system based on an external PID controller
providing a speed reference signal as output.
Closed-loop
[3]: Motor speed will be deter-
mined by a reference from the built-in PID
controller varying the motor speed as part of
a closed-loop control process (constant pres-
sure or temperature, e.g.). The PID controller
must be configured in par. 20-**, Drive
Closed-loop or via the function set-ups ac-
cessed by pressing the [Quick Menus] button.
This parameter cannot be changed when the
motor is running.
1-03 Torque Characteristics
Value:
Compressor [0]
Variable torque [1]
Auto energy optim. compressor [2]
Auto Energy Optim. VT [3]
Function:
Compressor
[0]: For speed control of screw
and scroll compressors. Provides a voltage
that is optimized for a constant torque load
characteristic of the motor in the entire range
down to 15 Hz.
Variable Torque
[1]: For speed control of cen-
trifugal pumps and fans. Also to be used when
controlling more than one motor from the
same adjustable frequency drive (multiple
condenser fans or cooling tower fans, e.g.).
Provides a voltage that is optimized for the
squared torque load characteristic of the mo-
tor.
Auto Energy Optimization Compressor
[2]:
For optimum energy and efficient speed con-
trol of screw and scroll compressors. Provides
a voltage that is optimized for a constant tor-
que load characteristic of the motor in the
entire range down to 15 Hz. 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
that is automatically adjusted when the motor
data is programmed. These settings will typi-
cally 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.
Auto Energy Optimization VT
[3]: For opti-
mum energy efficient speed control of centri-
fugal pumps and fans. Provides a voltage that
is optimized for a squared torque load char-
acteristic of the motor. In addition the AEO
feature will adapt the voltage exactly to the
current load situation, thereby reducing ener-
gy consumption and audible noise from the
motor. To obtain optimal performance, the
motor power factor cos-phi must be set cor-
rectly. 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 typi-
cally 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)
Value:
OFF [0]
Enable complete AMA [1]
Enable reduced AMA [2]
Function:
The AMA function optimizes dynamic motor
performance by automatically optimizing the
advanced motor parameters (par. 1-30 to par.
1-35) while the motor is stationary.
Select the type of AMA.
Enable complete
AMA
[1] 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
.
6. How to program the adjustable frequency
drive
VLT
®
HVAC Drive Instruction Manual
76
MG.11.A4.22 - VLT
®
is a registered Danfoss trademark
6