Check first when you have some troubles
4.6.12 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
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 is performed.
(Pr. 3, Pr. 14, Pr. 19)
Stall prevention is activated due to a heavy load.
Auto tuning is not performed under Advanced magnetic
flux vector control or General-purpose magnetic flux
During PID control, output frequency is automatically controlled to make measured value = set point.
Brake resistor is connected between terminal P/+ and
P1 or between terminal P1 and PR by mistake.
4.6.13 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
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.
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.
Use Pr. 19 Base frequency voltage to set the base voltage
(e.g. rated motor voltage).
Change Pr. 14 Load pattern selection according to the load
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.
Perform offline auto tuning.
Connect an optional brake transistor (MRS type, MYS
type, FR-ABR) between terminal P/+ and PR.
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.