How To Determine The Causes Of Other Problems - Toshiba TOSVERT VF-nC3 Instruction Manual

13.4 How to determine the causes of other problems

The following table provides a listing of other problems, their possible causes and remedies.
The motor runs in the
wrong direction.
The motor runs but its
speed does not change
normally.
The motor does not
accelerate or decelerate
smoothly.
A too large current flows
into the motor.
The motor runs at a higher
or lower speed than the
specified one.
The motor speed fluctuates
during operation.
Parameter settings cannot
be changed.
Communication will not take
13
place.
How to cope with parameter setting-related problems
If you forget parameters
which have been reset
If you want to return all
reset parameters to their
respective default settings
Problems

Invert the phases of the output terminals U, V and W.

Invert the forward/reverse run-signal terminals of the external input device.
(Refer to section 7.2.1 "Assignment of functions to control terminals")

Change the setting of the parameter  in the case of panel operation.

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 6.5.2)

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.
Adjust the torque boost amount () and the acceleration time ().
(Refer to section 5.12 and 5.3)

The acceleration time () or the deceleration time () is set too short.
Increase the acceleration time () or the deceleration time ().

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.
(Refer to section 5.12)

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
5.10)
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 5.10)

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 5.11)
Change the setting of the parameter setting selection prohibited parameter  to
 (enabled) if it is set to  or  (prohibited).
* For reasons of safety, some parameters cannot be reprogrammed while the inverter is
running. (Refer to section 6.18.1 and 11.8)
Refer to "Appendix 4 Troubleshooting" in Communication Manual (E6581656).

You can search for all reset parameters and change their settings.
* Refer to section 4.3.1 for details.

You can return all parameters which have been reset to their default settings.
* Refer to section 4.3.2 for details.
Causes and remedies
M-8
E6581595