Fuji Electric FRENIC-HVAC User Manual page 474

H63 Low Limiter (Mode selection)
For details, refer to the description of F15.
H64 Low Limiter (Lower limiting frequency)
H64 specifies the lower limit of frequency to be applied when the current limiter, torque
limiter, automatic deceleration (anti-regenerative control), or overload prevention control is
activated. Normally, it is not necessary to change this data.
- Data setting range: Inherit, 0.0 to 60.0 (Hz)
H68 Slip Compensation 1 (Operating conditions)
For details, refer to the description of F42.
H69 Automatic Deceleration (Mode selection)
H69 toggles anti-regenerative control on and off.
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.
To avoid such an overvoltage trip, enable the automatic deceleration (anti-regenerative
control) with this function code, and the inverter controls the output frequency to keep the
braking torque around 0 N·m in both the acceleration/deceleration and constant speed
running phases.
The FRENIC-HVAC series of inverters have two braking control modes; torque limit control
and DC link bus voltage control. Understand the feature of each control and select the suitable
one.
Control mode
Torque limit
control
(H69=2 or 4)
DC link bus
voltage control
(H69=3 or 5)
H76 (Torque Limiter for Braking, Frequency increment limit)
Control process
Output frequency is Enabled during
controlled so that the acceleration, running
braking torque is kept at the constant speed,
at the regeneration and deceleration.
avoidance operation
level (H114).
Control the output Enabled during
frequency to lower deceleration.
the DC link bus
Disabled during
voltage if the voltage
running at the
exceeds the limiting
constant speed.
level.
6-164
Operation mode
Quick response.
Causes less
overvoltage trip with
heavy impact load.
Shorter deceleration
time by making good
use of the inverter's
regenerative
capability.
(
Refer to F15.)
(
Refer to F42.)
Features