VLT
®
8000 AQUA
Programming
■
Load and motor 100-124
This parameter group allows the configuration
of regulation parameters and the choice of
torque characteristics to which the frequency
converter is to be adapted.
The motor nameplate data must be set and automatic
motor adaptation can be carried out. In addition,
DC brake parameters can be set and the motor
thermal protection can be activated.
■
Configuration
The selection of configuration and torque characteristics
influences the parameters that can be seen in the
display. If
Open loop
[0] is selected, all parameters
relating to PID regulation will be hidden.
Consequently, the user is only able to see
the parameters that are of significance for
a given application.
100 Configuration
(CONFIG. MODE)
Value:
✭
Open loop (OPEN LOOP)
[0]
Closed loop (CLOSED LOOP)
[1]
Function:
This parameter is used for selecting the configuration
to which the frequency converter is to be adapted.
Description of choice:
If
Open loop
[0] is selected, normal speed control is
obtained (without feedback signal), i.e. if the reference
is changed, the motor speed will change.
If
Closed loop
[1] is selected, the internal process
regulator is activated to enable accurate regulation
in relation to a given process signal.
The reference (setpoint) and the process signal
(feedback) can be set to a process unit as
programmed in parameter 415
Process units
.
See
Feedback handling
.
101 Torque characteristics
(VT CHARACT)
Value:
✭
Automatic Energy Optimization
(AEO FUNCTION)
[0]
Constant Torque (CONSTANT TORQUE)
[1]
Variable Torque Low (VT LOW)
[2]
Variable Torque Medium (VT MED)
[3]
Variable Torque High (VT HIGH)
[4]
Function:
This parameter allows a choice of whether the frequency
converter operates with the controller adjusting the U/f
curve automatically in response to the load, or whether
variable or constant torque operation is selected.
Description of choice:
For variable torque loads such as centrifugal pumps
and fans, the drive provides two operational modes.
Automatic Energy Optimization enables the controller
to dynamically adjust the U/f ratio in response to the
motor load or speed changes to maximize motor and
drive efficiency while reducing motor heat and noise.
Parameter 118 makes it possible to set the power
factor (Cos
ϕ
) which is used by the AEO function.
In AEO mode the drive will provide constant torque
until it reaches reference or maximum frequency.
Then it changes to AEO function.
The Variable Torque option provides low, medium and
high levels of voltage as shown in the figure below (as a
percentage of nominal motor voltage.) VT may be used
with more than one motor connected to the output in
parallel. Select the torque characteristic with the most
reliable operation and the least energy consumption,
motor heat and noise. The starting voltage can be
selected in parameter 108,
VT Start Voltage.
For constant torque loads such as conveyor belts,
presses, mixers, screws and so forth, select
Constant
✭
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.83.A2.02 - VLT is a registered Danfoss trademark
99
