Speed varies during operation
Under Advanced magnetic flux vector control the output frequency varies between 0 and 2 Hz as the
load fluctuates. This is a normal operation and not a fault.
Load varies during an operation.
Frequency setting signal is varying.
The frequency setting signal is affected by
Malfunction is occurring due to the
undesirable current generated when the
transistor output unit is connected.
Multi-speed command signal is chattering.
Fluctuation of power supply voltage is too
Pr. 80 "Motor capacity" and Pr. 81 "Number
of motor poles" are not appropriate for the
motor capacity under Advanced magnetic
flux vector control, or PM motor control.
Wiring length exceeds 30 m when
Advanced magnetic flux vector control, or
PM motor control is selected.
Under V/F control, wiring is too long and a
voltage drop occurs.
Hunting occurs by the generated vibration,
for example, when structural rigidity at load
side is insufficient.
Check first when you have a trouble
Select Advanced magnetic flux vector control.
Check the frequency setting signal.
Set filter to the analog input terminal using
Pr. 74 "Input filter time constant", Pr. 822 "Speed
setting filter 1".
Take countermeasures against EMI, such as
using shielded wires for input signal lines.
Use terminal PC (terminal SD when source
logic) as a common terminal to prevent a
malfunction caused by undesirable current.
Take countermeasures to suppress chattering.
Under V/F control, change the Pr. 19 "Base
frequency voltage" setting (approximately by
Check the settings of Pr. 80 and Pr. 81.
Perform offline auto tuning.
In the low-speed range, set 0.5% in Pr. 0 "Torque
Change the control method to Advanced
magnetic flux vector control.
Disable automatic control functions, such as the
energy saving operation, fast-response current
limit operation regeneration avoidance
function, Advanced magnetic flux vector
control stall prevention, and online auto tuning.
Under PID control, set smaller values to Pr. 129
"PID proportional band" and Pr. 130 "PID
Adjust so that the control gain decreases and
the level of safety increases.
Change Pr. 72 "PWM frequency selection"
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