Danfoss VT2800 Series Design Manual page 75

Description of choice:
To be set as a percentage value of the max. DC
brake voltage, which depends on the motor.
133 Start voltage
(START VOLTAGE)
Value:
0.00 - 100.00 V
Function:
A higher start torque can be obtained by increasing
the start voltage. Small motors (< 1.0 kW)
normally require a high start voltage.
Description of choice:
The factory setting will be suitable for must
applications, the value may need to be increase
gradually for high torque application.
Warning: If the use of start voltage
is exaggerated, this may lead to
over-energizing and overheating of the
motor and the frequency converter may cut out.
134 Load compensation
(LOAD COMPENSATIO)
Value:
0.0 - 300.0%
Function:
In this parameter, the load characteristic is set. By
increasing the load compensation, the motor is gi v en an
extra voltage and frequency supplement at increasing
loads. This is used e.g. in motors/applications in
which there is a big difference between the full-load
current and idle-load current of the motor.
NB!:
If this value is set too high, the frequency
converter may cut out because of overcurrent.
= factory setting. () = display text [] = value for use in communication via serial communication port
MG.28.E9.02 - VLT is a registered Danfoss trademark
Description of choice:
If the factory setting is not adequate, load
compensation must be set to enable the motor
to start at the gi v en load.
case of quick load changes. Too high load
compensation may lead to instability.
Depends on unit
135 U/f-ratio
Value:
0.00 - 20.00 at Hz
Function:
This parameter enables a shift in the ratio between
output voltage (U) and output frequency (f) linearly,
so as to ensure correct energizing of the motor and
thus optimum dynamics, accuracy and efficiency.
The U/f-ratio only affects the voltage characteristic
if a selection has been made of Constant torque
[1] parameter 101 Torque characteristic.
Description of choice:
The U/f-ratio is only to be changed if it is not
possible to set the correct motor data in parameter
102-109. The value programmed in the factory
settings is based on idle operation.
136 Slip compensation
Value:
-500 - +500% of rated slip compensation
Function:
100.0%
Slip compensation is calculated automatically, on
the basis of such data as the rated motor speed
n
M,N
fine-tuned, thereby compensating for tolerances on
the value for n
a selection has been made of Speedregulation, open
loop [0] in parameter 100 Configuration and Constant
torque [1] in parameter 101 Torque characteristic.
Description of choice:
Key in a % value.
®
VLT 2800 Series
Warning: Should be set to 0% in
connection with synchronous and
parallel-coupled motors and in the
(U/F RATIO)
(SLIP COMP.)
. In this parameter, the slip compensation can be
. Slip compensation is only acti v e if
M,N
Depends on unit
100%
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