Hitachi L300P Series Instruction Manual page 210

6–4
Troubleshooting
Symptom/condition
The motor speed will not reach the
target frequency (desired speed).
The rotation is unstable.
The RPM of the motor does not
match the inverter output
frequency setting.
True for certain
A parameter
parameters
will not
change after
an edit
True for all
(reverts to old
parameters
setting).
Probable Cause
• If using the analog input, is there
current or voltage at [O] or [OI]?
• Is the load too heavy?
• Is the inverter internally limiting the
output frequency?
• Is the load fluctuation too great?
• Is the supply voltage unstable?
• Is the problem occurring at a particular
frequency?
• Does the instability occur at various
frequencies?
• Is the maximum frequency setting
A004 correct?
• Does the monitor function D001
display the expected output frequency?
• Is the inverter in Run Mode? Some
parameters cannot be edited during
Run Mode.
• If you're using the [SFT] intelligent
input (software lock function)—is the
[SFT] input ON?
Solution
• Check the wiring.
• Check the potentiometer or
signal generating device.
• Reduce the load.
• Heavy loads activate the
overload restriction feature
(reduces output as needed).
• Check max frequency setting
(A004)
• Check frequency upper limit
setting (A061)
• If using analog inputs, check
their settings (A101– A104) or
(A111–A114), or (A011–
A014)
• Increase the motor capacity
(both inverter and motor).
• Fix power supply problem.
• Change the output frequency
slightly, or use the jump
frequency setting to skip the
problem frequency.
• Try adjusting H006 up or
down.
• See "Adjusting Motor Stabil-
ity" on page 4–57.
• Verify the V/F settings match
motor specifications.
• Make sure all scaling (such as
A011 to A014) is properly set.
• Put inverter in Stop Mode
(press the Stop/reset key). Then
edit the parameter.
• Change the state of the SFT
input, and check the B031
parameter (SFT mode).