Danfoss VLT 2800 Series Operating Instructions Manual page 22

1. Use the factory settings of R
quency converter itself chooses on the basis
of the motor nameplate data.
2. The value is stated by the motor supplier.
3. The value is obtained through manual meas-
urements: R can be calculated by measur-
S
ing the resistance R
phase terminals. Where R
er than 1-2 Ohms (typical for motors > 5.5
kW, 400 V), a special Ohm-meter should be
used (Thomson-bridge or similar). R
R .
PHASE-PHASE
4. R is set automatically when AMT has been
S
completed. See parameter 107 Auto motor
adaption.
109 Stator reactance X
(STATOR REACTANCE)
Value:
0.00 - X,XX Ω
Depends on choice of motor
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 and X , see procedure below.
S S
Description of choice:
X can be set as follows:
S
1. The value is stated by the motor supplier.
2. The value is obtained through manual meas-
urements X is obtained by connecting a mo-
S
tor to mains and measuring the phase-phase
voltage U and the idle current
M
U
M
X
=
s
I
3 ×
ϕ
X : See parameter 142.
L
3. Use the factory settings of X
quency converter itself chooses on the basis
of the motor nameplate data.
117 Resonance damping
(resonance damping)
Value:
OFF - 100%
OFF %
= factory setting, () = display text, [] = value for use in communication via serial communication port
®
MG.27.A2.02 - VLT is a registered Danfoss trademark
which the fre-
S
between two
PHASE-PHASE
is low-
PHASE-PHASE
= 0.5 x
S
S
.
S
.
φ
X
L
−
2
which the fre-
S
[OFF - 100]
[OFF]
®
VLT 2800 Series
Function:
It is possible to optimise the resonance damping in CT
mode. The grade of the influence is adjusted in this
parameter.
The value may be set between 0% (OFF) and 100%.
100% corresponds to 50% reduction of U/F ratio.
Default value is OFF.
Internal settings (fixed):
The resonance filter is active from 10% of nominal
speed and above.
In this case 5Hz and above.
Speed to go from 0 to nominal flux level: 500ms
Speed to go from nominal to 0 flux level: 500ms
Description of functionality:
The filter monitors the active motor current and
changes the motor voltage according to the figure be-
low. The filter reacts on levels referring to the nominal
motor current.
If the active motor current is below 10%, the motor
voltage will be decreased by the speed mentioned
above until the voltage reaches the setting for Par.
117. If the active motor current comes over 20% the
voltage will be increased by the above mentioned
speed. If the active motor current reaches 40% the
motor voltage will be increased immediately to normal
motor voltage.
The reduction in motor voltage depends on the pa-
rameter 117 setting.
Description of choice:
Set the grade of Motor current [Imact] influence on the
U/F ratio between 0% (OFF) and 100%. 100% corre-
sponds to 50% reduction of U/F ratio. Default value is
OFF.
21