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Description of choice:
Set the required voltage necessary to cut out the
mechanical brake. It is assumed that parameter
121 Start function, is set to Start frequency/voltage
clockwise [3] or Start frequency/voltage in reference
direction [4] and that in parameter 120 Start delay a
time is set, and that a reference signal is present.
132 DC brake voltage
(DC BRAKE VOLTAGE)
Value:
0 - 100% of max. DC brake voltage
Function:
In this parameter, the DC brake voltage is set which is
to be activated at stop when the DC brake frequency
set in parameter 127 DC brake cut-in frequency is
reached, or if DC braking inverse is active via a digital
input or via serial communication. Subsequently,
the DC brake voltage will be active for the time
set in parameter 126 DC brake time.
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 HP) normally
require a high start voltage.
= factory setting. () = display text [] = value for use in communication via serial communication port
46
Description of choice:
The factory setting will be suitable for must
applications, the value may need to be increase
gradually for high torque application.
motor and the variable frequency drive may cut out.
134 Load compensation
Value:
0%
Function:
In this parameter, the load characteristic is set. By
increasing the load compensation, the motor is given 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.
Description of choice:
If the factory setting is not adequate, load
compensation must be set to enable the motor
to start at the given load.
Depends on unit
case of quick load changes. Too high load
compensation may lead to instability.
135 U/f-ratio
Value:
Function:
This parameter enables a linear shift in the ratio
between output voltage (V) and output frequency
(f) to ensure correct energizing of the motor and
VLT® 2800 Series
Warning: If the use of start voltage
is exaggerated, this may lead to
over-energizing and overheating of the
(LOAD COMPENSATIO)
0.0 - 300.0%
NOTE
If this value is set too high, the variable frequency
drive may cut out because of overcurrent.
Warning: Should be set to 0% in
connection with synchronous and
parallel-coupled motors and in the
(U/F RATIO)
0.00 - 20.00 at Hz
MG.28.A8.22 - VLT is a registered Danfoss trademark
100.0%
Depends on unit
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