Danfoss VT2800 Series Design Manual page 71

Ohm-meter should be used (Thomson-bridge or
similar). R = 0.5 x R
S PHASE-PHASE
4. R is set automatically when AMT has
S
been completed. See parameter 107
Auto motor adaption.
109 Stator reactance X
(STATOR REACTANCE)
Value:
0.00 - X,XX
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
S
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
measurements X is obtained by connecting a
S
motor to mains and measuring the phase-phase
voltage U and the idle current
M
X : See parameter 142.
L
3. Use the factory settings of X
frequency converter itself chooses on the basis
of the motor nameplate data.
117 Resonance damping
(RESONANCE DAMPING)
Value:
OFF - 100%
OFF %
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 acti v e from 10% of
nominal speed and above.
In this case 5Hz and above.
Speed to go from 0 to nominal flux level: 500ms
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.28.E9.02 - VLT is a registered Danfoss trademark
.
S
.
which the
S
[OFF - 100]
[OFF]
®
VLT 2800 Series
Speed to go from nominal to 0 flux level: 500ms
Description of functionality:
The filter monitors the acti v e motor current and
changes the motor voltage according to the
figure below. The filter reacts on levels referring
to the nominal motor current.
If the acti v e 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 acti v e motor current comes over 20% the voltage
will be increased by the above mentioned speed. If the
acti v e motor current reaches 40% the motor voltage
will be increased immediately to normal motor voltage.
The reduction in motor voltage depends on
the parameter 117 setting.
Description of choice:
Set the grade of Motor current [Imact] influence
on the U/F ratio between 0% (OFF) and 100%.
100% corresponds to 50% reduction of U/F
ratio. Default value is OFF.
119 High start torque
(HIGH START TORQ.)
Value:
0.0 - 0.5 sec.
Function:
To ensure a high start torque approx. 1.8 x I
permitted for max. 0.5 sec. The current is, however,
limited by the frequency converter's (inverter's) safety
limit. 0 sec. corresponds to no high start torque.
0.0 sec.
can be
INV.
71