Hitachi P1-00080-L Basic Manual page 116

Chapter 5
Event ▶
・Overload restriction function is
in use
・Frequency is being limited
Motor speed does
not increase
・Frequency source is low
・Acceleration time is long
・Several parameters are not
adequately set
・Big variation in the load
Output frequency
is unstable
・Supply voltage fluctuates
・V/f control is in use
・It is being used for unwinding
No torque
・Very heavy load
In operation the
・Large leakage current
circuit breaker gets
activated
Noise interferes
・Irradiated noise from the
with the TVs and
radios nearby the
inverter
inverter
Estimated cause ▶
Corrective action
・
If output current is high, the overload restriction function
[bA122] lowers the frequency. To increase the acceleration
time [AC120], it is necessary to suppress the current increase.
・The upper limit [bA102] setting may be low, and it should
be increased. The frequency limiting does not make use of
the maximum frequency, but the upper limit function.
・Increase the frequency source or cancel any other high
priority frequency command such as jogging or multi-speed.
・Acceleration time [AC120] setting is long, so will accelerate
really slowly. Shorten gradually the acceleration time.
・Check for the motor basic parameters.
・Review the power capacity of both the inverter and motor.
・To keep to a minimum the supply fluctuations, by using an
optional AC reactor, DC choke or and input filter,
improvement is possible.
・Can switch in [AA121] to torque boost, sensorless vector
control, ... etc.
・If the torque in the regenerative operation is not enough,
you can use a braking resistor or regenerative braking unit.
・Review the capacity of both the inverter and motor.
・Lower the carrier frequency [bb101]
・Increase the current sensitivity of the circuit breaker, or
replace the sensitivity current sensor/part.
・If possible, separate the wiring from the TV and radio
・Put a zero-phase reactor either in the main supply input or
in the output
5-6
Troubleshooting