Danfoss VLT, Instruction Manual, Page: 80 / 179

1-03 Torque Characteristics
Option: Function:
[0] Compressor torque
Compressor
[0]: For speed control of screw and scroll compressors. Provides a voltage which is
optimized for a constant torque load characteristic of the motor in the entire range down to 10 Hz.
[1] Variable torque Variable Torque [1]: For speed control of centrifugal pumps and fans. Also to be used when con-
trolling more than one motor from the same adjustable frequency drive (e.g., multiple condenser
fans or cooling tower fans). Provides a voltage which is optimized for a squared torque load char-
acteristic of the motor.
[2] Auto Energy Optim. CT
Auto Energy Optimization Compressor
[2]: For optimum energy efficient speed control of screw and
scroll compressors. Provides a voltage which is optimized for a constant torque load characteristic
of the motor in the entire range down to 15Hz, but in addition, the AEO feature will adapt the voltage
exactly to the current load situation, thereby reducing energy consumption and audible noise from
the motor. To obtain optimal performance, the motor power factor cos phi must be set correctly.
This value is set in par. 14-43
Motor Cos-Phi
. The parameter has a default value which is automat-
ically adjusted when the motor data is programmed. These settings will typically ensure optimum
motor voltage but if the motor power factor cos phi requires tuning, an AMA function can be carried
out using par.1-29
Automatic Motor Adaptation (AMA)
. It is very rarely necessary to adjust the motor
power factor parameter manually.
[3] * Auto Energy Optim. VT Auto Energy Optimization VT [3]: For optimum energy efficient speed control of centrifugal pumps
and fans. Provides a voltage which is optimized for a squared torque load characteristic of the motor
but in addition the AEO feature will adapt the voltage exactly to the current load situation, thereby
reducing energy consumption and audible noise from the motor. To obtain optimal performance,
the motor power factor cos phi must be set correctly. This value is set in par. 14-43
Motor Cos-
Phi
. The parameter has a default value and is automatically adjusted when the motor data is
programmed. These settings will typically ensure optimum motor voltage but if the motor power
factor cos phi requires tuning, an AMA function can be carried out using par.1-29
Automatic Motor
Adaptation (AMA)
. It is very rarely necessary to adjust the motor power factor parameter manually.
1-29 Automatic Motor Adaptation (AMA)
Option: Function:
The AMA function optimizes dynamic motor performance by automatically optimizing the advanced
motor parameters par. 1-30
Stator Resistance (Rs)
to par. 1-35
Main Reactance (Xh)
) while the
motor is stationary.
[0] * Off No function
[1] Enable complete AMA performs AMA of the stator resistance R
S
, the rotor resistance R
r
, the stator leakage reactance X
1
,
the rotor leakage reactance X
2
and the main reactance X
h
.
[2] Enable reduced AMA performs a reduced AMA of the stator resistance R
s
in the system only. Select this option if an LC
filter is used between the adjustable frequency drive and the motor.
Activate the AMA function by pressing [Hand on] after selecting [1] or [2]. See also the section
Automatic Motor Adaptation
. After a normal sequence,
the display will read: “Press [OK] to finish AMA”. After pressing the [OK] key, the adjustable frequency drive is ready for operation.
Note:
• For the best adaptation of the adjustable frequency drive, run AMA on a cold motor
• AMA cannot be performed while the motor is running.
6 How to program the adjustable frequency
drive VLT ® HVAC Drive Instruction Manual
6-22
MG.11.A9.22 - VLT ® is a registered Danfoss trademark
6