Fuji Electric FRENIC-Ace series - Page 345

5.3 Description of Function Codes
5-175
FUNCTION CODES
Chap 5
H69
Anti-regenerative control (Mode selection)
Related function codes: H76 (Torque limiter) (Frequency rising limit for braking)
Enable the automatic deceleration (anti-regenerative control) with this function code. In the inverter not equipped
with a PWM converter or braking unit, if the regenerative energy returned exceeds the inverter’s braking capability,
an overvoltage trip occurs. Turning digital input “AR-CCL” ON cancels anti-regenerative control.
( Function codes E01 to E05, data =82)
If anti-regenerative control is selected, the output frequency is controlled to suppress the regenerative energy for
avoiding an overvoltage trip.
H69
Function
AR-CCL
Control mode
Force-to-stop with actual deceleration time
exceeding three times the specified one
0 Disable automatic deceleration — OFF
2 Torque limit control Enable OFF
3 DC link bus voltage control Enable OFF
4 Torque limit control Disable OFF
5 DC link bus voltage control Disable OFF
— Disable automatic deceleration — ON
FRENIC-Ace is equipped with two control modes: torque limiter and DC link bus voltage control.
Understand the features of the respective modes and select the appropriate one.
Control mode Control operation Operation mode Characteristics
Torque limiter
(H69 = 2, 4)
Controls the output
frequency so that the
braking torque is
approximately 0.
Enabled during
acceleration,
constant speed
operation and
deceleration.
Features high response and makes
less prone to overvoltage trips under
impact load.
DC link bus
voltage control
(H69 = 3, 5)
Controls the output
frequency so that the DC
link bus voltage is
decreased when it
exceeds the limit level.
Enabled only during
deceleration
Disabled during
constant speed
operation
Regenerative capability of the
inverter will be maximum use.
Deceleration time will be shorter
than the torque limit control.
■ Torque limiter (Frequency rising limit for braking) (H76)
• Data setting range: 0.0 to 500.0 (Hz)
With the torque limiter, the inverter increases the output frequency to limit the output torque. Excessive increase of
the output frequency may cause danger, and therefore the frequency increment limit for braking (H76) is provided.
This prevents the output frequency from increasing to exceed the “reference frequency + H76.” If the limit is
reached, however, anti-regenerative control is restricted and an overvoltage trip may occur. Increasing the
frequency increment limit for braking improves the anti-regenerative capability.
If a run command is turned OFF, the anti-regenerative control causes the frequency to increase and operation may
not stop depending on the load conditions. For safety, a function is provided in which the anti-regenerative control
is forced to be disabled if the actual deceleration time becomes three times the deceleration time currently selected
forcing the operation to stop. The function can be enabled/disabled by the setting of H69.
• The deceleration time may be automatically increased by anti-regenerative control.
•
Disable the anti-
regenerative control when a braking unit is connected. Otherwise, the
anti-regenerative control may be activated at th
e same time as the operation of the braking unit,
resulting in a deceleration time not in accordance with the setting.
•
An excessively short deceleration time causes the DC link bus voltage of the inverter to rise too fast
for the anti-regenerative control to function. In that case, specify a longer deceleration time.