Toshiba TOSVERT VF-AS1 Instruction Manual page 145

Precautions on auto-tuning
(1) The inverter is tuned automatically (auto-tuning =) when the inverter is started for the first
time after setup. During auto-tuning, which takes several tens of seconds, the motor is energized,
although it is standing still. Noise may be produced by the motor during auto-tuning, which, however,
does not indicate that something is wrong with the inverter or the motor.
(2) Conduct auto-tuning only after the motor has been connected and operation completely stopped.
If auto-tuning is conducted immediately after operation stops, the presence of a residual voltage may
result in abnormal tuning.
(3) Usually, auto-tuning terminates in some seconds. If an error occurs, however, the inverter trips
(display ) and no motor constant is set. For these motors, perform manual tuning using
Selection 3 described below.
(4) High-speed motors, high-slip motors or other special motors cannot be auto-tuned. For these motors,
perform manual tuning using Selection 3 described below.
(5) Provide cranes and hoists with sufficient circuit protection such as mechanical braking. Without
sufficient circuit protection, the result of insufficient motor torque during tuning could create the risk of
the machine stalling/failing.
(6) If auto-tuning is impossible or an auto-tuning error () is displayed, perform manual tuning with
Selection 3.
Precautions on vector control
[Selection 3: Setting sensorless vector control and manual
independently]
Setting motor constants
6
Perform all operations in up to (1) in the flowchart on the previous page. If the motor specifications are unknown,
enter only the motor capacity () and set parameter  to . After that, run the motor and set other
parameters with the following explanation about parameter adjustments as a guide.
This section describes how to set motor constants. Select the items to be improved and change the related motor
constants.
(1) Slip frequency gain 
This parameter is to adjust the slippage of the motor.
Setting this parameter at a larger number can reduce the slippage of the motor. However, setting it at an
excessively large number may result in hunting, etc., and thus cause an unstable operation.
(2) Motor constant 1  (Torque boost) (Motor test reports may be useful.)
This parameter is to adjust the primary resistance of the motor. Setting this parameter at a larger value can prevent
the drop of the motor torque in low speed ranges due to a voltage drop. However, setting it at an excessively large
number may result in large current in low speed range and appearance of an overload trip, etc.
(3) Motor constant 2  (No-load current) (Motor test reports may be useful.)
This parameter is to adjust the exciting inductance of the motor. The larger the set value, the more exciting current
can be increased. Note that specifying a too large value for the motor constant may cause hunting.
(4) Motor constant 3  (Leak inductance) (Motor test reports may be useful.)
This parameter is to adjust the leakage inductance of the motor. The larger the set value, the larger torque the
motor can produce in high-speed ranges.
(5) Motor constant 4  (Rated slip)
This parameter is to adjust the secondary resistance of the motor. The amount of compensation for slip increases
with increase in this value.
(6)  (Moment of inertia of load)
This parameter is used to adjust the excess response speed. Specifying a large value reduces the amount of
overshoot at the completion of acceleration. So, specify a value appropriate to the actual moment of inertia of the
load.
⇒
Refer to Section 5.6.8.
F-38
E6581301