VLT
®
2800 Series
Programming
Ohm-meter should be used (Thomson-bridge or
similar).
R
S
= 0.5 x R
PHASE-PHASE
.
4.
R
S
is set automatically when AMT has
been completed. See parameter 107
Auto motor adaption.
109 Stator reactance X
S
(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
S
. The shaft performance can be improved by
fine-tuning R
S
and X
S
, see procedure below.
Description of choice:
X
S
can be set as follows:
1. The value is stated by the motor supplier.
2. The value is obtained through manual
measurements X
S
is obtained by connecting a
motor to mains and measuring the phase-phase
voltage U
M
and the idle current
.
X
L
: See parameter 142.
3. Use the factory settings of X
S
which the
frequency converter itself chooses on the basis
of the motor nameplate data.
117 Resonance damping
(RESONANCE DAMPING)
Value:
OFF - 100%
[OFF - 100]
✭
OFF %
[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 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 below. 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 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.
✭
0.0 sec.
Function:
To ensure a high start torque approx. 1.8 x I
INV.
can be
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.
✭
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.28.E9.02 - VLT is a registered Danfoss trademark
71
