Technical data

NB!
The max. value equals f
M,N
x 60. f
M,N
to be
set in parameter 104 Motor frequency,
f
M,N
.
107 Automatic motor tuning, AMT
(auto motor tun.)
Value:
Optimisation off (AMT off) [0]
Optimisation on (AMT start) [2]
Function:
NB!
AMT is not possible on VLT 2880-82.
Automatic motor tuning is an algorithm that measures
stator resistance R
S
without the motor axle turning.
This means that the motor is not delivering any torque.
AMT can be used with benefit when initialising units
where the user wishes to optimise adjustment of the
frequency converter to the motor being used. This is
used in particular when the factory setting does not
sufficiently cover the motor.
For the best possible tuning of the frequency converter
it is recommended that AMT is performed on a cold
motor. It should be noted that repeated AMT runs can
cause heating of the motor, resulting in an increase in
the stator resistance R
S
. As a rule, however, this is not
critical.
AMT is performed as follows:
Start AMT:
1. Give a STOP signal.
2.
Parameter 107 Automatic motor tuning is set
at value [2] Optimisation on.
3.
A START signal is given and parameter 107
Automatic motor tuning is reset to [0] when
AMT has been completed.
Complete AMT:
AMT is completed by giving a RESET signal. Param-
eter 108 Stator resistance, Rs is updated with the
optimised value.
Interrupting AMT:
AMT can be interrupted during the optimisation pro-
cedure by giving a STOP signal.
When using the AMT function the following points
should be observed:
-
For AMT to be able to define the motor pa-
rameters as well as possible, the correct type
plate data for the motor connected to the fre-
quency converter must be keyed into param-
eters 102 to 106.
-
Alarms will appear in the display if faults arise
during tuning of the motor.
-
As a rule the AMT function will be able to
measure the R
S
values for motors that are 1-2
times larger or smaller than the frequency
converter's nominal size.
-
If you wish to interrupt automatic motor tun-
ing, press the [STOP/RESET] key.
NB!
AMT may not be performed on motors
connected in parallel, nor may setup
changes be made while AMT is running.
The procedure for AMT controlled from
the SLCP:
See section entitled Control unit.
Description of choice:
Select Optimisation on [2] if you want the frequency
converter to perform automatic motor tuning.
108
Stator resistance R
S
(STATOR RESISTAN)
Value:
0.000 - X.XXX 
Depends on choice of motor
Function:
After setting of parameters 102-106 Nameplate data, a
number of adjustments of various parameters is car-
ried out automatically, including stator resistance R
S
.
A manually entered R
S
must apply to a cold motor. The
shaft performance can be improved by fine-tuning R
S
and X
S
, see procedure below.
NB!
Parameters 108 Stator resistance R
S
and
109 Stator reactance X
S
are normally not
to be changed if nameplate data has been
set.
Description of choice:
R
S
can be set as follows:
VLT
®
2800 Series
= factory setting, () = display text, [] = value for use in communication via serial communication port
MG.27.E3.02 - VLT
®
is a registered Danfoss trademark 71
Programming