IMO Jaguar CUB, Instruction Manual

Page: 116 / 170

5-44
H12
Instantaneous Overcurrent Limiting
Selects whether the inverter will perform current limiting processing or cause an
overcurrent trip if the output current exceeds the instantaneous overcurrent limit
level.
If the instantaneous overcurrent limiting is enabled, the inverter will immediately
turn off its output gates to suppress the increase of current and control the output
frequency.
If current limiting processing makes the motor decrease its torque temporarily so as
to cause any problem, then disable overcurrent limiting to cause an overcurrent trip
and apply brake to the motor.
The same functions to limit the output current are implemented by soft-
ware as function codes F43 and F44. Generally, software features have
an operation delay, so enable function code H12 as well.
Depending upon the load, acceleration in an extremely short period may
activate the current limiter to suppress the increase of the inverter output
frequency, causing the system oscillate (hunting) or making the inverter
enter the
OU alarm mode and trip. When setting the acceleration time,
therefore, you need to take into account the load condition and moment of
inertia.
H69
Regenerative Energy Suppressing
The moment a regenerative energy exceeding the braking capacity of inverter is
returned during deceleration, the inverter will stop its output and enter overvoltage
Alarm mode. If regenerative energy suppressing control is enabled, the inverter
lengthens the deceleration time to 3 times the preset time and decreases the de-
celeration torque to 1/3 when the DC link voltage exceeds the preset voltage sup-
pressing level. In this way, the inverter makes the motor reduce the regenerative
energy tentatively.
This control is used to suppress the torque generated by the motor in
deceleration. Conversely, when the load on the motor results in a braking
effect, the control does not have any effect, so do not use it in this case.
Disable this control when the inverter features a braking resistor. If it is
enabled, the braking resistor and regenerative energy suppressing control
may conflict with each other, which may change the deceleration time
unexpectedly.