Check first when you have a trouble
6.6.12 Speed does not accelerate
Start command and frequency command are chattering.
The wiring length used for analog frequency command
is too long, and it is causing a voltage (current) drop.
Input signal lines are affected by external EMI.
Pr. 1, Pr. 2, Pr. 18, calibration parameter C2 to C7 settings
The maximum voltage (current) input value is not set
during the external operation. (Pr.125, Pr.126, Pr.18)
Torque boost (Pr. 0, Pr. 46) setting is improper under V/F
control, so the stall prevention function is activated.
V/F pattern is improper when V/F control or Simple
magnetic flux vector control is performed.
(Pr. 3, Pr. 14, Pr. 19)
Stall prevention function is activated due to a heavy
During PID control, output frequency is automatically controlled to make measured value = set point.
6.6.13 Unable to write parameter setting
Operation is being performed (signal STF or STR is
You are attempting to set the parameter in the External
Parameter is disabled by the Pr. 77 Parameter write
Key lock is activated by the Pr. 161 Frequency setting/key
lock operation selection setting.
Operation mode and a writing device do not
Attempted to set "25" in Pr.72 PWM frequency selection
under IPM motor control. Attempted to perform IPM
motor control while Pr.72 ="25."
6.6.14 Power lamp is not lit
Wiring or installation is improper.
Check if the start command and the frequency
command are correct.
Perform analog input bias/gain calibration.
Take countermeasures against EMI, such as using
shielded wires for input signal lines.
Check the settings of Pr. 1 Maximum frequency and Pr. 2
Minimum frequency. If you want to run the motor at 120Hz
or higher, set Pr. 18 High speed maximum frequency.
Check the calibration parameter C2 to C7 settings.
During IPM motor control, maximum frequency is limited to
the maximum motor speed (frequency) of the IPM motor.
Check the Pr.125 Terminal 2 frequency setting gain
frequency and Pr.126 Terminal 4 frequency setting gain
frequency settings. To operate at 120Hz or higher, set
Pr.18 High speed maximum frequency.
Increase/decrease Pr. 0 Torque boost setting value by
0.5% increments so that stall prevention does not occur.
Set rated frequency of the motor to Pr. 3 Base frequency.
(V/F control, Simple magnetic flux vector control)
Use Pr. 19 Base frequency voltage to set the base voltage
(e.g. rated motor voltage). (V/F control, Simple magnetic
flux vector control)
Change Pr. 14 Load pattern selection according to the load
characteristic. (V/F control)
Reduce the load weight.
Set Pr. 22 Stall prevention operation level higher according
to the load. (Setting Pr. 22 too large may result in
frequent overcurrent trip (E.OC ).)
Check the capacities of the inverter and the motor.
Stop the operation.
When Pr. 77 = "0" (initial value), write is enabled only
during a stop.
Choose the PU operation mode.
Or, set Pr. 77 = "2" to enable parameter write regardless
of the operation mode.
Check Pr. 77 Parameter write selection setting.
Check Pr. 161 Frequency setting/key lock operation selection
Check Pr. 79, Pr. 338, Pr. 339, Pr. 550, Pr. 551, and select
an operation mode suitable for the purpose.
Pr.72 cannot be set to "25" during the IPM motor control.
(The sine wave filter (MT-BSL/BSC) cannot be used
under IPM motor control.)
Check for the wiring and the installation.
Power lamp is lit when power supply is input to the
control circuit (R1/L11, S1/L21).