Toshiba Q9 Plus ASD, Installation & Operation Manual

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E6581611
M-9
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
wrong direction.

Invert the phases of the output terminals U/T1, V/T2 and W/T3.

Invert the forward/reverse run-signal terminals of the external input device.
(Refer to section 7.2.1)

Change the setting of the parameter

in the case of panel operation.
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. (Refer to section 3.5)

The maximum frequency  and the upper limit frequency  are set too low.
Increase the maximum frequency

and the upper limit frequency

.

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. (Refer to section 6.6.2)

If the motor runs at a low speed, check to see that the stall prevention function is
activated because the torque boost value is too large.
Adjust the torque boost value (
 ) and the acceleration time (  ).
(Refer to section 5.13 and 5.4)
The motor does not
accelerate or decelerate
smoothly.

The acceleration time (  ) or the deceleration time (  ) is set too short.
Increase the acceleration time (

) or the deceleration time (

).
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 value is too large.
(Refer to section 5.13)
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 (

) . (Refer to section
5.11)
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. (Refer to section 5.11)
The motor speed fluctuates
during operation.

The load is too heavy or too light. Reduce the load fluctuation.

T he 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.

If the V/F control selection parameter  is set at 3 , check the vector control setting,
operation conditions, etc. (Refer to section 5.12)
Parameter settings cannot
be changed.

Change the setting of the parameter setting selection prohibited parameter

to

(enabled) if it is set to

to
4
(prohibited).

Set the verification code to

, if password has entered by the password setting

. (Refer to section 6.29.1)

Switch off the logic input terminal, if this terminal is assigned to input terminal
menu 200 to 203 (Parameter editing / reading prohibition).

For reasons of safety, some parameters cannot be reprogrammed while the inverter is
running. (Refer to section 4.2)
How to cope with parameter setting-related problems
If you forget parameters
which have been reset 
You can search for all reset parameters and change their settings.
* Refer to section 4.3.1 for details.
If you want to return all
reset parameters to their
respective default settings 
You can return all parameters which have been reset to their default settings.
* Refer to section 4.3.2 for details.