5-74
H45
H97
Mock Alarm
Clear Alarm Data
H45 causes the inverter to generate a mock alarm in order to check whether external
sequences function correctly at the time of machine setup.
Setting the H45 data to "1" displays mock alarm
err
on the LED monitor. It also issues alarm
output
ALM
(if assigned to a digital output terminal specified by E20 or E27). (Accessing the
H45 data requires simultaneous keying of "
key +
key.") After that, the H45 data
automatically reverts to "0," allowing you to reset the alarm.
Just as for data (alarm history and relevant information) of those alarms that could occur in
running the inverter, the inverter saves mock alarm data, enabling you to confirm the mock
alarm status.
To clear the mock alarm data, use H97. (Accessing the H97 data requires simultaneous
keying of "
key +
key.") H97 data automatically reverts to "0" after clearing the alarm
data.
H69
H76
Automatic Deceleration (Anti-regenerative control) (Mode selection)
Automatic Deceleration (Frequency increment limit for braking)
H69 specifies the anti-regenerative control.
In inverters not equipped with a PWM converter or braking resistor, if regenerative energy
returned exceeds the inverter's braking capability, an overvoltage trip occurs.
When H69 = 1: The anti-regenerative control is functionally equivalent to that of the original
FRENIC-Mini series (FRN
C1
-
). That is, when the DC link bus voltage exceeds
the preset voltage limiting level, the inverter lengthens the deceleration time to three times
the specified time to decrease the deceleration torque to 1/3. In this way, the inverter
reduces the regenerative energy tentatively. This control applies only in deceleration. When
the load on the motor results in a braking effect, the control does not have any effect.
When H69 = 2 or 4: The inverter controls the output frequency to keep the braking torque at
around 0 N·m in both acceleration/deceleration and constant speed running phases in order
to avoid an overvoltage trip.
Since increasing the output frequency too much under anti-regenerative control is
dangerous, the inverter has a torque limiter (Frequency increment limit for braking) that can
be specified by H76. The torque limiter limits the inverter's output frequency to less than
"Reference fre H76 setting."
Note that the torque limiter activated restrains the anti-regenerative control, resulting in a
trip with an overvoltage alarm in some cases. Increasing the H76 data (0.0 to 400.0 Hz)
makes the anti-regenerative control capability high.
In addition, during deceleration triggered by turning the run command OFF, the
anti-regenerative control increases the output frequency so that the inverter may not stop
the load depending on the load state (huge moment of inertia, for example). To avoid that,
H69 provides a choice of cancellation of the anti-regenerative control to apply when three
times the specified deceleration time is elapsed, thus decelerating the motor.
