Danfoss VLT 2800 Series Operating Instructions Manual page 17

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 con-
verter 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
ever, 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 Auto-
matic motor tuning is reset to [0] when AMT has
been completed.
Complete AMT:
AMT is completed by giving a RESET signal. Pa-
rameter 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 parame-
ters as well as possible, the correct type plate
data for the motor connected to the frequency
converter must be keyed into parameters 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 mea-
sure the R values for motors that are 1-2 times
S
larger or smaller than the frequency converter's
nominal size.
- If you wish to interrupt automatic motor tuning,
press the [STOP/RESET] key.
NB!:
AMT may not be performed on motors con-
nected 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.
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.28.A5.02 - VLT is a registered Danfoss trade mark
VLT
Description of choice:
Select Optimisation on [2] if you want the frequency
converter to perform automatic motor tuning.
108 Stator resistance R
108
Value:
0.000 - X.XXX
Function:
. As a rule, how-
S
After setting of parameters 102-106 Nameplate data,
a number of adjustments of various parameters is
carried out automatically , including stator resistance
R . A manually entered R
S
tor. The shaft performance can be improved by
fine-tuning R
changed if nameplate data has been set.
Description of choice:
R
S
1. Use the factory settings of R
2. The value is stated by the motor supplier.
3. The value is obtained through manual measure-
4. R
109 Stator reactance X
109
Value:
0.00 - X,XX
Function:
After setting of parameters 102-106 Nameplate data,
a number of adjustments of various parameters are
made automatically , including stator reactance X
The shaft performance can be improved by fine-
tuning R
®
2800 Series
S
(STATOR RESISTAN)
Depends on choice of motor
must apply to a cold mo-
S
and X , see procedure below.
S S
NB!:
Parameters 108 Stator resistance R
Stator reactance X are normally not to be
S
can be set as follows:
quency converter itself chooses on the basis of
the motor nameplate data
ments: R can be calculated by measuring the
S
resistance R between two phase ter-
PHASE-PHASE
minals. Where R
PHASE-PHASE
Ohms (typical for motors > 5.5 kW, 400 V), a spe-
cial Ohm-meter should be used (Thomson-bridge
or similar). R = 0.5 x R
S PHASE-PHASE
is set automatically when AMT has been com-
S
pleted. See parameter 107 Auto motor adaption.
S
(STATOR REACTANCE)
Depends on choice of motor
and X , see procedure below.
S S
and 109
S
which the fre-
S
is lower than 1-2
.
S
17