
• Invert the forward/reverse run-signal terminals of the external input
device. (See 6.2 "Assignment of functions to control terminals".)
The motor runs but
its speed does not
change normally.
• The load is too heavy.
Reduce the load.
• The soft stall function is activated.
Disable the soft stall function. (See 5.10.)
• The maximum frequency HJ and the upper limit frequency WN are set
too low.
Increase the maximum frequency HJ and the upper limit frequency
WN.
• The frequency setting signal is too low.
Check the signal set value, circuit, cables, etc.
• Check the setting characteristics (point 1 and point 2 settings) of the
frequency setting signal parameters. (See 6.4.)
• If the motor runs at a low speed, check to see that the stall prevention
function is activated because the torque boost amount is too large.
Ad
j
ust the torque boost amount
(
XD
)
and the acceleration time
(
CEE
)
.
(See 5.1.)
The motor does not
accelerate or
decelerate smoothl
y
.
• The acceleration time (CEE) or the deceleration time (FGE) is set too
short.
Increase the acceleration time
(
CEE
)
or the deceleration time
(
FGE
)
.
A too large current
flows into the motor.
• The load is too heavy.
Reduce the load.
• If the motor runs at a low speed, check whether the torque boost amount
is too large. (See 5.9.)
The motor runs at a
higher or lower
speed than the
specified one.
• The motor has an improper voltage rating.
Use a motor with a proper voltage rating.
• The motor terminal voltage is too low.
Check the setting of the base frequency voltage parameter (H).
(See 6.12.)
Replace the cable with a cable larger in diameter.
• The reduction gear ratio, etc., are not set properly.
Adjust the reduction gear ratio, etc.
• The output frequency is not set correctly.
Check the output frequency range.
• Adjust the base frequency. (See 5.8.)
The motor speed
fluctuates during
operation.
• The load is too heavy or too light.
Reduce the load fluctuation.
• The inverter or motor used does not have a rating large enough to drive
the load.
Use an inverter or motor with a rating large enough.
• Check whether the frequency setting signal changes.
Parameter settings
cannot be chan
g
ed.
Change the setting of the parameter H (prohibition of change of
parameter setting) to .. (permitted) if it is set at ...
(prohibited).
*For safety’s sake, some parameters cannot be set during operation.
(See 4.1.4.)
How to cope with parameter setting-related problems
If you forget
parameters which
have been reset
Yo u c a n sea r c h f o r all reset parameters and change their settings.
*Refer to 4.1.3 for details.
If you want to return
all reset parameters
to their respective
default settings
Yo u c a n r e t u r n a l l parameters which have been reset to their default
settings.
*Refer to 4.1.5 for details.